Wildlife Exposure Factors Handbook: Volume 1 of 2


                                                  EPA/600/R-93/187a
                                                  December 1993
           WILDLIFE EXPOSURE FACTORS
                     HANDBOOK
                    Volume I of II
       Office of Health and Environmental Assessment
            Office of Research and Development
           U.S. Environmental Protection Agency
                 Washington, DC 20460
Additional major funding for this Handbook was provided by the
        Office of Emergency and Remedial Response,
       Office of  Solid Waste and Emergency Response
                       and by the
      Office of Science and Technology, Office of Water
           U.S.  Environmental Protection Agency
                 Washington, DC 20460
                                            Printed on Recycled Paper

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                                 DISCLAIMER
      This document has been reviewed in accordance with U.S. Environmental
Protection Agency policy and approved for publication.  Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.

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                                 CONTENTS


Foreword	 .      xi

Preface	      xii

Authors, Managers, Contributors, and Reviewers	    xiii

1.   INTRODUCTION	     1-1

    1.1.   PURPOSE AND SCOPE	     1-1
    1.2.   ORGANIZATION OF THE HANDBOOK	    1-5
    1.3.   LIST OF SELECTED SPECIES	'	     1-6
    1.4.   LIST OF EXPOSURE FACTORS	    1-11

          1.4.1.   Normalizing Factors	    1-11

                 1.4.1.1.   Body Weight	    1-13
                 1.4.1.2.   Growth Rate	    1-13
                 1.4.1.3.   Metabolic Rate	    1-14

          1.4.2.   Contact Rate Factors	.- • • •    1-14
               f

                 1.4.2.1.   Oral  Route	 ....    1-14
                 1..4.2.2.   Inhalation Route  ..-..-	    1-16
                 1.4.2.3.   Dermal Route		    1-16

          1.4.3.   Population Dynamics	    1-17

                 1.4.3.1.   Social Organization	    1-17
                 1.4.3.2.   Home Range/Territory Size/Foraging Radius  	   1-17
                 1.4.3.3.   Population Density	 . . .    1-19
                 1.4.3.4.   Annual Fecundity	 . .	    1-19
                 1.4.3.5.   Annual Mortality and Longevity ...'.'	   1-19

          1.4.4.   Seasonal Activities	    1-20

    1.5.   DATA PRESENTATION  FORMAT	    1-20
                                                                      *

          1.5.1.   Normalizing and Contact Rate Factors	   1-21

                 1.5.1.1.   All Animals	    1-21
                 1.5.1.2.   Birds	    1-22
                 1.5.1.3.  .Mammals	    1-23
                 1.5.1.4.   Reptiles and Amphibians	    1-23
                                      in

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                             CONTENTS (continued)
          1.5.2.  Dietary Composition	   1-24

                 1.5.2.1.  All Animals	   1-24

          1.5.3.  Population Dynamics  	   1-25

                 1.5.3.1.  All Animals	   1-25
                 1.5.3.2.  Birds  	   1-26
                 1.5.3.3.  Mammals	   1-27
                 1.5.3.4.  Reptiles and Amphibians	   1-27

          1.5.4.  Seasonal Activities	   1 -28

                 1.5.4.1.  Birds	   1-29
                 1.5.4.2.  Mammals	   1 -29
                 1.5.4.3.  Reptiles and Amphibians	   1-29

          1.5.5.  Abbreviations Used in Tables	   1-29

    1.6.  LITERATURE SEARCH STRATEGY	   1-30
    1.7.  REFERENCES	   1-32

2.  EXPOSURE FACTORS AND DESCRIPTIONS OF SELECTED SPECIES	   2-1

    2.1.  BIRDS	   2-1

          2.1.1.  Great Blue Heron  	   2-3
          2.1.2.  Canada Goose	   2-19
          2.1.3.  Mallard	   2-39
          2.1.4.  Lesser Scaup	   2-53
          2.1.5.  Osprey  	   2-65
          2.1.6.  Red-Tailed Hawk  :	   2-79
          2.1.7.  Bald Eagle	   2-91
          2.1.8.  American Kestrel  	 2-109
          2.1.9.  Northern Bobwhite	 2-121
          2.1.10. American Woodcock	 2-137
       '   2.1.11. Spotted Sandpiper	, . . ,	 2-149
          2.1.12. Herring Gull	 2-157
          2.1.13. Belted Kingfisher	 . 2-173
          2.1.14. Marsh Wren	 2-183
          2.1.15. American Robin	 2-193
                                       IV

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                            CONTENTS (continued)
    2.2.  MAMMALS  . .			 ...'•	  2-207

         2.2.1.   Short-Tailed Shrew	  2-209
         2.2.2.   Red Fox	  2-221
         2.2.3.   Raccoon	  2-233
         2.2.4.   Mink	  2-247
         2.2.5.   River Otter	 . .	  2-261
         2.2.6.   Harbor Seal	  2-275
         2.2.7.   Deer Mouse	 .	 .  2-291
         2.2.8.   Prairie Vole  . .	  2-311
         2.2.9.   Meadow Vole			  2-323
         2.2.10. Muskrat		  2-337
         2.2.11. Eastern Cottontail	  2-351

    2.3.  REPTILES AND AMPHIBIANS	  2-365

         2.3.1.   Snapping Turtle	  2-367
         2.3.2.   Painted Turtle	  2-381
         2.3.3.   Eastern Box Turtle	 .  2-397
         2.3.4.   Racer			  2-407
         2.3.5.   Northern Water Snake	  2-419
         2.3.6.   Eastern Newt		  2-429
         2.3.7.   Green Frog	 .  2-443
         2.3.8.   Bullfrog	 .  2-453

3.   ALLOMETRIC EQUATIONS	,	    3-1

    3.1.  FOOD INGESTION RATES	    3-3

         3.1.1.   Birds	    3-4
         3.1.2.   Mammals		    3-5
         3.1.3.   Reptiles and Amphibians	    3-6

    3.2.  WATER INTAKE RATES  			    3-7

         3.2.1.   Birds	 .	    3-8
         3.2.2.   Mammals  . .		   3-10
         3.2.3.   Reptiles and Amphibians	   3-10

    3.3.  INHALATION RATES		  3-11

         3.3.1.   Birds	   3-11
         3.3.2.   Mammals		   3-12
         3.3.3.   Reptiles and Amphibians	   3-12

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                             CONTENTS (continued)
    3.4.  SURFACE AREAS			   3-13

          3.4.1.  Birds	   3-13
          3.4.2.  Mammals	   3-14
          3.4.3.  Reptiles and Amphibians	   3-14

    3.5.  ALLOMETRIC EQUATIONS FOR METABOLIC RATE  	   3-15

          3.5.1.  Birds	   3-18

                 3.5.1.1   Basal Metabolic  Rate	   3-19
                 3.5.1.2.  Existence Metabolic Rates	   3-20
                 3.5.1.3.  Free-Living Metabolic Rate  	   3-22
                 3.5.1.4.  Temperature and Metabolic Rate	   3-24

          3.5.2.  Mammals	   3-26

                 3.5.2.1.  Basal Metablic Rate	   3-26
                 3.5.2.2.  Resting Metabolism	   3-27
                 3.5.2.3.  Field Metabolic Rate	   3-27
                 3.5.2.4.  Temperature and Metabolic Rate	   3-28

          3.5.3.  Reptiles and Amphibians	   3-29

                 3.5.3.1.  Basal and Resting Metabolic Rates	   3-29
                 3.5.3.2.  Free-Living Metabolic Rates  	   3-30

    3.6.  MATH PRIMER AND UNIT CONVERSIONS  	   3-32

          3.6.1.  Summary of Operations Involving Logarithms  	   3-32
          3.6.2.  Summary of Operations Involving Powers	   3-32
          3.6.3.  Unit Conversions 	   3-33

                 3.6.3.1.  Approximate Factors for Metabolic Equations	   3-33
                 3.6.3.2.  Exact Conversions	   3-33

    3.7.  ESTIMATING CONFIDENCE  INTERVALS	   3-34

    3.8.  REFERENCES	   3-38

4.  EXPOSURE ESTIMATES	    4-1

    4.1.  GENERAL DOSE EQUATIONS  	    4-1

          4.1.1.  Drinking Water	    4-3

                                       vi

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                            CONTENTS (continued)
         4.1.2.   Diet	 .	    4-6

                 4.1.2.1.   Dose Equations	    4-6
                 4.1.2.2.   Energy Content and Assimilation Efficiencies  .....   4-10

         4.1.3.   Soil and Sediment Ingestion	   4-16

                 4.1.3.1.   Background	   4-18
                 4.1.3.2.   Methods	   4-18
                 4.1.3.3.   Results	   4-19
                 4.1.3.4.   Dose Equations	   4-21

         4.1.4.   Air	   4-21
         4.1.5.   Dermal Exposure	 .	   4-23

    4.2.  ANALYSIS OF UNCERTAINTY	   4-23

         4.2.1.   Natural Variation	   4-24
         4.2.2.   Sampling Uncertainty . .	   4-25
         4.2.3.   Model Uncertainty  	• • • •	  •	   4-26

2   4.3.  REFERENCES	   4-26

APPENDIX:  LITERATURE REVIEW DATABASE	   See Volume II
                                      VII

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                                LIST OF TABLES


Table 1-1.  Characteristics of Selected Birds	    1-8

Table 1-2.  Characteristics of Selected Mammals  	    1-9

Table 1-3.  Characteristics of Selected Reptiles and Amphibians	   1-10

Table 1-4.  Wildlife Exposure Factors Included in the Handbook  	   1-12

Table 1-5.  Wildlife Contact Rate Exposure Factors	   1-15

Table 1-6.  Column Headers for Tables of Normalizing and Contact
           Rate Factors	   1-21

Table 1-7.  Column Headers for Tables on Dietary Composition  	   1-24

Table 1-8.  Column Headers for Tables of Factors  for Population  Dynamics  	   1-26

Table 1-9.  Column Headers for Tables on Seasonal Activities  .	   1-28

Table 2-1.  Birds Included in the Handbook	    2-2

Tables for  2.1.1.   Great Blue Heron	    2-8
           2.1.2.   Canada Goose  	   2-23
           2.1.3.   Mallard	   2-43
           2.1.4.   Lesser Scaup	   2-56
           2.1.5. . Osprey  	   2-68
           2.1.6.   Red-Tailed Hawk  	   2-82
           2.1.7.   Bald Eagle	   2-95
           2.1.8.   American Kestrel  	 2-112
           2.1.9.   Northern  Bobwhite	 2-126
           2.1.10. American Woodcock	 2-140
           2.1.11. Spotted Sandpiper  	 2-152
           2.1.12. Herring Gull	 2-162
           2.1.13. Belted Kingfisher  	 2-176
           2.1.14. Marsh Wren	 2-186
           2.1.15. American Robin	 2-197

Table 2-2.  Mammals Included in the Handbook	 2-208

Tables for  2.2.1.   Short-Tailed Shrew	 2-213
           2.2.2.   Red Fox	 2-224
           2.2.3.   Raccoon  	 2-236
           2.2.4.   Mink	 2-251
           2.2.5.   River Otter	 2-264
                                        VIII

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                           LIST OF TABLES (continued)


           2.2.6.   Harbor Seal	  2-280
           2.2.7.   Deer Mouse  .	 .	  2-295
           2.2.8.   Prairie Vole	  2-314
           2.2.9.   Meadow Vole	  2-327
           2.2.10.  Muskrat		  2-340
           2.2.11.  Eastern Cottontail	  2-355

Table 2-3.  Reptiles and Amphibians Included in the Handbook	2-366

Tables for  2.3.1.   Snapping Turtle	  2-370
           2.3.2.   Painted Turtle	  2-386
           2.3.3.   Eastern Box Turtle	  .  2-400
           2.3.4.   Racer	  2-411
           2.3.5.   Northern Water Snake	  2-423
           2.3.6.   Eastern Newt	 .	  2-433
           2.3.7.   Green Frog	  2-446
           2.3.8.   Bullfrog	  2-456

Table 3-1.  Metabolizable Energy  (ME) of Various Diets for Birds
           and Mammals	 . .	 . .	:  .    3-5

Table 3-2.  Allometric Equations for Basal Metabolic Rate (BMR) in Birds	   3-21

Table 3-3.  Regression Statistics for Nagy's (1987) Allometric Equations
           for Food Ingestion Rates for Free-Living Animals	   3-36

Table 3-4.  Regression Statistics for Nagy's (1987) Allometric Equations
           for Free-Living (Field)  Metabolic Rates	 .	   3-37

Table 4-1.  Gross Energy and Water Composition of Wildlife Foods:
           Animal  Prey		   4-13
                      •
Table 4-2.  Energy  and Water Composition of Wildlife Foods:
           Plants	 .   4-14

Table 4-3.  General Assimilation Efficiency (AE) Values	   4-15

Table 4-4.  Percent Soil or Sediment in Diet Estimated From
           Acid-Insoluble Ash of  Scat	   4-20

Table 4-5.  Other Estimates of Percentage of Soil or Sediment in Diet  . .	   4-21
                                        IX

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                                LIST OF FIGURES
Figure 3-1.  Monthly Variation in Energy Budget Estimated for a
            House Sparrow	   3-25

Figure 4-1.  Wildlife Dose Equations for Drinking Water Exposures	    4-4

Figure 4-2.  Wildlife Dose Equations for Dietary Exposures	    4-6

Figure 4-3.  Estimating NIRk When Dietary Composition Is Known on a
            Wet-Weight Basis	    4-8

Figure 4-4.  Estimating NIRk Based on Different ME Values When
            Dietary Composition Is Expressed as Percentage of
            Total Prey Captured  	    4-9

Figure 4-5.  Utilization of Food Energy by Animals	   4-11

Figure 4-6.  Metabolizable Energy (ME) Equation 	   4-12

Figure 4-7..  Example of Estimating Food Ingestion Rates for
            Wildlife Species From Free-Living Metabolic Rate and
            Dietary Composition:  Male Mink  	   4-17

Figure 4-8.  Wildlife Oral Dose Equation for Soil or Sediment
            Ingestion Exposures  	   4-22

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                                  FOREWORD

      The Exposure Assessment Group (EAG) of EPA's Office of Research and
Development has three main functions:  (1) to conduct human health and ecological
exposure and risk assessments, (2) to review exposure and risk assessments and related
documents, and (3) to develop guidelines and handbooks for use in these assessments.
The activities under each of these functions are supported by and respond to the needs of
the various program offices, regional offices, and the technical community.
      The Wildlife Exposure Factors Handbook was produced in response to the increased
interest in assessing risks to ecological systems.  Its purpose is to improve exposure
assessments for wildlife and support the quantification of risk estimates. It is a companion
document to the Exposure Factors Handbook, which contains information useful for
quantifying exposure to humans.  Because information and methods for estimating
exposure are continually improving,  we will revise these handbooks as necessary in the
future.    .
                                                  Michael A. Callahan
                                                  Director
                                                  Exposure Assessment Group
                                        XI

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PREFACE

The Exposure Assessment Group of the Office of Health and Environmental
Assessment (OHEA) has prepared the Wildlife Exposure Handbook in support of the Office
of Solid Waste and Emergency Response and the Office of Water. The Handbook provides
information on various factors used to assess exposure to wildlife. The goals of the
project are (1) to promote the application of risk assessment methods to wildlife species,
(2) to foster a consistent approach to wildlife exposure and risk assessments, and (3) to
increase the accessibility of the literature applicable to these assessments.
The bulk of the document summarizes literature values for exposure factors for 34
species of birds, mammals, amphibians, and reptiles. In addition, we include a chapter on
allometric equations that can be used to estimate some of the exposure factors when data
are lacking. Finally, we describe some common equations used to estimate exposure. The
basic literature search was completed in May 1990 and was supplemented by targeted
searches conducted in 1992.
We anticipate updating this Handbook and would appreciate any assistance in
Identifying additional sources of information that fill data gaps or otherwise improve the
Handbook. Comments can be sent to:

Exposure Assessment Group
Wildlife Exposure Factors Handbook Project
USEPA (8603)
401 M Street, SW
Washington, DC 20460
XII

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        AUTHORS, MANAGERS, CONTRIBUTORS, AND REVIEWERS


      The Exposure Assessment Group (EAG) within EPA's Office of Health and

Environmental Assessment (OHEA) was responsible for preparing this document.

Additional major contract funding was provided by the Office of Emergency and Remedial

Response within the Office of Solid Waste and Emergency Response (OSWER) and by the

Office of Science and Technology within the Office of Water. The document was

prepared by ICF, Incorporated under contracts 68-C8-0003, 68-W8-0098, 68-DO-0101,

and 68-C2-0107. Susan Braen Norton served as the EAG project manager and provided

overall direction and coordination of the project.  Thanks to Doug Norton for the cover

illustration.

AUTHORS

      Dr. Margaret McVey
      Kimberly Hall, Peter Trenham, Alexander Soast, Leslie Frymier, and Ansara Hirst
      ICF, Incorporated

PROJECT MANAGER

      Susan Braen Norton
      Exposure Assessment Group, Office of Health and Environmental Assessment
      Office of Research and Development
      U.S. Environmental Protection Agency

TASK MANAGERS

      Cynthia. Nolt
      Office of Science and Technology
      Office of Water
      U.S. Environmental Protection Agency

      Ron Preston
      Office of Emergency and Remedial  Response
      Office of Solid Waste and Emergency Response
      U.S. Environmental Protection Agency

CONTRIBUTORS

      Dr. Sarah Gerould
      Office of Water Quality
      U.S. Geological Survey
                                      XIII

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      Dr. Ronald Kirby
      Office of Information Transfer
      U.S. Fish and Wildlife Service (USFWS)
      Department of the Interior
REVIEWERS
      Dr. Cynthia Annett, USFWS, Arkansas Cooperative Fish and Wildlife Research
        Unit, AR
      Dr. Richard J. Aulerich, Michigan State University, Ml
      Dr. Richard Bennett, USEPA, Environmental Research Laboratory (ERL),
        Corvallis, OR
      Dr. Christine A. Bishop, Canadian Wildlife Service/Ontario, Canada
      Dr. Brad Bortner, USFWS, Office of Migratory Bird Management, MD
      Dr. Steven Bradbury, USEPA, ERL-Duluth, MN
      Dr. Robert Burr, USFWS, VA
      Ms. Janet Burris, ABB Environmental Services, Washington, DC
      Dr. Joseph Chapman, Utah State University, UT
      Dr. Lewis Cowardin, USFWS, Northern Prairie Wildlife Research Center, ND
      Ms. Deanna Dawson, USFWS, Patuxent Wildlife Research Center, MD
      Dr. Donald L. DeAngelis, Oak Ridge National Laboratory, TN
      Dr. Bruce Duncan,  USEPA, Region 10, Seattle, WA
      Dr. Robert Foley, USFWS, Annapolis Field Office, MD
      Dr. Glen Fox, Canadian Wildlife Service, Ontario, Canada
      Dr. J.H.B. Garner, USEPA, OHEA, Environmental Criteria and Assessment Office
        (ECAO), Research Triangle Park, NC
      Dr. J. Whitfield Gibbons, University of Georgia, Savannah  River Ecology
        Laboratory, GA
      Mr. Keith A. Grasman, Virginia Polytechnic Institute and State University, VA
      Dr. Fred Guthery, Caesar Kleberg Wildlife Research Institute, Texas A&l
        University, TX
      Dr. Richard S. Halbrook, Oak Ridge National Laboratory, TN
      Dr. Michael J. Hamas, Central Michigan  University, Ml
      Dr. Charles J. Henny, USFWS, Pacific Northwest Research Station, OR
      Dr. Paula F. P. Henry, USFWS, Patuxent Wildlife Research Center, MD
      Dr. Gary Heinz, USFWS, Patuxent Wildlife Research Center, MD
      Dr. Doug James, University of Arkansas, AR
      Mr. K. Bruce Jones, USEPA, Environmental Monitoring Systems Laboratory,
        EMAP Terrestrial Ecosystems, CA
      Dr. Dennis G. Jorde, USFWS, Patuxent Wildlife Research Center, MD
      Dr. Norm Kowal, USEPA, OHEA, ECAO, Cincinnati, OH
      Dr. Gary L. Krapu, USFWS, Northern Prairie Wildlife Research Center, ND
      Dr. David Krementz, USFWS, Patuxent Wildlife Research Center, MD
      Dr. James Kushlan, University of Mississippi, MS
      Dr. John T. Lokemoen, USFWS, Northern Prairie Wildlife Research Center, ND
      Dr. Dave Ludwig, EA Engineering, Inc., MD
      Dr. Drew Major, USFWS, Concord, NH
      Dr. Karen McBee, Oklahoma State University, OK
                                       XIV

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REVIEWERS (continued)

      Dr. Linda Meyers-Schone, International Technology Corp., NM
      Mr. Jerry Moore, USEPA, OHEA, Washington, DC
      Dr. Lewis Oring, University of Nevada at Reno, NV
      Dr. Raymond Pierotti, University of Arkansas, AR
      Dr. Richard M. Poch6, Genesis Laboratories, Wl
      Dr. Douglas Reagan, Woodward-Clyde Consultants, CO
      Dr. Lorenz Rhomberg, USEPA, OHEA, Human Health Assessment Group,
        Washington, DC
      Dr. Robert Ringer, Mount Dora, FL
      Dr. John L. Roseberry, Southern Illinois University at Carbondale, IL
      Dr. Alan Sargeant, USFWS, Northern Prairie Wildlife Research Center, ND
      Dr. Edward Schafer, USDA, Denver Wildlife Research Center, CO
      Dr. Laird Schutt, Canadian Wildlife Service, Quebec, Canada
      Ms. Anne Sergeant, USEPA, OHEA, EAG, Washington, DC
      Dr. Kim Smith, University of Arkansas, AR
      Dr. Mark Sprenger, USEPA, OSWER, Environmental Response Team, Edison, NJ
      Dr. George  A. Swanson, USFWS, Northern Prairie Wildlife Research Center, ND
      Dr. Sylvia Talmage, Oak Ridge National Laboratory, TN
      Dr. Bob Trost, USFWS, Office of Migratory Bird Management, MD
      Dr. D.V. (Chip) Weseloh, Canadian Wildlife Service, Ontario, Canada
      Dr. Nathaniel Wheelwright, Bowdoin College, ME
      Dr. Donald  H. White, USFWS, Southeast Research Station, GA
      Dr. Stanley N. Wiemeyer, USFWS, Patuxent Wildlife Research Center, MD
      Dr. Bill Williams, Environmental  Planning and Toxicology, Corvallis, OR
      Dr. Dean M. Wilkinson, U.S. Department of Commerce, National Oceanic and
        Atmospheric Administration, National Marine Fisheries Service
      Dr. Jerry 0. Wolff, USEPA, ERL, Corvallis, OR
      Dr. John P. Wolfin, USFWS, Annapolis Field Station, MD
                                       xv

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                               1.   INTRODUCTION

      The Wildlife Exposure Factors Handbook (hereafter referred to as the Handbook)
provides data, references, and guidance for conducting exposure assessments for wildlife
species exposed to toxic chemicals in their environment.  It is the product of a joint effort
by EPA's Office of Research and  Development (ORD), Office of Solid Waste and
Emergency Response (OSWER), and Office of Water (OW).  The goals  of this Handbook
are (1) to promote the application of risk assessment methods to wildlife species, (2) to
foster a consistent approach to wildlife exposure and risk assessments, and (3) to increase
the accessibility of the literature applicable to these assessments.

1.1.   PURPOSE AND SCOPE

      The purpose of the Handbook is to provide a convenient source of information and
an analytic framework for screening-level risk assessments for common wildlife species.
These screening-level risk assessments may be used for several purposes, including: to
assess potential effects of environmental contamination on wildlife species and to support
site-specific decisions (e.g., for hazardous waste sites); to support the development of
water-quality or other media-specific criteria for limiting environmental levels of toxic
substances to protect wildlife species; or to focus research and monitoring efforts.  The
Handbook provides data (analogous to EPA's Exposure Factors Handbook for humans,
USEPA, 1989c) and methods for estimating wildlife intakes or doses of environmental
contaminants. Although the data presented in the Handbook can be used for screening
analyses, we recommend that anyone establishing a cleanup goal or criterion on the basis
of values contained herein obtain the original literature on which  the values are based to
confirm that the study quality is sufficient to support the criterion. This Handbook does
not include data or extrapolation  methods required to assess the  toxicity of substances to
wildlife species, nor does it include any chemical-specific data (e.g., bioavailability factors).
       For the Office of Water, data gathered for the Handbook were used to identify
wildlife species that are likely to be at greater risk from bioaccumulative pollutants in
surface waters and to estimate likely exposures for these species.  Data on diets and on
                                        1-1

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food and water ingestion rates can be used with chemical-specific information, such as
bioaccumulation potential and wildlife toxicity, to calculate site- or region-specific
concentrations of a chemical in water (or soil or sediment) that are unlikely to cause
adverse effects.

For the Superfund program, this Handbook supplements the existing environmental
evaluation guidance. EPA's Risk Assessment Guidance for Superfund: Volume II--
Environmental Evaluation Manual (U.S. EPA, 1989a) provides an overview of ecological
assessment in the Superfund process. It includes a description of the statutory and
regulatory bases for ecological assessments in Superfund and fundamental concepts for
understanding ecological effects of environmental contaminants. The Environmental
Evaluation Manual also reviews elements of planning an ecological assessment and how to
organize and present the results of the assessment. EPA's Ecological Assessment of
Hazardous Waste Sites:, A Field and Laboratory Reference (U.S. EPA, 1989b) and
Evaluation of Terrestrial Indicators for Use in Ecological Assessments at Hazardous Waste
Sites (U.S. EPA, 1992) are companion documents that describe biological assessment
strategies, field sampling designs, toxicity tests, biomarkers, biological field assessments,
and data interpretation. The ECO Update intermittent bulletin series (published by EPA's
Office of Solid Waste and Emergency Response, publication no. 9345.0-05I, available from
the National Technical Information Service, Springfield, Virginia) provides supplemental
guidance for Superfund on selected issues. Although these documents have identified
decreases in wildlife populations as potential endpoints for ecological assessments, they
do not provide guidance on how to conduct a wildlife exposure assessment that is
comparable to the guidance provided by the Superfund program for human health exposure
assessments. This Handbook provides both guidance and data to facilitate estimating
wildlife exposure to contaminants in the environment.
Exposure assessments for wildlife and humans differ in several important ways.
One key distinction is that many different wildlife species may be exposed, as compared
with a single species of concern for a human health assessment. Exposure varies between
different species and even between different populations of the same species; behavioral
attributes and diet and habitat preferences influence this variation. Second, whereas it is
1-2

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seldom possible to confirm estimated levels of human exposure without invasive sampling
of human tissues, confirmatory sampling for many chemicals can be done in wildlife
species (protected species excepted).  However, the tissue sampling required to quantify
actual exposure levels can be costly, and interpretation of tissue concentrations can be
complex.                                                                  •

       For both human health and wildlife exposure assessments, the most cost-effective
approach  is often to first screen for potentially significant exposures using measures (or  ,
estimates) of environmental contamination (e.g., in soils, water, prey species) to estimate
contaminant intakes or doses by significant routes of exposure.  If estimated doses fall far
below the toxicity values associated with adverse effects, especially from chronic
exposures, further assessment may be unnecessary.  If estimated doses far exceed
reference  toxicity values, it may be  possible to determine appropriate actions on the basis
of these estimates alone.  When a screening-level exposure assessment indicates that
adverse effects are likely, additional confirmatory data may be needed in the decision-
making process. For humans, it is usually not practicable to obtain additional types of data
(e.g., tissue concentrations, biomarkers), and human exposure estimates are often refined
by using more site-specific data for  exposure parameters. For wildlife, confirmatory data
may be obtained from chemical analyses of tissue samples from potentially exposed
wildlife or their prey and from observed incidence of disease, reproductive failure, or death
in exposed wildlife. These are reviewed in EPA's field and laboratory reference and
terrestrial  indicators documents described above (EPA, 1989b, 1992).  If this more direct
approach  is not possible, the exposure analysis can be refined on the basis of more site-
specific data for the species of concern.

       Wildlife can be exposed to environmental contaminants through inhalation, dermal
contact with contaminated water or soil, or ingestion of contaminated food, water, or soil.
Exposure assessment seeks to answer several questions, including:

       •     What organisms are actually or potentially exposed to contaminants?
                                        1-3

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       •     Which organisms or life stages might be most vulnerable to environmental
             contaminants (e.g., ingest the largest quantities of contaminated media
             relative to body size}?
       •     What are the significant routes of exposure?
       •     To what amounts of each contaminant are organisms actually or potentially
             exposed?
       •     How long is each exposure?
       •     How often does or will exposure to the environmental contaminants take
             place?
       •     What seasonal and climatic variations in conditions are likely to affect
             exposure?
                                                                         *
       •     What are the site-specific geophysical, physical, and chemical conditions
             affecting exposure?

The parameters for which data are presented in the Handbook are intended to help a risk
assessor answer these questions. The population  parameter data (e.g., birth and death
rates) may be useful for placing estimates of risks  to wildlife populations in a  broader
ecological context and for planning monitoring  activities.

       This Handbook focuses on selected groups  of mammals, birds, amphibians, and
reptiles. Fish and aquatic or terrestrial invertebrates were not included in this effort.  The
profiles on amphibians and reptiles are, in general, less developed than those for birds and
mammals.  We emphasized birds and mammals because methods for assessing their
exposure are more common and well developed. As more assessments are done for
amphibians and reptiles, we anticipate that additional methods and supporting factors will
be necessary.  Until then, we hope the  information presented here will encourage
assessors to begin considering and quantifying  their exposure.
       For all exposure parameters and species in the Handbook, we try to present data
indicative of the range of values that different populations of a species may assume across
North America.  For site-specific ecological risk assessments, it is important to note that
the values for exposure factors presented in this Handbook may not accurately represent
                                        1-4

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specific local populations. The species included in the Handbook have broad geographic
ranges, and they may exhibit different values for many of the exposure factors in different
portions of their range. Some species exhibit geographic variation in body size, survival,
and reproduction. Breeding and migration also influence exposure. Site-specific values for
these parameters can be determined more accurately using published studies of local
populations and assistance from the U.S. Fish and Wildlife Service, state departments of
fish and game, and organizations such as local Audubon Society chapters. In addition.
The Nature Conservancy develops and maintains wildlife databases (including endangered
species) in cooperation with all 50 states. Local information increases the certainty of a
risk assessment. Thus, for site-specific assessments, we strongly recommend contacting
local wildlife experts to determine the presence and characteristics of species of concern.

Finally, we do not intend to imply that risk assessments for wildlife should be
restricted to the species described in this Handbook, or should always be conducted for
these species. We emphasize that locally important or rare species not included in this
Handbook may still be very important for site-specific risk assessments. To assist users
who wish to evaluate other species, we list general references for birds, mammals,
reptiles, and amphibians in North America. The Handbook also provides allometric
equations to assist in extrapolating exposure factors (e.g., water ingestion rate, surface
area) to closely related species on the basis of body size.

1.2. ORGANIZATION OF THE HANDBOOK

The Handbook is organized into four chapters. The remainder of this chapter
provides an overview of the species and exposure factors included in the Handbook and
discusses the literature search strategy used to identify factors. Chapter 2 presents
exposure profiles for the selected species (described in greater detail below). Chapter 3
provides allometric models that may be used to estimate food and water ingestion rates,
inhalation rates, surface areas, and metabolic rates for wildlife species on the basis of
body size. Chapter 4 describes common equations used to estimate wildlife exposure to
environmental contaminants. Included are methods for estimating diet-specific food
1-5

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ingestion rates on the basis of metabolic rate and for estimating exposure to chemicals in
soil and sediment.
*

Chapter 2 is the core of the Handbook; it presents exposure profiles for selected
birds (Section 2.1), mammals (Section 2.2), and reptiles and amphibians (Section 2.3),
along with brief descriptions of their natural history. Each species profile includes an
introduction to the species' general taxonomic group, qualitative description of the species,
list of similar species, table of exposure factors, and reference list (which also covers that
species' section in Volume II, the Appendix). The values included in the exposure factors
tables are a subset of those we found in the literature and also include values that we
estimated using the allometric equations presented in Chapter 3. We selected values for
the tables in Chapter 2 based on a variety of factors including sample size, quantification
of variability (e.g., standard deviations, standard errors, ranges), relevance of the
measurement technique for exposure assessment, and coverage of habitats, subspecies,
and the variability seen in the literature. A complete listing of the parameter values
identified in our literature survey is provided in the Appendix. The Appendix also includes
more details concerning sample size, methods, and qualifying information than the species
profiles. Users are encouraged to consult the Appendix to select the most appropriate
values for their particular assessment.

The remainder of this introductory chapter describes the species and exposure
factors covered in the Handbook in greater detail. The literature search strategy is
discussed in Section 1.6.

1.3. LIST OF SELECTED SPECIES

Wildlife species were selected for the Handbook to provide several types of
coverage:
Major taxonomic groups (major vertebrate groups, orders, and families);
A range of diets (e.g., piscivore, probing insectivore) likely to result in
contact with contaminated environmental media;
1-6

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       •      A variety of habitat types (e.g., fields, marshes, woodlands, coastal areas);
             and
       •      Small to large body sizes.

       Other attributes also were considered when selecting species for the Handbook,
including:

       •      Species with wide geographic distribution within the United States (or
             replaced regionally by similar species);
       •      Species of concern to EPA or other regulatory agencies (managed by state or
             Federal agencies); and
       •      Species of societal significance (familiar or of concern to most people).

       Tables 1-1, 1-2, and 1-3 list the birds, mammals, and reptiles and amphibians,
respectively, included in the Handbook.  The species are listed according to diet, general
foraging habitat, and relative body size.

       The species included in this Handbook were necessarily limited; however, we do
not recommend limiting wildlife exposure assessments to the species or similar species
identified in the Handbook.  Instead, the Handbook should be used as a framework to
guide development of exposure factors and assessments for species of concern in a risk
assessment. Species selection criteria for site-specific risk assessments might include the
following considerations:
             Species that play important roles in community structure or function (e.g.,
             top predators or major herbivores);
             Diet, habitat preferences, and behaviors that make the species likely to
             contact the stressor;
             Species from different taxa that might exhibit different toxic effects from
             contaminants;
             Local species that are of concern to Federal and state regulatory agencies
             (e.g., endangered and threatened species);

                                         1-7

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       Table 1-1.  Characteristics of Selected Birds
Diet
Insectivorea
probing/soil-dwelling invertebrates
gleaning/insects
Herbivore
gleaning/seeds
grazing/shoots
Omnivore
Carnivoreb
Carnivore/Piscivore/Scavenger
small birds & mammals/fish/dead fish
fish/invertebrates/small birds/garbage
Piscivore0
Aquatic lnsectivored
probing/soil-dwelling invertebrates
diving/aquatic invertebrates
Aquatic Herbivore/lnsectivore
General Foraging Habitat
woodlands, marshes
marshes
woodlands, fields and brush
open fields
open woodland, suburbs
open fields, forest edge
most open areas
open water bodies
Great Lakes and coastal
most streams, rivers, small
lakes
most freshwater and saltwater
bodies
large water bodies
most rivers and streams
oceans and coastal areas
most wetlands, ponds
Body Size
medium
small
medium
large
small
medium
medium
large
medium
medium
large
large
small
medium
medium
Selected Bird Species
American woodcock
marsh wren
northern bobwhite
Canada goose
American robin
American kestrel
red-tailed hawk
bald eagle
herring gull
belted kingfisher
great blue heron
osprey
spotted sandpiper
lesser scaup
mallard
00
       Includes consumption of insects, other arthropods, worms, and other terrestrial invertebrates.
       blncludes consumption of terrestrial vertebrates and large invertebrates.
       Includes consumption of fish, amphibians, crustaceans, and other larger aquatic animals.
       dlncludes consumption of aquatic invertebrates and amphibian larvae by gleaning or probing.

-------
      Table 1 -2.  Characteristics of Selected Mammals
Diet
Insectivore8
gleaning/surface-dwelling invertebrates
Herbivore
gleaning/seeds
grazing or browsing/shoots, roots, or
leaves
Omnivore
Carnivore
Piscivore0
Aquatic Herbivore
General Foraging Habitat
most habitat types
most dry-land habitats
grassy fields, marshes, bogs
prairie grass communities
most habitat types
woodlands, suburbs
mixed woodlands and open
areas
most areas near water
rivers
coastal, estuaries, lakes
most aquatic habitats
Body Size
small
small
small
small
medium
medium
medium
medium
medium
medium
medium
Selected
Mammal Species
short-tailed shrew
deer mouse
meadow vole
prairie vole
eastern cottontail
raccoon
red fox
mink
river otter
harbor seal
muskrat
CO
       Includes consumption of insects, other arthropods, worms, and other terrestrial invertebrates.
       Includes consumption of aquatic and terrestrial vertebrates and large invertebrates.
       Includes consumption of fish, amphibians, crustaceans, molluscs, and other large aquatic animals.

-------
Table 1-3.  Characteristics of Selected Reptiles and Amphibians
Adult Diet
General Foraging Habitat
for Adults
Body Size
Selected Reptile or
Amphibian Species
REPTILES
Terrestrial Carnivore8
Aquatic Piscivoreb
Omnivore
Aquatic Herbivore
open woods, fields and brush
most types of water bodies
open fields, forest edge,
marshes
most freshwater bodies
most wetlands, ponds
medium
medium
medium
large
medium
racer
northern water snake
eastern box turtle
snapping turtle
painted turtle
AMPHIBIANS
Insectivore0
Aquatic Piscivore/Insectivored
shallow freshwater bodies
lakes, ponds, bogs, streams
small lakes, ponds, streams
small
medium
small
green frog
bullfrog
eastern newt
Includes consumption of terrestrial vertebrates and invertebrates, insects, other arthropods, worms, and other terrestrial invertebrates.
blncludes consumption of fish, amphibians, and crustaceans.
"Includes consumption of insects, other arthropods, worms, and other terrestrial invertebrates.
dlncludes consumption of fish, amphibians, crustaceans, molluscs, other aquatic animals, and terrestrial insects and other invertebrates.

-------
« Species of societal significance or concern (e.g., game species, familiar
species); and
• Species that have been shown to be particularly sensitive to the stressor
being addressed.

When species of concern for a risk assessment include species for which data are
presented in this Handbook, it can serve as a readily available source of data for screening-
level exposure analyses.

1.4. LIST OF EXPOSURE FACTORS

Three routes of exposure may be of concern for wildlife in the vicinity of
contaminated surface waters and terrestrial habitats: oral, inhalation, and dermal. Oral
exposures might occur via ingestion of contaminated food (e.g., aquatic prey) or water or
incidental ingestion of contaminated media (e.g., soils, sediments) during foraging or other
activities. Inhalation of gases or particulates might be a significant route of exposure for
some animals. Dermal exposures are likely to be most significant for burrowing mammals
(i.e., via contact with contaminated soils) and animals that spend considerable amounts of
time submerged in surface waters. This Handbook tabulates selected data for all three
routes of exposure (Table 1-4), emphasizing oral exposures. It also provides quantitative
information on population parameters and qualitative information related to seasonal
activities, geographic ranges, habitats, and other life-history characteristics.

The exposure factors presented in the Handbook are conceptually separated into
four types: normalizing factors (Section 1.4.1), contact rates (Section 1.4.2), population
dynamics (Section 1.4.3), and seasonal activities (Section 1.4.4). Section 1.5 describes
the format in which values for these exposure factors are presented in Chapter 2.

1.4.1. Normalizing Factors

Normalizing factors include body weight, growth rate, and metabolic rate, which
are discussed in turn below.
1-11

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Table 1-4.  Wildlife Exposure Factors Included in the Handbook
Parameter Type
NORMALIZING FACTORS
CONTACT RATES
POPULATION DYNAMICS
SEASONAL ACTIVITIES
Exposure Route/
Factor Category
Body Weight
Metabolic Rate
Oral
Inhalation
Dermal
Distribution (by life
stage and season)
Birth, Maturation, and
Death Rates
Timing of Activities
(those that can modify
habitat preferences and
exposure)
Factor
body weight
growth rate
metabolic rate
food ingestion rate
dietary composition
water ingestion rate
soil/sediment intake
rate
inhalation rate
surface area
social organization
home range size
population density
annual fecundity
age at sexual maturity
annual mortality rates
average longevity
mating season
parturition/hatching
molt/metamorphosis
dispersal/migration/
hibernation
                                       1-12

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7.4.1.7. Body Weight

Body weights (in units of mass) are reported as fresh weight as might be obtained
by weighing a live animal in the field. Several of the contact rate parameters are
normalized to body weight. For example, both food and water ingestion rates are reported
on a per body weight basis (e.g., gram of fresh food or water per gram of fresh body
weight per day). Using empirical models, body weight data also were used to estimate
contact rate parameters for which we could not find measured values.

Adult body weights are listed for all species. For birds, we also provide egg weight,
weight at hatching, nestling or chick weights, and weight at fledging, when available, to
assist risk assessors concerned with estimating exposures of embryos and young birds.
For mammals, we also provide gestating female weight, birth weight, pup weights at
various ages, weight at weaning, and weight at sexual maturity, when available, for a
similar purpose. Finally, for reptiles and amphibians, we also provide egg weight, larval or
juvenile weights with age, and weight at metamorphosis, if available and applicable. Body
size for reptiles and amphibians is often reported as body length instead of body weight,
so we also provide data on body length and the relationship between body length and
body weight, when available.

1.4.1.2. Growth Rate
Young animals generally consume more food (per unit body weight) than adults
because they grow and develop rapidly. Growth rates change as animals mature, whether
expressed as absolute (g/day) or relative (percent body weight) terms. Weight gain is
rapid after birth, but slows over time. Different types of animals exhibit different patterns
of growth over time. Plots of body weight versus age for some animal groups are
sigmoidal whereas others may approximate logistic functions or other shapes. As a result,
investigators often report growth rates as various constants associated with particular
mathematical models (e.g., Gompertz equation, von Bertalanffy equation; see Peters,
1983) that fit the growth pattern for a given species. Instead of presenting a variety of
growth constants and models, however, we report growth rates for young animals, when

1-13

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available, in grams per day for specific age groups. Growth rates also can be inferred from
a series of juvenile body weights with age. These measures are included under body
weight (see Section 1.4.1.1).

1.4.1.3. Metabolic Rate

Metabolic rate is reported on the basis of kilocalories per day normalized to body
weight (e.g., kcal/kg-day). If metabolic rate was measured and reported on the basis of
oxygen consumption only, we provide those values as liters 02/kg-day. Normalized
metabolic rates based on kilocalories can be used to estimate normalized food ingestion
rates (see Section 4.1.2). Metabolic rates based on oxygen consumption can be used to
estimate metabolic rates based on kilocalories for subsequent use in estimating food
ingestion rates (see Section 3.6.3.1).

1.4.2. Contact Rate Factors

Table 1-5 summarizes the six contact rate factors included for the oral, inhalation,
and dermal routes of exposure.

1.4.2.1. Oral Route

Three environmental media are the primary contributors to wildlife exposure by the
oral route: food, water, and soils and sediments. Four contact rate exposure parameters
related to these three exposure media are discussed below.
7.4.2.7.7. Food ingestion rates. Food ingestion rates are expressed in this
Handbook as grams of food (wet weight) per gram of body weight (wet weight) per day
(g/g-day). Food ingestion rates can vary by age, size, and sex and by seasonal changes in
ambient temperature, activity levels, reproductive activities, and the type of diet
consumed. Food ingestion rates have not been measured for many wildlife species.
Methods for estimating food ingestion rates on the basis of free-living (or field) metabolic
rate, energy content of the diet, and assimilation efficiency are discussed in Section 4.1.2.

1-14

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Table 1-5. Wildlife Contact Rate Exposure Factors
Exposure
Route
ORAL
INHALATION
DERMAL
Medium
Food
Water
Soil/Sediment
Vapor or
Particulates
Water or
Soil/Sediment
Factor
ingestion rate
dietary
composition
ingestion rate
intake rate
inhalation rate
surface area
Expression
fraction body
weight
fraction of total
intake represented
by each food type
fraction body
weight
fraction of total
food intake
daily volume
total area
potentially
exposed8
Units
6 g/g-day
g/g-day
g/g-day
m3/day
cm2
aTotai unprotected or permeable surface area that might be exposed under some circumstances (e.g., dust
bathing), even though it would not be exposed under other conditions (e.g., swimming with a trapped air
layer between the feathers or fur and skin).
7.4.2.1.2. Dietary composition. Dietary composition varies seasonally and by
age, size, reproductive status, and habitat. Dietary composition (e.g., proportion of diet
consisting of various plant or animal materials), often measured by stomach-content-
analyses, is expressed whenever possible as percentage of total intake on a wet-weight
basis. This convention facilitates comparison with contaminant concentrations in dietary
items reported on a wet-weight basis. Methods for converting other measures of dietary
composition (e.g., percentage of total prey items captured, proportion of intake on a dry-
weight basis) to estimates of dietary intake on a wet-weight basis are provided in Section
4.1.2.

1.4.2.1.3. Water ingestion rates. For drinking-water exposures, ingestion rates
are expressed in this Handbook as grams of water per gram of wet body weight per day
(g/g-day). Water consumption rates depend on body weight, physiological adaptations.
1-15

-------
diet, temperature, and activity levels. It is important to remember that, under some
conditions, some species can meet their water requirements with only the water contained
in the diet and metabolic water production (see Section 3.2).

1.4.2.1.4. Incidental soil and sediment intakes. Wildlife can incidentally ingest
soils or sediments while foraging or during other activities such as dust bathing and
preening or grooming. Data quantifying soil and sediment ingestion are limited; we present
available values for selected species in Section 4.1.3.

1.4.2.2. Inhalation Route

Average daily inhalation rates are reported in the Handbook in units of m3/day.
Inhalation rates vary with size, seasonal activity levels, ambient temperature, and daily
activities. EPA's current approach to calculating inhalation exposures requires additional
information on species' respiratory physiology to fully estimate inhalation exposures (see
Section 4.1.4).

7.4.2.3. Dermal Route

Dermal contact with contaminated soil, sediment, or water is likely to be an
exposure pathway for some wildlife species. An animal's surface area could be used to
estimate the potential for uptake of contaminants through its skin. For some exposures
(e.g., dust bathing), the entire surface area of the animal might be important. For other
types (e.g., swimming), only the uninsulated portions (e.g., no fur or feathers that create a
trapped air layer) of the animal might contact the contaminated medium. In the Handbook,
we provide measures or estimates of the entire potentially exposed surface area of an
animal, when possible. We have not attempted to determine what portions would be
exposed and protected for swimming animals.
1-16

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1.4.3. Population Dynamics

Several parameters can be used to describe the spatial distribution and abundance
of a population of animals in relation to the spatial extent of contamination. Three
parameters related to spatial distribution are social organization, home-range size, and
population density. These are important for estimating the number of individuals or
proportion of a population that might be exposed to a contaminated area. Parameters
related to population size and persistence include age at sexual maturity and maturation,
mortality, and annual fecundity rates. These parameters may be useful to assessors
planning or evaluating field studies or monitoring programs.

1.4.3.1. Social Organization

The Handbook includes a qualitative description of each species' social
organization, which influences how animals of various ages and sizes are distributed in
space. In some species, individual home ranges do not overlap. In others, all individuals
use the same home range. In between these extremes, home ranges can be shared with
mates, offspring, or extended family groups.

Social organization can vary substantially among species that appear otherwise
similar; therefore, it is not possible to extrapolate the social organization of similar species
from the selected species in this Handbook. Consult the general bibliographies for
information sources to determine the social organization of species not covered in the
Handbook.

1.4.3.2. Home Range/Territory Size/Foraging Radius
Home range size can be used to determine the proportion of time that an individual
animal is expected to contact contaminated environmental media. Home range is defined
as the geographic area encompassed by an animal's activities (except migration) over a
specified time. While home range values often are expressed in units of area, for species
dependent on riparian or coastal habitats, a more meaningful measure can be foraging
1-17

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radius, or the distances the animals are willing to travel to potential food sources.
Although home ranges may be roughly circular in homogeneous habitats, it is important to
remember that depending on habitat needs and conditions, home ranges may be irregular
in shape. The size and spatial attributes of a home range often are defined by foraging
activities, but also might depend on the location of specific resources such as dens or nest
sites in other areas. An animal might not visit all areas of its home range every day or
even every week, but over longer time periods, it can be expected to visit most of the
areas within the home range that contain needed resources such as forage, prey, or
protected resting areas.

Home range size for individuals within a population can vary with season, latitude,
or altitude as a consequence of changes in the distribution and abundance of food or other
resources. It generally varies with animal body size and 'age because of differences in the
distribution of preferred forage or prey. It can also depend on habitat quality, increasing as
habitat quality decreases to a condition beyond which the habitat does not sustain even
sparse populations. Finally, home ranges can vary by sex and season. For example, if a
female is responsible for most or all of the feeding of young, her foraging range might be
restricted to an area close to her nest or den when she has dependent young, whereas the
foraging range of males would not be so restricted.

Nonterritorial species may allow significant overlap of activity areas among
neighboring individuals or groups. For example, several individuals or mated pairs may
share the same area, although signalling behaviors may ensure temporal segregation. For
these species, we report a home range size or foraging radius. Other species are strongly
territorial and defend mutually exclusive areas: individuals, breeding pairs, or family units
actively advertise identifiable boundaries and exclude neighboring individuals or groups.
Foraging activities are usually restricted to the defended territories. For these species, we
report the size of the defended territory and note whether foraging occurs outside of the
territory.
1-18

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1.4.3.3. Population Density

Population density (the number of animals per unit area) influences how many
individuals (or what proportion of a local population) might be exposed within a
contaminated area. For strongly territorial species, population density can be inferred from
territory size in many cases. For species with overlapping home ranges, particularly
colonially breeding animals (e.g., most seabirds), population density cannot be inferred
from home range size.

1.4.3.4. Annual Fecundity

Attributes related to the number of offspring produced each year that reach sexual
maturity (annual fecundity) are measured in different ways depending on the life history of
the species. For birds, data are generally available for clutch size, number of clutches per
year, nest success (generally reflecting predation pressure), number of young fledged per
successful nest (generally reflecting food availability), and number of young fledged per
active nest (reflecting all causes of mortality). For mammals, litter size in wild populations
often is determined by placental scars or embryo counts, and the number of young
surviving to weaning is seldom known. For reptiles that lay eggs, clutch size and percent
hatching can be measured in the field. For viviparous reptiles, we report the number born
in a litter. For amphibians, egg masses may include thousands of eggs, but these are
seldom counted.

1.4.3.5. Annual Mortality and Longevity

Longevity can influence the potential for cumulative deleterious effects and the
appropriate averaging times for chronic exposures. For birds, annual adult mortality tends
to be constant. For large mammalian species, however, annual adult mortality tends to be
constant for several years, and then increases rapidly with age. For reptiles and
amphibians, annual adult mortality can decrease with age for some time as the animals
continue to grow larger and become less susceptible to predation. In the Handbook, we
1-19

-------
report annual mortality rates by age category and typical or mean and maximum
longevities, when possible.

1.4.4. Seasonal Activities

Many life-cycle attributes affect an animal's activity and foraging patterns in time
and space. For example, many species of birds are present in the northern hemisphere
only during the warmer months or move seasonally between the northern and southern
parts of North America. Some species of mammals, reptiles, and amphibians hibernate or
spend a dormant period in a burrow or den during the winter months. The species profiles
describe these and other seasonal activity patterns that can influence exposure frequency
and duration.

For each species, we summarize information on the seasonal occurrence of several
activities including breeding, molting, migration, dispersal, and occurrence of
dormancy/denning (if applicable). Deposition and utilization of fat reserves are discussed
where information is available. Trends in these factors with latitude are identified.

1.5. DATA PRESENTATION FORMAT

Species-specific values for the exposure factors are presented in Chapter 2.
Quantitative data for each species are presented in tables arranged in four main sections:

• Normalizing and Contact Rate Factors;
• Dietary Composition;
• Population Dynamics; and
• Seasonal Activities.

The parameter values and units used for each exposure factor are described in the
remainder of this section. In the species profiles and in the Appendix, all values are
identified as measured or estimated, and references are provided.
1-20

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1.5.1.   Normalizing and Contact Rate Factors


      Normalizing and contact rate factors are presented under the heading "Factors" in

Chapter 2.  Several of them apply to all animals included in the Handbook, whereas some
apply only to specific groups, as described in Sections 1.5.1.1 through 1.5.1.4.  The

column headers for these factors are explained in Table 1-6.


Table 1-6.  Column Headers for Tables of Normalizing and Contact Rate Factors
   Age/Sex/    Age (e.g., A for adult, J for juvenile)
   Cond./Seas.  Sex (e.g., M for male, F for female)
               Condition (e.g., I for incubating, NB for nonbreeding)
               Season (e.g., SP for spring, SU for summer).

               [Note: Only information needed to correctly interpret the value is
               included.]

   Mean       Mean value for population sampled ± standard deviation (SD), if
               reported.  If SD is not reported, mean value for population sampled
               ± standard error (SE) of the mean, if reported. For some studies, a
               range of typical values may be presented instead of a mean value
               (check the notes).

   Range or    Range of values reported for the population sampled, or
   (95% Cl of  (95th percent confidence interval of the mean value).
   Mean)

   Location     State(s) or province(s) in which the study was conducted
   (subspecies)  (subspecies studied, if reported).
   Reference

   Note No.
Reference for study.

Footnote number.
1.5.1.1.  All Animals

Body weight (grams or
kilograms)
                Measured values only. Although we use the term
                weight, all data are presented in units of mass.  The age
                and sex of the animal are specified as appropriate, and
                                       1-21

-------
Metabolic rate (liters 02/kg-day)
Metabolic rate (kcal/kg-day)
Food ingestion rate (g/g-day)
Water ingestion rate (g/g-day)
Sediment/soil ingestion rate
Inhalation rate (m3/day)
Surface area (cm2)
weights may include age-weight series for young
animals.

Included only if measured values were available. These
data can be used to estimate metabolic rate on a kcal
basis.

Measured or estimated basal and free-living (or field)
metabolic rates. Most of the free-living values were
estimated from body weight using an appropriate
allometric equation.

Measured on a wet-weight basis. For birds and
mammals, values measured in captivity are generally
lower than for free-ranging animals.  For reptiles and
amphibians, food ingestion rates can be higher in
captivity than in the field.  Food ingestion rates can also
be different in captivity than in the wild if the diet
differs substantially from that consumed in the wild
(e.g., dry laboratory chow has a substantially lower
water content than most natural diets).

Most of these values were  estimated from body weight
using an allometric equation.

These values are not presented in the individual species
profiles in Chapter 2; instead, the limited data available
for soil/sediment ingestion rates (as percent soil or
sediment in diet on a dry weight basis) for selected
species are presented in Section 4.1.3.

Note that this value is not normalized to body weight,
but is the total volume inhaled each day.  Most values
were estimated from body weight using an  appropriate
allometric equation.

Most values were estimated from body weight using an
appropriate allometric equation.
7.5.7.2.  Birds

Egg weight (grams)

Weight at hatching (grams)
Included only if measured values were available.

Included only if measured values were available.
                                        1-22

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Chick or nestling growth
rate (g/day)

Weight at fledging (grams)
Included only if measured values were available. The
ages to which the growth rate applies are indicated.

Included only if measured values were available.
1.5.1.3.  Mammals

Neonate weight (grams)

Pup growth rate (g/day)


Weight at weaning (grams)
Included only if measured values were available.

Included only if measured values were available. The
ages to which the growth rate applies are indicated.

Included only if measured values were available.
1.5.1.4.  Reptiles and Amphibians

Body length (mm)
Egg weight (grams)

Weight at hatching (grams)

Juvenile growth rate (g/day)


Tadpole weight (grams)


Larval or eft weight (grams)
Length is the most common measure of size and growth
rate reported for reptiles and amphibians. Body length-
weight relationships are reported whenever possible.
Data for snakes include snout-to-vent lengths (SVL) and
total lengths; for frogs, SVLs only; and for turtles,
carapace (dorsal shell) and plastron (ventral shell)
lengths.

Included only if measured values were available.

Included only if measured values were available.

Included only if measured values were available. The
ages to which the growth rate applies are indicated.

For frogs only; included only if measured values were
available.

For newts only; included only if  measured values were
available.
                                        1-23

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1.5.2.  Dietary Composition
 1.5.2.1.  All Animals


      The diet of all animals is separated by season whenever possible.  Up to three
months of data were combined for each of the four seasons, provided the animals were in
the same location and habitat during the 3-month period (Table 1-7). The diet components
are listed in the first column shaded in grey.  The measure of dietary composition is
enclosed in parentheses under the "Location (subspecies)/Habitat (measure)" column
header.
Table 1-7.  Column Headers for Tables on Dietary Composition
   Dietary Composition    List of food types.
   Spring
   Summer
   Fall

   Winter
   Location
   (subspecies)/
   Habitat
   (measure)

   Reference

   Note No.
Dietary composition during spring (March, April, May).
Dietary composition during summer (June, July, August).
Dietary composition during fall (September, October,
November).
Dietary composition during winter (December, January,
February).

State(s) or Canadian province(s) in which study was
conducted (subspecies studied, if reported).
Type of habitat associated with the reported values
(measure used to quantify dietary composition).

Reference for study.

Footnote number.
      Dietary composition can be expressed in many ways.  In the Appendix, we have

presented all measures of dietary composition encountered in the literature review.  In the

species profiles in Chapter 2, we have emphasized dietary composition measured as the

percentage of the total food intake of each food type on a wet-weight basis. These data
                                       1-24

-------
are usually determined by analysis of stomach or other digestive tract contents. For

entries based on these measures, the total of the values listed under each seasonal column

should approximate 100 percent. As Chapter 4 indicates, it is relatively simple to estimate

contaminant intakes when dietary composition is measured on a wet-weight basis. Dietary

composition may also be measured on a dry-weight basis; information on the relative

water content of the different dietary items provided in Chapter 4 can be used to convert

dry-weight composition to wet-weight composition if needed. Dietary composition is often

reported as frequency of occurrence in digestive tract contents, scats, or regurgitated

pellets. For these measures, the total of the values in the seasonal columns can exceed

100 (e.g., fish occurred in 90 percent of scats, amphibia in 75 percent of scats, and

molluscs in 15 percent of scats). We do not provide guidance on how to estimate

contaminant intakes based on these measures; however, studies using these measures can

indicate seasonal and geographic differences in diet.

1.5.3. Population Dynamics

Distribution and mortality parameters can be defined similarly for birds, mammals,
reptiles, and amphibians (Section 1.5.3.1). Reproductive parameters, however, differ

among these groups (Sections 1.5.3.2 through 1.5.3.5). The column headers for

population dynamics are described in Table 1-8.
1.5.3.1. All Animals

Home range size (ha)/
Territory size (ha)/
Foraging radius (m)
Area usually listed in hectares, radius in kilometers. The home
range for species such as mink or kingfishers, which spend
most of their time along shoreline areas, is sometimes
described as kilometers of shoreline. For some species with
extremely small breeding territories, we used m2 instead of
hectares. For colonially nesting birds, foraging radii are listed
in kilometers. For frogs, we found information only on male
breeding territory size, which does not include the foraging
range of either sex.
Population density
(N/ha)
Usually listed as number (N) of individuals per hectare,
although numbers of breeding pairs or nests per hectare are
used for some species.
1-25

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Table 1-8. Column Headers for Tables of Factors for Population Dynamics
   Age/Sex/     Age (e.g., A for adult, J for juvenile)
   Cond./Seas.  Sex (e.g., M for male, F for female)
                Condition (e.g., I for incubating, NB for nonbreeding)
                Season (e.g., SP for spring, SU for summer).

                [Note:  Only information needed to correctly interpret the value is
                included.]
   Mean
   Range
Mean value for population sampled ± standard deviation (SD), if
reported.  If SD is not reported, mean value for population sampled
± standard error (SE) of the mean, if reported. For some studies, a
range of typical values may be presented instead of a mean.

Range of values reported for the population sampled.
   Location     State(s) or province(s) in which the study was conducted
   (subspecies)/ (subspecies studied, if reported).
   Habitat       Type of habitat associated with the reported values.

   Reference    Reference for study.

   Note No.     Footnote number.
Age at sexual maturity
          Age at which first successful reproduction occurs. In many
          long-lived species, only a portion of the population breeds at
          this age.
Annual mortality rates
Longevity
          Usually listed as percent per year.  Can vary with age and sex
          of the animal.

          Mean longevity of adult members of the population (does not
          include juvenile mortality).  When available, an estimate of
          maximum longevity is also provided (usually from studies of
          captive individuals).
1.5.3.2.  Birds

Clutch size
          Number of eggs laid per active nest (usually the number laid
          per female, but in some species, more than one female may lay
          in a single nest).
                                        1-26

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Clutches per year


Days incubation


Age at fledging
Number fledged per
active nest
Number of successful clutches laid per year.  Additional
clutches may be laid if a clutch is lost early in incubation.

Measured from day incubation starts (often after laying of last
egg) to hatching.

Age at which young can maintain sustained flight.  Parents
usually continue to feed or to accompany young for some time
after fledging.

Number fledged for each nest for which incubation was
initiated.
Percent nests
successful

Number fledged per
successful nest
Percent of active nests hatching eggs.
Number fledged for each nest for which at least one young
hatched.
1.5.3.3.  Mammals

Litter size



Litters per year

Days gestation


        9
Pup growth rate



Age  at weaning
Based on embryo counts whenever possible. Use of placental
scars can result in overestimation of litter size and counts of
live pups in dens can result in underestimation of litter size.

Number of litters born each year.

Days of active gestation. For species with delayed
implantation, this period can be substantially shorter than the
period from mating to birth.

Usually reported as grams per day during a specified age
interval.  May be reported instead as a series of weights for
pups of specified ages.

Age when the pups begin to leave the nest or den to actively
feed for most of their food.
7.5.3.4.   Reptiles and Amphibians
Clutch or litter size
Number of eggs laid per female for egg-laying species; number
of live offspring born for species bearing live young (e.g.,
water snake).  Reported by age and size of the female when
appropriate.
                                        1-27

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Clutches or litters
per year

Days incubation

Juvenile growth rate
Number of clutches or litters produced each year. Not limited
to successful clutches because there is no parental care in
most temperate species.

Measured from laying of last egg to hatching. The duration of
incubation depends on the temperature of the substrate into
which eggs are laid.

Usually reported as grams per day during a specified age (or
size) interval. May be reported instead as a series of weights
for juveniles of specified sizes if those are the only data
available.
Length at sexual maturity Length at which the first successful reproduction usually
occurs (see above). More commonly reported than weight or
age at sexual maturity.
1.5.4. Seasonal Activities

The meaning of most of the factors included under seasonal activities are self-
evident. Those requiring additional explanation are described in Sections 1.5.4.1 through
1.5.4.3. The column headers for this section of the table are shown in Table 1-9.

Table 1-9. Column Headers for Tables on Seasonal Activities
Begin

Peak

End
Month that the activity usually begins.

Month(s) that the activity peaks (most of the population is involved).

Month that the activity usually ends.
Location State(s) or province(s) in which the study was conducted
(subspecies) (subspecies studied, if reported).

Reference Reference for study.

Note No. Footnote number.
1-28

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1.5.4.1.  Birds

Mating/laying



1.5.4.2.  Mammals

Mating



Parturition
These two factors are combined because birds lay eggs within
a day or two of mating (they begin mating a day or two prior to
laying the first egg).
Although for most mammals the mating season corresponds to
conception and is followed immediately by gestation, some
species exhibit delayed implantation.

Birth of the pups (also known as whelping for canids).
1.5.4.3.  Reptiles and Amphibians
Mating
Nesting
Because fertilization is external for many amphibians (i.e., most
toads and frogs and some salamanders), mating occurs at the
same time as egg-laying for these species. For reptiles,
fertilization is internal, and for some species, sperm may be
stored for months or years following mating.

Because many female reptiles can store sperm, nesting (i.e.,
egg-laying) often occurs weeks or months after mating.
1.5.5.  Abbreviations Used in Tables

Age (life stage)

       A     adult (for all groups)
       B     both adults and juveniles/yearlings (for all groups)
       C     chick (for birds)
       E     eft (for newts)
       F     fledgling (for birds)
       H     hatchling (for birds, reptiles, and amphibians)
       J     juvenile (for all groups)
       N     nestling (for birds)
             or
             neonate (for mammals, water snakes)
       P     pup (for mammals)
       T     tadpole (for frogs)
       Y     yearling (for all groups)
                                        1-29

-------
Sex
       B
       F
       M
both sexes
female
male
Units
  time:
      d
      wk
      yr

  mass:
      9
      kg

  length:
      mm
      cm
      m
      km
day
week
year
gram
kilogram
millimeter
centimeter
meter
kilometer
                   energy:
      cal   calorie
      kcal  kilocalorie
area:
      ha    hectare
      m2   square meter

volume:
      ml    milliliter
      I     liter
  temperature:
       °C    degrees Centigrade
Other
      NS    not stated
1.6.   LITERATURE SEARCH STRATEGY


      The profiles in this Handbook are intended to provide a readily available

compendium of representative data for each selected species to assist in conducting

screening-level exposure assessments. They are not intended to provide complete reviews

of all available published and unpublished information or indepth biological summaries.

Moreover, the Handbook is not intended to replace field guides or natural history or animal

physiology texts.  We have attempted to balance generalities, accuracy, and coverage of

each species relative to the available literature to meet  our stated purposes.  We describe

the process by which we identified literature for the Handbook below.
                                       1-30

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The U.S. Fish and Wildlife Service (USFWS) Office of Information Transfer
conducted the primary literature search for species-specific information using their Wildlife
Review/Fisheries Review database. The database is compiled by USFWS personnel from a
review of over 1,130 publication sources (largely journals, but also USFWS publications)
from the United States and other countries, most dating back to 1971. The search was
conducted in May 1990 using common and scientific species names, but no further
restrictions on search terms were applied. All titles identified for each species were
reviewed to determine potential utility for the Handbook, and promising references were
reviewed in full. Recent review articles, handbooks, and natural history texts were used to
identify other relevant literature and literature from before 1971. Commercial databases
were not searched initially. Following peer review of the Handbook in 1991 and 1992, all
references submitted or identified by peer reviewers were evaluated, and additional
relevant citations were obtained for review. Limited (1970 forward) literature searches for
some species were conducted using commercial databases in 1992.

For information concerning physiology, allometric equations, energetics, and other
general topics, literature was identified on the basis of recent review articles or books in
the field suggested by experts in the field and by peer reviewers.

Because of resource limitatipns, we have included some values from secondary
citations. In these cases, our intent was to carefully record the original source and to
clearly indicate from which secondary source it was obtained. Users are encouraged to
obtain the primary sources to verify these values.

We used certain field guides consistently throughout each taxonomic category to
provide greater comparability of general species characteristics. The use of a specific field
guide does not constitute endorsement.
Because our literature search strategy may not have included all journals of interest
and did not consistently cover other sources of information (e.g., books, theses,
dissertations, state wildlife reports, conference proceedings), we would appreciate any
assistance that users might provide in identifying additional sources of information that

1-31

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would help to fill data gaps or to improve the information in the Handbook.  In particular,
Ph.D. dissertations and master's theses often contain relevant but unpublished
information.


1.7.   REFERENCES
Peters, R.H. (1983) The ecological implications of body size. Cambridge, England:
      Cambridge University Press.

U.S. Environmental Protection Agency. (1989a) Risk assessment guidance for Superfund:
      volume ll-environmental evaluation manual, interim final. Washington, DC: Office
      of Solid Waste, Office of Emergency and Remedial Response; EPA report no.
      EPA/540/1-89/001 A.

U.S. Environmental Protection Agency. (1989b) Ecological assessment of hazardous waste
      sites: a field and laboratory reference. Corvallis, OR: Environmental Research
      Laboratory; EPA report no. EPA/600/3-89/013.

U.S. Environmental Protection Agency. (1989c) Exposure factors handbook.  Washington,
      DC: Office of Health and Environmental Assessment; EPA report no. EPA/600/8-
      89/043.

U.S. Environmental Protection Agency. (1992) Evaluation of terrestrial indicators for use in
      ecological assessments at hazardous waste sites. Washington, DC: Office of
      Research and Development; EPA report no. EPA/600/R-92/183.
                                      1-32

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2. EXPOSURE FACTORS AND DESCRIPTIONS
OF SELECTED SPECIES

Chapter 2 includes exposure profiles for the selected species in three subsections:
birds (Section 2.1), mammals (Section 2.2), and reptiles and amphibians (Section 2.3).
Each species profile follows the same format, beginning with an introduction to the
taxonomic group to which the species belongs and a qualitative description of relevant
aspects of the species' natural history. Next, a list of similar species is provided to help
identify species that might share certain exposure characteristics, although they may have
different geographic ranges, diets, and habitat preferences. Each species profile then
presents a series of tables presenting values for normalizing and contact rate factors,
dietary composition, population dynamics, and seasonal activity patterns that represent the
range of values that we identified in our literature review. Table format is described in
Section 1.5. Data on soil and sediment ingestion are limited; we present these data in a
separate section (4.1.3) for easy comparison among species. Finally, each profile includes
the references cited in the species profile and in the corresponding Appendix tables.

2.1. BIRDS

Table 2-1 lists the bird species described in this section. For range maps, refer to
the general references identified in individual species profiles. The remainder of this
section is organized by species in the order presented in Table 2-1. The availability of
published information varies substantially among species, as is reflected in the profiles.
Some species include two or more subspecies; these are indicated in the profiles when
reported by the investigators. For many studies, the subspecies, although not identified,
can be inferred from the study location and geographic range of the subspecies. Average
lengths of birds are reported from museum study skins measured from bill tip to tail tip.
Body weight is reported as fresh wet weight with plumage, unless otherwise noted.
2-1

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Table 2-1.  Birds Included in the Handbook
Order
Family
Ciconiformes
Ardeidae ,
Anseriformes
Anatidae
Falconiformes
Accipitridae
Falconidae
Galliformes
Phasianidae
Charadriiformes
Scolopacidae
Laridae
Coraciiformes
Alcedinidae
Passeriformes
Troglodytidae
Muscicapidae
Common name
great blue heron
Canada goose
mallard
lesser scaup
osprey
red-tailed hawk
bald eagle
American kestrel
northern bobwhite
American woodcock
spotted sandpiper
herring gull
belted kingfisher
marsh wren
American robin
Scientific name
Ardea herodias
Branta canadensis
Anas platyrhynchos
Ay thy a af finis
Pandion haliaetus
Buteo jamaicensis
Haliaeetus leucocephalus
Falco sparverius
Colinus virgin/anus
Scolopax minor
Act/'tis macularia
Larus argentatus
Ceryle a Icy on
Cistothorus palustris
Turdus migratorius
Section
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.1.7
2.1.8
2.1.9
2.1.10
2.1.11
2.1.12
2.1.13
2.1.14
2.1.15
                                     2-2

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2.1.1.  Great Blue Heron (herons)

       Order Ciconiiformes, Family Ardeidae. Herons, egrets, and bitterns are medium to
large wading birds with long necks and spear-like bills.  Nearly all species feed primarily on
aquatic animal life (e.g., fish, frogs, crayfish, insects) and are common along the margins
of most freshwater and saltwater bodies and wetlands (Kushlan, 1978). Their long legs,
necks, and bills are adapted for wading in shallow water and stabbing prey.  Most species
build their nests in trees near their foraging habitat, and many nest colonially. Members of
this group range in size from the  least bittern (28 to 36 cm bill tip to tail tip) to the great
blue heron  (106 to 132 cm tall).  The sexes are similar in size and appearance.

Selected species

       The great blue heron (Ardea herodias) is the  largest member of the group in North
America and feeds primarily on aquatic animals.  It is widely distributed in both saltwater
and freshwater environments.  There are four subspecies in the United States and Canada:
A. h. wardi (Kansas and Oklahoma across the Mississippi River to Florida), A. h. herodias
(remainder  of the  North and Central American range), A. h. fannini (Pacific coast of North
America from Alaska to Washington), and A. h. occidentalis (extreme south of Florida)
(Bancroft, 1969, cited in Hancock and Kushlan,  1984).  A. h. occidentalis (the great white
heron)  is an all white color morph that was formerly considered a separate species
(National Geographic Society, 1987).                                      :

       Body size.  Males average slightly heavier in  weight than females (Hartman, 1961;
Palmer, 1962).  Northern continental herons are  somewhat smaller than those found in the
south (Palmer, 1962). Quinney (1982) determined  a relationship between age and body
weight for nestling great blue herons (r = 0.996, N =  16 nestlings, and 274
measurements):

                               BW = 55.6 x  A-47.4

where  BW equals body weight in grams and A equals age in days.

       Habitat.  Great blue herons inhabit a variety of freshwater and marine areas,
including freshwater lakes and rivers, brackish marshes, lagoons, mangroves, and coastal
wetlands, particularly where small fish are plentiful  in shallow areas (Spendelow and
Patton, 1988; Short and Cooper, 1985).  They are often seen on tidal flats and sandbars
and occasionally forage in wet meadows, pastures, and other terrestrial habitats (Palmer,
1962). Great blue herons tend to nest in dense colonies, or heronries. The  location  of the
heronry is generally close to foraging grounds, and tall trees are preferred over shorter
trees or bushes for nest sites (Bent, 1926; Palmer,  1962; Gibbs et al., 1987). They also
may nest on the ground, on rock  ledges,  or on sea cliffs (Palmer, 1962).

       Food habits. Fish are the preferred prey, but great blues also eat amphibians,
reptiles, crustaceans, insects, birds, and mammals (Alexander, 1977; Bent, 1926;
Hoffman, 1978; Kirkpatrick,  1940; Peifer, 1979). When fishing, they mainly use two
foraging techniques:  standing still and waiting for fish to swim within striking distance or
                                        2-3
Great Blue Heron

-------
slow wading to catch more sedentary prey (such as flounder and sculpin) (Bent, 1926;
Willard, 1977). To fish, they require  shallow waters (up to 0.5 m) with a firm substrate
(Short and Cooper, 1985).  Fish up to about 20 cm in length were dominant in the diet of
herons foraging in southwestern Lake Erie (Hoffman, 1978), and  95 percent of fish
consumed by great blues in a Wisconsin population were less than 25 cm in length
(Kirkpatrick, 1940).  Great blues sometimes forage in wet meadows and pastures in
pursuit of lizards, small mammals, and large insects (Palmer, 1962; Peifer, 1979).  In
northern areas, small mammals such  as meadow voles may be an important part of the
diet early in the breeding season, possibly because some aquatic  foraging areas may still
be partially frozen when the herons arrive (Collazo, 1985).  Consumption of larger prey
(fish, frogs, rodents)  is often followed by drinks of water (Hedeen, 1967); terrestrial prey
such as voles are usually dunked in water before they are swallowed (Peifer,  1979).  Adult
herons tend to deliver the same type  and size of food to their nestlings that they consume
themselves, but they deliver it well digested for young nestlings and less well digested as
the nestlings grow (Kushlan, 1978).  Adults tend to feed  solitarily, although they may feed
in single or mixed species flocks where there are large concentrations of prey (Bayer,
1978;  Krebs, 1974; Kushlan,  1978; Willard, 1977); fledglings are frequently seen foraging
together (Dowd and Flake, 1985).  Kushlan (1978) developed a regression equation
relating the amount of food ingested per day to body weight for wading birds (N = seven
species):

                          log(FI) = 0.966 log(BW) - 0.640

where  Fl equals food ingestion in grams per day and BW equals body weight in grams.

       Molt. Adults undergo a complete molt in the late summer  and fall and a partial molt
of the  contour feathers in the late winter and early spring (Bent, 1926).  Young herons
attain full adult plumage in the summer/fall molt at the end of their second year (Bent,
1926).

       Migration.  In the northern part of its range, most great blues are migratory, some
moving to the southern Atlantic and Gulf States to overwinter with  the resident
populations of herons (Bent, 1926; Palmer, 1962), others continuing on to Cuba  and
Central and South America (Hancock  and Kushlan, 1984). Most migrating herons leave
their breeding grounds by October or  November and return between  February and April
(Bent,  1926).

       Breeding activities and social organization.  The male great blue heron selects the
site for the breeding territory,  and nests generally  consist of a stick platform over 1 m in
diameter (Palmer, 1962). Great blues often use a nest for more than 1 year, expanding it
with each use (Palmer, 1962). Mean  clutch sizes  range from three to five (see table);  in
general, clutch size tends to increase  with latitude (Pratt,  1972).  Only one brood is raised
per year; however, if a clutch  is destroyed, great blues may lay a  replacement clutch,
usually with fewer eggs than the initial clutch (Palmer, 1962;  Pratt and Winkler, 1985).
Both parents incubate and feed the young (Palmer, 1962; Hancock and Kushlan, 1984).
During  the breeding season, great blues are monogamous and colonial, with from a few to
hundreds of pairs  nesting in the same area or heronry (Gibbs et al., 1987). Colonies may
                                        2-4
Great Blue Heron

-------
include other species, such as great egrets or double-crested cormorants (Pratt and
Winkler, 1985; Mock et al., 1987).

      Home range and resources.  Breeding colonies are generally close to foraging
grounds (Bent,  1926;  Palmer, 1962; Gibbs et al., 1987). Mathisen and Richards (1978)
found the distance between heronries and possible feeding areas in Minnesota lakes to
range from 0 to 4.2 km, averaging  1.8 km.  Another study found that most heronries
along the North Carolina coast were located near inlets with large concentrations of fish,
an average of 7 to 8 km away (Parnell and Soots, 1978, cited in Short and Cooper, 1985).
Fifteen to 20 km is the farthest great blue herons regularly  travel between foraging areas
and colonies  (Gibbs et al., 1987; Gibbs, 1991;  Peifer, 1979).  In the northern portion of
their range, great blue herons often build nests in tall trees over dry land, whereas in the
southern part of their range, they usually nest in swamp trees, including mangroves
(Palmer, 1962). Each breeding pair defends a small territory around the nest, the size  of
which depends on local habitat and the birds' stage of reproduction (Hancock and Kushlan,
1984). Herons in some areas also defend feeding territories (Peifer, 1979).  In other areas,
great blues appear to be opportunistic foragers, lacking strict fidelity to particular feeding
sites (Dowd and Flake, 1985). A study in North Dakota found that herons often returned
to the same general areas, but different individuals often used the same areas at different
times (Dowd and  Flake, 1985).

      Population density. Because great blues nest colonially, local population  density
(i.e., colony density, colony size, and number of colonies) varies with the availability of
suitable nesting habitat as well as foraging habitat.  On islands in coastal Maine, Gibbs and
others (1987) found a significant correlation  between colony size and the area of tidal  and
intertidal  wetlands within 20 km  of the colonies, which was the longest distance herons in
the study colonies traveled on foraging trips. In western Oregon, the size of heronries was
found to range from 32 to 161 active nests; the area enclosed by peripheral nest trees
within the colonies ranged from 0.08 to 1.21 ha (Werschkul et al., 1977).

      Population dynamics. Most nestling loss is a result of starvation, although some
losses to predation do occur (Collazo, 1981; Hancock and Kushlan, 1984). In a study of
243  nests in  a coastal California colony, 65 percent of the  chicks fledged, 20 percent
starved, 7 percent were taken by predators, and 7 percent were lost to other causes (Pratt
and Winkler,  1985).  Estimates of the number of young fledged each year by breeding
pairs range from 0.85 to 3.1 (Pratt, 1970; Pratt, 1972; McAloney, 1973; Pratt and
Winkler, 1985; Quinney,  1982).  Based on banding studies, about two-thirds of the
fledglings do not survive more than 1 year, although they may survive better in  protected
wildlife refuges (Bayer, 1981 a). Values for later years indicate that about one-third to one-
fifth  of the 2-year-old and older birds are lost each year (Bayer, 1981 a; Henny, 1972;
Owen, 1959).

Similar species  (from general references)

      •      The great egret (Casmerodius a/bus) is almost the same size (96 cm length)
             as the great blue heron and  is found over a limited range in the breeding
             season,  including areas in the central and eastern United States and the  east
             and west coasts.  It winters in coastal areas of the United States and in
                                        2-5
Great Blue Heron

-------

Mexico and farther south. The great egret's habitat preferences are similar
to those of the great blue heron.

The snowy egret (Egretta thula), one of the medium-sized herons (51 to 69
cm), shuffles its feet to stir up benthic aquatic prey. It is found mostly in
freshwater and saltwater marshes but also sometimes follows cattle and
other livestock as does the cattle egret.  It breeds in parts of the western,
southeastern, and east coasts of the United States and winters along both
coasts of the southern United States and farther south.

The cattle egret (Bubulcus ibis) is seen in agricultural pastures and fields,
where it follows livestock to pick up insects disturbed by grazing.  An Old
World species, it was introduced into South America and reached Florida in
the 1950's.  It reached California by the 1960's and has been continuing to
expand its range.

The green-backed heron (Butorides striatus), one of the smaller herons (41 to
56 cm), breeds over most of the United States except for the northwest and
southern midwest.  It has a winter range similar to that of the snowy egret
and seems to prefer water bodies with woodland cover.

The tricolored heron (Egretta tricolor) (formerly known as the Louisiana
heron) is common in salt marshes and mangrove swamps of the east and
gulf coasts, but it is rare  inland.

The little blue heron (Egretta caerulea) is common in freshwater ponds,
lakes, and marshes and coastal saltwater wetlands of the Gulf Coast States.
Juveniles are easily confused with juvenile snowy egrets. This species
hunts by walking slowly in shallow waters, and its diet typically includes
fish, amphibians, crayfish, and insects.

The black-crowned night heron (Nycticorax nycticorax), characterized by a
heavy body, short thick neck, and short legs (64 cm), is a common heron of
freshwater swamps and tidal marshes, roosting by day in trees. It typically
feeds by night, predominantly on aquatic species, fish, amphibians, and
insects.  This heron is extremely widespread, occurring in North and South
America, Eurasia, and Africa. It breeds over much of the United States and
parts of central Canada and winters along both coasts of the United States
and farther south.

The yellow-crowned night heron  (Nyctanassa violacea) (61 cm) is similar to
the black-crowned but is more restricted in its range to the southeastern
United States.  It roosts in trees in wet woods, swamps, and low coastal
shrubs.                        	-

The American bittern (Botaurus lentiginosus), another of the medium-sized
herons (58 to 70 cm), is a relatively common but ejusive  inhabitant of
freshwater and brackish marshes and reedy lakes.  It is a solitary feeder.
                           2-6
Great Blue Heron

-------
             consuming fish, crayfish, reptiles, amphibians, insects, and even small
             mammals. Its breeding range includes most of Canada and the United
             States, although much of the southern United States is inhabited only during
             the winter.

      •      The least bittern (Ixobrychus exiffs), the smallest of the North American
             herons (33 cm), also is an elusive inhabitant of reedy areas.  Its breeding
             range is restricted largely to the eastern half of the United States.

Genera/ references

      Hancock and Kushlan (1984); Bobbins et al. (1983); National Geographic Society
(1987); Palmer (1962); Short and Cooper (1985).
                                        2-7
Great Blue Heron

-------
                                         Great Blue Heron (Ardea herodias)

Factors
Body Weight
(g»




,







;
Metabolfc Rate
(kcal/kg-day] i

Food Ingestion
Rate (g/g-day)
Water
Ingestion Hate
{g/gnday)
Inhalation Rate
[ma/dayj
Surface Area
fern2)
Age/Sex/
Cond./Seas.
AB
AF
AM
yearlings
juveniles
nestlings:
day 1
day 5
day 10
day 15
day 20
day 25
day 30
day 35
day 40
A B basal

A B free-living
AB

AB


AB

AB

^ -•
Mean
2,229 ± 762 SD
2,204 ± 337 SD
2,576 ± 299 SD
2,340 ± 490 SD
1,990 ± 550 SD

86
170
567
983
1,115
1,441
1,593
1,786
2,055
62

165
0.18

0.045


0.76

1,711

Range or
{95% CI of mean)



1,940-2,970
1,370-2,750












(78 - 353)










Location
eastern North America
NS

central Oregon

Nova Scotia, Canada












NS









Reference ; ;
Quinney, 1982
Hartman, 1961

Bayer, 1981b

McAloney, 1973









estimated

estimated
Kushlan, 1978

estimated


estimated

estimated

Note
No.

1













2

3
4

5


6

7

ro
CO
O

CD
Q]
r-f

ro
c
CD

I
CD

-------
                                         Great Blue Heron (Ardea herodias)

Dietary Composition
trout
non-trout fish •
crustaceans/amphibians

trout
non-trout fish
crustaceans
amphibians
birds and mammals
Atlantic sifverside
mummtchog
American eel
Gaspereaux
pollack
yellow perch
staghorn sculpin
small ,
medium
large
starry flounder
small
medium
large
other
small
medium

Spring



























Summer
59
39
2

89
5
1
4
1
3.6
2.4
52.6
29.9
8.9
2.6

27.8
7.6
2.2

15.0
8.1
5.2

30.6
3.5

Fall



























Winter


























Location/Habitat ;
(measure)
lower Michigan/lake

(% wet weight; stomach
contents)
lower Michigan/river

(% wet weight; stomach
contents)

Nova Scotia/Boot Island

(% wet weight; items
regurgitated by nestlings)


Vancouver, BC/coastal
island

(% of fish observed caught;
small = less than 1 /3 beak
length; medium = about 1/2
beak length; large = longer
than beak; other includes
shiner sea perch and
penpoint gunnels)


Reference
Alexander, 1977



Alexander, 1977




Quinney, 1982





Krebs, 1974










Note
No,


























CO
to
CD
Q>
i-t-

00

c
CD

I
CD

O

-------
                                         Great Blue Heron (Ardea herodias)
Population
Dynamics
Size Feeding
Territory
, Foraging
Distance from
Colony
Population
Density



Clutch Size

', *
Clutches/Year
Days
Incubation

Age at Fledging
(days}
Number Fledge
per Paif
Age/Sex
Cond./Seas.
A B fall
A B winter
A B summer
A B summer
summer
along stream
along river
summer

summer








Mean
0.6 ± 0.1 SD ha
8.4 ± 5.4 SD ha
3.1 km
7 to 8 km
2.3 birds/km
3.6 birds/km
149 ± 53 SD
nests/ha
461 nests/ha
3.16 + 0.04 SE
4.17 ± 0.85 SD
4.37
1
27.1
28
45
60
49 to 56
1.7
1.96
2.8
Range

up to 24.4 km




447 - 475
1 -5
3-6
3-6

25-30



Location/Habitat
Oregon/freshwater marsh
Oregon/estuary
South Dakota/river &
streams
North Carolina/coastal
North Dakota/rivers &
streams
Maine/coastal islands

Oregon/coastal island
California/coastal canyon
Nova Scotia/island
Pennsylvania/NS
Pennsylvania; Oregon/NS
Nova Scotia/island
United States/NS
Nova Scotia/island
NS/NS
Nova Scotia/island
central California/coastal
northwest Oregon/river
Nova Scotia/island
Reference
Bayer, 1978
Dowd & Flake, 1 985
Parnell & Soots, 1 978
Dowd & Flake, 1985
Gibbsetal., 1987

Werschkul et al., 1977
Pratt & Winkler, 1985
McAloney, 1973
Miller, 1943
Miller, 1 943; English, 1978
McAloney, 1973
Bent, 1926
McAloney, 1973
Hancock & Kushlan, 1984
Quinney, 1982
Pratt, 1972
English, 1978
Quinney, 1982
Note
No.


8






9
10


11

ro

o
CD
co
l-¥

ro
c
CD

T.
CD

-------
                                                   Great Blue Heron  (Ardea herodias)
Population
Dynamics
Number
fledge per
Successful
Nest
Age at Sexual
Maturity
Annual
Mortality Rates
(percent)
Seasonal
Activity
Mating/Laying
Matching
Migration (fall)
(spring arrival!
Age/Sex
Cond./Seas.

B
during 1st yr
during 2nd yr
during 3rd yr
Begirt
Nov. to Dec.
mid-February
mid-March
late March
mid-April
mid-April
mid-May
mid-Sept.
mid-February
mid-March
late March
Mean
2.19 ± 0.25 SD
2.43
3.09
2 years
64
36
22
Peak
mid-March
early May
early May

Range
2 --3


End
April
June
early April
late May
mid-July
late October
mid-March
Location/Habitat
central California/coastal
northwest Oregon/river
Nova Scotia/island
NS
United States and
Canada/NS
Location
Florida
central California
northwest Oregon
Pennsylvania
Nova Scotia
northwest Oregon
Idaho
Ohio
northern US
western Oregon
Wisconsin; Minnesota
Nova Scotia
Reference
Pratt & Winkler, 1985
English, 1978
McAloney, 1973
Bent, 1926
Henny, 1972
Reference
Howell, 1932
Pratt & Winkler, 1985
English, 1978
Miller, 1943
McAloney, 1973
English, 1978
Collazo, 1981
Hoffman & Curnow, 1979
Palmer, 1962
Werschkul et al., 1977
Bent, 1926
Bent, 1926
Mote
No. |



Note
No,
9
9


10
CD
CO
!•+

ED
C
CD

I
CD

O
1   As cited in Dunning, 1984.
2   Estimated using equation 3-28 (Lasiewski and Dawson, 1967) and body weights from Quinney (1982).
3   Estimated using equation 3-37 (Nagy, 1987) and body weights from Quinney (1982).
4   Estimated from Kushlan's (1978) allometric equation for wading birds, assuming a body weight of 2,230 g.
5   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Quinney (1982).

-------
                                                   Great Blue Heron (Ardea herodias)

     6   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Quinney (1982).
     7   Estimated using equation 3-21 (Meeh, 1879 and Rubner,  1883, as cited in Walsberg and King, 1978) and body weights from
         Quinney (1982).
     8   Cited in Short and Cooper (1985).
     9   Cited in Palmer (1962).
    10   May replace clutch if eggs are lost, but only rear one brood (Henny, 1972).
    11   Young fed around colony for 10 days after leaving nest at 45 days of age.
ro

to
Q
CD
£B
rt-
ro
c
CD
CD
O

-------
References (including Appendix)

Alexander, G. (1977) Food of vertebrate predators on trout waters in north central lower
      Michigan. Michigan Academician 10: 181-195.

Altman, P. L.; Dittmer, D. S., eds. (1968) Biology data book. 2nd ed., 3v. Bethesda, MD:
      Federation of American Societies for Experimental Biology.

Baird, S. F.; Brewer, T. M.; Ridgeway, R. (1884) Water birds of North America. Boston,
      MA: Little, Brown & Co.

Bancroft, G. (1969) (as cited in Hancock and Kushlan, 1984). Auk 86: 141-142.

Bayer, R. D.  (1978) Aspects of an Oregon estuarine great blue heron population. In:
      Sprunt, A.; Ogden, J.; Winckler, S., eds. Wading birds. Natl. Audubon Soc. Res.
      Rep. 7; pp. 213-217.

Bayer, R. D.  (1981 a)  Regional variation of great blue heron Ardea herodias longevity. J.
      Field Ornithol.  52: 210-213.

Bayer, R. D.  (1981b)  Weights of great blue herons (Ardea herodias) at the Yaquina
      Estuary, Oregon. Murrelet  62: 18-19.

Benedict, F. G.; Fox,  E. L. (1927) (cited in Altman and Dittmer,  1968). Proc. Am. Phil.
      Soc. 66:411.

Bent, A. C. (1926)  Life histories of North American marsh birds. Washington, DC: U.S.
      Government Printing Office; Smithsonian Inst. U.S. Nat. Mus., Bull. 135.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Collazo, J. A. (1981) Some aspects of the breeding ecology  of the great blue heron at
      Heyburn State Park. Northwest Sci. 55: 293-297.

Collazo, J. A. (1985)  Food habits of nestling great blue herons (Ardea herodias) at
      Heyburn State Park, Idaho. Northwest Sci. 59: 144-146.

Cottam, C. A.; Uhler, F. M. (1945) Birds in relation to fishes. U.S. Fish Wildl. Serv. Leaflet
      272.

Cottam, C. A.; Williams, J. (1939) (as cited in Palmer, 1962). Wilson Bull. 51: 150-155.

Dowd, E.;  Flake,  L. D. (1985) Foraging habitats and movements of nesting great blue
      herons in a prairie river ecosystem, South Dakota. J. Field Ornithol. 56: 379-387.
                                       2-13
Great Blue Heron

-------
Dunning, J. B., Jr. (1984) Body weights of 686 species of North American birds. Western
      Bird Banding Association, Monograph No. 1. Cave Creek, AZ: Eldon Publishing.

English, S. M.  (1978) Distribution and ecology of great blue heron colonies on the
      Willamette River, Oregon. In: Sprunt, A.; Ogden, J.; Winckler, S., eds. Wading
      birds. Natl. Audubon Soc. Res. Rep. 7; pp. 235-244.

Forbes,  L. S.; Simpson, K.; Kelsall, J. P., et al. (1985) Reproductive success of great blue
      herons in British Columbia. Can. J. Zool. 6.3: 1110-1113.

Gibbs, J. P. (1991) Spatial relationships between nesting colonies and foraging areas of
      great blue herons. Auk 108: 764-770.

Gibbs, J. P.; Woodward, S.; Hunter, M. L., et al. (1987) Determinants of great blue heron
      colony distribution in coastal Maine. Auk 104: 38-47.

Hancock, J.; Kushlan, J. (1984) The herons handbook. New York, NY: Harper & Row.

Hartman, F. A. (1961) Locomotor mechanisms in birds. Washington, DC: Smithsonian
      Misc. Coll. 143.

Hedeen, S. (1967) Feeding behavior of the great blue heron in Itasca State Park,
      Minnesota. Loon 39: 116-120.

Henny, C. J. (1972) An analysis of the population dynamics of selected avian species with
      special reference to changes during the modern pesticide era. Washington, DC: Bur.
      Sport. Fish. Wildl.; Wildl. Res. Rep. 1.

Henny, C. J.; Bethers, M. R. (1971) Ecology of the great blue heron with special reference
      to western Oregon.  Can. Field-Nat. 85: 205-209.

Hoffman, R.  D. (1978) The diets of herons and egrets in southwestern Lake Erie. In:
      Sprunt,  A.; Ogden, J.; Winckler, S., eds. Wading birds. Natl.  Audubon Soc. Res.
      Rep. 7:  365-369.

Hoffman, R.  D.; Curnow, R. D. (1979)  Mercury in herons, egrets, and  their foods. J. Wildl.
      Manage 43: 85-93.               ,

Howell,  A. H. (1932) Florida bird life. Florida Dept. Game and Freshwater Fish  and Bur.
      Biol. Survey, USDA.

Kelsall, J. P.; Simpson, K. (1979) A three year study of the great blue  heron in
      southwestern British Columbia. Proc. Col. Waterbird Group 3: 69-74.

Kirkpatrick, C.  M. (1940) Some foods of young great blue herons. Am. Midi. Nat. 24:
      594-601.
                                       2-14
Great Blue Heron

-------
Krebs, J. R. (1974) Colonial nesting and social feeding as strategies for exploiting food
      resources in the great blue heron (Ardea herodias). Behaviour 51: 93-134.

Kushlan, J. A. (1978) Feeding ecology of wading birds. In: Sprunt, A.; Ogden, J.;
      Winckler, S., eds. Wading birds. Natl. Audubon Soc. Res. Rep. 7; pp. 249-296.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
      variables in resting birds. Resp. Phys. 11: 152-166.

Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation between standard
      metabolic rate and body weight in birds. Condor 69: 12-23.

Mathisen, J.; Richards, A. (1978) Status of great blue herons on the Chippewa National
      Forest. Loon 50: 104-106.

McAloney,  K. (1973) The breeding biology of the great blue heron on Tobacco Island,
      Nova Scotia.  Can.  Field-Nat. 87:  137-140.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Miller, R. F. (1943) The great blue  herons: the  breeding birds of the Philadelphia region
      (Part II). Cassinia 33: 1-23.

Mitchell, C. A. (1981) Reproductive success of great blue herons at Nueces Bay, Corpus
      Christi, Texas. Bull. Texas Ornithol. Soc. 14: 18-21:

Mock, D. W.; Lamey, T. C.; Williams, C. F.; et al. (1987) Flexibility in the development of
      heron sibling aggression: an interspecific test of the prey-size hypothesis. Anim.
      Behav. 35: 1386-1393.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987)  Field guide to the birds of North America.
      Washington, DC: National Geographic Society.

Owen, D. F. (1959) Mortality of the great blue heron as shown by banding recoveries. Auk
      76: 464-470.

Page, P. J.  (1970) Appendix. San Joaquin River rookery study 1970. Sacramento, CA:
      Calif. Dept. Fish and Game; statewide heron rookery survey progress report.

Palmer, R. S. (1949) Marine birds.  Bull. Mus. Comp. Zool. Harvard  102.

Palmer, R. S. (1962) Handbook of North American birds: v. 1. New Haven, CT: Yale
      University Press.
                                       2-15
Great Blue Heron

-------
Parnell, J. F.; Soots, R. F. (1978) The use of dredge islands by wading birds. Wading
       birds. Nat. Audubon Soc. Res. Rep. 7: 105-111.

Peifer, R. W. (1979) Great blue herons foraging for small mammals. Wilson Bull. 91:
       630-631.

Poole, E. L.  (1938) Weights and wing areas in North American birds. Auk 55: 511-517.

Powell, G. V.; Powell, A. H. (1986) Reproduction by great white herons Ardea herodias in
       Florida Bay as an indicator of habitat quality. Biol. Conserv. 36: 101-113.

Pratt, H. M. (1970) Breeding biology of great blue herons and common egrets in central
       California. Condor 72: 407-416.

Pratt, H. M. (1972) Nesting success of common egrets and great blue herons in the San
       Francisco Bay region. Condor 74: 447-453.

Pratt, H. M.; Winkler, D. W. (1985) Clutch size timing of laying and  reproductive success
       in a colony of great blue herons (Ardea herodias) and great egrets (Casmerodius
       a/bus). Auk 102: 49-63.

Quinney, T. E. (1982) Growth, diet, and mortality of nestling great blue herons. Wilson
       Bull.  94: 571-577.

Robbins, C.  S.; Bruun, B.; Zim, H. S. (1983) A guide to field identification: birds of North
       America. New York, NY: Golden Press.

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol.  19: 535-562.

Short, H. L.; Cooper, R. J. (1985) Habitat suitability index models: great blue heron. U.S.
       Fish Wildl. Serv. Biol. Rep. No. 82(10.99); 23 pp.

Spendelow, J. A.; Patton, S. R. (1988) National atlas of coastal waterbird colonies:
       1976-1982.  U.S. Fish Wildl. Serv. Biol. Rep. No. 88(5).

Thompson, D. H. (1978)  Feeding areas of great blue herons and great egrets nesting
       within the floodplain of the upper Mississippi River. Colonial Waterbirds 2:
       202-213.

Vermeer, K. (1969) Great blue  heron colonies in Alberta. Can. Field-Nat. 83: 237-242.

Walsberg, G. E.; King, J.  R. (1978) The relationship of the external surface area of birds to
       skin surface area and body mass. J. Exp. Biol. 76: 185-189.

Werschkul, D.  F.; McMahon, E.; Leitschuh, M.;  et al. (1977) Observations on the
       reproductive  ecology of  the great blue heron (Ardea herodias) in western Oregon.
       Murrelet 58:  7-12.
                                       2-16
Great Blue Heron

-------
Willard, D. E. (1977) The feeding ecology and behavior of five species of herons in
      southeastern New Jersey. Condor 79: 462-470.

Wood (1951) (cited in Palmer, 1962). Univ. Mich. Mus. Misc. Publ. No.  75.
                                       2-17
Great Blue Heron

-------

-------
2.1.2.  Canada Goose (geese)

       Order Anseriformes. Family Anatidae. Geese are large herbivorous waterfowl that
feed on grains, grass sprouts, and some aquatic vegetation.  Although adapted for life on
the water, they forage primarily in open fields.  They breed in open forested areas near
lake shores and coastal marshes from the arctic tundra through temperate climates.  These
birds migrate in noisy flocks in the familiar V-formation, stopping in cultivated fields,
wetlands, and grasslands to feed. Geese show a wide variation in size even within a
species; the sexes look alike.

Selected species

       The Canada goose (Branta canadensis) is the most widespread and abundant goose
in North America. It is a popular game species and is commonly encountered  on cultivated
fields,  golf courses, other parklands, and wetland refuge areas. Depending on subspecies,
these geese can range in size  from 64 to 114 cm (bill tip to tail tip), the larger geese
breeding in more southerly locations than the smaller subspecies.  The reverse is true in
winter, with the larger subspecies wintering in the more northerly parts of the range
(Palmer, 1962). The number of existing recognized subspecies varies, but most
ornithologists agree that there are 11: canadensis (Atlantic Canada goose), fulva
(Vancouver Canada  goose), hutchinsii (Richardson's Canada goose), interior (interior
Canada goose), leucopareia (Aleutian Canada goose), maxima (giant Canada goose),
minima (cackling Canada goose), moffitti (Great Basin or western Canada goose),
occidentalis (dusky Canada goose), parvipes (lesser Canada goose), and taverneri
(Taverner's Canada  goose) (Bellrose, 1976; Johnson et al., 1979; Palmer, 1962).  Several
subspecies usually mingle during migration and in wintering areas, but they breed in
geographically distinct ranges. Six of the subspecies breed in Alaska (fulva, leucopareia,
minima, occidentalis, parvipes, and tavern/] (Johnson et al., 1979). The leucopareia
subspecies, found in Oregon, Washington, California, and Alaska, currently is  a United
States federally designated threatened species (50 CFR 17.11, 1992).  It is only known to
breed on one of the  western Aleutian islands off Alaska (Byrd and Woolington, 1983).
See Bellrose (1976)  for ranges, migration corridors, and wintering areas of specific
subspecies and populations.

       Body size.  Canada  geese subspecies vary greatly in size, but males are on average
larger than females (see table).  Body weight reaches its maximum just prior to or during
the spring migration and then  declines during egg-laying and incubation, sometimes by as
much as 20 percent (Mainguy and Thomas,  1985; McLandress and Raveling,  1981).  Most
of the weight lost during incubation reflects loss of fat, which can provide over 80 percent
of the energy requirements for the incubating females (Mainguy and Thomas,  1985;
Murphy and Boag, 1989).  Young are similar to parents in size by 2 months  of age
(Palmer, 1962).

       Habitat. Breeding habitat includes tundra, forest muskeg in the far north, tall- and
shortgrass prairie, marshes, ponds, and  lakes. Most nesting  sites are close to open water
with high visibility in all directions (Palmer, 1962; Steel et al., 1957). In many areas,
Canada geese nest predominantly on islands in ponds  or lakes (Geis, 1956). Former
                                       2-19
Canada Goose

-------
muskrat houses often serve as nest sites in marshes (Steel et al., 1957). Brood-rearing
habitats, on the other hand, require adequate cover, and riparian areas are used more
frequently than open water (Eberhardt et al., 1989a). During the fall and winter in
Maryland, Harvey et al. (1988) found Canada geese to spend 57 percent of their time in
farmlands (mostly corn, soybeans, and winter wheat fields) and 24 percent in forested
areas.

Food habits. Canada geese are almost exclusively vegetarian, and feeding activity
is concentrated in areas where food is plentiful (e.g., standing crops, scattered whole
grain) (Palmer, 1962). They are primarily grazers, but must consume grit at some point to
assure proper digestion (Palmer, 1962). They prefer certain foods, but will change their
diet depending on the availability of a food type (Coleman and Boag, 1987). For example,
when water levels are low in the south Yukon (Canada) river delta, Canada geese forage
on rhizomes of Potamogeton richardsonii even though other forage is available; at higher
water levels when the Potamogeton is unreachable, the geese will feed on other plants
{Coleman and Boag, 1987). During fall, geese often consume green crops (e.g., winter
wheat). During winter, however, they consume more energy-rich foods such as corn
(Harvey et al., 1988; McLandress and Raveling, 1981). In late winter and early spring,
green crops that are high in nitrogen and other important nutrients again constitute an
important part of the diet (McLandress and Raveling, 1981). Canada geese often feed
preferentially on the blade tips of many plants, which are higher in nitrogen than other
parts of the plant (Buchsbaum et al., 1981). In Minnesota, Canada geese begin consuming
green grasses as soon as they are exposed by the melting snow (McLandress and
Raveling, 1981). In Maryland, on the other hand, Harvey et al. (1988) found that Canada
geese did not begin consuming green crops before migration to the breeding grounds,
indicating that this population may rely on green forage available at staging areas to obtain
the protein and lipids required for reproduction. In the spring in Falmouth Harbor,
Massachusetts, Canada geese initially consume predominantly the marsh grasses Spartina
spp. and rushes Juncus gerardi, which are high in protein (Buchsbaum and Valiela, 1987).
As the summer progresses, however, they feed increasingly on submerged eelgrass,
Zostera marina, which provides more carbohydrates (Buchsbaum and Valiela, 1987).

Molt. Nonbreeders and yearlings migrate to a separate molting ground soon after
arrival at the breeding grounds, while breeding birds molt on the brood-rearing grounds
(Bellrose, 1976). Molting occurs earlier in nonbreeders, at least a month earlier in the
larger subspecies (Palmer, 1962). Molting parents do not regain flight feathers until just
prior to the time when their young first attain flight (Palmer, 1962). The flightless period
of B. c. interior is estimated to be 32 days. For B. c. maxima and B. c. moffitti, the
flightless period lasts from 39 to 40 days (Balham, 1954; Hanson, 1965, as cited in
Palmer, 1962).

Migration. Migratory Canada geese leave their breeding grounds during late
summer and early autumn; they return in the spring around the time the first water is
opening (i.e., ice melting) but well before snow cover has disappeared (Bellrose, 1976).
Spring migration begins later for northerly populations, with geese that winter in mild
climates departing as early as mid-January, while those wintering in the coldest areas do
not move northward until the beginning of March (Bellrose, 1976). The bulk of the
migrants typically arrive on the summer breeding grounds 3 weeks after the first birds
<>
2-20 Canada Goose

-------
(Bellrose, 1976).  Some populations have become resident year-round, for example,
B. c. maxima in Missouri (Brakhage, 1965) and in southeast Georgia and southwest
Alabama (Combs et al., 1984).  During both the spring and fall migrations, geese tend to
gather in large flocks and feed for several weeks in "staging" areas along major waterfowl
flyways (Bellrose, 1976).

      Breeding activities and social organization.  Canada geese arrive on the breeding
grounds in flocks, and soon after, the male becomes territorial and aggressive toward
other birds (Palmer, 1962). Lifelong monogamy following their first breeding is the general
rule with these geese (Palmer, 1962).  Nests are built  on the ground in a position with
good visibility (Palmer,  1962). During incubation the male stands guard, while the female
incubates the eggs, which she normally leaves two or three times daily to feed, bath,
drink, and preen (Murphy and Boag, 1989). Both parents accompany the young through
the brood period (Bellrose, 1976; Brakhage, 1965).  Canada geese return to the breeding
grounds as family units, but the yearlings leave their parents soon after arrival (Bellrose,
1976).

      Home range and resources.  The foraging home range of Canada geese varies with
season, latitude, and breeding condition. Soon after hatching, goose families move away
from the nesting sites to other areas with adequate cover and forage to rear their broods
(Byrd and Woolington,  1983).  Newly hatched families may have to travel 10 to 20 km
from the nest site to reach areas with adequate aquatic vegetation or pasture grasses
(Geis, 1956).  Although the families stay predominantly on land, often in riparian  areas,
they usually are clo'se to water.  Eberhardt  et al. (1989a) found  goslings  within 5  m of
water most of the time; only 7 percent of sightings were farther than 50 m away. During
the spring and fall migrations and in winter, Canada geese can be found on open water or
refuges near grain fields or coastal estuaries (Leopold et al., 1981).

      Population  density. Breeding population densities of Canada geese vary widely.
Low nesting densities (i.e., less than 0.005 per hectare) are common in the Northwest
Territories of Canada (Smith and Sutton, 1953, 1954) and intermediate densities  (i.e.,
0.02 to 0.7 per hectare) have been reported for Alaska (Cornley et al., 1985). In some
more southerly locations (e.g., California), colonial nesting situations have been reported,
with as many as 32 nests located on half an acre (Naylor, 1953, as cited in Palmer,
1962).                                                      ;

      Population  dynamics.  The earliest Canada geese begin breeding is around  2 to 3
years of age (Maclnnes and Dunn, 1988; Brakhage, 1965). In the larger subspecies, only
a small proportion of the birds under 4 years may attempt to breed.  For example, in
Manitoba, Moser and Rusch (1989) found that only 7 percent of 2-year-old and 15 percent
of 3-year-old B. c. interior laid eggs. Canada geese only attempt to rear one brood per
year.  In the more southerly latitudes, Canada geese will renest if a clutch is lost prior to
incubation (Brakhage, 1965; Geis, 1956).  In general, both clutch size and success at
rearing goslings increase with the age of the breeder (Brakhage, 1965). Raveling  (1981)
found that older B. c. maxima (4 plus years) raised more than twice as many goslings to
fledging as did younger (2 to 3 years) birds. Population age structure and annual  mortality
vary with hunting  pressure as well as natural factors.
                                       2-21
Canada Goose

-------
Simitar species (from general references)

      •      The Brant goose (Branta bernicla) is approximately the size of the smaller
             Canada geese subspecies (length 25 cm).  It is primarily a sea goose and is
             rare inland.  It winters along both the east and west coasts of the United
             States, where it feeds on aquatic plants in shallow  bays and  estuaries.  It
             breeds in the high arctic.

      •      The greater white-fronted goose (Anser albifrons) is limited to certain areas
             west of the Mississippi River and averages 71 cm in length.  Its habits are
             similar to those of other geese.

      *      The snow goose (Chen caerulescens) breeds in the  Arctic and winters in
             selected coastal areas across the United States. However, this average-
             sized goose (71 cm) is a migratory visitor  to much of the central United
             States.

      •      The Ross' goose (Chen rosii) breeds in the high arctic tundra  and winters in
             some areas of the southwest United States.  This relatively small (58 cm)
             goose is a rare visitor to the mid-Atlantic States and is always seen with
             snow geese.

General references
       Bellrose (1976); Kortright (1955); National Geographic Society (1987); Palmer
(1962).
                                        2-22
Canada Goose

-------
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-------
r
                                                Canada Goose (Branta canadensis}
Factors
Body Fat
(g lipid)
r
,


Egg Weight
fg)
Metabolic Rate
(kcat/kg-day)






- '
Age/Sex/ •
Cond./Seas,
F fall migr.
F winter
F spring migr.
F prelaying
F end incub.
F early molt
F prelaying
F incubating
F late incub.
F molting

free-living:
A M winter
A M spring
A M summer
A M fall
A F spring
A F summer
free-living:
AM
AF
AM
AF
AM
AF
Mean
182 ± 24 SE
57 ± 6 SE
172 ± 25 SE
171 (no SE; N=2)
33 ± 5 SE
108 ± 13SE
751 ± 45 SE
611 ±40 SE
166 ± 18SE
485 ± 37 SE
96
127
163



185
187 '
141
147
135
142
Range or
(95% CI of
mean)
117-264
34-71
68 - 362
136-205
14-51
62- 179



105-209
105-203
115-253
100-209
130-220
143-274
(87-391)
(88 - 397)
(65 - 304)
(69-316)
(63 - 292)
(66 - 305)
Location (subspecies)
Alaska in winter (minima]
California in summer

Ontario, Canada (maxima)

NS (minima)
NS (leucopa)
Alberta, Canada (moffitti)
Illinois in winter (interior)
Ontario, Canada in summer

(interior)
(minima)
(interior)

(maxima)

*
Reference
Raveling, 1979

Thomas etal., 1983

Owen, 1980
Owen, 1980
LeBlanc, 1987a
Williams & Kendeigh, 1982

Williams & Kendeigh, 1 982
estimated
estimated

estimated

Note
No.




2
2
3

3
4a
4b

4c

            Ni

            to
            O
            Q)

            Q)
            Q.
            CO

            O
            O
            O
            w
            CD
-------
                                              Canada Goose (Branta canadensis)
                     Age/Sex/
                     C0nd,/$eas
                                                                         location

                                                                         (interior] captive
A M winter
A F winter
                                                                                                Reference

                                                                                                Joyner et al., 1984
                    A M spring
                    A F spring
                                                    (interior captive

                                                          •

                                                    (minima}
                                                                                                  Joyner etal., 1934

                                                                                                  -

                                                                                                  estimated
water Ingestton
Rate
  Jnhalatfon Rate
 Surface Area
 tenrt
                                                                    Location/Habitat
                                                                      (measure)
                                                                           Reference
                                                                                   .

                                                                           Yelverton & Quay,  1959
mtive grasses
                                                                    North Carolina/lake
-------
                                    Canada Goose [Branta canadensis}


Dietary Composition
Equisefum sp.
(shoot)


Triglochin pafustris
(root)
grasses {root]
(Shoot)
sedges (shoof)
(root)
(reed)






Ptantago marltima
(root)

unidentified plants
invertebrates
com


unidentified plants
alfalfa
Gramineae
oats



Setaiia lutescens
Trifotium repens
Population ,
Dynamics
Home Range
Size

Spring

9.2

3.4
23.4
2.1
25.3
5.3
17.9

6.5
6.1
0.7












'

Age/Sex/
Cond./Seas.
A F & brood

A F & brood

Summer






















Fall

23
8.6
10.4
12.6
25.1
8.4
10.9

Mean
983 + 822 SD ha

8.8 ± 4.4 SD km

Winter




















Location/Habitat
(measure]
Ontario, Canada/bay

(% dry weight; esophagus
and proventriculus contents)









Wisconsin/marsh

{% dry volume; gizzard
and proventriculus contents)



Location (subspecies)/
Range , habitat* '
290 - 2,830 Washington (moffittD/nver

2.8 - 18.1 Washington (moffitti)/r\ver
' • ' •*'.••
Reference
Prevett et al., 1985












Craven & Hunt, 1 984







Reference
Eberhardt et al., 1989a

Eberhardt etal., 1989a
Note
No.




















Note
No.



to
o
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Q.
Q]

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o
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CD
-------
                                     Canada Goose (Branta canadensis}
Population
Dynamics
Population
Density



Clutch Size
Clutches/Year
Days
Incubation
Age at
Fledging Ways)
Percent Nests
Successful
Number Fledge
per Active
Nest 1
Age/Sex/ %
Cond./Seas.
summer

fall
winter






Mean
16.6 nests/ha
1 .3 nests/ha
0.35 nests/ha
22 birds/ha
4 birds/ha
4.7
5.6 ± 0.1 SE
4.6
5.6
1
25
28
40-46
55
63
71-73
91
44
2.19 + 2.42 SD
Range
0.02-1 2.4 nests/ha



2-8



89-93
27-64
0-7
Location (subspecies)/
habitat*
various locations
Montana (moffitti)/
on 0.2-0.8 ha island
Montana (moffitti)/
on 8-121 ha island
Alaska (leucopus)!
island preferred habitat
Missouri/wildlife refuge
Missouri/wildlife refuge
Alaska [minima]
Alaska (leucopa]
Ontario, Canada (interior]
Alabama, Georgia (maxima)
Missouri
NS (minima) '
Missouri (maxima)
Alaska (minima)
NS (leucopa)
Ontario, Canada (interior)
Michigan (maxima)
Alaska/island (leucopa)
Alabama, Georgia (maxima)
Washington (moffitti)
Reference
Cooper, 1978
Geis, 1956
Byrd & Woolington, 1 983
Humburg et al., 1 985
Humburg et al., 1 985
Spencer et al., 1951
Byrd & Woolington, 1 983
Raveling & Lumsden, 1 977
Combs et al., 1984
Brakhage, 1985
Laidley, 1939
Brakhage, 1965
Mickelson, 1973
Lee (pers. comm.) in Byrd
& Woolington, 1983
Hanson, 1965
Sherwood, 1965
Byrd & Woolington, 1 983
Combs etal., 1984
Eberhardt et al., 1989b
Note
No* %
9



10
2

10
11
11
11


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3
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CD
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0 0
Z Z.



Reference




Location (subspecies]/
habitat"


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Alaska (leucopa)
IL, Wl (interior)
Washington (moffitti)


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Northwest Territories
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Manitoba, Canada (inte
Missouri (maxima)


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eorgia, Alabama (maxim
R, WA, CA (moffitti)
lontana (moffitti)
iaho (moffitti)
ntario, Canada (maxima]
laska (leucopa)
13 U .2 ±i . ro ~ §

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                                    2-28
Canada Goose
-------
                                                   Canada Goose [Branta canadensis)
Seasonal
Activity
Molt (fall)
Migration fait
spring
Begin
mid-June
mid-July
late June
mid-Sept.
October
February
late March
Peak
mid-August
November
early November
early March
early April
End
late August
late October
mid-December

Location (subspecfes)
Idaho (moffitti)
Alaska (leucopa)
Illinois (interior)
arrive south Illinois (interior)
arrive CO, TX (parvipes)
leave Illinois (interior)
leave Minnesota (maxima)
Reference
Steel etal., 1957
Byrd & Woolington, 1 983
Williams & Kendeigh, 1982
Bell & Klimstra, 1970
Grieb, 1970
Bell & Klimstra, 1 970
Raveling, 1978b
Note
No*



ro
to
(0
 1   Weights estimated from graph.
 2   Cited in Dunn and Maclnnes (1987).
 3   Estimated range of existence to maximum free-living metabolism at typical breeding ground (Ontario, Canada in spring and summer) and at typical
     wintering ground (south Illinois in fall and winter). Estimated using regression equations developed by the authors, measures of metabolic rates at
     temperatures from -40 to 41 °C, and temperatures typical for the season and location.
 4   Estimated using equation 3-37 (Nagy, 1987) and body weights from (a) Raveling (1979); (b) Raveling (1968); and (c) Brakhage (1965).
 5   Reported as grams dry weight of feed; corrected to grams wet weight of feed using the measured moisture content of 11 percent (on average) of
     the feed items (i.e., corn, sunflower seeds, wheat, and rnilo).
 6   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from (a) Raveling (1979) and (b) Brakhage (1965).
 7   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from (a) Raveling (1979) and (b) Brakhage (1965).
 8   Estimated using equation 3-21  (Meeh,  1879 and Rubner, 1883, as cited in Walsberg and King, 1978) and body weights from (a)  Raveling (1979)
     and (b) Brakhage (1965).
 9   Summarizing several studies, cited in Byrd & Woolington (1983).
10   Cited in Palmer (1976).
11   Cited in Bellrose (1976).                •
12   For parents older than 5 years of  age.
O
o>
3
Q)
Q.
Q)
o
o
to
CD
-------
References (including Appendix)

Akesson, T. R.; Raveling, D. G. (1981)  Endocrine and body weight changes of nesting and
       non-nesting Canada geese. Biol.  Reprod. 25: 792-804.

Balham, R. W. (1954) The behavior of the Canada goose (Branta canadensis) in Manitoba
       [Ph.D. dissertation]. Columbia, MO: University of Missouri.

Bell, R. Q.; Klimstra, W. D. (1970) Feeding activities of Canada geese (Branta canadensis
       interior) in southern Illinois. Trans. III. State. Acad. Sci. 63: 295-304.

Bellrose, F. C. (1976) Ducks, geese, and swans of North America. Harrisburg, PA: The
     ,  Stackpole Co.

Best, R. G.; Fowler, R.; Hause, D., et al. (1982) Aerial thermal infrared census of Canada
       geese in  South Dakota. Photogr. Eng.  Remote Sens. 48: 1869-1877.

Brakhage, D. H. (1985) A second brood by Canada geese. Wilson Bull. 97: 387-388.

Brakhage, D. H.; Baskett, T. S.; Graber, D. A., et al.  (1987) Impacts of a new reservoir on
       resident Canada geese. Wildl. Soc. Bull.  15: 192-196.

Brakhage, G. K. (1965) Biology and behavior of tub-nesting Canada geese. J. Wildl.
       Manage. 29: 751-771.

Buchsbaum, R.; Valiela, I. (1987) Variability in the chemistry of estuarine plants and its
       effects on feeding  by Canada geese. Oecologia (Berlin) 73: 146-153.

Buchsbaum, R.; Valiela, I.; Teal, J. M. (1981) Grazing by Canada geese and related
       aspects of the chemistry of salt marsh grasses. Colonial Waterbirds 4: 126-131.

Buchsbaum, R.; Valiela, I.; Swain, T. (1984) The role of phenolic  compounds and other
       plant constituents in feeding  by Canada geese  in a coastal marsh.  Oecologia (Berlin)
       63: 343-349.

Bultsma, P. M.;  Under, R. L; Kuck, T. L. (1979) Reproductive success of giant Canada
       geese in western South Dakota.  Proc. SD Acad. Sci. 58: 35-38.
                                                         t
Byrd, G. V.; Woolington, D. W. (1983) Ecology of Aleutian Canada geese at Buldir Island,
       Alaska. U.S. Fish Wildl. Serv. Spec. Sci. Rep.  No. 253.

Caider, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physioi. 244: R601-R606.

Chapman, J. A. (1970) Weights and measurements of dusky Canada geese wintering in
       Oregon. Murrelet 51: 34-37.
                                      2-30
Canada Goose
-------
Chapman, J. A.; Henny, C. J.; Wight, H. M. (1969) The status, population dynamics, and
       harvest of the dusky Canada goose.  Wildl. Monogr. 18.

Coleman, T. S.; Boag, D. A. (1987) Foraging characteristics of Canada geese on the
       Nisutlin River delta, Yukon. Can. J. Zool. 65: 2358-2361.

Collias, N. E.; Jahn, L. R. (1959) Social behavior and breeding success in Canada geese
       (Branta canadensis) confined under semi-natural conditions. Auk 76: 478-509.

Combs, D. L.;  Ortego, B.; Kennamer, J.  E. (1984) Nesting biology of a resident flock of
       Canada geese. Proc. Annu. Conf. Southeast. Assoc. Fish Wildl. Agencies 38:
       228-238.
Cooper, J. A. (1978) Canada geese at Marshy Point, Manitoba. Wildl. Monogr. 51: 1-87.

Cornley, J. E.; Campbell, B. H.; Jarvis, R. L. (1985) Productivity, mortality and population
      status of dusky Canada geese. Trans. North Am. Wildl.  Nat. Resour. Conf. 50:
      540-548.

Craven, S. R. (1981) The Canada goose (Branta canadensis)—an annotated bibliography.
      U.S. Fish Wildl. Serv. Spec. Sci. Rep. No. 231.

Craven, S. R.; Hunt, R. A. (1984) Fall food habits of Canada geese in Wisconsin. J. Wildl.
      Manage. 48: 169-173.

Cummings, G. E. (1973) The Tennessee Valley population of Canada geese.  U.S. Fish
      Wildl. Serv.  Unpublished Report.

Dey, N.  H. (1966) Canada goose production and population stability, Ogden  Bay waterfowl
      management area, Utah. Utah State Dept. Fish and Game Publ.  66-7.

Dow, J. S. (1943) A study of nesting Canada geese in Honey Lake Valley, California. Calif.
      Fish and Game 29: 3-18.

Dunn, E. H.; Maclnnes, C. D. (1987) Geographic variation in clutch size and  body size of
      Canada geese. J. Field Ornithol. 58: 355-371.

Eberhardt, L. E.; Anthony, R. G.; Rickard, W. H. (1989a) Movement and habitat use by
      Great Basin Canada goose  broods. J. Wildl. Manage. 53: 740-748.

Eberhardt, L. E.; Anthony, R. G.; Rickard, W. H. (1989b) Survival of juvenile Canada geese
      during the rearing period. J. Wildl. Manage. 53: 372-377.

Eberhardt, L. E.; Books, G. G-; Anthony, R. G.;  et al. (1989c) Activity budgets of Canada
      geese during brood rearing. Auk 106: 218-224.

Estel, B. L. (1983) Winter weights of Canada geese in southern Illinois during 1982-83. III.
      Dep. Conserv. Per. Rep.  No. 38.                                       '
                                      2-31
Canada Goose
-------
Fitzner, R. E.; Rickard, W. H. (1983) Canada goose nesting performance along the Hanford
       Reach of the Columbia River, 1971-1981. Northwest Sci. 57: 267-272.

Geis, M. B. (1956) Productivity of Canada geese in the Flathead Valley, Montana. J. Wildl.
       Manage. 20: 409-419.

Geis, A. D.; Taber, R. D. (1963) Measuring hunting and other mortality. In: Mosby, H. S.,
       ed. Wildlife investigational techniques. Washington, DC: The Wildlife Society; pp.
       284-298.

Grieb, J. R. (1970) The shortgrass prairie Canada goose populations. Wildl. Monogr. 22:
       4-49.

Gulden, N. A.; Johnson, L. L. (1968) History, behavior and management of a flock of giant
       Canada geese in southeastern Minnesota. In: Nine, R. L.; Schoenfeld, C., eds.
       Canada goose management. 1st ed. Madison, Wl: Dembar Educ. Res. Serv.; pp.
       58-71.

Hanson, H. C.  (1965) The giant Canada goose.  Carbondale, IL: Southern Illinois University
       Press.

Hanson, H. C.; Smith, R. H. (1950) Canada geese of the Mississippi flyway with  special
       reference to an Illinois flock. III.  Nat. Hist. Surv. Bull. 25: 67-210.

Hanson, W. C.; Eberhardt, L. L. (1971) A Columbia River Canada goose population,
       1950-1970. Wildl. Monogr. 28.

Hardy, J. D.; Tacha, T. C. (1989) Age-related recruitment of Canada geese from the
       Mississippi Valley population. J. Wildl. Manage. 53: 97-98.

Harvey, W. F., IV; Maleki, R. A.; Soutiere, E. C. (1988) Habitat use by foraging Canada
       geese in Kent County, Maryland.'Trans Northeast Sect. Wildl. Soc. 45: 1-7.

Hilley, J. D. (1976) Productivity of a resident giant Canada goose flock in northwestern
       South Dakota [master's thesis].  Brookings,  SD: South Dakota  State University.

Humburg, D. D.; Graber, D. A.; Babcock, K. M.  (1985) Factors  affecting autumn and
      winter distribution  of Canada geese. Trans. North Am. Wildl. Nat. Resour.  Conf. 50:
       525-539.

Jensen, G. H.;  Nelson, A. L. (1948) (cited in Palmer, 1962) U.S. Fish Wildl. Serv., Spec.
      Sci. Rept.-Wildlife no. 60.
                                       2-32
Canada Goose
-------
Johnson, D. H.; Timm, D. E.; Springer, P. F. (1979) Morphological characteristics of
      Canada geese in the Pacific flyway. In: Jarvis, R. L.; Bartonek, J. C., eds.
      Management and  biology of flyway geese: a symposium; February 16,1979;
      Portland, OR. Corvallis, OR: OSU Book Stores; pp. 56-68.

Joyner, D. E.; Arthur, R.  D.; Jacobson, B. N. (1984) Winter weight dynamics, grain
      consumption and  reproductive potential in Canada geese. Condor 86: 275-280.

Korschgen, L. J. (1955) Fall foods of waterfowl in Missouri. Missouri  Dept. Conserv.  P-R
      Ser. 14.

Kortright, F. H. (1942) The ducks, geese, and swans of North America. Harrisburg, PA:
      The Stackpole Co.

Kortright, F. H. (1955) The ducks, geese, and swans of North America. Harrisburg, PA:
      The Stackpole Co. and Washington, DC: Wildlife Management  Institute.

Laidley (1939) (cited in Palmer, 1962). Avicultural Mag. 5th Ser.: 102-103.

Lasiewski, R. C.; Calder,  W. A. (1971) A preliminary allometric analysis of respiratory
      variables in resting birds. Resp. Phys. 11: 152-166.

Lebeda, C. S.;  Ratti, J. T. (1983)  Reproductive biology  of Vancouver Canada  geese on
      Admiralty Island, Alaska. J. Wildl. Manage 47: 297-306.

LeBlanc, Y. (1987a) Intraclutch variation in egg size of  Canada geese. Can. J. Zool. 65:
      3044-3047.

LeBlanc, Y. (1987b) Relationships between sex of gosling and position in the  laying
      sequence, egg mass, hatchling size, and fledgling size. Auk 104: 73-76.

LeBlanc, Y. (1987c) Egg  mass, position in the laying sequence, and brood size in relation
      to Canada goose reproductive success. Wilson Bull. 99: 663-672.

Leopold, A. S.; et al. (1981) North American game birds and mammals. New York, NY:
      Charles Scribner & Sons.

Maclnnes, C. D. (1962) Nesting of small Canada geese near Eskimo Point, Northwest
      Territories. J. Wildl. Manage. 26: 247-256.

Maclnnes, C. D.; Davis, R. A.; Jones, R. N., et al. (1974) Reproductive efficiency of
      McConnell River small Canada geese. J. Wildl. Manage. 38: 686-707.

Maclnnes, C. D.; Dunn, E. H. (1988) Estimating proportion of an age class nesting in
      Canada  geese. J. Wildl. Manage. 52: 421-423.

Mainguy, S.  K.; Thomas, V.  G. (1985) Comparisons of  body reserve buildup and  use in
      several groups of Canada geese. Can. J. Zool. 63: 1765-1772.
                                      2-33
Canada Goose
-------
Manning, T. H. (1978) Measurements and weights of eggs of the Canada goose, (Branta
       canadens/s), analyzed and compared with those of other species. Can. J. Zopl. 56:
       676-687.

Martin, F. W. (1964) Behavior and survival of Canada geese in Utah. Utah State Dep. Fish
       and Game Inform. Bull. 64-7.

Martin, A. C.; Zim, H. S.; Nelson, A.  L. (1951) American wildlife and plants. New York,
       NY: McGraw-Hill Book Company, Inc.

McCabe, T. R. (1979) Productivity and nesting habitat of great basin Canada geese,
       Umatilla, Oregon. In: Jarvis, R. L.; Bartonek, J. C., eds. Management and biology of
       flyway geese: a symposium; February 16,  1979; Portland, OR. Corvallis, OR: OSU
       Book Stores;  pp. 117-129.

McLandress, M. R.; Raveling, D. G. (1981) Changes in diet and body composition of
       Canada geese before spring migration. Auk 98: 65-79.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Mickelson, P. G. (1973) Breeding biology of cackling geese (Branta canadensis minima
       Ridgeway) and associated species on the Yukon-Kuskokwim  Delta, Alaska [Ph.D.
       dissertation].  Ann Arbor, Ml: University of  Michigan.

Miller, A. W.; Collins, B. D. (1953) A nesting study of Canada geese on Tule Lake and
       Lower Klamath National Wildlife Refuges, Siskiyou County, California. Calif. Fish
       and Game 39: 385-396.

Moffitt, J. (1931) The status of the Canada goose in California. Calif. Fish and Game 17:
       20-26.

Moser, T. J.; Rusch, D. H. (1989) Age-specific-breeding rates of female interior Canada
       geese. J. Wildl. Manage. 53: 734-740.

Murphy, A. J.; Boag, D. A. (1989)  Body reserve and food use by incubating Canada
       geese. Auk 106: 439-446.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

National Geographic  Society. (1987) Field guide to the birds of North America.
      Washington, DC: National Geographic Society.

Naylor, A. E. (1953)  Production of the Canada goose on Honey Lake Refuge, Lassen
      County, California. Calif. Fish and Game 39: 83-94.

Nelson, A. L.; Martin, A. C. (1953) Gamebird weights. J. Wildl. Manage. 17: 36-42.
                                      2-34
Canada Goose
-------
Nelson, U. C.; Hansen, H. A. (1959) The cackling goose-its migration and management.
      Trans. North Am. Wiidl. Nat. Resour. Conf. 24: 174-187.

Owen, M. (1980) Wild geese of the world. Their life history and ecology. London, UK: B.
      T. Batsford Ltd.

Palmer, R. S. (1962) Handbook of North American birds: v. 1. New Haven, CT: Yale
       University Press.

Palmer, R. S. (1976) Handbook of North American birds: v. 2. New Haven, CT: Yale
       University Press.

Peach, H. C.; Thomas, V. G. (1986) Nutrient composition of yolk in relation to early
      growth of Canada geese. Physiol. Zool. 59: 344-356.

Prevett, J. P.; Marshall, I. F.; Thomas, V.  G. (1985) Spring foods of snow and Canada
     . geese at James Bay.  J.  Wildl. Manage. 49: 558-563.

Ratti, J. T.; Timm, D. E.; Robards, F. L. (1977) Weights and measurements of Vancouver
       Canada geese. Bird Banding 48: 354-357.

Raveling, D. G.  (1968) Weights of Bfanta canadensis interior during winter. J. Wildl.
       Manage. 32: 412-414.

Raveling, D. G.  (1978a) Morphology of the cackling Canada goose. J. Wildl. Manage. 42:
      897-900.

Raveling, D. G.  (1978b) Dynamics of distribution of Canada geese in winter. Trans. North
      Am. Wildl. Nat. Resour. Conf. 43: 206-225.

Raveling, D. G.  (1979) The annual cycle of body composition of Canada geese with special
      reference to control of reproduction. Auk 96: 234-252.

Raveling, D. G.  (1981) Survival, experience, and age in relation to breeding success of
      Canada geese. J. Wildl. Manage. 45: 817-829.

Raveling, D. G.; Lumsden, H. G. (1977) Nesting ecology of Canada geese in the Hudson
      Bay lowlands of Ontario: evolution and population regulation. U.S. Fish Wildl. Res.
      Rep. 98; pp. 1-77.

Rienecker, W. C. (1987) Population trends, distribution, and survival of Canada geese in
      California and western Nevada. Calif. Fish and Game 73: 21-36.

Rienecker, W. C.; Anderson, W. (1960) A waterfowl nesting study on Tule Lake and
      Lower Klamath National Wildlife Refuges, 1957. Calif. Fish and Game 46: 481-506.

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
      Biol. 19: 535-562.
                                      2-35
Canada Goose
-------
 Samuel, M. D.; Rusch, D-. H.; Craven, S. (1990) Influence of neck bands on recovery and
       survival rates of Canada geese. J. Wildl. Manage.  54: 45-54.

 Sedinger, J. S. (1986) Growth and development of Canada goose goslings. Condor 88:
       169-180.

 Sedinger, J. S.; Raveling, D. G. (1984) Dietary selectivity in relation to availability and
       quality of food for goslings of cackling geese. Auk 101: 295-306.

 Sedinger, J. S.; Raveling, D. G. (1986) Timing of nesting  by Canada geese in relation to
       the phenology and availability of their food plants.  J. Anim. Ecol. 55: 1083-1102.

 Sherwood, G. A. (1965) Canada  geese of the Seney National Wildlife Refuge. Minneapolis,
       MN: U.S. Fish Wildl. Serv. Compl. Rep., Wildl. Manage. Stud. 1,2.

 Sherwood, G. A. (1966) Flexible  plastic collars compared to nasal discs for marking geese.
       J. Wildl. Manage. 30: 853-855.

 Smith, R. H.; Sutton, E. L. (1953) Waterfowl breeding ground survey in northern Alberta,
       the Northwest Territories, and the Yukon. In: Waterfowl population and breeding
       conditions. U.S. Fish Wildl. Serv. and Canadian Wildl. Serv.; Spec, Sci. Rep., Wildl.
       25; pp. 7-15.

 Smith, R. H.; Sutton, E. L. (1954) Waterfowl breeding ground survey in northern Alberta,
       the Northwest Territories, and the Yukon. In: Waterfowl population and breeding
       conditions. U.S. Fish Wildl. Serv. and Canadian Wildl. Serv.; Spec. Sci. Rep., Wildl.
       27; pp. 11-20.

 Spencer, D. L., et al. (1951) America's greatest Brant goose nesting area. Trans. North
       Am. Wildl. Nat. Resour. Conf. 16: 290-295.

 Steel, P. E., et al. (1957)  Canada goose production at Gray's Lake, Idaho, 1949-1951.  J.
       Wildl. Manage. 21: 38-41.

 Szymczak, M. R. (1975) Canada  goose restoration along the foothills of Colorado. Colo.
       Dept. Nat. Resources Wildl. Div. Tech. Publ. 31.

 Thomas, V. G.; Peach Brown, H.  C.  (1988) Relationships  among egg size, energy reserves,
       growth rate,  and fasting resistance of Canada goose goslings from southern
       Ontario. Can. J. Zool. 66:  957-964.

Thomas, V. G.; Mainguy,  S.  K.; Prevett, J. P. (1983) Predicting fat content of geese from
       abdominal fat weight. J. Wildl. Manage. 47: 1115-1119.

Thornburg, D. D.; Tacha, T. C.; Estel, B. L., et al. (1988)  Spatial and temporal variation in
       winter weights of Mississippi Valley Canada geese. In: Weller, M. W., ed.
       Waterfowl in winter. Minneapolis, MN: University of Minnesota Press; pp. 271-275.
                                       2-36
Canada Goose
-------
Timm, D. (1974) Status of lesser Canada geese in Alaska. Juneau, AK: Alaska Dep. Fish
      and Game; Pacific Flyway Tech. Com. Rep. 38-50.

Trainer, C. E. (1959) The 1959 western Canada goose (Branta canadensis occidentalism
      study of the Copper River Delta, Alaska. U.S. Bur. Sport Fish. Wildl. Annu.
      Waterfowl Rep., Alaska (mimeo).

Vaught, R. W.; Kirsch, L. M. (1966) Canada geese of the eastern prairie population, with
      special reference to the Swan Lake flock. Missouri Dept. Conserv. Tech. Bull. 3.

Walsberg, G. E.;  King, J. R. (1978) The relationship of the external surface area of birds to
      skin surface area and body mass. J. Exp. Biol. 76: 185-189.

West, W, L.  (1982) Annual cycle of the giant Canada goose flock at the Trimble Wildlife
      Area [master's thesis]. Columbia, MO: University of Missouri.

Will, G.  C. (1969) Productivity of Canada geese in Larimer County, Colorado, 1967-1968.
      [master's  thesis]. Fort Collins, CO: Colorado State University.

Williams, J. E.; Kendeigh,  S. C. (1982) Energetics of the Canada goose. J. Wildl. Manage.
      46: 588-600.

Yelverton, C. S.; Quay, T. L. (1959) Food habits of the Canada goose at Lake
      Mattamuskeet, North Carolina. North Carolina Wildlife Resources Commission.

Yocom, C. F. (1972) Weights and measurements of Taverner's and Great Basin Canada
      geese. Murrelet 53: 33-34.                                      .
                                       2-37
Canada Goose
-------
-------
2.1.3.  Mallard (surface-feeding ducks)

       Order Anseriformes, Family Anatidae.  Surface-feeding ducks are the most familiar
ducks of freshwater and saltwater wetlands.  They feed by dabbling and tipping up in
shallow water, often filtering through soft mud for food. They feed primarily on seeds of
aquatic plants and cultivated grains, although they also consume aquatic invertebrates,
particularly during the breeding season (Jorde et al., 1983; Swanson et al., 1985). All
species have a bright colored patch of feathers on the trailing edge of each wing,  and the
overall plumage of the males is more colorful than that of the females. Dabbling ducks
range in size from the green-winged teal (average  37 cm bill tip to tail tip) to the northern
pintail (average 66 cm).

Selected species

       The mallard (Anas platyrhynchos) feeds mostly on aquatic plants,  seeds, and
aquatic invertebrates, depending on the season, and forages  in ponds and wetlands by
dabbling and filtering through sediments.  It is widespread throughout most of the United
States and is the most abundant of the United States ducks (USFWS, 1991). In the past
decade, however, its numbers have declined markedly across its principal range in the mid-
continental region because of habitat degradation and drought (USFWS, 1991). Mallards
interbreed with domestic ducks and black ducks (Anas rubripes).

      Body size.  Mallards average 58 cm from bill tip to tail tip.  Male mallards are
generally heavier than females (Delnicki and Reinecke, 1986; Whyte and  Bolen, 1984; see
table).  Female mallards lose weight during the laying and incubation periods; males lose
weight from their spring  arrival through the peak of the breeding season and then  gain
weight while the females are incubating (Lokemoen et al., 1990a).

      Habitat.  Wintering mallards prefer natural bottomland wetlands and  rivers to
reservoirs and farm ponds (Heitmeyer and Vohs, 1984); water depths of  20 to 40 cm are
optimum for foraging (Heitmeyer, 1985, cited in Allen, 1987).  The primary habitat
requirement for nesting appears to be dense grassy vegetation at least a half meter high
(Bellrose, 1976).  Mallards prefer areas that provide concealment from predators such as
seeded cover (fields established on former croplands) (Klett et al.,  1988;  Lokemoen et al.,
1990b), cool-season introduced legumes and grasses (Duebbert and Lokemoen, 1976),
and idle grassland with tall, dense, rank cover in the area (Duebbert and Kantrud,  1974).
Nests usually are located within a few kilometers of water, but if choice nesting habitat is
not available nearby, females may  nest further away (Bellrose, 1976; Duebbert and
Lokemoen, 1976).

      Food habits.  In winter, mallards feed primarily on seeds but also on invertebrates
associated with leaf litter and wetlands, mast, agricultural grains, and to a limited  extent,
leaves, buds, stems, rootlets, and tubers (Goodman and Fisher, 1962;  Heitmeyer, 1985,
cited in Allen, 1987).  In spring, females shift from a largely herbivorous diet to a  diet of
mainly invertebrates to obtain protein for their prebasic molt and then for egg production
(Swanson and Meyer, 1973; Swanson et al., 1979; Swanson et al., 1985; Heitmeyer,
1988b).  Laying females consume  a higher proportion of animal foods on the breeding
                                       2-39
Mallard
-------
grounds than do males or nonlaying females (Swanson et al., 1985). The animal diet
continues throughout the summer, as many females lay clutches to replace destroyed
nests (Swanson et al., 1979; Swanson et al., 1985). Ducklings also consume aquatic
invertebrates almost exclusively, particularly during the period of rapid growth (Chura,
1961).  Mallards concentrate in wetlands at night, apparently feeding on emerging insects
(Swanson and Meyer, 1973).  Flocks may feed in unharvested grain fields and stubble
fields during fall and winter (Dillon, 1959).  During periods of food shortage, fat reserves
are used as an energy source. During breeding, females continue to feed but also use fat
to meet the demands of egg production; females may lose 25 percent of their body mass
(in fat) during laying and  early incubation (Krapu, 1981).

      Molt.  Female mallards molt into basic plumage in late winter or early spring, except
for the wing molt, which is delayed until about the time broods are fledged.  In males,
head-body-tail molt commences in early summer and overlaps or is followed by the wing
molt. Mallards generally  are flightless for about 25 days during the wing molt (Palmer,
1976).

      Migration. Although the mallard winters in all four waterfowl flyways of North
America (i.e., Pacific, Central, Mississippi, and Atlantic), the Mississippi flyway (alluvial
valley from Missouri to the Gulf of Mexico) contains the highest numbers (Bellrose, 1976).
Human  creation and alteration of water bodies and plant communities have changed the
migration and wintering patterns of mallards; in  North America the ducks winter farther
north than in the past (Jorde et al., 1983).  Mallards tend to arrive at their wintering
grounds in the Mississippi Valley in mid-September through early November and depart for
their northerly breeding grounds again in March  (Fredrickson and Heitmeyer, 1988). Adult
females that reproduce successfully are likely to return to the same nesting ground the
following year (Lokemoen et al., 1990a, 1990b).

      Breeding activities and social organization. Older females arrive at breeding grounds
earlier than yearling birds, which probably increases their chances of reproductive success
because they can select the best nest sites (Lokemoen et al., 1990b).  First clutches are
generally finished by mid-April in the southern part of the breeding range and late April to
May in the northern United States (Palmer, 1976).  High rates of nest failure require
females to renest persistently to reproduce successfully (Swanson et al., 1985). Average
clutch size decreases as the season progresses because the clutch size of renesting
females is smaller than initial clutches (Eldridge and Krapu, 1988;  Lokemoen et al.,
1990b).  Older females produce larger clutches than do yearlings (Lokemoen et al.,
1990a).  Mallards mate for one breeding season, and males typically leave the females at
the onset of incubation (Palmer, 1976).  Females remain with the  brood until fledging.
Mallards are serially monogamous and thus remate annually (Palmer, 1976).

      Home range and resources.  Each pair of  mallards uses a home range, and the drake
commonly establishes a territory that he defends against other mallards (Bellrose, 1976).
Home-range size depends on habitat, in particular the type and distribution of water
habitats (e.g., prairie potholes, rivers), and population density (Bellrose, 1976; Dwyer et
al., 1979; Kirby et al., 1985).
                                        2-40
Mallard
-------
      Population density. Mallard densities during the breeding season are positively
correlated with availability of terrestrial cover for nesting and with availability of wetlands
and ponds that provide the aquatic diet of mallards (Pospahala et al., 1974).  Availability
of suitable wetland habitat for breeding and wintering depends on environmental
conditions (e.g., rainfall) (Heitmeyer and Vohs, 1984; Lokemoen et al., T990a). Average
densities of breeding mallards in the prairie pothole region range from 0.006 to 0.67 pairs
per hectare (Duebbert and Kantrud,  1974; Duebbert and  Lokemoen, 1976; Kantrud and
Stewart, 1977; Lokemoen et al., 1990b). Mallards attain their highest densities in prairie
and parkland  of the southern prairie provinces and in the Cooper River and Athabasca River
deltas of Canada (Johnson and Grier, 1988).

      Population dynamics. Nest success or failure is an important factor affecting
mallard populations.  Mammalian predation is the main cause of nest failure, followed by
human disturbance (e.g., farming operations) and adverse weather conditions (Klett et al.,
1988; Lokemoen et al., 1988).  Mammalian predators include fox, badger, and skunk;
crows also prey  on mallard nests (Johnson et al., 1988).  Mallards usually renest if the
first nest fails (Palmer, 1976).  Juvenile survival depends on food and  preferred habitat
availability, factors that in turn are affected by environmental conditions. For example,
high rainfall is related to increased wetland area, which is positively correlated with
duckling growth (Lokemoen et al., 1990a). Annual adult mortality rates vary  with year,
location, hunting pressure, age, and sex.  Females suffer greater natural mortality rates
(e.g., typical values of 40 to 50 percent) than  do males (e.g., typical values of 30 to 40
percent) (Chu and Hestbeck, 1989).  By fall, there is a higher proportion of males than
females in most  populations  (Bellrose, 1976).  Immature  mortality rates of 70 percent have
been recorded in many areas, although lower immature mortality rates are more common
(Bellrose, 1976;  Chu and Hestbeck, 1989).  Annual mortality rates also are greater in
areas with higher hunting pressure  (Bellrose, 1976).

Similar species (from general references)

      •      The American black duck (Anas rubripes) is "only present in the wooded parts
             of northeastern and north central United States. It nests near woodland
             lakes and streams or in freshwater and tidal marshes. It is similar in size (58
             cm) to  mallards using the same habitats.

      •      The northern pintail (Anas acuta) is widespread, occurring in most parts of
             North America and breeding throughout Canada and the north central United
             States.  Although formerly farily abundant. North American pintail
           . populations have declined dramatically during the  past decade (USFWS,
             1991). It prefers marshes and open areas with ponds and lakes.  Pintails
             average slightly longer (66 cm) than mallards.

      •      The gadwall (Anas strepera) (51  cm) occurs throughout most of the United
             States.  In Canada, its breeding range is limited to the south central potholes
             region. It is more common in the west than in the east.

      •      The American wigeon (Anas americana) (48 cm) breeds throughout most of
             Canada and in  the prairie pothole regions of the United States.  It winters
                                        2-41
Mallard
-------
r
                        along both the east and west coasts of the United States as well as farther
                        south into Mexico.

                 «      Northern shovelers (Anas c/ypeata) (48 cm), inhabitants of marshes, ponds,
                        and bays, breed throughout mid to western Canada and the prairie pothole
                        regions of the United States. They winter along the gulf coast, southern
                        Atlantic coast, in Texas, and a few other southwestern states as well as
                        throughout Mexico.

                 •      Blue-winged teal (Anas discors) (39 cm) are fairly common in open country
                        in marshes and on ponds and1 lakes.  Breeding populations occur throughout
                        the central United States and Canada, but wintering populations are
                        restricted to Atlantic and Pacific coastal areas.

                 •      The green-winged teal (Anas crecca) (37 cm) is the smallest of the dabbling
                        ducks.  A. c. carolinensis is the most common subspecies in the United
                        States.  It breeds throughout most of Canada and the prairie pothole region
                        of the United States.  It overwinters in the southern half of the United States
                        and in Mexico.

                 •      Cinnamon tea! (Anas cyanoptera)  (41 cm) breeding populations are restricted
                        to the western United States and  Mexico, with few reaching southern
                        Canada. Some populations in California and Mexico are year-round
                        residents.

           General references

                 Allen (1987);-National Geographic Society (1987); Pospahala et al. (1974); Palmer
           (1976); Bellrose (1976).
                                                  2-42
Mallard
-------
Mallard Duck (Anas platyrhynchos)
factors
	 ~ 	 .
Body Weight
M




"
• '



I Age/$ex/
I CondJSeas,
1 	 — 	
AM
AF
A M winter
A F winter
A M winter
A F winter
A F spring
egg
at hatching
B at 3.5 days
Fat 9.5 days
Fat 15.5 days
F at 30.5 days
F fledging at
56.0 days



L 	 _
Body Fat
W (9 1'P'dl
—
5"
S.

1 ii •••••_•--•
111 -^-^^= • • '— - '
M at 9.5 days
Mat 15.5 days
M at 30.5 days
M fledging at
56.0 days
A M winter
A F winter

A F April
Y F April
A F June
Y F June
1
Mean
•
1,225
1,043
1,246 ± 108SD
1,095 ± 106SD
1,237 ± 118SD
1,088 ± 105 SD
1,197 ± 105SD
52.2 '
32.4 ± 2.4 SD
32.4 ± 2.4 SD
1 1 5 ± 37 SD
265 ± 92 SD
401 + 92 SD

740 ± 1 1 5 SD
92 ± 12 SD
215 ± 5 SD
j Range or
j 195% Cl of nteanl
up to 1,814
up to 1 ,633



32.2 - 66.7







460 ± 93 SD

817 ± 91 SD
	 • 1
L
174 + 66 SD
171 ± 56 SD

106 + 34 SD
82 ± 37 SD
22 + 22 SD
9.6 ± 8.3 SD
L..


	 1




•
-j 	 =5=5==?====— 5— s:
\ Location
throughout North America
western Mississippi
(alluvial valley)
Texas
North Dakota
North Dakota
central North Dakota
central North Dakota
central North Dakota



central North Dakota

I Reference ,
"i" ' '
Nelson & Martin, 1 953
Delnicki & Reinecke, 1 986
Whyte &Bolen, 1984
Krapu &Doty, 1979
Eldridge & Krapu, 1988
Lokemoen et al., 1 990a
Lokemoen et al., 1990b
Lokemoen et al., 1 990b



Lokemoen et al., 1 990b



	 	 	 1
Texas

North Dakota


— 	 _ 	
Whyte & Bolen, 1 984

Krapu & Doty, 1979

	 	 _„ __
Note
| No.









.





	
n




-------
                               Mallard Duck (Anas platyrhynchos)

Factors
Metabolic Rate
(kcal/kg-day)




Food Ingestion
Rate (g/g-day)
Water
Ingestion
Rate (g/g-day)
Inhalation
Rate (m3/day)
Surface Area
(cm2)
Age/Sex/
Cond./Seas.
A F basal
A M basal
A F winter
A M winter
A F free-living
A M free-living


AF
AM

AF
AM
AF
AM
Dietary
Composition
adults:
rice
jungle rice
brownseed paspalurn
barnyard grass
red rice
knot grass
signal grass
coast cockspur
Mamaica sawgrass
snails
other

Mean
77
73
280
220
200
192


0.058
0.055

0.42
0.48
1,030
1,148




























Range or
(95% Cl of mean)




(94 - 424)
(91 - 408)

























Winter
24
21
19
8.0
8.0
6.5
2.5
1.9
1.3
1.0
6.8

Location


Texas












Location/Habitat
, (measure)
Louisiana/coastal marsh and
prairie

(% volume; gullet contents)









Reference
estimated

Whyte & Bolen, 1984

estimated



estimated


estimated

estimated


Reference
Dillon, 1959











Note
No.
1

2

3

4

5


6

7

Note
No,












ro
w.
5T
Q.
-------
                                Mallard Duck (Anas platyrhynchos)
Dietary
Composition
breeding female:
(total animal)
gastropods
insects
Crustacea
annelids
miscv animal
(.total plant)
seeds
tubers
stems
Population
Dynamics
Home Range
Size (ha)




Population
Density
(pairs/ha)

Clutch
Size'

Clutches
/Year


Days
Incubation


April
(67.8)
trace
13.1
7.9
38.3
8.5
(32.2)
28.7
2.4
1.1
Age/Sex
Cond./Seas,
spring:
A F total
A F laying
spring:
AF
AM
A B spring
(area 1)
A B spring
(area 2)
yearling
A

if lost


if successful




May
(66.8)
24.9
25.6
15.1
0.2
1.0 .
(33.2)
28.7
4.3
0.2

Mean

468 ± 159SD
111 ± 76 SD

540
620
0.036

0.047

9.3 ± 1.7 SE
10.3 ± 1.1 SE
9



1
26
25


June
(89.4)
16.5
48.1
13.9
10.9
-
(10.6)
10.6
-
-














Range

307-719
38 - 240

40 - 1 ,440
70v1,140
0.006 - 0.076

0.031 -0.087



1-18
up to 4.5



23-29

location/Habitat
{measure}
south central North
Dakota/prairie potholes

(% wet volume; esophagus
contents)







Location/Habitat

North Dakota/prairie
potholes

Minnesota/wetlands, river

central North Dakota/range
Of 6 years of data from
two different pothole
areas
North Dakota/prairie
potholes
NS/NS
North Dakota/experimental
ponds (nests purposely
destroyed)
North America/NS
NS/NS
North Dakota/wetlands

Reference
Swanson et al., 1985











Reference

Dwyer et al., 1979


Kirby et al., 1985

Lokemoen et al., 1 990a



Krapu & Doty, 1 979

Bellrose, 1976
Swanson, unpublished in
Swanson et al., 1985

Bellrose, 1976
Bent, 1923
Klett & Johnson, 1 982
Note
No,










-
Note
No.

















8

ro
4».
01
2L
5T
a.
-------
                               Mallard Duck (Anas platyrhynchos)
Population
Dynamics
Age at
Fledging
(days]
Percent Nests
Successful
Number
Fledge per
Successful
Nest
Age at
Sexual
Maturity
' Annual
.Mortality
"Rates
(percent!
Seasonal
Activity
Mating

Hatching
Age/Sex
Cond./Seas.



•
AM
AF
AM fall
J M fall
AF fall
J F fall
AM fall
J M fall
AF fall
J F fall
Begin

early April

Mean
52-60
56
51 -61
9- 10
4.9
8.4
1 yr
27.2
38.2
40.1 ± 3.1 SE
41.1 ± 7.2 SE
49.9 ± 3.3 SE
48.8 ± 6.0 SE
39.0 ± 2.3 SE
48.1 ± 5.3 SE
51.5 ± 1.9 SE
56.8 ± 3.2 SE
' Peak
May
early May
June
Range




22-51
31 -59
20-72
15- 68
9-60
7-69
33-64
38-68
End

mid-July

Location/Habitat
NS/NS
central North Dakota/
potholes
South Dakota/prairie
potholes and fields
eastern South Dakota/
potholes
NS/NS
United States/NS
United States/NS
eastern-central flyway/NS
western mid-Atlantic/NS
1971 to 1985
northeastern United
States/NS
1971 to 1985
Location
CA, UT, MT, SD, NY, VT
south central N Dakota
NW Territory, Canada
Reference
Bellrose, 1976
Lokemoen et a!., 1 990a
Duebbert & Lokemoen, 1976
Klettetal., 1988
Cowardin & Johnson, 1979
Bellrose, 1976
Krapu & Doty, 1 979
Bellrose, 1976
Chu & Hestbeck, 1 989
Chu & Hestbeck, 1 989
Reference
Bellrose, 1976
Krapu & Doty, 1 979
Toftetal., 1984
Note
No.


9


Note
No.



O
SL
5"
o.
-------
   to
       8
       9
                                              Mallard Duck (Anas p,atyrhynchos)
Molt
 Spring
 fan
 Location,
  "

 Mississippi Valley
Reference
       _


Fredrickson&Heitmeyer, 1988
                         December
                         mid-Sept.
March
November
          Migration
           spring
arrive north central US
     northern US
                                                                                                    Johnson etal., 1937
                                                                                                          , 1973
Cited in Palmer (1978).
Cited in Johnson etal. (1987).
.,

 a'SberQ and Kin9- 1978) and body weiohts from M ,
                            Y We'9hts fro^ Nelson and Martin
•a.
-------
References (including Appendix)
                                                 *

Allen, A. W. (1987) Habitat suitability index models: mallard (winter habitat, lower
       Mississippi Valley). U.S. Fish Wildl. Serv. Biol. Rep. No. 82(10.132).

Bellrose, F. C. (1976) Ducks, geese, and swans of North America. Harrisburg, PA: The
       Stackpole Co.; pp. 229-243.

Bellrose, F. C.; Hawkins, A. S. (1947) (cited in Palmer, 1976). Auk 64: 422-430.

Bent, A. C. (1923) Life histories of North American wild fowl. Washington, DC: U.S.
       Government Printing  Office; Smithsonian Inst. U.S. Nat. Mus., Bull. 126.

Brownie, C.; Anderson, D. R.; Burnham, K. P.; et al. (1978) Statistical inference from  band
       recovery data-a handbook. U.S. Fish Wildl. Serv.  Resour. Publ. 131.

Brownie, C.; Anderson, D. R.; Burnham, K. P.; et al. (1985) Statistical inference from  band
       recovery data-a handbook. U.S. Fish Wildl. Serv.  Resour. Publ. 156.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and  birds.
       Am. J. Physiol. 244: R601-R606.

Chu, D. S.; Hestbeck, J. B.  (1989) Temporal and geographic estimates of survival and
       recovery rates for the mallard, 1950 through  1985. Washington, DC: U.S. Fish
       Wildl. Serv. Tech. Rep. No. 20.

Chura, N. J. (1961) Food availability and preference of juvenile mallards. Trans. N. Am.
       Wildl. Nat. Resour. Conf. 26: 121-134.

Coulter, M. W.; Miller, W. R. (1968) Nesting biology of black ducks and mallards in
       northern New England. Vermont Fish and Game Dept. Bull. 68-2.

Cowardin, L. M.; Johnson, D. H. (1979) Mathematics and mallard management. J. Wildl.
       Manage. 43: 18-35.

Delnicki, D.; Reinecke, K. J. (1986)  Mid-winter food use and body weights of mallards and
       wood ducks in Mississippi. J. Wildl. Manage.  50: 43-51.

Dillon,  0. W. (1959) Food habits of wild mallard ducks in three Louisiana parishes. Trans.
       North Am. Wildl. Nat. Resour. Conf. 24: 374-382.

Doty, H. A. (1975) Renesting and second broods of wild  mallards. Wilson Bull. 87: 115.

Duebbert, H. F.; Kantrud, H. A. (1974) Upland duck nesting related to land use and
       predator reduction. J. Wildl. Manage. 38: 257-265.
                                       2-48
Mallard
-------
Duebbert, H. F.; Lokemoen, J. T. (1976) Duck nesting in fields of undisturbed grass-
      legume cover. J. Wildl. Manage. 40: 39-49.

Dwyer, T. J.; Krapu, G. L; Janke, D. M. (1979) Use of prairie pothole habitat by breeding
      mallards. J. Wildl. Manage. 43: 526-531.

Dzubin, A. (1955) Some evidences of home range in waterfowl. Trans. North Am. Wildl.
      Nat. Resour.  Conf. 20: 278-298.

Eldridge,  J. L.; Krapu, G. L.  (1988) The influence of diet quality on clutch size and laying
      pattern in mallards. Auk 105: 102-110.

Fredrickson, L. H.; Heitmeyer, M. E. (1988) Waterfowl use of forested wetlands of the
      southern United States: an overview. In: Weller, M. W., ed. Waterfowl in winter.
      Minneapolis,  MN: University of Minnesota Press; pp. 307-323.

Fuller, R. W. (1953) Studies in the life history and ecology of the American pintail, Anas
      acuta tzitzihoa (Vieillot), in Utah [master's thesis]. Logan, UT: Utah State
      Agricultural College.

Gilmer, D. S.; Ball, I. J.; Cowardin, L. M.; et al. (1975) Habitat use and home range of
      mallards breeding in Minnesota. J. Wildl. Manage. 39: 781-789.

Girard, G. L. (1941) The mallard: its management in western  Montana.  J. Wildl. Manage.
      5: 233-259.

Gollop, J. B.; Marshall, W. H. (1954) A guide to aging duck broods in the field (mimeo).
      MS: Mississippi Flyway Council Tech. Sect.

Goodman, D. C.; Fisher, H.  I. (1962) Functional anatomy of the feeding apparatus in
      waterfowl Aves: Anatidae. Carbondale, IL: Southern Illinois University Press.

Heitmeyer, M. E. (1985) Wintering strategies of female mallards related to dynamics of
      lowland hardwood wetlands in the upper Mississippi Delta [Ph.D. dissertation].
      Columbia, MO: University of Missouri.

Heitmeyer, M. E. (1988a) Body composition  of female mallards in winter in relation to
      annual cycle  events.  Condor 90: 669-680.

Heitmeyer, M. E. (1988b) Protein costs of the prebasic molt of female mallards. Condor
      90: 263-266.
                                                                 *

Heitmeyer, M. E.; Vohs, P. A.  (1984) Distribution and habitat use of waterfowl wintering
      in  Oklahoma. J. Wildl. Manage. 48: 51-62.

Johnson, D. H.; Grier, J. W. (1988) Determinants of breeding distributions of ducks. Wildl.
      Monogr. 100: 1-37.
                                       2-49
Mallard
-------
Johnson, D. H.; Sparling, D. W.; Cowardin, L. M. (1987) A model of the productivity of
       the mallard duck. Ecol. Model. 38: 257-275.

Johnson, M. A.; Hinz, T. C.; Kuck, T. L.  (1988) Duck nest success and predators in North
       Dakota, South Dakota, and Montana: The Central Flyway Study. In: Uresk, D. W.;
       Schenbeck, G. L.; Cefkjn, R., tech. coords. Eighth Great Plains wildlife damage
       control workshop proceedings; April 28-30, 1987; Rapid City, South Dakota. Fort
       Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest
       and Range Experiment Station; pp. 125-133.

Jorde, D. G.; Krapu, G. L.; Crawford, R. D. (1983) Feeding ecology of mallards wintering
       in Nebraska. J. Wildl. Manage. 47: 1044-1053.

Kantrud, H. A.; Stewart, R. E. (1977) Use of natural basin wetlands by breeding  waterfowl
       in North Dakota. J. Wildl. Manage. 41:  243-253.

Kirby, R. E.; Cowardin, L. M. (1986) Spring and summer survival of female mallards from
       northcentral Minnesota. J. Wildl. Manage. 50: 38-43.

Kirby, R. E.; Riechmann, J. H.; Cowardin, L. M. (1985)  Home range and habitat use of
       forest-dwelling mallards in Minnesota. Wilson Bull. 97: 215-219.

Klett, A. T.; Johnson, D. H. (1982) Variability  in nest survival rates and implications to
       nesting studies. Auk 99: 77-81.

Klett, A. T.; Shaffer, T. L.; Johnson, D. H. (1988) Duck nest success in the prairie pothole
       region. J. Wildl. Manage. 52: 431-440.

Krapu, G. L. (1981) The role of nutrient reserves in mallard reproduction. Auk 98: 29-38.

Krapu, G. L.; Doty, H. A. (1979) Age-related aspects of mallard reproduction.  Wildfowl 30:
       35-39.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
       variables in resting birds. Resp. Phys. 11: 152-166.

Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation between standard
       metabolic rate and body weight in birds. Condor  69: 12-23.

Lee, F. B.; Jessen, R. L.; Ordal, N. J.; et al. (1964) In: Moyle, J. B., ed. Ducks and land
       use in Minnesota. Minn. Dept. Conserv. Tech. Bull. 8.

Lokemoen, J. T.; Schnaderbeck, R. W.; Woodward, R. 0. (1988) Increasing waterfowl
       production  on points and islands by reducing mammalian predation. In: Uresk, D.
      W.; Schenbeck, G. L.; Cefkin, R., tech.  coord. Eighth Great Plains wildlife  damage
      control workshop proceedings; April 28-30, 1987; Rapid City, South Dakota. Fort
       Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain  Forest
      and Range  Experiment Station; pp. 146-148.
                                       2-50
Mallard
-------
Lokemoen, J. T.; Duebbert, H. F.; Sharp, D. E. (1990a) Homing and reproductive habits of
      mallards, gadwalls, and blue-winged teal. Wildl. Monogr. 106: 1-28.

Lokemoen, J. T.; Johnson, D. H.; Sharp, D. E. (199Gb) Weights of wild mallard Anas
      platyrhynchos, gadwall A. strepera, and blue-winged teal A. discors during the
      breeding season. Wildfowl 41: 122-130.

Martin, A. C.; Zim, H. S.; Nelson, A. L. (1951) American wildlife and plants. New York,
      NY: McGraw-Hill Book Company, Inc.

McAtee, W.  L. (1918) Food habits of the mallard ducks of the United States. U.S. Dept.
      Agric. Bull. 720.

McEwan, E.  H.; Koelink,  A. F. (1973) The heat production of oiled mallards and scaup.
      Can. J.Zool. 51:  27-31.

Meeh, K. (1879)  Oberflachenmessungen des mensclichen Korpers.  Z. Biol. 15: 426-458.

Nagy, K. A. (1987) Field  metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

National Geographic Society.  (1987) Field guide  to the birds of North America.
      Washington, DC:  National Geographic Society.

Nelson, A. L.; Martin, A.  C. (1953) Gamebird weights. J. Wildl. Manage. 17: 36-42.

Palmer, R. S. (1976) Handbook of North American birds: v. 1. New Haven, CT: Yale
      University Press.

Perret, N. G. (1962) The  spring and summer foods of the common mallard (Anas
      platyrhynchos platyrhynchos L.) in south central Manitoba [master's thesis].
      Vancouver, BC: University of British Columbia.

Poole, E. L. (1938) Weights and wing areas in North American birds. Auk 55: 511-517.

Pospahala, R. S.; Anderson, D.  R.; Henny, C. J.  (1974) Breeding habitat conditions, size of
      the breeding populations, and production  indices in population ecology of the
      mallard. Bureau of Sport Fish, and Wildl.,  Res. Publ. 115, U.S. GPO Stock No.
      2410-00387.

Ringelman, J. K.; Eddleman, W. R.; Miller, H. W. (1989) High plains reservoirs and
      sloughs. In: Smith, L. M.; Pederson, R. L.; Kaminski, R. M., eds. Habitat
      management for wintering waterfowl in North America. Lubbock, TX: Texas Tech
      University Press; pp. 311-340.

Rubner,  M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
      Biol. 19: 535-562.
                                      2-51
Mallard
-------
Rutherford, W. H. (1966) Chronology of waterfowl migration in Colorado. Colo. Div.
      Wildl.; Game Inf. Leafl. No. 42.

Simpson, S. G. (1988) Duck nest success on South Dakota game production areas. In:
      Uresk, D. W.; Schenbeck, G. L; Cefkin, R., tech. coords. Eighth Great Plains
      wildlife damage control workshop proceedings; April 28-30, 1987; Rapid City,
      South Dakota. Fort Collins, CO: U.S. Department of Agriculture, Forest Service,
      Rocky Mountain Forest and Range Experiment Station; pp. 140-145.

Stoudt, J. H. (1944) Food preferences of mallards on the Chippewa National Forest,
      Minnesota. J. Wildl. Manage  8: 100-112.

Swanson, G. A.; Meyer, M.  I. (1973) The role of invertebrates in the feeding ecology of
      Anatinae during the breeding season. In: The Waterfowl Habitat Management
      Symposium at Moncton, New Brunswick, Canada; July 30 - August 1, 1973; The
      Atlantic Waterfowl Council; pp. 143-180.

Swanson, G. A.; Krapu, G. L.; Serie, J. R. (1979) Foods of laying female dabbling ducks
      on the breeding grounds.  In: Bookhout, T. A., ed. Waterfowl and wetlands--an
      integrated review:  proceedings of 1977 symposium. Madison, Wl: The Wildlife
      Society, NC Sect.; pp. 47-57.

Swanson, G. A.; Meyer, M.  I.; Adomaitis, V.A. (1985) Foods consumed by breeding
      mallards on wetlands of south-central North Dakota. J. Wildl. Manage. 49: 197-
      203.

Toft, C. A.; Trauger, D. L.; Murdy, H. W. (1984) Seasonal decline  in brood sizes of
      sympatric waterfowl  (Anas and Athya, Anatidae) and a proposed evolutionary
      explanation. J. Anim. Ecol. 53: 75-92.

USFWS. (1991) 1991 Status of waterfowl & fall flight forecast. Laurel, MD: U.S. Fish
      Wildl. Serv., Office of Migratory Bird Management.

Walsberg, G. E.; King, J. R.  (1978) The relationship of the external surface area of birds to
      skin surface area and body mass. J. Exp. Biol. 76: 185-189.

Whyte, R. J.; Bolen, E. G. (1984) Impact of winter stress on mallard body composition.
      Condor 86: 477-482.
                                      2-52
Mallard
-------
2.1.4.  Lesser Scaup (bay ducks)

       Order Anseriformes.  Family Anatidae.  Bay ducks are adapted for diving and
characteristically need a running start to become airborne because their legs are located
further back on their body than on other ducks. They breed at mid to high latitudes and
winter in flocks on large water bodies and in protected coastal bays and river mouths.  Bay
ducks dive for their food, and their diet is omnivorous (i.e., both plant and animal matter)
and depends on the seasonal and regional abundance of food  resources.  Because of their
food habits, bay ducks prefer deeper, more permanent ponds than dabbling ducks
(Bellrose, 1976).  The sexes vary in coloration, and different bay duck species range in
length  from 42 to 53 cm (bill tip to tail tip).

Selected species

       The lesser  scaup (Aythya afffnis) is one of the most abundant North American
ducks (Allen, 1986). They breed principally throughout western Canada and Alaska,
although their  breeding range extends into the western United States as far south as
Colorado and Ohio. Lesser scaup winter in the United States in the Mississippi flyway and
the Atlantic flyway (Bellrose, 1976). They also winter along all coastal areas in the
southern states and into Mexico (National  Geographic Society, 1987).

       Body size.  The lesser scaup averages 42 cm from bill tip to tail tip.  Males are
larger and more colorful than the brown females {Bellrose, 1976; see table). Following
their postbreeding molt, scaups increase their fat reserves in preparation for migration
(Austin and Fredrickson, 1987; see table).

       Habitat. Lesser scaup are found on large lakes and bays during the fall and winter
and are common on smaller bodies of water (e.g., ponds) during the spring.  They breed in
the prairie potholes region, most often  on permanent or semipermanent wetlands of 0.85
to 2.0 ha with trees and shrubs bordering at least half of the shorelines (Bellrose, 1976;
Smith, 1971, cited in Allen, 1986). Primary brood habitat is characterized by permanent
wetlands dominated by emergent vegetation (Smith,  1971, cited in Allen,  1986).  In a
study of ducks wintering in  South  Carolina, Bergan and Smith  (1989) found lesser scaup
would forage primarily in areas with submergent vegetation but also in areas of emergent
vegetation, shallow open water, and floating-leaved  vegetation. They found some
differences in foraging habitat use by season and between males and females. In
particular, females tended to use more shallow habitats than males, and males preferred
open water in late fall  (Bergan and Smith,  1989).

      Food habits. Most populations of lesser scaup consume primarily aquatic
invertebrates, both from the water column and from the surfaces of aquatic vegetation  and
other substrates (Tome and  Wrubleski, 1988; Bartonek and Mickey, 1969). Common prey
include snails,  clams, scuds (amphipods), midges, chironomids, and leeches (see  table).
Scaup are omnivorous, however, and the percentage of plant materials (almost exclusively
seeds)  in the diet varies seasonally as the availability of different foods changes (Afton et
al., 1991; Dirschl,  1969; Rogers and Korschgen, 1966). When seeds are locally  abundant,
they may be consumed in large quantities {Dirschl, 1969). Breeding females and ducklings
                                       2-53
Lesser Scaup
-------
eat mostly aquatic invertebrates (Sugden, 1973). Young ducklings feed primarily on
water-column invertebrates (e.g., phantom midges, clam shrimps, water mites), whereas
older ducklings forage mainly on bottom-dwelling invertebrates (e.g., scuds or amphipods,
dragonflies, caddisflies) (Bartonek and Murdy, 1970).  During the winter, there are no
significant differences in diet between juvenijes and adults or between males and females
(Aftonetal., 1991).

       Molt.  Nonbreeding and postbreeding males and nonbreeding females generally
leave the breeding grounds in June to molt on lakes. However, some males complete their
molt on the breeding grounds (Trauger, 1971, cited in Bellrose, 1976).  Large flocks of
molting birds become flightless during the wing molt phase, which begins in July and  is
usually complete by late August (McKnight and Buss,  1962).

       Migration.  The axis of the main migration corridor extends from the breeding
grounds on the Yukon Flats, Alaska, to wintering areas in Florida (Bellrose, 1976). Most
scaup  winter in the United States, with the greatest numbers in the Mississippi flyway and
the Atlantic flyway.  They start to arrive at their wintering areas in mid-October (Bellrose,
1976). The timing of northward migration in the spring varies from February to May.
(Bellrose,  1976).  Before migration, scaup gain weight by increasing their body fat content
(Austin and Fredrickson, 1987).

       Breeding activities and social organization. Scaup build nests on the ground among
tall grasses, shrubs, or forbs where plant heights range from 20 to 60 cm (Mines, 1977).
Nests can be located along the edge of shorelines to upland areas (Bellrose,  1976).
Courtship  and pair bonds start to form on the wintering grounds, and pairs typically remain
together for only one season.  Males do not remain long after incubation commences
(Trauger, 1971, cited in  Bellrose, 1976). The female and her brood leave the vicinity of
the nest shortly after the ducklings have hatched. Most broods are on their own by 4 to 5
weeks of age (Gehrman, 1951, cited in Bellrose, 1976) and fledge between 7 and 9 weeks
of age  (Bellrose, 1976; Lightbody and Ankney, 1984).  Females of this species often lay
eggs in other lesser scaup nests (nest parasitism), which can result in large compound
clutches of lesser scaup  eggs in a single nest (Mines, 1977). Mines (1977) also found that
mixing of broods was common in Saskatchewan; by August, groups of 15 to 40 ducklings
led by  two to three hens would be common.  Female lesser scaup also occasionally lay
eggs in the nests of other ducks (e.g., gadwall; Mines, 1977).

       Home range and resources.  Relatively small nesting territories and large highly
overlapping foraging ranges are characteristic of lesser scaup (Hammel, 1973, cited in
Allen,  1986). Several pairs can nest in close proximity without aggression, each defending
only a  small area immediately surrounding the  nest {Bellrose, 1976; Vermeer, 1970). In
Manitoba, Hammel (1973) estimated the mean minimum foraging home range to be 89 ±
6.5 ha. Initial areas occupied by pairs usually contain stumps, logs, boulders, or  beaches
as loafing sites, but later lesser scaup rely solely on open water (Gehrman, 1951, cited in
Bellrose, 1976).

       Population density. In winter, local densities  of scaup can be very high, as large
flocks float on favored feeding areas (Bellrose, 1976).  In summer, the  density of breeding
                                       2-54
Lesser Scaup
-------
pairs increases with the permanence and size of the ponds (Kantrud and Stewart, 1977;
see table).

      Population dynamics. In some populations, many yearling and some 2-year-olds do
not breed; the proportion  breeding tends to increase with improving water and habitat
conditions (Afton, 1984;  McKnight and Buss, 1962).  In a 4-year study in Manitoba, Afton
(1984) found that, on average, 30 percent of 1-year-olds and 10 percent of 2-year-olds,
did not breed. Clutch size and reproductive performance of adult females generally
increase with age (Afton, 1984). Most nest failures are due to predation (e.g., by mink,
raccoons, red fox), and scaup often attempt to  renest if the .initial nest fails (Afton,  1984;
Bellrose,  1976).  Annual mortality for juveniles is higher than that for adults, and adult
female mortality  exceeds  adult male mortality (Smith,  1963; see table).

Similar species (from general references)

      •      The redhead (Aythya  americana),  a larger bay duck (48 cm), breeds on lakes
             and ponds in the northwestern United States and in mid western Canada.
             They winter in coastal areas and the southern United States and Mexico. In
             summer, adult female and juvenile redheads consume predominantly animal
             matter (e.g., caddis flies,  midges, water fleas, snails), while males include
             more plant materials in their diet.

      •      The canvasback (Aythya valisineria) is the largest bay duck (53 cm). They
             are common on lakes and ponds in the northern United  States and southern
             Canada during the breeding season and along coastal areas of the United
             States during winter.  Studies during the winter in North and  South  Carolina
             have found  varying diets for canvasbacks, consuming mostly animal matter
             (e.g., clams); others eat only vegetation. In summer, adult female and
             juvenile canvasbacks  eat predominantly  animal material (e.g., caddis flies,
             snails, mayflies, midges),  whereas adult males may eat predominantly
             vegetable material, particularly tubers of Potamogeton.

      •      The ring-necked duck (Aythya collaris) is similar in size (43 cm) to the lesser
             scaup and prefers freshwater wetlands.  They are commonly  seen on
             woodland lakes and ponds, but in winter also use southern coastal marshes.
             During the winter, ring-necked ducks eat mostly plant materials (81  percent)
             and a variety of animal matter (19 percent).

      •      The greater scaup (Aythya marila) (46 cm) is common in coastal areas and
             the Great Lakes during winter. They are omnivorous, eating 50 to .99
             percent animal matter and the remainder plant foods during the winter.

General references

      Allen (1986); Bartonek and Mickey (1969); Bellrose (1976); National Geographic
Society (1987); Perry and Uhler (1982).
                                       2-55
Lesser Scaup
-------
                                      Lesser Scaup (Aythya a f finis)

Factors
Body Weight
(9)



'
Adult Body Fat
{grams Ifpidt
'- % of total
"body weight)
Duckling
Growth Rate



Metabolic Rate
(kcal/kg-day)

e
\



Food ingestfon
Bate (g/g-day)


Water
togestion
Rate (flF/g-dayj
Inhalation
Rate fm^/dayi
Age/Sex/
Cond./Seas.
F preflightless
F flightless
F postflightless
F migratory
F
M
F preflightless
F flightless
F postflightless
F migratory
age in weeks
0-3
3-6
6-9
9-12
A F basal
A M basal

A B resting
20 to 30°C

A F free-living
A M free-living
juveniles.
both sexes:
1-5 weeks
6-12 weeks
AF
AM

AF
AM

Mean
688
647
693
842
770
860
50.7 (7.4%)
37.2 (5.7%)
46.5 (6.7%)
188.1 (22.3%)
growth in g/day
6.9
14
1.5
1.2
83
81
90


216
211

dry matter intake/
wet body weight
0.162
0.077
0.064
0.062

0.34
0.36
Range or
(95% Ct of mean)




up to 950
up to 1,100




(final body weight)
(190g)
(485 g)
(51 6 g)
(542 g)






(102-457)
(99 - 445)









Location or
subspecies
Manitoba, Canada



United States

Manitoba, Canada



Utah or Canada







Canada




Saskatchewan/captive:
reared in large brooder
and in outdoor pens







Reference
Austin & Fredrickson, 1987



Nelson & Martin, 1953

Austin & Fredrickson, 1987



Sugden & Harris, 1 972




estimated


McEwan & Koelink, 1973


estimated

Sugden & Harris, 1 972



estimated


estimated
*
Note
No.
1





1



2




3





4

5



6


7

to

01
O)
CD
tn
c/>
CD
-n

CO
o
0)
c
-------
                                             Lesser Scaup (Aythya affinis}
                    Age/Sex/
                    CwitUSe'as.
                                                                           Location or
                                                                           subspecies
                                                                                                      Reference
                                                                                                      ——^____
                                                                                                      estimated
   Dietary
   Composition
                                                                        Location/Habitat
                                                                          (measure)
                                   Summer I Fall
(animal)
 midges
 snails
                                                                                                     Reference

                                                                                                     Afton etal.,  1991
                                    Louisiana/lakes, marshes
    9i"9ss shrimp
  (plant
    bulrush
  (plant - vegetative}
   green algae
                                                                     (% dry weight;
                                                                     esophageal & proventricular
                                                                     contents)
 Juveniles only;
 (animal)
   scuds
   phantom midges
   dam shrimps
  dragon/damsefflies
  water bugs
 water mites
 caddis flies
 water beetles
 mayflies
(plants}
                                                                    Northwest Territories/lak
(100)
1 ± 1
54  ± 8
30  ± 8
                                                                                                 Bartonek & Murdy,  1970
                                                                      wet volume ± SE;
                                                                   esophageal contents)'
                                 1  ± 1
                                 2  ± 1
                                 (trace)
-------
                                    Lesser Scaup (Aythya affinis}
Dietary
Composition
adults only:
(animal)
scuds (amphipods)
dragonflies
caddfs flies
midges
other insects
snails ' \
fingernail clams
% brook stickleback
fathead minnow
other fish ; -
(plants - seeds}
(plants - vegetative}
(animal)
scuds
diptera *
leeches
fingernail clams
cyprinid fish
caddis flies ,
clam -shrimps
(plant - seedsj
Nuphar variegatum
other* seeds

Spring

(91.8)
33.2
-
8.8
2.3
4.9
31.9
6.0
.
-
3.5
(6.0)
(2.2)
(90.9)
66.0
-
12.0 -
12.7
-
0.2
-
(9.1)-
-
9.1

Summer














(75.1)
9.8
1.3
23.7
25.7
2.9
1.6
3.1
(24.9)
13.2
11.7

Fall

(90.5)
54.9
2.4
7.6
-
-
10.2
.5.1
4.1
5.0

(9.4)
(0.1)
(49.6)
42.5
0.1
1.6
-
-
1.9
0.5
(50.4)
42.8
7.6

Winter

























Location/Habitat
(measure)
nw Minnesota: spring and fall
migrations/lakes, marshes,
pools

(% dry weight;
esophageal & proventricular
contents)







Saskatchewan,
Canada/shallow lakes

(% dry weight; esophagus
and proventriculus contents)







Reference
Aftonetal., 1991













Dirschl, 1969










Population Age/Sex ' ^ ;
Dynamics Cond./Seas. Mean ' Range Location/Habitat ; Reference
Home Range breeding 89 ± 6.5 SE Manitoba, Canada , Hammel, 1973
Size (ha)
Note
No.

























Note
No.
9

cn
03
CD
co
to
CD


U)
O
ffl
c
-------
                                           Lesser Scaup (Aythya affinis)
    •a==ft-4S^_U-
Population
Density
1 (pairs/ha}
-
••
" 	 *" 	 iiiim:
j .
j A B seasonal
wetland
A B permanent
wetland
-
A B island in
-j- • . | i
0.029
0.061
28.9
lake
	
    Clutch
    Si?e
   Clutehe$
   /Year
  **"i  i ,.
   Days
   Incubation
  ~	
  Age at
  Fledging
  Waysj  ..

  Percent Wests
  Hatching
 Percent Broods
 Surviving

 Age at First
Jfreedjng

 Annual
 Mortality Rates
 (percent)
                   2nd yr female
                  _4th yr female
                   9-47 ± 0.18 SE

                   10.0 ± 0.2 SE
                       _± 0.2 SE

                   1, but often
                  renest if lost
  1styr female
  2nd yr female
  3rd yr female
 up to 20 days
 of age
juveniles
A males
A females
 76
 ———

 67.5 ± 4.9 SE
 most in 2nd yr
JL' 2 years

 68-71
 38-52
49-60
                                                    Range ,
                                                   13.1-58.5
                                                   7-12
                                  21 -27
                                                                       Jf!£rtlon/Habitat
                                                                                     .
                                                                       North Dakota/
                                                                        prairie potholes
                                        Alberta, Canada/islands in
                                          lakes of parklands and
                                         _bpreal forest
                                                    —~'	

                                        Saskatchewan/marsh island

                                        Manitoba/lake
                                       -

                                       NS/NS

                                      —    —

                                       NS/NS

                                      —"'

                                      Manitoba/captive
                                                                     Manitoba/lake
                                                                                                                           10
                                                                                   Reference
                                                                                   *"       11.

                                                                                   Kantrud & Stewart, 1977
                               Vermeer, 1970


                              •	
                              Hines, 1977

                              Afton, 1984

                             —	.	
                              Afton, 1984

                             	—	

                              Vermeer, 1968           i  1Q

                                             	—   — '
                             Lightbody & Ankney, 1984


                             •—••	_

                             Afton, 1984
 Manitoba/lake

—     —

NS/NS

Manitoba/lake
"""

NS/NS
jslands  | Mines, 1977
         ^"^""""^"^•^•^•"^•^™^^

          Afton, 1984
         Palmer, 1976
               .1976; Afton. 1984

         Smith, 1963
-------
                                                Lesser Scaup (Aythya affinis]
Seasonal
Activity
Mating/Laying
Hatching
Molt {fall)
Migration
spring
fall
Begin
early June
early May
early July
July
early February
mid-April
September
mid-October
Peak
early June
mid-July

March - April
mid-November
End
early July
early August
September
May
mid-November
December
Location
Manitoba, Canada
Montana
NW Territory and
Saskatchewan, Canada
Manitoba, Canada
departing United States
arriving Manitoba, Canada
Pacific flyway (s OR, n CA)
arriving United States
Reference
Afton, 1984
Ellig, 1955
Toft et al., 1984; Hines, 1977
Austin & Fredrickson, 1987
Bellrose, 1976
Afton, 1984
Gammonley & Heitmeyer,
1990
Bellrose, 1976
Note
No.
10

•

Ni
o>
o
CD
CO
(/>
CD
T
C/)
o
CD
c
 1   Four stages of feather molt evaluated.
 2   Ducklings stopped growing at rate typical of wild birds around 6 weeks of age. By 12 weeks, they weighed approximately 200 g less than typical
     of wild scaup.
 3   Estimated using equation 3-28 (Lasiewski and Dawson, 1967} and body weights from Nelson and Martin (1953).
 4   Estimated using equation 3-37 (Nagy, 1987) and body weights from Nelson and Martin (1953).
 5   Young ducklings maintained in 18 to 27°C brooder, then in outdoor pens with same temperature range.  Metabolizable energy of amphipods
     (estimated to be 3.11 kcal/g dry wt), a typical scaup food, is similar to the commercial diet used in the experiment (3.09 kcal/g dry wt). Ducklings
     stopped growing as rapidly as would wild ducklings at about 6 weeks of age.  For methods of estimating food ingestion rates for adult scaup, see
     Chapters 3 and 4.
 6   Estimated using equation 3-15 (Calder and  Braun, 1983) and  body weights from Nelson and Martin (1953).
 7   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Nelson and Martin (1953).
 8   Estimated using equation 3-21 (Meeh, 1879 and Rubner, 1883, cited in Walsberg and King, 1978) and body weights from Nelson and Martin
     (1953).
 9   Relatively small, highly overlapping, home ranges.  Cited in Allen (1986).
10   Cited in Bellrose (1976).
-------
References (including Appendix)

Afton, A. D. (1984) Influence of age and time on reproductive performance of female
      lesser scaup. Auk 101: 255-265.

Afton, A. D.; Hier, R. H.; Paulus, S. L. (1991) Lesser scaup diets during migration and
      winter in the Mississippi flyway. Can. J. Zool. 69: 328-333.

Allen, A. W. (1986) Habitat suitability index models: lesser scaup. U.S. Fish Wildl. Serv.
      Biol. Rep. 82(10.117).

Austin, J. E.; Fredrickson, L. H. (1987) Body and organ mass and body composition of
      postbreeding female lesser scaup. Auk 104: 694-699.

Bartonek, J. C.; Hickey, J. J. (1969) Food habits of canvasbacks, redheads, and lesser
      scaup in Manitoba. Condor 71: 280-290.

Bartonek, J. C.; Murdy, H. W. (1970) Summer foods of lesser scaup in subarctic taiga.
     • Arctic 23: 35-44.

Belirose, F.  C. (1976) Ducks, geese, and swans  of North  America. Harrisburg, PA: The
      Stackpole Co.

Bergan,  J. F.; Smith, L. M. (1989) Differential habitat use by diving ducks wintering in
      South Carolina. J. Wildl. Manage. 53: 1117-1126.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Chabreck, R. H.; Takagi, T. (1985) Foods of lesserscaup in crayfish impoundments in
      Louisiana. Proc. Annu. Conf. Southeast. Assoc.  Fish Wildl. Agencies 39: 465-470.

Chappel, W. A.; Titman, R. D. (1983) Estimating reserve  lipids in greater scaup (Aythya
      mar/la) and lesser scaup (A. affinfs). Can. J. Zool.  61: 35-38.

Dirschl,  H. J. (1969) Foods of lesser scaup and blue-winged teal in the Saskatchewan
      River Delta. J. Wildl.  Manage. 33: 77-87.

Dunning, J. B., Jr. (1984) Body weights of 686  species of North  American birds. Western
      Bird  Banding Association, Monograph No.  1. Cave Creek, AZ: Eldon Publishing.

Ellig, L. J. (1955) Waterfowl relationships to Greenfields Lake, Teton County, Montana.
      Mont. Fish, and Game Comm. Tech. Bull. 1.

Gammonley, J. H.; Heitmeyer, M. E. (1990) Behavior, body condition, and foods of
      buffleheads and lesser scaups during spring migration through the Klamath Basin,
      California. Wilson Bull. 102: 672-683.
                                       2-61
Lesser Scaup
-------
Gehrman, K. H. (1951) An ecological study of the lesser scaup duck (Athaya affinis Eyton)
      at West Medical Lake, Spokane County, Washington [master's thesis]. Pullman,
      WA: Washington State College.

Gollop, J. B.; Marshall, W. H. (1954) A guide for aging duck broods in the field (mimeo).
      MS: Mississippi Flyway Council Tech. Sect.

Hammel, G. S. (1973) The ecology of the lesser scaup (Athaya affinis Eyton) in
      southwestern Manitoba [master's thesis]. Guelph, Ontario: University of Guelph.

Mines, J. E. (1977) Nesting and brood ecology of lesser scaup at Waterhen Marsh,
      Saskatchewan. Can. Field-Nat. 91: 248-255.

Hoppe, R. T.; Smith, L. M.; Wester, D. B. (1986) Foods of wintering diving ducks in South
      Carolina. J. Field Ornithol. 57: 126-134.

Hunt, E. G.; Anderson, W. (1966) Renesting of ducks at Mountain Meadows, Lassen
      County, California. Calif. Fish and Game 52: 17-27.

Kantrud,  H. A.; Stewart, R. E. (1977) Use of natural basin wetlands by breeding waterfowl
      in North Dakota. J. Wildl. Manage. 41: 243-253.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
      variables in resting birds. Resp. Phys. 11: 152-166.

Lasiewski, R. C.; Dawson, W. R. (1967). A  reexamination of the relation between standard
      metabolic rate and body weight in birds. Condor 69: 12-23.

Lightbody, J. P.; Ankney, C. D. (1984) Seasonal influence on the strategies of growth and
      development of canvasback and lesser scaup ducklings. Auk 101: 121-133.

McEwan, E. H.; Koelink, A. F. (1973) The heat  production of oiled mallards and scaup.
      Can. J. Zool. 51: 27-31.

McKnight, D. E.; Buss, I. O. (1962) Evidence of breeding  in yearling female lesser scaup.
      J. Wildl. Manage.  26: 328-329.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Nagy, K. A. (1987) Field  metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

Nasser, J. R. (1982) Management of impoundments for crayfish and waterfowl [master's
      thesis]. Baton Rouge, LA: Louisiana State University.

National Geographic Society.  (1987) Field guide to the birds of North America.
      Washington, DC: National Geographic Society.
                                      2-62
Lesser Scaup
-------
Nelson, A. L.; Martin, A. C. (1953) Gamebird weights. J. Wildl. Manage.  17: 36-42.

Palmer, R. S. (1976) Handbook of North American birds: v. 2, 3. New Haven, CT: Yale
       University Press.

Perry, M. C.; Uhler, F. M. (1982) Food habits of diving ducks in the Carolinas. Proc. Annu.
       Conf. Southeast. Assoc. Fish Wildl. Agencies 36: 492-504.

Poole,  E. L. (1938) Weights and wing areas in North American birds. Auk 55: 511-517.

Rienecker, W. C.; Anderson, W. (1960) A waterfowl nesting study on Tule Lake and
       Lower Klamath National Wildlife Refuges,  1957. Calif. Fish and Game 46: 481-506.

Ringelman, J. K.; Eddleman, W. R.; Miller, H. W.  (1989) High plains reservoirs and
       sloughs. In:  Smith, L. M.; Pederson, R. L.; Kaminski, R. M., eds. Habitat
       management for wintering waterfowl  in North America. Lubbock, TX: Texas Tech
       University Press; pp. 311-340.

Rogers, J. P. (1962) The ecological effects of drought  on reproduction of the lesser scaup,
       Aythya affinis (Eyton) [Ph.D. dissertation]. Columbia, MO: University of Missouri.

Rogers, J. P.; Korschgen, L. J. (1966) Foods of lesser  scaups on breeding, migration, and
       wintering areas. J. Wildl. Manage. 30: 258-264.

Rowinski, L. J. (1958) A review of waterfowl investigations and a comparison of aerial
       and ground censusing of waterfowl at Minto Flats, Alaska. Mimeogr. Rep.

Rubner, M. (1883)  Uber den Einfluss der Korpergrosse  auf Stoff- und Kraftweschsel. Z.
       Biol. 19: 535-562.

Rutherford, W. H. (1966) Chronology of waterfowl migration in Colorado. Colo. Div.
       Wildl.; Game Inf. Leafl. No. 42.

Siegfried, W. R. (1974) Time budget of behavior among lesser scaups on  Delta Marsh. J.
       Wildl. Manage.  38: 708-713.

Smith,  A. G. (1971) Ecological factors affecting waterfowl production in Alberta
       parklands. U.S. Fish Wildl. Serv. Resour. Publ. 92.

Smith,  R. I. (1963)  Lesser scaup and  ring-necked  duck shooting pressure and mortality
       rates. Bur. Sport Fish & Wildl. Adm. Rep. 20.

Sugden, L. G. (1973) Feeding  ecology of pintail, gadwall, American widgeon and  lesser
      scaup ducklings in Southern Alberta. Can.  Wildl. Serv. Rep. Ser.  No. 24.

Sugden, L. G.;  Harris, L. E. (1972) Energy requirements and growth of captive lesser
      scaup. Poultry Sci. 51:  625-633.
                                       2-63
Lesser Scaup
-------
Swanson, G. A.; Krapu, G. L.; Bartonek, J. C.; et al. (1974) Advantages in mathematically
      weighting waterfowl food habits data. J.  Wildl. Manage. 38: 302-307.

Toft, C. A.; Trauger, D. L.; Murdy, H. W. (1984) Seasonal decline in brood sizes of
      sympatric waterfowl (Anas and Athya, Anatidae) and a proposed evolutionary
      explanation. J. Anim. Ecol. 53: 75-92.

Tome, M. W.; Wrubleski, D. A. (1988) Underwater foraging behavior of canvasbacks,
      lesser scaups, and ruddy ducks. Condor 90: 168-172.

Townsend, G. H. (1966) A study of waterfowl nesting on the Saskatchewan River delta.
      Can. Field. Nat. 80: 74-88.

Trauger, D. L. (1971) Population ecology of lesser scaup (Athaya affinis) in subarctic taiga
      [Ph.D. dissertation]. Ames, IA: Iowa State University.

Vermeer, K. (1968) Ecological aspects of ducks nesting  in  high densities among larids.
      Wilson Bull. 80: 78-83.

Vermeer, K. (1970) Some aspects of the nesting of ducks on islands in Lake Newell,
      Alberta. J. Wildl. Manage. 34: 126-129.

Walsberg, G. E.; King, J. R. (1978) The relationship of the  external surface area of birds to
      skin surface area and body mass. J. Exp.  Biol. 76: 185-189.
                                      2-64
Lesser Scaup
-------
2.1.5.  Osprey (Pandion haliaetus)

       Order Falconiformes. Family Accioitridae. The only North American member of the
subfamily Pandioninae, these large birds of prey have long narrow wings, a sharp hooked
bill, and powerful talons. Osprey are found near freshwater or saltwater, and their diet is
almost completely restricted to fish.  They are adapted for hovering over the water and
dive feet-first, seizing fish with their talons (Robbins et al.,  1983).  Once very rare owing
to DDT accumulation in their food (1950's to early 1970's), osprey now are  increasing in
numbers.  In the United States, there are five regional populations of osprey  (in order of
abundance): Atlantic coast, Florida and gulf coast, Pacific Northwest, western interior, and
Great Lakes (Henny, 1983).  In North America, osprey breed primarily in a wide band from
coast to coast across Canada and the southern half of Alaska, where they are not
restricted to coastal and Great Lake areas as they are in the United States. However,
osprey are reported from all States during the fall and spring migrations (Henny, 1986).

       Body size. The various subspecies of osprey around the world differ in size, and in
general females are heavier than males (Poole, 1989a; see table). Osprey found in the
United States are considered to be of the subspecies carolinenesis and average 56 cm
from bill tip to tail tip (Robbins et al., 1983) and weigh between 1.2 and 1.9 kg (see
table).

       Habitat. In the United States, the majority of osprey populations are associated
with marine environments, but large inland rivers, lakes, and reservoirs also may support
osprey (Henny, 1986, 1988b). Good nesting sites in proximity to open, shallow water and
a plentiful supply of fish are the primary resources required  for osprey success (Poole,
1989a). The tops of isolated and  often dead trees and man-made structures are preferred
nesting sites.  Osprey often nest in colonies (Poole, 1989a).

       Food habits. Osprey are almost completely piscivorous,  although they have been
observed on occasion taking other prey including birds, frogs, and crustaceans (Brown and
Amadon, 1968). Their prey preferences change seasonally with the abundance of the
local fish (Edwards, 1988; Greene et al., 1983). Osprey occasionally will pick up dead fish
but only if fresh (Bent, 1937). Osprey are most successful  catching species  of slow-
moving fish that eat benthic organisms in shallow waters and fish that remain near the
water's surface (Poole, 1989a).  Osprey consume all parts of  a  fish except the larger
bones; later, bones and other undigestible parts are ejected in fecal pellets (Bent,  1937).

       Molt. Juvenile plumage is fully developed by fledging at about 60 days of age
(Henny, 1988b). Juveniles undergo a gradual molt to adult plumage at approximately 18
months of age (Brown and Amadon, 1968). For adults, the basic molt takes place in two
phases; the first phase occurs primarily on the wintering grounds prior to spring migration.
Completion of the molt occurs in the summer range prior to fall  migration (Henny, 1988b).

       Migration.  Osprey are year-round residents in the most southern parts of their
range (e.g., south Florida, Mexico) but are migratory over the  rest of their range in the
United States and Canada (Poole,  1989a).  Studies of banded osprey have shown that the
fall migration begins in late August in the north temperate zone, with adults and juveniles
                                       2-65
Osprey
-------
from the eastern and central United States comprising a broad front flying south and then
directly across open ocean to their wintering grounds in Central and South America (Poole,
1989a). Spring migration appears to follow the same routes with birds reaching, for
example, the Chesapeake Bay area in mid-March (Reese, 1977) and Minnesota by the first
half of April (Dunstan,  1973; Henny and Van Velzen, 1972).  The majority of migrating
osprey appear to follow the coastline, perhaps because they come from coastal colonies or
because the coast offers abundant food (Poole, 1989a).  After their first migration south,
juveniles remain in their wintering grounds for about a year and a half, returning north to
the breeding grounds as 2-year-olds {Henny and Van Velzen, 1972).

       Breeding activities and social organization.  Nonmigratory (i.e., year-round resident)
populations breed during the winter; whereas migratory populations breed during the
summer (Poole, 1989a).  Monogamy is the general rule for osprey; breeding pairs remain
together and return to the same nest site year after year (Fernandez and Fernandez, 1977;
Henny, 1988b). Colonies of osprey occur in areas such as islands, reservoirs, or lakes that
offer secure nesting sites and abundant food (Henny, 1986), but most osprey are solitary
nesters, often separated from other nests by tens  to hundreds of kilometers (Poole,
1989a). The female performs most of the incubation and relies completely on the male for
food from just after mating until the young have fledged (Poole,  1989a).  Van Daele and
Van Daele (1982) found that ospreys at successful nests incubated 99.5  to 100 percent of
the daylight hours; disturbance of the nest during this time can kill the eggs if the adults
are kept from returning to the nest for some time.  After hatching, the female is in
constant attendance at the nest for the first 35 days but may perch nearby at intervals
after that (Henny, 1988b). The female distributes the food delivered by the male by biting
off pieces to feed to the young (Poole,  1989a). By 30 days, the nestlings have reached
70 to 80 percent of their adult weight and begin to be active in the nest (Poole, 1989a).
The young  fledge by age 60 to 65 days in nonmigratory populations and by about 50 to
55 days in migratory populations (Henny et a!., 1991). After fledging, the young remain
dependent  on both parents for food usually for an  additional 2 to 3 weeks (Poole, 1989a),
but dependency can continue up to 6 weeks in the more southern populations (Henny,
1986).

      Home range and resources. Osprey build large stick nests in the tops of tall trees
or artificial structures such as buoys and radio towers (Poole, 1989a). In the Chesapeake
Bay area, less than one third of the 1,450 breeding pairs built their nests in trees, while
over half nested on  channel markers and duck blinds, and the remainder on miscellaneous
man-made structures (Henny et al., 1974).  Osprey build their nest at the top of the
chosen site, which can make it vulnerable to destruction from high winds (Henny,  1986).
If not lost, the same nest often is used  year after year, and it can become quite large (e.g.,
over 2 m tall and 1.5 m across) (Dunstan, 1973; Henny, 1988a). On islands where no
predators are present, osprey will nest on the ground (Poole, 1989b). The distance osprey
travel from their nests to forage (i.e., foraging radius) depends  on the availability of
appropriate nest sites near areas  with sufficient fish; osprey will travel up to  10 to 15 km
to obtain food (Van Daele and Van Daele, 1982).

      Population density. Population density depends on the availability and distribution
of resources and can be highly variable.  Henny (1988a) reported as many as 1.9 nests per
hectare in one of the largest osprey colonies in the western United States in 1899, with an

                                       2-66                                 Osprey
-------
estimated 1.0 to 1.2 nests per hectare occupied that year.  Lower densities on the order of
0.005 to 0.1  nests per hectare are more common (see table).

      Population dynamics. Breeding data from many locations in the United States and
Canada during the years 1950 to 1976 show low productivity (fewer than one chick
fledged  per active nest on average).  Evidence indicates the cause to be egg-shell thinning
that resulted from the ospreys' exposure to DDT that had bioaccumulated in fish (Henny
and Anthony, 1989; Henny et al., 1977; Poole, 1989a). Thus, data from reproductive
studies conducted during this time can only be used with this in mind  (Spitzer et al.,
1978).a  Because of their terminal position in the aquatic food  chain, osprey can be a
sensitive indicator of toxic contaminants that bioaccumulate {Henny et al., 1978; Henny,
1988b).

      Osprey are only known to start a second clutch if the first one is destroyed (Poole,
1989a).  Juveniles do not return to their place of birth until 2 years of age, and they do
not breed until their third season (Henny and Van Velzen, 1972). Often, breeding is
delayed until 4 to 7 years of age in areas such as the Chesapeake Bay, where good
nesting sites are scarce (Poole, 1989b).

General references

      Poole (1989a); Brown and Amadon (1968); Henny (1986); Henny (1988b).
aln the table beginning on the next page, data on the number fledged per active nest and the
 number fledged per successful nest are provided only for studies of populations that appeared
 to be unaffected by DDT.
                                       2-67
Osprey
-------
                                          Osprey (Pandion haliaetus]
Factors
Body Weight
fa)

-
Egg Weight Igl
Metabolic Rate
(kcal/kg-day)

Food Ingestion
Rate (g/g-dayl
Water Ingest
Rate fg/g-dayl
inhalation
Rate (ma/day)
Surface Area
Age/Sex/
Cond./Seas.
AF
AM
A F courtship
A F incubation
A F late nestl.
A M courtship
A M late nestl.
F at fledging
M at fledging

A F basal
A M basal
A F free-living
A M free-living
A F courtship
period
AF
AM
AF
AM
AF
Mean
1,568
1,403
1,880 ± 20 SE
1,925 ± 25 SE
1,725 ± 25 SE
1,480 ± 15 SE
1,420 ± 15 SE
1,510
1,210
72.2 ± 5.35 SD
69
71
181
186
0.21
0.051
0.053
0.578
0.531
1,353
Range or
(95% Cl of mean)
1,250-1,900
1,220-1,600


66.0-81.3

(85 - 384}
(87 - 395)




Location (subspecies)
NS
se Massachusetts
Maryland, Virginia
North Carolina (carolinensisj


se Massachusetts



Reference
Brown & Amadon, 1968
Poole, 1984
McLean, 1986
Whittemore, 1984
estimated
estimated
Poole, 1983
estimated
estimated
estimated
Note
No.

1


2-
3

4
5
6
oo
O
co
-------
                                           Osprey (Pandion haliaetus]
Dietary
Composition
atewife
smelt
pollock
winter flounder
starry flounder
cutthroat trout
carp
crapple
gizzard shad
sunfish.
targemouth bass
golden shjner
browtf bullhead
salroonids
northern squawfish
yellow perch
fargescale sucker
Sfze of fish caught:
< 10crn
11 -20cm
21 - 30 cffi
31 <-4Ocm
41 -f cm
Spring



63
29
5
3
37,7
20.8
19.3
11.6
10.6

Summer
32
5
53
10
95
5
67
33


3.3
42.1
46.7
6.6
1.3
Faff :






Winter






Location/Habitat i
{measure)
Nova Scotia, Canada/
harbor, bay
(% wet weight; observed
captures)
se Alaska/NS
(% wet weight; observed
captures, noting fish length)
w Oregon/NS
(% wet weight; observed
captures, noting fish length)
Florida/lake
(% of prey caught; identified
at nests)
Idaho/reservoir
(% of fish caught; observed
captures)
Idaho/reservoir
(% of fish in each size class;
determined from remains at
nest)
Reference
Greene et al., 1983
Hughes, 1983
Hughes, 1983
Collopy, 1984
Van Daele & Van Daele, 1 982
Van Daele & Van Daele, 1982
Note
No.
7
7
7



to

O)
CO
O
CO

-------
                                             Osprey (Pandion haliaetus]
Population
Dynamics
Foraging
Radius (km)
Population
Density
[nests/ha)
Clutch
Size
Clutches/Year
Days
Incubation
Age at
Fledging {days]
Number
Fledge per
Active Nest
Age/Sex
Cond/Seas
AM
A B spring
AB
A B summer
A B spring
A B spring
A B spring



non-migr. pop.
migratory pop.

Mean
1.7-
10
3 to 8
1.9
0.028
0.10
0.005
3.23 ± 0.03 SE
2.84 ± 0.07 SE
2.67 ± 0.07 SE
3.23 ± 0.09 SE
2.82
1
38.1 ± 3.2 SD
62.5 ± 4.9 SD
54 ± 3.0 SD
1.16
1.34
1.58
1.92
Range
0.7 - 2.7
> 1

1 -4

32-42
35-43
52-76
48-59
0.79- 1.47 (10
yrs)
1.17-1.89 (3
yrs)
Location/Habitat
Minnesota/lakes
Nova Scotia/coastal
nw California/coastal, bay
Oregon/lake in 1 899 only
Florida/wetland
North Carolina/reservoir
North Carolina/lake
Atlantic Seaboard/NS
Georgia, Florida/NS
s California, n Mexico/NS
ne United States/NS
Idaho/river, lakes
NS/NS
Baja California,
Mexico/coastal islands
Massachusetts/NS
Baja California,
Mexico/coastal islands
Maryland/Cheasapeake Bay
N. Carolina/lake
S. Carolina/lake
Idaho/reservoir
e United States/coastal
Reference
Dunstan, 1973
Greene etal., 1983
Koplin, 1981
Henny, 1988a
Eichholz, 1980
Henny & Noltemeier, 1 975
Henny & Noltemeier, 1975
Judge, 1983
Judge, 1983
Judge, 1983
Spitzer, 1980
Henny et al., 1991
Poole, 1989a
Judge, 1983
Poole, 1989a
Judge, 1983
Stotts & Henny, 1 975
Whittemore, 1984
Henny & Noltemeier, 1 975
Van Daele & Van Daele, 1 982
Poole, 1984
Note
No.



8

9
9

ro

vi
o
o
C/>
•D

CD
-------
                                          Osprey (Pandion halsaetus]
Population
Dynamics
'Number
. Fledge per
Successful
Nest
Age at
Sexua!
Maturity
Annual
Mortality
Rates {percent)
Average
Longevity
Seasonal
Activity
Mating
Hatching
Migration fall
spring
Age/Sex
Cond/Seas

B
B
1 st year
years 2-18
JB
AB
if reach sex.
maturity
Begin
late April
early Dec.
early January
mid-March
late April
February .
late August
early April
early March
Mean
1.7
2.14
1.83
1.79
2.05
3yrs
57.3
18.5 ± 1.8
41
15
4.8
Peak
May
May
early May
mid-May
September
Range

3 - 5 yrs


End
mid-June
late February
early March
late May
mid-June
late April
November
Location/Habitat
Baja California,
Mexico/coastal islands
Idaho/river
Florida/lake
Delaware/coastal bay
Montana/lake
New York,
Massachusetts/NS
-North America/NS
New York, New Jersey/NS
NS/NS
NS/NS
Location
Delaware, New Jersey
Minnesota
Florida (nonmigratory)
Baja California, Mexico
(nonmigratory}
Maryland, Virginia
New York/New England
Baja California, Mexico
(nonmigratory)
most of United States
Minnesota
North Carolina
Reference ;
Judge, 1983
Henny et a!., 1991
Collopy, 1984
Henny et al., 1977
Henny et al., 1991
Spitzer, 1980
Henny & Wight, 1 969
Henny & Wight, 1969
Spitzer, 1980
Brown & Amadon, 1 968
Reference
Bent, 1937
Dunstan, 1973
Poole, 1989a
Judge, 1983
Bent, 1937
Bent, 1937
Judge, 1983
Henny, 1986
Dunstan, 1973
Parnell & Walton, 1977
Note
No,

10


Wots
No.


11
O
w
•o

s
-------
                                                          Osprey  (Pandion hallaetus]

      1   Late nestl. indicates late nestling stage of the breeding season. Cited in Poole (1989a).
      2   Estimated using equation 3-28 (Lasiewski and Dawson, 1967) and body weights from Brown and Amadon (1968).
      3   Estimated using equation 3-37 (Nagy, 1987) and body weights from Brown and Amadon (1968).
      4   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Brown and Amadon (1968).
      5   Estimated using equation 3-19 {Lasiewski and Calder,  1971) and body weights from Brown and Amadon (1968).
      6   Estimated using equation 3-21 (Meeh, 1879 and Rubner, 1883, cited in Walsberg and King, 1978) and body weights from Brown and Amadon
          (1968).
      7   Percent wet weight of food ingested by free-flying osprey estimated by identifying species of fish captured (using binoculars), estimating the
          length of each fish captured by comparison with osprey, and using laboratory measures of weights and lengths of samples of these fish species.
      8   Second clutch produced only if first is lost.
      9   Nestlings in  migratory populations fledge at an earlier age than nestlings in nonmigratory populations, such as those in Mexico and south Florida.
     10   Cited in Henny (1988b).
     11   Cited in Henny (1986).
ro
vl
to
O
CO
•o
I
-------
References (including Appendix)

Bent, A. C. (1937) Life histories of North American birds of prey. Part 1: Order
      Falconiformes. Washington, DC: U.S. Government Printing Office; Smithsonian Inst.
      U.S. Nat. Mus.,  Bull. 167.

Brown, L.; Amadon, D. (1968) Eagles, hawks, and falcons of, the world, v. 1. New York,
      NY: McGraw-Hill.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Collopy, M. W. (1984)  Parental care, productivity, and predator-prey relationships of
      ospreys in three North Florida Lakes: preliminary report. In: Westall, M. A., ed.
      Proc. southeastern U.S. and Caribbean osprey symposium; pp. 85-98.

Cramp, S., chief ed. (1980) Handbook of the birds of Europe, the Middle East and North
      Africa: v. 2. Oxford, UK: Oxford University Press.
                                                     , 5
Dunstan, T. C. (1968) Breeding success of osprey in Minnesota from 1963-1968. Loon
      40: 109-112.

Dunstan, T. C. (1973) The biology of ospreys in Minnesota. Loon 45: 108-113.

Edwards, T.  C., Jr. (1988) Temporal variation in prey preference patterns of adult ospreys.
      Auk 105: 244-251.

Eichholz, N. F. (1980) Osprey nest concentrations in northwest Florida. Fla. Field Nat. 8:
      18-19.

Fernandez, G.; Fernandez, J. (1977) Some instant benefits and long range hopes of color
      banding ospreys. Transactions of the  North American osprey research conference.
      U.S. Natl. Park Serv. Trans. Proc. Ser. 2.

French, J. M. (1972)  Distribution, abundance, and breeding status of ospreys in
      northwestern California [master's thesis]. Arcata,  CA: Humboldt State University.

French, J. M.; Koplin, J. R. (1977) Distribution, abundance, and breeding status of ospreys
      in northwestern  California. Transactions of the North American osprey research
      conference. U.S. Natl. Park Serv. Trans. Proc. Ser. 2: 223-240.

Garber, D. P. (1972) Osprey nesting ecology in Lassen and Plumas Counties, California
      [master's thesis]. Arcata, CA: Humboldt State University.
                                       2-73
Osprey
-------
 Greene, E. P.; Greene, A. E.; Freedman, B. (1983) Foraging behavior and prey selection by
       ospreys in coastal habitats in Nova Scotia, Canada. In: Bird, D. M.; Seymour, N. R.;
       Gerrard, J. M., eds. Biology and management of bald eagles and  ospreys. St. Anne
       de Bellvue, Quebec: Harpell Press; pp. 257-267.

 Grubb, T. C., Jr. (1977) Weather dependent foraging in ospreys. Auk 94: 146-149.
                             *
 Hagan, J. M. (1984) North Carolina osprey population: social group or breeding
       aggregation? In: Westall, M. A., ed. Proc. southeastern U.S. and  Caribbean osprey
       symposium.

 Henny, C. J. (1977) Research, management and status of the osprey in  North America. In:
       Chancellor, R. D., ed. Proc. world birds of prey conf. Internat. Council Bird Preserv.;
       Vienna, Austria; pp. 199-222.

 Henny, C. J. (1983) Distribution and abundance of nesting ospreys in the United States.
       In: Bird, D. M.; Seymour, N.  R.; Gerrard, J. M., eds. Biology and management of
       bald eagles and ospreys. St. Anne de Bellvue, Quebec: Harpell Press; pp. 175-186.

 Henny, C. J. (1986) Osprey (Pandion haliaetus), Section 4.3.1, US Army Corps of
       Engineers Wildlife Resources Management Manual. Prepared by U.S. Fish Wildl.
       Serv., Patuxent Wildl. Res. Center,  Corvallis, OR for US Army Engineer Waterways
       Experiment Station, Vicksburg, MS: Technical Report EL-86-5.

 Henny, C. J. (1988a) Large osprey colony discovered in Oregon. Murrelet 69: 33-36.

 Henny, C. J. (1988b) Osprey [sections]. In: Palmer, R. S., ed. Handbook of North
      American birds: v. 4. New Haven, CT: Yale University  Press.

 Henny, C. J.; Anthony, R. G. (1989) Bald eagle and osprey. Natl. Wildl.  Fed. Sci. Tech.
       Ser. No. 12: 66-82.

 Henny, C. J.; Noltemeier, A. P. (1975) Osprey nesting populations  in the coastal Carolines.
      Amer. Birds 29:  1073-1079.

 Henny, C. J.; Van Velzen, W. T. (1972) Migration patterns and wintering localities of
      American ospreys. J. Wildl. Manage. 36: 1133-1141.

 Henny, C. J.; Wight, H. M. (1969) An endangered osprey population: estimates of
      mortality and production. Auk 86: 288-198.

 Henny, C. J.; Smith, M.  M.; Stotts, V. D. (1974) The 1973 distribution and abundance of
      breeding ospreys in the Chesapeake Bay. Chesapeake Sci. 15: 125-133.

Henny, C. J.; Byrd, M. A.; Jacobs, J. A.; et al. (1977) Mid-Atlantic coast osprey
      population: present numbers, productivity, pollutant contamination, and status. J.
      Wildl. Manage. 41: 254-265.
                                       2-74
Osprey
-------
Henny, C. J.; Collins, J. A.; Deibert, W. J. (1978) Osprey distribution, abundance, and
      status in western North America. Murrlet 59: 14-25.

Henny, C. J.; BIus, L. J.; Hoffman, D. J.; et al. (1991) Lead accumulation and osprey
      production near a mining site on the Coeur d'Alene River, Idaho. Arch. Environ.
      Contam. Toxicol. 21: 415-424.

Hughes, J. (1983) On osprey habitat and productivity: a tale of two habitats. In: Bird, D.
      M.; Seymour, N. R.; Gerrard, J. M., eds. Biology and management of bald eagles
      and ospreys. St. Anne de Bellvue, Quebec: Harpell Press; pp. 269-273.

Judge, D. S. (1983) Productivity of ospreys in the gulf of California. Wilson Bull. 95:
      243-255.

Kennedy, R. S. (1973) Notes on the migration of juvenile ospreys from Maryland and
      Virginia. Bird-Banding 44: 180-186.

Koplin, J. R. (1981) Reproductive performance of ospreys (Pandion halfaetus) in
      northwestern California. Natl. Geogr. Soc. Res. Rep.  13: 337-344.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
      variables in resting birds. Resp. Phys.  11:152-166.

Lasiewski, R. C.; Dawson, W. R. (1967) A re-examination of the relation between standard
      metabolic rate and body weight in birds. Condor 69:  12-23.

Lind, G. S. (1976) Production, nest site selection, and food habits of ospreys in Deschutes
      National Forest, Oregon [master's thesis].  Corvallis, OR: Oregon State University.

MacCarter, D. S. (1972) Food habits of osprey at Flathead Lake, Montana [master's
      thesis]. Arcata, CA: Humboldt State University.

MacNamara, M. (1977) Sexing the American  osprey using secondary sexual
      characteristics. Transactions of the North American osprey research conference.
      U.S. Natl. Park Serv. Trans. Proc. Ser.  2: 43-45.

McLean, P. K. (1986) The feeding ecology of  Chesapeake Bay ospreys and the growth and
      behavior of their young [master's thesis]. Williamsburg, VA: College of William and
      Mary.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Melquist, W. E.; Johnson, D. R.; Carrier, W. D. (1978) Migration patterns of northern
      Idaho and eastern Washington ospreys. Bird-Banding 49: 234-236.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.
                                       2-75
Osprey
-------
Nesbitt, S. (1974) Foods of the osprey at Newnans Lake. Fla. Field Nat. 2: 45.

Ogden, J. C. (1977) Preliminary report on a study of Florida ospreys. In: Ogden, J. C., ed.
       Transactions of the North American osprey research conference; pp. 143-151.

Parnell, J. F.; Walton, R. (1977) Osprey reproductive success in southeastern North
       Carolina. Transactions North American osprey research conference. U.S. Natl. Park
       Serv. Trans. Proc. Ser. 2: 139-142.

Peakall, D. B. (1988) Known effects of pollutants on fish-eating birds in the Great Lakes of
       North America.  In: Toxic contamination in large lakes; v.  1; pp. 39-54.

Poole, A. F. (1982) Brood reduction in temperate and subtropical ospreys. Oecologia (Berl.)
       53: 111-119.

Poole, A. F. (1984) Reproductive limitation in coastal ospreys: an ecological and
       evolutionary perspective [Ph.D. dissertation]. Boston, MA: Boston  University.

Poole, A. F. (1983) Courtship feeding, clutch size, and egg size in ospreys: a preliminary
       report. In:  Bird,  D. M.; Seymour, N. R.; Gerrard, J. M., eds. Biology and
       management of bald eagles and ospreys. St. Anne de Bellvue, Quebec: Harpell
       Press; pp.  243-256.

Poole, A. F. (1989a) Ospreys: a natural and unnatural history. Cambridge, MA: Cambridge
       University  Press.

Poole, A. F. (1989b) Regulation of osprey Pandion haliaetus populations: the role of nest
       side availability. In: Meyburg, B.-U.; Chancellor, R. D., eds. Raptors in the modern
       world: proceedings of the 3rd world conference on birds of prey and owls; 22-27
       March 1987; Eilat, Israel. Berlin, London, Paris: World Working Group on Birds of
       Prey and Owls;  pp. 227-234.

Prevost, Y. A. (1977) Feeding ecology of ospreys in Antigonish County, Nova Scotia
       [master's thesis]. Montreal, Quebec: MacDonald College of McGill  University.

Prevost, Y. A. (1982) The wintering ecology of ospreys in Senegambia [Ph.D.
       dissertation]. Edinburgh,  Scotland: University of Edinburgh.

Prevost, Y. A.;  Bancroft, R. P.; Seymour, N. R. (1978) Status of the osprey in Antigonish
       County,  Nova Scotia. Can.  Field-Nat. 92: 294-297.

Reese, J. G. (1977) Reproductive success of ospreys in central Chesapeake Bay. Auk 94:
       202-221.

Robbins, C. S.;  Bruun,  B.; Zim, H. S. (1983) A guide to field identification: birds of  North
       America. New York, NY: Golden Press.
                                        2-76
Osprey
-------
Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol. 19: 535-562.

Spitzer, P. (1980) Dynamics of a discrete coastal breeding population of ospreys in the
       northeastern U.S. during  a period of decline and recovery, 1969-1979 [Ph.D.
       dissertation]. Ithaca, NY: Cornell University.

Spitzer, P. R.; Risebrough, R. W.; Walker, W. I.; et al. (1978) Productivity of ospreys in
       Connecticut - Long  Island increases as DDE  residues decline. Science 202:
       333-335.

Stinson, C. H. (1977) Familial longevity in ospreys. Bird-Banding 48: 72-73.

Stocek, R. F.; Pearce, P. A. (1983) Distribution and reproductive success of ospreys in
       New Brunswick, 1974-1980. In: Bird, D. M.; Seymour, N. R.; Gerrard, J. M., eds.
       Biology and management of bald eagles and ospreys. St. Anne de Bellvue, Quebec:
       Harpell Press; pp. 215-221.

Stotts, V. D.; Henny, C. J. (1975) The age at first flight for young American ospreys.
       Wilson Bull. 87:  277-278.

Swenson, J. E.  (1978) Prey and foraging behavior of ospreys on Yellowstone Lake,
       Wyoming. J. Wildl.  Manage. 42: 87-90.

Swenson, J. E.  (1979) Factors affecting status and reproduction of ospreys in Yellowstone
       National  Park. J. Wildl. Manage.  43: 595-601.

Szaro, R. C.  (1978) Reproductive success and foraging behavior of the osprey at Seahorse
       Key, Florida. Wilson Bull. 90: 112-118.

Ueoka, M. L.  (1974) Feeding behavior of ospreys at Humboldt Bay, California [master's
       thesis]. Arcata, CA: Humboldt State University.

Van Daele, L. J.; Van Daele, H. A. (1982) Factors affecting the productivity of ospreys
       nesting in west-central Idaho. Condor 84: 292-299.

Walsberg, G.  E.; King, J. R. (1978) The relationship of the external surface area of birds  to
       skin surface area and body mass. J. Exp. Biol. 76: 185-189.

Whittemore, R.  E. (1984) Historical overview of osprey at the Mattamuskeet National
       Wildlife Refuge: results from ten  years of nest and productivity surveys. In: Westall,
       M. A., ed. Proceedings of the Southeastern U.S. and Caribbean Osprey Symposium;
       pp. 17-41.

Wilcox (1944) (cited in  Henny, 1988b) Univ. of State of N.Y. Bull, to the Schools 30:262-
       264.
                                       2-77
Osprey
-------
-------
2.1.6.  Red-Tailed Hawk (buteo hawks)

       Order Falconiformes, Family Accipitridae. The family Accipitridae includes most
birds of prey except falcons, owls, and American vultures.  Buteo hawks are covered in
this section.b  Buteo hawks are moderately large soaring hawks that inhabit open or semi-
open areas. They are the most common daytime avian predators on ground-dwelling
vertebrates, particularly rodents and other small mammals.  They range in size from the
broad winged hawk (41 cm bill tip to tail tip) to the ferruginous hawk (58 cm).  Hawks
egest pellets that contain undigestible parts of their prey, such as hair and feathers, that
can be useful in identifying the types of prey eaten (bones usually are digested completely;
Duke etal., 1987).

Selected species

       The red-tailed hawk (Buteo jamaicensis) is the most common Buteo species in the
United States (National Geographic Society, 1987).  Breeding populations are distributed
throughout most wooded and semiwooded regions of the United  States and Canada south
of the tundra (Adamcik et al., 1979), although some populations  are found in deserts and
prairie  habitats. Six subspecies are recognized  (Brown and Amadon, 1968). Nesting
primarily in woodlands, red-tails feed in open country on a wide variety of small- to
medium-sized prey.

       Body size.  Males of this medium-sized buteo (46 cm) weigh about 1  kg, and
females are approximately 20 percent heavier than the males (see table). Otherwise, the
sexes look  alike (Brown and Amadon, 1968).

       Habitat. Red-tails are found in habitats ranging from woodlands, wetlands, .
pastures, and prairies to deserts (Bohm 1978b; Gates, 1972; MacLaren et al.,  1988;
Mader, 1978). They appear to prefer a mixed  landscape containing old fields, wetlands,
and pastures for foraging interspersed with groves of woodlands  and  bluffs, and streamside
trees for perching and nesting (Brown and Amadon,  1968; Preston, 1990).  Red-tails build
their nests  close to the tops of trees in low-density forests and often in trees that are on a
slope (Bednarz and Dinsmore, 1982). In  areas where trees are scarce, nests are built on
other structures, occasionally in cactus (Mader, 1978), on rock pinnacles or ledges, or
man-made structures (Brown and Amadon, 1968; MacLaren et al., 1988).  In winter, night
roosts  usually are in thick conifers if available and in other types of trees otherwise (Brown
and Amadon, 1968).

       Food habits.  Red-tails  hunt primarily from an elevated perch, often near woodland
edges (Bohm, 1978a; Janes, 1984; Preston, 1990). Small mammals, including mice,
shrews, voles, rabbits, and squirrels, are  important prey, particularly during winter.  Red-
tails also eat a wide variety  of foods depending on availability, including birds, lizards,
snakes, and large insects (Bent, 1937; Craighead and Craighead,  1956; Fitch et al., 1946).
In general,  red-tails are opportunistic and will feed on whatever species are most abundant
bOther members of the family Accipitridae, eagles and the osprey, are covered in Sections 2.1.7
 and 2.1.5, respectively.

                                       2-79                        Red-Tailed Hawk
-------
(Brown and Amadon, 1968).  Winter food choices vary with snow cover; when small
mammals such as voles become unavailable (under the snow), red-tails may concentrate
on larger prey, such as pheasants (Gates, 1972).
           •
       Molt.  Juveniles molt into adult plumage in a gradual process from the spring (age
about  14 months) to summer or early fall (Bent, 1937).

       Migration. The more northerly red-tailed hawk populations are migratory while the
more southerly are year-round residents (Bent, 1937).

       Breeding activities and social organization.  Red-tails lay one clutch per year
consisting of one to three eggs, although a replacement clutch is possible if the initial
clutch  is lost early in the breeding season (Bent, 1937). Their nests are large and built of
twigs (Bohm, 1978b). Both sexes incubate, but the male provides food for the female
during  incubation and the entire family following hatching (Brown and Amadon, 1968).
The  parents continue  to feed their young after fledging while they are learning to hunt
(Brown and Amadon,  1968).

       Home range and resources.  Red-tailed hawks are territorial throughout the year,
including winter (Brown and Amadon, 1968).  Trees or other sites for nesting  and perching
are important requirements for breeding territories and can determine which habitats are
used in a particular area (Preston, 1990; Rothfels and Lein, 1983). Home range size can
vary from a few hundred hectares to over 1,500 hectares, depending on the habitat
(Andersen and Rongstad, 1989; Petersen, 1979).  In a 10-year study in Oregon, Janes
(1984) found that the size of  red-tail territories and the location of boundaries between
territories varied little  from year to year, even though individual birds or pairs died and
were replaced.

       Population density. Population densities generally do not exceed 0.03 pairs per
hectare, and  usually are lower than 0.005 pairs per hectare (see Appendix). Populations in
southern areas such as Florida can increase substantially in the winter with the influx of
migrants from the more northerly populations (Bohall and Collopy, 1984).

       Population dynamics. Beginning at 2 years of age, most red-tailed hawks attempt
to breed, although the proportion breeding can vary by population and environmental
conditions (Henny and Wight, 1970,  1972). Average clutch size varies regionally, tending
to increase from east to west and from south to north (Henny and Wight, 1970, 1972).  In
a 10-year study of red-tails in Alberta, Canada, Aclamcik et al. (1979) found that the
breeding population of adults remained stable despite strong cyclical fluctuations in the
density of their main prey, the snowshoe hare, over the years. The mean clutch size for
the red-tail population, however, appeared to vary with prey density, from 1.7 to 2.6
eggs/nest  (Adamcik et al., 1979). Over the course of the study, about  50 percent of
observed nestling losses occurred within 3 to 4 weeks after hatching due to starvation.
Most of the variance in yearly mortality of nestlings could be attributed  to the amount of
food supplied and the frequency of rain.  Large raptors such as horned owls also can be
important sources of mortality for red-tail nestlings in some areas {Adamcik et al.,  1979).
                                       2-80
Red-Tailed Hawk
-------
Similar species (from general references)

      •      The ferruginous hawk (Buteo regalis), one of the larger buteos (58 cm),
             inhabits the dry open country of the western United States.

      •      The red-shouldered hawk (Buteo lineatus) is slightly smaller (53 cm) and
             feeds on snakes, frogs, crayfish, mice, and some small birds.  Its range is
             east of the Rocky Mountains and in California, with moist mixed woodlands
             preferred.

      •      Swainson's hawk (Buteo swainsoni) is restricted to the open plains of the
             western United States.  Although it is as large (53 cm) as the red-tail, it
             preys mostly on insects.

      •      The broad-winged hawk (Buteo platypterus) is one of the smaller buteos (41
             cm) and preys on mice, frogs, snakes, and insects. It prefers woodlands and
             is found almost exclusively east of the Mississippi River.

      •      Harris'  hawk (Parabuteo unicinctus) is similar in  size (53 cm) to the red-tailed
             hawk but is restricted to the semiarid wood and brushlands of the
             southwest.  This bird nests in saguaro, mesquite, and yucca arid preys on
             rodents, lizards, and small birds.

      •      The rough-legged hawk (Buteo lagopus) is one of the larger
             buteos (56 cm).  It winters throughout most of the United
             States in open country but breeds only  in the  high arctic of
             North America.

      •      The zone-tailed hawk (Buteo albonotatus) is slightly smaller
             (51  cm) than most  buteos and feeds on rodents, lizards, fish,
             frogs, and small birds.  It can be found  in mesa and mountain
             country within its limited range between the southwest United
             States and Mexico.

      •      The short-tailed hawk (Buteo brachyurus) is the  smallest buteo
             (39  cm) and can  only be found in the southern tip of Florida in
             mixed woodland  and grassland habitats.

General references

      Brown and Amadon (1968); Craighead and Craighead (1956); Fitch et al. (1946);
National Geographic Society (1987).
                                       2-81
Red-Tailed Hawk
-------
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                                     Red-Tailed Hawk (Buteo jamaicensis]
Dietary
Composition
summary of 1 0 years:
srrawshoe tiare
Richard's ground
$quirret
Franklin's ground j
squirref ;
voles & mice
other mamraafs
waterfowl , \
ruffed grouse ;
sharp-tailed grouse
other grouse ;
other birds
{mammals)
Beiding's ground
squirrel
mtn cottontail
pocket gopher '••
Townsertd's ground
squirrel ;
(birds) ' ;
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western meadowlark
(snakes)
gopher $nake
ground squirrel
rabbit -
pocket gopher
other mammals
gopher snake
wniptatl fizard
birds

Spring













(78.5)

52.8
13.1
7.3

2.9
(8.5)
3.5
1.8
(13.1)
6.1








Summer
mean ± SD
25.6 ± 19

30.4 ± 10

5.1 ± 2
4.8 ± 2
7.8 ± 6
16.2 ± 10
2.0 ± 2
1.2 ± 1
0.9 ± 1
6.3 ± 3












60.8
26.5
4.3
2.6
3.8
0.3
1.3

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brought to nests; March to
June)






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Reference
Adarricik et al., 1979












Janes, 1 984











Fitch et al., 1 946






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                                    2-84
Red-Tailed Hawk
-------
                                     Red-Tailed Hawk (Buteo jamaicensis]
Population
, Dynamics
Growth Rate
Age at
Fledging
Number Fledge
per Active
Nest
Number
Fledge per
Successful
Nest
Age at
Sexual ;
Maturity
Annual
Mortality
Rates {percent)
Longevity
Seasonal
Activity
Mating
Age/Sex
Cond./Seas,
to 1 week
1 to 2 weeks
2 to 3 weeks
3 to 4 weeks
4 to 5 weeks

high prey
low prey

B
J B 1 st year
AB
J B 1 st year
AB

Begin
mid-February
mid-April
late March
Mean
20 g/day
34 g/day
39 g/day
26 g/day
1 0 g/day
45 to 46 days
1.47 ± 0.25 SE
1.15
1.9
1 .2
2.12
1.85
2 years
62.4
20.6 ± 1.3SE
66.0
23.9 ± 2.2 SE

Peak ' '
early May
Range


0.28-1.90/
10yrs



maximum 1 8 yrs
End
early April
mid-May
early April
Location/Habitat
Ohio/free-living, habitat NS
California/foothills
Oregon/pasture
Alberta, Canada/farm,
woodlands
Idaho/canyon, shrub steppe
north of 42 °N latitude/
North America
south of 42 °N latitude/
North America
throughout range
north of 42 °N latitude/
North America
south of 42 °N latitude/
North America
North America/NS
Location
Arizona
Alberta Canada
south Michigan
Reference
Springer and Osborne, 1983
Fitch et al., 1 946
Janes, 1984
Adamcik et al., 1979
Steenhof & Kochert, 1 985
Henny & Wight, 1970
Henny & Wight, 1970
Henny & Wight, 1 970
Henny & Wight, 1970, 1972
Henny & Wight, 1970, 1972
Henny & Wight, 1970, 1972
Reference
Mader, 1978
Luttich etal., 1971
Craighead & Craighead, 1 956
Note
No*
11


12
12

13
13

Note
No.

Ni
I
CO
OI
33
CD
D.
c
Q.

I
CD
-------
                                                    Red-Tailed Hawk (Buteo jamaicensis]
Seasonal
Activity
Hatchfng
Fall Migration
Spring
Migration
Begin
late March
mid-May
late April

late February
mid-March
early April
Peak
early June

early March
Enrf
early May
mid-June
early May
mid-October
late October
late November

Location
Arizona
Alberta, Canada
south Michigan
Montana, Alberta, Canada
North Dakota
Minnesota
south Michigan
Maine, Montana
Alberta, Canada
Reference
Mader, 1978
Luttich etal., 1971
Craighead & Craighead, 1956
Bent, 1937; Luttich et al.,
1971
Bent, 1937
Bent, 1937
Craighead & Craighead, 1 956
Bent, 1937
Luttich etal., 1971
Note
No.

14
15
ro
CO
o>
CD
Q.
CD
Q.
I
Q)
 1   Estimated from data provided by authors.
 2   Estimated using equation 3-28 (Lasiewski and Dawson,  1967) and body weights from Craighead and Craighead (1956).
 3   Estimated from time and energy budgets for breeding season only.
 4   Estimated using equation 3-37 (Nagy, 1987) and body weights from Craighead and Craighead (1956).
 5   Hawks maintained outdoors using falconer's techniques; fed lean raw beef supplemented with natural prey.  Overall activity levels not described.
     Winter temperatures averaged 3 to 5°C and summer temperatures averaged-15°C during trials.  Females weighed  1,218 g; males in winter
     weighed 1,147 g; males in summer weighed 855 g.
 6   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Craighead and  Craighead (1956).
 7   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Craighead and Craighead (1956).
 8   Estimated using equation 3-21 (Meeh, 1879 and Rubner, 1883, as cited in Walsberg and King, 1978) and body weights from Craighead and .
     Craighead (1956).
 9   Percent biomass (wet weight) estimated from observations of prey brought to the nest (identified to species) and remains of prey found at the
     nests, using standard wet weights for each species of prey from other studies or measured in the lab.
10   Home range determined by 95 percent ellipse method; radio-tagged hawks, two of each sex.
11   Estimated from figure.
12   Summarizing data from several studies.
13   Summarizing banding recoveries prior to 1951.
14   Late departure  dates.
15   Early arrival dates.
-------
References (including Appendix)

Adamcik, R. S.; Tood, A. W.; Keith, L. B. (1979) Demographic and dietary responses of
      red-tailed hawks during a snowshoe hare fluctuation. Can. Field-Nat.  93: 16-27.

Andersen, D. E.; Rongstad, O. J. (1989) Home-range estimates of red-tailed hawks based
      on random  and systematic relocations. J. Wildl. Manage. 53: 802-807.

Baker, J. A.; Brooks, R. J. (1981) Distribution patterns of raptors in relation  to density of
      meadow voles. Condor 83: 42-47.                              ,

Bednarz, J. C.; Dinsmore, J. J. (1982) Nest-sites and habitat of red-shouldered and
      red-tailed hawks in Iowa. Wilson Bull. 94: 31-45.

Bent, A. C. (1937) Life histories of North American birds of prey. Part 1: Order
      falconiformes. Washington, DC: U.S. Government Printing Office; Smithsonian Inst.
      U.S. Nat. Mus., Bull.  167.

Bohall, P. G.; Collopy, M. W. (1984) Seasonal abundance, habitat use, and perch sites of
      four raptor  species in north-central Florida. J. Field Ornithol. 55: 181-189.

Bohm, R. T. (1978a) Observation of nest decoration and food habits of red-tailed hawks.
      Loon 50: 6-8.

Bohm, R. T. (1978b) A study of nesting red-tailed hawks in central Minnesota. Loon 50:
      129-137.

Bosakowski, T.; Smith, D. G. (1992) Comparative diets of sympatric nesting raptors in the
      eastern deciduous forest biome. Can. J. Zool 70: 984-992.

Brown, L.; Amadon, D. (1968) Eagles, hawks, and falcons of the world: v. 1. New York,
      NY:  McGraw-Hill.

Calder, W. A.; Braun, E.  J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Craighead, J. J.; Craighead, F. C. (1956) Hawks, owls  and wildlife. Harrisburg, PA: The
      Stackpole Co. and Washington, DC: Wildl. Manage. Inst.

Duke, G. E.; Evanson, O. A.; Jegers, A. A. (1976) Meal to pellet intervals in  14 species of
      captive raptors. Comp. Biochem. Physiol. 53A: 1-6.

Duke, G. E.; Mauro, L.; Bird, D. M. (1987) Physiology. In: Pendleton, B. A.; Millsap, B. A.;
      Cline, K.  W.; et al., eds. Raptor management techniques manual. Washington, DC:
      Institute for Wildlife Research, National Wildlife Federation;  Sci. Tech. Ser. No. 10;
      pp. 262-267.                               V
                                      2-87'
Red-Tailed Hawk
-------
 Fitch, H. S.; Swenson, F.; Tillotson, D. F. (1946) Behavior and food habits of the red-tailed
       hawk. Condor 48: 205-237.

 Gates, J. M. (1972) Red-tailed hawk populations and ecology in east-central Wisconsin.
       Wilson Bull. 84: 421-433.

 Gatz, T. A.; Hegdal, P. L. (1987) Local winter movements of four raptor species in central
       Colorado. West. Birds 17: 107-114.

 Hagar, D. C., Jr. (1957) Nesting populations of red-tailed hawks and horned owls in
       central New York state. Wilson Bull. 69: 263-272.

 Hardy, R. (1939) Nesting habits  of the western red-tailed hawk. Condor 41: 79-80.

 Henny, C. J.; Wight, H. M. (1970) Population ecology and environmental pollution:
       red-tailed and Cooper's hawks. Symposium: Population ecology of migratory birds;
       Patuxent Wildlife Research Center; pp. 229-249.

 Henny, C. J.; Wight, H. M. (1972) Population ecology and environmental pollution:
       red-tailed and Cooper's hawks. U.S. Bur. Sport Fish. Wildl., Wildl. Res.  Rep. 2:
       229-250.

 Janes, S. W. (1984) Influences of territory composition and interspecific competition on
       red-tailed hawk reproductive success. Ecology 65: 862-870.

 Johnson, S. J. (1975) Productivity of the red-tailed hawk in southwestern Montana. Auk
       92: 732-736.

 Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
       variables in resting birds.  Resp. Phys. 11: 152-166.

 Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation between standard
       metabolic rate and body weight in birds. Condor 69: 12-23.

 Luttich, S. N.; Keith, L. B.; Stephenson, J. D. (1971) Population dynamics of the red-tailed
       hawk (Buteo jamaicensis)  at Rochester, Alberta. Auk 88: 75-87.

MacLaren, P. A.; Anderson, S. H.; Runde, D. E. (1988) Food habits and nest
       characteristics of breeding raptors in southwestern Wyoming. Great Basin Nat. 48:
       548-553.

Mader, W. J. (1978) A comparative nesting study of red-tailed hawks and Harris' hawks in
      southern Arizona. Auk 95: 327-337!

McGovern,  M.; McNurney, J. M.  (1986) Densities  of red-tailed hawk nests in aspen stands
      in the Piceance Basin,  Colorado.  Raptor Res. 20: 43-45.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

                                       2-88                        Red-Tailed Hawk
-------
Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987) Field guide to the birds of North America.
      Washington, DC: National Geographic Society.

Nice, M. M. (1954) Problems of incubation periods in North American birds. Condor 56:
      173-197.

Orians,  G.; Kuhlman, J. (1956) The red-tailed hawk and great horned owl populations in
      Wisconsin. Condor 58: 371-385.

Pakpahan, A. M.; Haufler, J.  B.; Prince, H. H. (1989) Metabolic rates of red-tailed hawks
      and great horned owls. Condor 91: 1000-1002.

Petersen, L. (1979) Ecology of great horned owls and red-tailed hawks in southeastern
      Wisconsin. Wise. Dept. Nat. Resour. Tech. Bull. No. 111.

Poole, E. L. (1938) Weights and wing areas in North American birds. Auk 55: 511-517.

Preston, C. R. (1990) Distribution of raptor foraging in relation to prey biomass and habitat
      structure. Condor 92:  107-112.

Rothfels, M.; Lein, M. R. (1983) Territoriality in sympatric populations of red-tailed and
      Swainson's hawks. Can. J. Zool. 61: 60-64.

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
      Biol. 19: 535-562.

Smith, D. G.; Murphy, J. R. (1973) Breeding ecology of raptors in the eastern Great Basin
      of Utah.  Brigham Young Univ. Sci. Bull., Biol. Ser. 18: 1-76.

Soltz, R. L. (1984) Time and energy budgets of the red-tailed hawk (Buteo jamaicensis) in
      southern California. Southwest Nat. 29: 149-156.

Springer, M. A.; Kirkley, J. S. (1978) Inter- and intraspecific interactions between
      red-tailed hawks and great horned owls in central Ohio. Ohio J. Sci. 78: 323-328.

Springer, M. A.; Osborne, D.  R. (1983) Analysis of growth  of the red-tailed hawk (Buteo
      jamaicensis). Ohio J. Sci 83: 13-19.

Steenhof, K. (1983)  Prey weights for computing percent biomass in raptor diets.  Raptor
      Res. 17: 15-27.

Steenhof, K. (1987) Assessing raptor reproductive success and productivity. In: Giron
      Pendleton, B. A.; Millsap, B. A.; Cline, K. W., et al., eds. Raptor management
      techniques manual. Washington, DC: National Wildlife Federation; pp. 157-170.
                                       2-89
Red-Tailed Hawk
-------
Steenhof, K.; Kochert, M. N. (1985) Dietary shifts of sympatric buteos during a prey
      decline. Oecologia 66: 6-16.

U. S. Department of Interior. (1979) Snake River birds of prey special research report.
      Boise, ID: Bureau of Land Management.

Walsberg, G. E.; King, J. R. (1978) The relationship of the external surface area of birds to
      skin surface area and body mass. J. Exp. Biol. 76: 185-189.
                                       2-90
Red-Tailed Hawk
-------
2.1.7.  Bald Eagle (eagles)

       Order Falconiformes. Family Accioitridae. Eagles have long rounded wings, large
hooked bills, sharp talons, and are the largest birds of prey in the United States. They
swoop down on their prey at high speeds, and their diet varies by species and considerably
by habitat.  In most species, the male is smaller than the female, but otherwise the sexes
are similar in appearance.  This family also includes kites and  hawks.

Selected species

       The bald eagle (Haliaeetus leucocephalus), our national symbol, is a federally
designated endangered species. Relatively common in Alaska, populations in- the lower 48
States have been seriously diminished, although they are recovering in some areas. Bald
eagles are most commonly sighted  in coastal areas or near rivers or lakes.  Bald eagles are
primarily carrion feeders.

       Body size.  Females are significantly larger than males, but otherwise the sexes look
alike (Brown and Amadon, 1968).  Body size increases with latitude and is the sole basis
by which the northern and southern subspecies are divided (Snow,  1973). Length from
bill tip to tail tip averages 81 cm in  the more northerly populations.

       Habitat. Bald eagles generally are restricted to coastal areas, lakes, and rivers
(Brown and Amadon, 1968), although some may winter in areas not associated with water
(Platt, 1976).  Preferred breeding sites include proximity to large bodies of open water and
large nest trees with sturdy branches (often conifers) and areas of old-growth timber with
an open and discontinuous canopy  (Andrew and Mosher, 1982; Anthony et al., 1982;
Grubb,  1980; Peterson,  1986). In an analysis of more than 200 nests, Grubb (1980)
found 55 percent within 46 m  of a  shoreline and 92 percent within  183 m of shore.
During migration and in winter, conifers often are used for communal roosting  both during
the day and at night, perhaps to minimize heat loss (Anthony  et al., 1982; Stalmaster,
1980).  Mature trees with large open crowns and stout, horizontal perching limbs are
preferred for roosting in  general (Anthony et al., 1982; Chester et al., 1990). Bald eagles
reach maximum densities in areas of minimal human activity and are almost never found in
areas of heavy human use (Peterson, 1986).

      Food habits.  Primarily carrion feeders, bald eagles eat  dead or dying fish when
available but also  will catch live fish swimming near the surface or fish in shallow waters
(Brown and Amadon, 1968). In general, bald eagles can be described as opportunistic
feeders, taking advantage of whatever food source is most plentiful and easy to scavenge
or to capture, including  birds and mammals (Brown and Amadon, 1968; Green, 1985;
Watson et al., 1991). In many areas, especially in winter, waterfowl, killed or injured  by
hunters, and shore birds are an important food source (Todd et al.,  1982).  Eagles forage
in upland areas in the winter when surface waters are frozen over, consuming carrion
including rabbits, squirrels, and dead domestic livestock such as pigs and chickens (Brown
and Amadon, 1968; Harper et al., 1988). Bald eagles also have been known to steal food
from other members of their own species as well as from hawks, osprey, gulls, and
mergansers {Grubb, 1971; Jorde and Lingle, 1988; Sobkowiak and  Titman, 1989). This
                                       2-91
Bald Eagle
-------
may occur when there is a shortage of a primary food source, such as fish, and an
abundance of other prey such as waterfowl being used by other predatory birds (Jorde and
Lingle, 1988). Some prey are important to a few populations; for example, in the
Chesapeake Bay region, turtles are consumed during the breeding season (Clark, 1982),
and at Amchitka Island in Alaska, sea otter pups are found regularly in bald eagle nests
(Sherrod et al., 1975). In the Pacific Northwest during the breeding season, Watson et al.
(1991) found that bald eagles hunted live prey 57 percent of the time, scavenged for 24
percent of their prey, and pirated 19 percent (mostly from gulls  or other eagles).  Because
bald eagles scavenge dead or dying prey, they are particularly vulnerable to environmental
contaminants and pesticides (e.g., from feeding  on birds that died from pesticides,
consuming lead shot from waterfowl killed or disabled by hunters) (Henny and Anthony,
1989; Harper et al., 1988; Lingle and Krapu, 1988). Bald eagles also are vulnerable to
biomagnification of contaminants in food chains. For example,  near Lake Superior (Wl),
herring gulls, which were consumed by over 20  percent of nesting bald eagle pairs, were
found to be a significant source of DDE and PCB intake by the eagles (Kozie and Anderson,
1991).  The gulls contained higher contaminant  levels than the  local fish because of their
higher trophic level.

       Molt.  Adult eagles molt yearly.  In northern populations, molting occurs from late
spring to early fall; in southern populations,  molting may be initiated earlier (McCollough,
1989).  It is likely that the molt is not complete, and that some  feathers are retained for 2
years. Young bald eagles generally molt into their adult plumage by their fifth year
(McCollough, 1989).

      Migration.  Bald eagles migrate out of areas where lakes  are completely frozen over
in winter, but will remain as far north as the availability of open water and a reliable food
supply allow (Brown and Amadon, 1968). Areas with ice-free waterways, such as the
Columbia  River estuary in Washington and Oregon, may support both resident and
migratory populations  in the winter (Watson et al., 1991). The  far northern breeding
populations migrate south for the winter and often congregate in areas  with abundant
food, particularly the Mississippi Valley and the northwestern States (Snow, 1973).  Some
populations of eagles that breed in southern latitudes (e.g., Arizona, Florida) show a
reverse migration  and  migrate north in midsummer (following breeding), returning south in
early autumn or winter (Brown and Amadon, 1968; Grubb et al., 1983).

      Breeding activities and social organization. Bald eagles have been observed to nest
successfully at 4 years of age, but most do not breed until at least their fifth year (Nye,
1983).  Breeding pairs remain together as long as both are alive (Brown and Amadon,
1968).  Large stick nests (approximately 1.5 m across and 0.6 m deep) are built near
water and most often  in a large tree, but sometimes on rocky outcrops  or even on the
ground on some islands (Brown and Amadon, 1968; Grubb,  1980).  In the absence of
disturbance, the same nest site may be used for many years (Nash et al., 1980). In
Florida, eggs are laid in late autumn or winter, while over the rest of the eagle's range,
mating and egg laying occur in spring (Brown and Amadon, 1968). Clutch sizes are larger
in the north, and both  sexes take responsibility for feeding the young (Brown and Amadon,
1968). Young fledge at about  10 to 12 weeks of age; after  leaving the nest, they are still
dependent on their parents for several weeks and often return to the nest for food (Sprunt
et al., 1973). After nesting, large groups will often  gather at sites with plentiful food
                                       2-92
Bald Eagle
-------
 resources, such as along rivers following a salmon spawn (Fitzner and Hanson, 1979;
 Keister et al., 1987; McClelland, 1973).

       Home range and resources.  During the breeding season, eagles require large areas
 in the vicinity of open water, with an adequate supply of nesting trees (Brown and
 Amadon, 1968). Distance from human disturbance is an important factor in nest site
 selection, and nests have been reported to fail as a result of disturbance (Andrew and
 Mosher, 1982). During incubation and brooding, eagles show territorial defense of an area
 around the nest site. Following fledging, there is little need for nest defense, and eagles
 are opportunistic in their search for abundant sources of prey (Mahaffy and Frenzel, 1987).
 During winter, eagles roost communally in large aggregations and share a foraging home
 range.  For example, Opp (1980) described a population of  150 eagles that fed on
 meadow voles in a 250-ha flooded field for a 4-week period. This group also established a
 communal night roost in the vicinity.

       Population density.  Because population density depends strongly on the
 configuration of the surface water bodies used for foraging, few investigators have
 published explicit density estimates on an area basis; most report breeding densities along
 a shoreline on a linear basis.  During the breeding season, 0.03 to 0.4 pairs have been
 recorded  per km shore (see table).  Eagles migrating south from their summer territories in
 Canada have aggregated in communal roosts of up to 400 eagles in a 40-ha area
 (Crenshaw and McClelland, 1989).  In the winter, communal roost sites may also contain
 large numbers of eagles. Opp (1980) described a group of  150 eagles that roosted and
 foraged together in the Klamath Basin (OR/CA), and communal night roosts of up to 300
 eagles in  Oregon in late winter.

       Population dynamics.  Not all adults in an area are part of the breeding population.
 Some pairs may establish territories and not breed, while others may not even pair. The
 percentage of adults breeding and the breeding success of those that do vary with local
 food  abundance, weather,  and habitat conditions (Hansen, 1987; Hansen and Hodges,
 1985; McAllister et al., 1986). In past years, bioaccumulation of organochlorine pollutants
 reduced the reproductive success of bald eagles.  Now, in many areas, these raptors are
 reproducing at rates similar to those prior to the widespread use of these pesticides
 (Green, 1985).  Eagles lay  one clutch per year, although replacement clutches may be laid
 upon loss of the initial one (Sherrod et al., 1987). Very little is known about mortality
 rates of bald eagles; Grier (1980) concluded from population models that adult survival is
 more important than reproductive rate to the continued success of bald eagle populations.
 In captivity, bald eagles have lived for up to  50 years (Snow, 1973), and one wild  eagle,
. banded and recaptured in Alaska, was estimated to be almost 22 years old (Cain, 1986).
 Upon loss of an initial clutch, bald eagles may lay replacement clutches if sufficient time
 remains (Sherrod et al., 1987).

 Similar species (from general references)

       •     The golden eagle (Aquila chrysaetos) is similar in size (81 cm) to the bald
             eagle, and its range encompasses all but the southeastern United States.
             Small mammals, snakes, birds, and carrion are primary prey items, and
             golden eagles prefer mountainous or hilly terrain.
                                        2-93
Bald Eagle
-------
General references

      Brown and Amadon (1968); Green (1985); Peterson (1986); Stalmaster and
Gessaman (1982, 1984).
                                    2-94
Bald Eagle
-------
                                      Bald Eagle (Haliaeetus leucocephalus}
Factors
Body Weight (g)
-




Metabolic Bate
(kcat/kg-day)

Age/Sexf
Cond./Seas,
J F summer
J M summer
AF
AM
egg
egg
at hatching
nestlings:
M 10 days
M 30 days
M 50 days
M 60 days
F 1 0 days
F 30 days
F 50 days
F 60 days
free-living
A winter
J winter
A F free-living
A M free-living
Mean
5,089
4,014
4,500
3,000
120.6 ± 8.2 SD
102.5 ± 17.9SD
91.5 ± 5.2 SD
500 (est.)
2,700 (est.)
3,600 (est.)
4,066 ±35.1 SE
500 (est.)
3,000 {est.)
4,600 (est.)
5,172 ± 46.5 SE
99
111
135
143
'Range or ;',
{95% Ci of mean)
4,359 - 5,756
3,524 - 4,568

108- 134
71 - 125

3,575 - 4,500
4,800 - 5,600

(62 - 290)
(66 - 307)
'£ocatioiii at
subspecies
Alaska
Florida
Wisconsin
Florida
Saskatchewan, Canada
Saskatchewan, Canada
Saskatchewan, Canada
Connecticut

Reference
Imler & Kalmbach, 1 955
Wiemeyer, 1991 (pers.
comm.)
Krantz et al., 1 970
Krantz et al., 1 970
Bortolotti, 1984b
Bortolotti, 1984a,b
Bortolotti, 1984a,b
Craig et al., 1988
estimated
Mote
No.
1



2
2
3
4
ro
cb
01
03
CD
m
OJ
CD
-------
                                       Bald Eagie (Haliaeetus leucocephalus}

Factors
Food Ingestion
Rate (g/g-day)







Water Ingestion
Rate (g/g-day)
Inhalation
Rate (m3/day)
Surface Area
(cm2)
Age/Sex/
Cond./Seas.
winter:
B B salmon
B B rabbit
B B duck
AB
subadult B
juvenile B
AB
juvenile B
AF
AM
AF
AM
AF
AM
Dietary
Composition
mallard
American widgeon
American coot
other birds
Chinook salmon
sucker
European cafp
other fish
unaccounted

Spring










Mean

0.092 ± 0.026 SD
0.075 ± 0.013 SD
0.065 ± 0.01 2 SD
0.12
0.10
0.091
0.12
0.14
0.035
0.037
1.43
1.19
2,970
2,530

Summer









Range or
{95% Ci of mean)
















Fall










Winter
32
9
9
3
21
4
1
, 1
20
Location or
subspecies

Utah (captive)


Washington (free-flying)


Connecticut (free-flying)








Reference

Stalmaster & Gessaman, 1982


Stalmaster & Gessaman, 1984


Craig et al., 1988

estimated

estimated

estimated
-
Location/Habitat
{measure)
Washington/river

{% biomass; prey remains
found below communal
roost)





Reference
Fitzner & Hanson, 1 979








Note
No.




5


6

7

8

9

Note
No,









to

-------
                                      Bald Eagle (Haliaeetus leucocephalus}
Dietary
Composition
brown bullhead
white sucker
chain pickerel
smallmouth bass
white perch
Other fish
black duck
other birds
mammals
(fish)
channel catfish
Sonora sucker
carp
other fish
(birds)
American coat
great blue heron "
(mammals)
desert cottontail
jackrabbit
rock squirrel
(reptiles!
pink salmon
herring
trout
other fish
other animals

Spring




























Summer
24.8
19.5
20.1
3.8
3.6
4.9
3.0
13.5
6.8
(57.6)
21.8
8.6
17.3
8.5
(14.1)
8.1
4.4
(28.1)
8.1
14.9
1.1
(0.2)
15.5
32.0
4.5
24.0
24.0

Fall




























Winter



























Location/Habitat
{measure)
Maine/inland river

(% occurrence in pellets)

samples from all seasons
except winter



central Arizona/desert
scrub, riparian

(% biomass; prey observed
brought to nest or found at
nests)







Alaska/coastal

(% frequency of occurrence;
prey observed brought to
the nest)

Reference
Toddetal., 1982


*





Haywood & Ohmart, 1986












Ofelt, 1975

»


Note
No.



























fO

CO
vl
00
ffl
m
Q>
CD
-------
                                      Bald Eagle (Haliaeetus leucocephalus}
Population
Dynamics
Territory Area
(ha)
Territory
Length (km)
Territory
Radius (km)
Winter Home
Range (ha)
Foraging
Distance JkmK
Population
Density
(pair/km
shore)


Clutch
Size
Clutches/Year
Days
Incubation
Age at
Fledging
(days)
Number
Fledge per
Active Nest


Age/Sex
Cond./Seas.
pair spring

pair
pair
pair incubat.
pair brooding
J B winter
A B winter
B B winter

summer

summer








M
F







Mean
3,494 ± 2,520 SD

3.5
15.8
0.56 ± 0.1 8 SE
0.72 ± 0.21 SE
1,830 ± 1,460SD
1,880 ± 900 SD
3 to 7

0.38


0.035
0.026
0.045
2
2.3
1
35

79.9 ± 1.08 SE
83.0 ± 0.94 SE

1.01
1.28
0.90
1.14
1.00 ± 0.06 SE

Range
1,821 -6,392

1.4-7.2
11.1 -26.6












1 -3
1 -4

34-38




0.58- 1.22/10yr
1.07- 1.58/9yr
0.76- 1.1 4/7 yr

0-3

Location/Habitat
Arizona/desert, riparian river

Washington/SJ Islands;
Grays Harbor
Minnesota/lake, woods

Missouri/lake

Connecticut/river

se Alaska/riverine

WY, ID, MT/:
Yellowstone
Continental
Snake
IMS/NS
PA, DE, MD, NJ
NS/NS
Maryland (captive)

Saskatchewan/lake


California/NS
Montana/NS
Washington/NS
Florida/NS
Alaska/IMS

Reference
Haywood & Ohmhart, 1983

Grubb, 1930

Mahaffy & Frenzel, 1 987

Griffin & Baskett, 1985

Craig et al., 1 988

Hansen, 1987

Swenson et al., 1986



Brown & Amadon, 1 968
Schmid, 1966-67
Sherrod et al., 1987
Maestrelli & Wiemeyer,
1975
Bortolotti, 1989


Henny & Anthony, 1989
Henny & Anthony, 1 989
Henny & Anthony, 1 989
McEwan & Hirth, 1 979
Sprunt et al., 1973
Note
No.





























CD

00
DO
0)
m
o>
CD
-------
                                       Bald Eagle (Haliaeetus leucocephalus}
Population
Dynamics
Number
Fledge per
Successful
Nest.
Age at
Sexual
Maturity
Annual
Mortality
(percent)
Longevity
Seasonal
Activity
Mating/Laying
Fledging
Fall Migration
Spring
Migration
Age/Sex
Cond./Seas,

B
AB
fledging to 1 yr
AB
Begin
late September
December
late October
February
early March
late March
April
early July
early October
late October
November
late March
early March
Mean
1.65 ± 0.26 SD
1.35 ± 0.11 SD
2.2
1.64
4
5.4
89.3

Peak
late December
late March
late July
late August
June
November
December/January
December
December
April
early April
Range
1.22- 1.48/6yr
1 -3
3-5

up to 50 yrs
End
November
late January
March
late April
early April
May
mid-August
mid-December
January

Location/Habitat
Arizona/desert scrub, river
Washington/San Juan Island
PA, DE, MD, NJ/NS
ID, MT, WY/river, lake
United States/NS
Alaska/Amchitka Island
captivity
Location
Florida, Texas
Arizona
se United States
MD, VA, DE
WY, MT, ID
Vancouver BC
s Louisiana
WY, MT, ID
se Alaska
Arizona
Montana
sc Oregon, n California
se Alaska
Arizona
sc Oregon,- n California
WY, MT, ID
Illinois
Reference
Grubb etal., 1983
Grubb etal., 1983
Schmid, 1966-67
Swenson etal., 1986
Nye, 1983
Sherrod etal,, 1977
Snow, 1973
Reference
Mager, 1977
Grubb etal., 1983
USFWS, 1989
LeFranc & Cline, 1 983
Swenson etal., 1986
Brown & Amadon, 1 968
Harris etal., 1987
Swenson et al., 1986
Hansen, 1987
Grubb etal., 1983
Crenshaw & McClelland,
1989
Keister et al., 1 987
Hodges etal., 1987
Grubb etal., 1983
Keister et al., 1987
Swenson et al., 1986
Sabine, 1981
Note
No,




Note
No-
10



10

-------
                                                  Bald Eagle (Haliaeetus leucocephalus]

      1   Cited in Maestrelli and Wiemeyer (1975) and Bortolotti (1984aJ; juveniles up to 3 years of age.
      2   Estimated from Figure 4.
      3   Daily energy budget for free-living eagles based on time-activity budgets and metabolic models; assuming 4.5 kg eagle.
      4   Estimated using equation 3-37 (Nagy, 1987) and body weights from Imler and Kalmbach (1955).
      5   Estimated from observed captures of preweighed salmon provided at feeding stations.  Eagle body weight assumed to be 4.5 kg. Some feeding
          may have occurred elsewhere.
      6   Estimate of food consumed based on observed feeding behaviors and an eagle body weight of 4.5 kg.
      7   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Imler and Kalmbach (1955).
      8   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Imler and Kalmbach (1955).
      9   Estimated using equation 3-21 (Meeh, 1879 and Rubner, 1883, as cited in Walsberg and King, 1978) and body weights from Imler and Kalmbach
          (1955).
     10   Cited in Green, 1985.
to

O
o
CD
9L
CL
m
Q>
CD_
CD
-------
References {including Appendix)

Andrew, J. M.; Mosher, J. A. (1982) Bald eagle nest site selection and nesting habitat in
      Maryland. J. Wild!. Manage. 46: 382-390.

Anthony, R. G.; Knight, R. L.; Allen, G. T.; et al. (1982) Habitat use by nesting and
      roosting bald eagles in the Pacific Northwest. Trans. North Am. Wildl. Nat. Resour.
      Conf. 47: 332-342.

Bortolotti, G. R. (1984a) Sexual size dimorphism and age-related size variation in bald
      eagles. J. Wildl. Manage. 48: 72-81.

Bortolotti, G. R. (1984b) Physical development of nestling bald eagles with emphasis on
      the timing of growth events. Wilson Bull. 96: 524-542.

Bortolotti, G. R. (1989) Factors influencing the growth of bald eagles in north central
      Saskatchewan. Can. J. Zool. 67: 606-611.

Brown, L.; Amadon, D. (1968) Eagles, hawks, and falcons of the world: v. 1. New York,
      NY: McGraw-Hill.

Cain, S. L.  (1986) A new longevity record for the bald  eagle. J. Field Ornithol. 57: 173.

Calder, W.  A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Chester, D. N.; Stauffer, D. F.; Smith, T. J.; et al. (1990) Habitat use by nonbreeding bald
      eagles in North Carolina. J. Wildl. Manage. 54: 223-234.

Chura, N. J.; Stewart, P. A. (1967) Care, food consumption, and behavior of bald eagles
      used in DDT tests. Wilson Bull. 79: 441-458.

Clark, W. S. (1982) Turtles as a  food source of nesting bald eagles in the Chesapeake Bay
      region. J.  Field Ornithol. 53: 49-51.

Craig, R. J.; Mitchell, E. S.; Mitchell, J. E.  (1988) Time and energy budgets of bald eagles
      wintering along the Connecticut River.  J. Field Ornithol. 59: 22-32.

Crenshaw,  J. G.; McClelland, B.  R. (1989) Bald eagle use of a communal roost. Wilson
      Bull. 101: 626-633.

Dugoni,  J. A.; Zwank, P. J.; Furman, G. C. (1986) Food of nesting bald eagles in
      Louisiana. Raptor Res. 20: 124-127.

Duke, G. E.; Evanson, O. A.; Jegers, A.. A. (1976) Meal to pellet intervals in 14 species of
      captive raptors. Comp. Biochem. Physiol. 53A: 1-6.
                                      2-101
Bald Eagle
-------
 Duke, G. E.; Mauro, L.; Bird, D. M. (1987) Physiology. In: Pendleton, B. A.; Millsap, B. A.;
       Cline, K. W.; et al., eds. Raptor management techniques manual. Washington, DC:
       Institute for Wildlife Research, National Wildlife Federation; Sci. Tech. Ser. No. 10;
       pp. 262-267.

 Dunning, J.  B., Jr. (1984) Body weights of 686 species of North American birds. Western
       Bird Banding Association, Monograph  No.  1. Cave Creek, AZ: Eldon Publishing.

 Dunstan, T. C.; Harper, J. F. (1975) Food habits of bald eagles in north-central Minnesota.
       J. Wildl. Manage.  39: 140-143.

 Dzus, E. H.; Gerrard, J. M. (1989) Interlake variations of bald eagle, Haliaeetus
       leucocephalus, populations-in north-central Saskatchewan. Can. Field-Nat. 103:
       29-33.

 Fielder, P. C. (1982) Food habits of bald eagles along the mid-Columbia River, Washington.
       Murrelet 63: 46-50.

 Fielder, P. C.; Starkey, R. G. (1980) Wintering bald eagle use along the upper Columbia
       River, Washington. In: Knight, R. L.; Allen, G. T.; Stalmaster, M. V.; et al., eds.
       Proceedings of Washington bald  eagle symposium, June; Seattle, WA. Seattle, WA:
       The Nature Conservancy; pp. 177-193.

 Fitzner, R. E.; Hanson, W. C. (1979) A congregation of wintering bald eagles. Condor 81:
       311-313.

 Fitzner, R. E.; Watson, D. G.; Rickard, W. (1980) Bald eagles of the Hanford  National
       Environmental Research Park. In:  Knight, R. L.; Allen, G. T.; Stalmaster, M. V.;
       et al., eds. Proceedings of Washington bald eagle symposium, June; Seattle, WA.
       Seattle, WA: The Nature Conservancy; pp. 207-218.

 Frenzel, R. W.; Anthony,  R. G. (1989) Relationship of diets and environmental
       contaminants in wintering bald eagles. J. Wildl. Manage. 53: 792-802.

 Gessaman, J. A.; Fuller, M. R.; Pekins, P. J.;  et al. (1991) Resting metabolic  rate of golden
       eagles, bald eagles, and barred owls with a tracking transmitter or an  equivalent
      load.  Wilson Bull. 103: 261-265.

 Green, N. (1985) The bald eagle. Audubon Wildl.  Rep.  508-531.

 Grier, J. W. (1977) Quadrant sampling of a nesting  population of bald eagles. J. Wildl.
      Manage. 41: 438-443.

Grier, J. W. (1980) Modeling approaches to bald eagle population dynamics. Wildl. Soc.
      Bull. 8: 316-322.

Grier, J. W. (1982) Ban of DDT and subsequent recovery of reproduction in bald eagles.
      Science 218: 1232-1235.
                                       2-102
Bald Eagle
-------
Griffin, C. R.; Baskett, T. S. (1985) Food availability and winter range sizes of immature
      and adult bald eagles. J. Wildl. Manage. 49: 592-594.

Grubb, T. C. (1971) Bald eagles stealing fish from common mergansers. Auk 88: 928-292.

Grubb, T. G. (1976) A survey and analysis of nesting bald eagles in western Washington
      [master's thesis]. Seattle, WA: University of Washington.

Grubb, T. G. (1980) An evaluation of bald eagle nesting in western Washington. In:
      Knight, R. L.; Allen, G. T.; Stalmaster, M. V.; et al., eds. Proceedings of
      Washington bald eagle symposium, June; Seattle,  WA. Seattle, WA: The Nature
      Conservancy; pp. 87-103.

Grubb, T. G.; Hensel, R. J. (1978) Food habits of nesting bald eagles on Kodiak Island,
      Alaska. Murrelet 59: 70-72.

Grubb, T. G.; Knight, R.  L.; Rubink, D.  M.; et al. (1983) A five year comparison of bald
      eagle productivity in Washington and Arizona. In: Bird, D. M.; Seymour, N. R.;
      Gerrard, J. M., eds. Biology and management of bald eagles and ospreys. St. Anne
      de Bellvue, Quebec: Harpell Press;  pp. 35-45.

Hansen, A. J. (1987) Regulation of bald eagle reproductive rates in southeast Alaska.
      Ecology  68: 1387-1392.

Hansen, A. J.; Hodges, J. I. (1985) High rates of non-breeding  adult bald eagles in
      southeastern Alaska. J. Wildl. Manage. 49: 454-458.

Harper; R. G.; Hopkins, D.  S.; Dunstan, T. C. (1988) Nonfish prey of wintering bald eagles
      in Illinois. Wilson Bull. 100: 688-690.

Harris, J. 0.; Zwank, P. J.; Dugoni, J. A. (1987) Habitat selection and behavior of nesting
      bald eagles in Louisiana. J. Raptor Res. 21: 27-31.

Haywood, D.  D.; Ohmart, R. D. (1983) Preliminary report on habitat utilization by two
      pairs of breeding bald eagles in Arizona.  In: Bird, D. M.; Seymour, N. R.; Gerrard, J.
      M., eds. Biology and management of bald eagles and ospreys.  St. Anne de Bellvue,
      Quebec: Harpell Press; pp. 87-94.

Haywood, D.  D.; Ohmart, R. D. (1986) Utilization of benthic-feeding fish by inland
      breeding bald eagles. Condor 88: 35-42.

Henny, C. J.; Anthony, R. G. (1989) Bald  eagle and  osprey.  Natl. Wildl. Fed.  Sci. Tech.
      Ser. No. 12: 66-82.

Hensel, R. J.; Troyer, W. A. (1964) Nesting  studies of the bald eagle in Alaska. Condor
      66: 282-286.

Herrick, F. H. (1932) Daily life of the American eagle: early phase. Auk 49: 307-323.

                                       2-103                              Bald Eagle
-------
Hodges, J. I.; King, J. G. (1979) Resurvey of the bald eagle breeding population in
       southeast Alaska. J. Wildl. Manage. 43: 219-221.

Hodges, J. I.; Boeker, E. L.; Hansen, A. J. (1987) Movements of radio-tagged bald eagles,
       Haliaeetus leucocephalus, in and from southeastern Alaska. Can. Field-Nat. 101:
       136-140.

Howard, R. P.; van Daele, L. J. (1980) An overview of the status of bald eagles in Idaho.
       In: Knight, R. L.; Allen,  G. T.; Stalmaster,  M. V.; et al., eds. Proceedings of
     . Washington bald eagle symposium, June;  Seattle, WA. Seattle, WA: The Nature
       Conservancy; pp. 23-34.

Hulce, H.  (1886) Eagles breeding in captivity. Forest and Stream 27: 327.

Hulce, H.  (1887) Eagles breeding in captivity. Forest and Stream 28: 392.

Imler, R. H.; Kalmbach, E. R. (1955) The bald eagle and its economic status. U.S. Fish
       Wildl.  Ser. Circ. 30.

Jorde, D.  G.; Lingle, G. R. (1988) Kleptoparasitism by bald eagles wintering in
       south-central Nebraska. J. Field Ornithol. 59:  183-188.

Keister, G. P., Jr.;  Anthony, R. G.; Holbo, H. R. (1985) A  model of energy consumption in
       bald eagles: an evaluation of night communal roosting. Wilson Bull. 97:  148-160.

Keister, G. P., Jr.;  Anthony, R. G.; O'Neill, E. J. (1987) Use of communal roosts and
       foraging areas by bald eagles wintering in  the Klamath Basin. J. Wildl. Manage. 51:
       415-420.

Kozie,  K. D.; Anderson, R. K. (1991) Productivity, diet, and environmental contaminants in
       bald eagles  nesting near the Wisconsin shoreline of Lake Superior. Arch. Environ.
       Contam. Toxicol. 20: 41-48.

Krantz, W. C.; Mulhern, B. M.; Bagley, G. E.; et al. (1970) Organochlorine and heavy metal
       residues in bald eagle eggs. Pestic. Monit. J. 4:  136-40.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
       variables in  resting birds. Resp. Phys. 11:  152-166.

LeFranc, M. N., Jr.; Cline, K. W. (1983) The occurrence of birds as prey at active bald
       eagle nests  in the Chesapeake Bay region. In:  Bird,  D. M.; Seymour, N. R.; Gerrard,
       J. M.,  eds. Biology and  management of bald eagles and ospreys. St. Anne de
       Bellvue, Quebec: Harpell Press; pp. 79-86.

Lingle, G.  R.;  Krapu, G. L. (1988) Ingestion of lead shot and aluminum bands by bald
       eagles during winter in Nebraska. Wilson Bull. 100: 326-327.
                                       2-104
Bald Eagle
-------
Maestrelli, J. R.; Wiemeyer, S. N. (1975) Breeding bald eagles in captivity. Wilson Bull. 87:
      45-53.

Mager, D. (1977) The life and the future of the southern bald eagle. In: Proceedings of the
      bald eagle conference on eagle movements. Apple River, IL: Eagle Valley
      Environmentalists; pp. 115-117.

Mahaffy, M. S.; Frenzel, L. D. (1987) Territorial responses of northern bald eagles near
      active nests. J. Wildl. Manage. 51: 551-554.

McAllister, K. R.; Owens, T. E.; Leschner, L.; et al. (1986) Distribution and productivity of
      nesting  bald eagles in Washington, 1981-1985.  Murrelet 67: 45-50.

McClelland, B.  R. (1973) Autumn concentrations of bald eagles in Glacier National Park.
      Condor  75:  121-123.

McCollough, M. A.'(1989) Molting sequence and aging of bald eagles. Wilson Bull. 101:
      1-10.

McEwan, L. C.; Hirth, D. H. (1979) Southern bald eagle productivity and  nest site
      selection. J. Wildl. Manage. 43: 585-594.

McEwan, L. C.; Hirth, D. H. (1980) Food habits of the bald eagle in north-central Florida.
     , Condor  82:  229-231.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Murphy, J. R. (1965) Nest site selection by the bald eagle in Yellowstone National Park.
      Proc. Utah Acad. Sci. Arts and Letters 12: 261-264.

Nagy, K. A. (1987) Field metabolic rate  and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

Nash, C.; Pruett-Jones, M.; Allen, T. G.  (1980) The San Juan Islands bald eagle nesting
      survey.  In: Knight, R. L.; Allen, G. T.; Stalmaster, M. V.; et al., eds. Proceedings of
      Washington bald eagle symposium, June; Seattle, WA. Seattle, WA: The Nature
      Conservancy; pp. 105-176.

Nicholson, D. J. (1952) Little known facts about Florida bald eagles. Florida Nat. 25:
      23-26.

Nye, P. E. (1983) A biological and economic review of the hacking process for the
      restoration of bald eagles. In: Bird, D. M.; Seymour, N. R.; Gerrard, J. M-, eds.
      Biology  and  management of bald  eagles and ospreys. St. Anne de  Bellvue, Quebec:
      Harpell Press; pp. 127-135.                                    .

Ofelt, C. H. (1975) Food habits of nesting bald eagles in southeast Alaska. Condor 77:
      337-338.
                                       2-105
Bald Eagle
-------
 Opp, R. R. (1980) Status of the bald eagle in Oregon - 1980. In: Knight, R. L.; Allen, G. T.;
       Stalmaster, M. V.; et al., eds. Proceedings of Washington bald eagle symposium,
       June; Seattle, WA. Seattle, WA: The Nature Conservancy; pp. 35-48.

 Peterson, A. (1986) Habitat suitability index models: bald eagle (breeding season). U.S.
       Fish Wildl. Serv. Biol. Rep. 82(10.126); 25  pp.

 Platt, J. B. (1976) Bald eagles wintering in Utah desert. American Birds 30: 783-788.

 Ricklefs, R.  E. (1973) Fecundity, mortality and avian demography. In: Farner, D. S., ed.
       Breeding biology of birds. Washington, DC:  National Academy of Sciences.

 Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- urid Kraftweschsel. Z.
       Biol.  19: 535-562.

 Sabine, N. (1981) Ecology of  bald eagles wintering in  southern Illinois [master's thesis]
       (abstract). Carbondale, IL: Southern Illinois University. •

 Schmid, F. C.  (1966-67) Numbers of eggs and young  of bald eagles in four middle Atlantic
       states.  Cassinia 50:  15-17.

 Sherrod, S. K.; Estes, J. A.; White, C.  M. (1975) Depredation of sea otter pups by bald
       eagles at Amchitka Island, Alaska. J. Mammal. 56: 701-703.

 Sherrod, S. K.; White, C. M.;  Williamson, F. S. (1977) Biology of the bald eagle on
       Amchitka Island, Alaska. Living Bird 15:  143-182.

 Sherrod, S. K.; Jenkins, M. A.; McKee, G.; et al. (1987) Using wild eggs for production of
       bald eagles for reintroduction into the  southeastern United States. In: Odom, R.  R.;
       Riddleberger, K. A.; Ozier, J. C., eds. Proceedings of the third southeastern
       nongame and endangered wildlife symposium; August; Athens, GA. Atlanta, GA:
       Georgia Dept. of Natural Resources; pp. 14-20.

 Snow, C. (1973)  Habitat management series for endangered species report number 5:
       southern bald eagle Haliaeetus leucocephalus leucocephalus and  northern bald eagle
       Haliaeetus feucocepha/us alascansus. Denver, CO: Bureau of Land Management;
       BLM-YA-PT-81-019-6601.

Snyder, N. F.;  Wiley, J. W.  (1976) Sexual size dimorphism in hawks and owls of North
       America. Ornithol. Monogr. 20.

Sobkowiak,  S.; Titman, R.  D.  (1989) Bald eagles killing American coots  and stealing coot
       carcasses from greater black-backed gulls. Wilson Bull. 101: 494-496.

Sprunt, A., VI; Robertson, W. B., Jr.; Postupalsky,  S.; et al. (1973) Comparative
       productivity of six bald eagle populations. Trans. North Am. Wildl. Nat. Resour.
       Conf. 38: 96-106.
                                       2-106
Bald Eagle
-------
Stalmaster, M. V. (1980) Management strategies for wintering bald eagles in the Pacific
      Northwest. In: Knight, R. L; Allen, G. T.; Stalmaster, M. V.; et al., eds.
      Proceedings of Washington bald eagle symposium, June; Seattle, WA. Seattle, WA:
      The Nature Conservancy; pp. 49-67.

Stalmaster, M. V.; Gessaman, J. A. (1982) Food consumption and energy requirements of
      captive bald eagles. J. Wildl. Manage. 46: 646-654.

Stalmaster, M. V.; Gessaman, J. A. (1984) Ecological energetics and foraging behavior of
      overwintering  bald eagles. Ecol. Monogr. 54: 407-428.

Sticket, L. F.; Chura,  N. J.; Stewart, P. A.; et al. (1966) Bald eagle pesticide relations.
      Trans. North Am. Wildl. Natur. Resour. Conf. 21:  190-200.

Swenson, J. E. (1975) Ecology of the bald eagle and osprey in Yellowstone National Park
      [master's thesis]. Bozeman, MT: Montana State University.

Swenson, J. E.; Alt, K.  L.; Eng, R. L. (1986) Ecology of bald eagles in the Greater
      Yellowstone ecosystem. Wildl. Monogr. 95: 1-46.

Todd, C.  S.; Young, L. S.; Owen, R. B., Jr.; et al.  (1982) Food habits of bald eagles in
      Maine. J. Wildl. Manage. 46: 636-645.

United States Fish and Wildlife Service (USFWS). (1989) Recovery plan:
      southeastern states bald eagle. Atlanta, GA: U.S.  Fish and Wildlife Service,
      Southeast Region.

Vermeer, K.; Morgan, K. H. (1989)  Nesting population, nest sites, and prey remains of
      bald eagles in  Barkley Sound, British Columbia. Northwest. Nat. 70: 21-26.

Walsberg, G. E.; King, J. R. (1978)  The relationship of the external surface area of birds to
      skin surface area and body mass. J. Exp. Biol. 76: 185-189.

Watson, J. W.; Garrett, M. G.; Anthony,  R. G.  (1991) Foraging ecology of bald eagles in
      the Columbia River estuary. J. Wildl. Manage. 55: 492-499.

Weaver, J. (1980) Habitat management program: threatened and endangered plants and
      animals. U.S. Forest Serv., Bridger-Teton Nat. Forest, Jackson Hole,  WY; 111  pp.
                                      2-107
Bald Eagle
-------
-------
2.1.8.  American Kestrel (falcons)

       Order Falcon/formes, Family Falconidae.  Falcons are the more streamlined of the
raptor species, with long pointed wings bent back at the wrists and large tails that taper at
the tips.  They consume many kinds of animals including insects, reptiles, small mammals,
and birds; Falcons are found in  a variety of habitats, from cities to the most remote areas.
Strong fliers that achieve high speeds, falcons range in size from the American kestrel (27
cm bill tip to tail tip) to the peregrine falcon (41 to 51  cm).

Selected species

       The American kestrel (Fa/co sparverius), or sparrow hawk, is the most common
falcon  in open and semi-open areas throughout North America. There are three recognized
subspecies: F. s. paulus (year-round resident from South Carolina to  Florida and southern
Alabama), F. s. peninsularis (year-round resident of southern Baja California), and F. s,
sparverius (widespread and migratory) (Bohall-Wood and Collopy, 1986).  Predators of the
kestrel include large raptors such as great horned owls, golden eagles, and red-tailed
hawks (Meyer and Balgooyen, 1987).

       Body size.  Weighing slightly over one tenth of a kilogram, the kestrel is the
smallest falcon native to the United States (Brown and Amadon, 1968). As for most
raptors, females are 10 to 20 percent larger than males (Bloom, 1973; Crajghead and
Craighead, 1956). Kestrel body weights vary seasonally, with maximum weight (and  fat
deposits) being achieved in winter and minimum weights in summer  (Bloom, 1973;
Gessaman and Haggas, 1987).

       Habitat.  Kestrels inhabit  open deserts, semi-open areas, the edges of groves
(Brown and Amadon, 1968), and even cities (National Geographic  Society, 1987). In
several areas, investigators have found that male kestrels tend to use woodland openings
and edges, while females tend to utilize more open areas characterized by short or sparse
ground vegetation, particularly during the winter (Koplin, 1973, cited in Mills, 1976; Meyer
and Balgooyen,  1987; Mills, 1975, 1976; Smallwood, 1987).  In other areas, however,
investigators have found no such differentiation (Toland, 1987; Sferra, 1984). In Florida,
kestrels appear to prefer sandhill communities (particularly pine/oak woodlands);  these
areas provide high-quality foraging habitat and the majority of available nest sites (Bohall-
Wood and Collopy, 1986). Kestrels are more likely to use habitats close to centers of
human activities than are most other raptors (Fischer et al., 1984).

       Food habits.  Kestrels prey on a variety of small animals including invertebrates
such as worms, spiders, scorpions, beetles, other large insects, amphibians and reptiles
such as frogs, lizards, and snakes, and a wide variety  of small- to medium-sized birds and
mammals (Brown  and Amadon,  1968; Mueller,  1987).  Large insects, such as
grasshoppers, are the kestrels' primary summer prey, although in their absence kestrels
will switch to small mammals (Collopy, 1973) and birds (Brown and Amadon,  1968).  In
winter, small mammals and birds comprise most of the diet (Collopy  and Koplin,  1983;
Koplin  et al., 1980).  Kestrels usually cache their vertebrate prey, often in  clumps of grass
or in tree limbs and holes, to be  retrieved later (Collopy, 1977; Mueller,  1987; Rudolph,
                                       2-109
American Kestrel
-------
 1982; Toland, 1984).  Invertebrate prey usually are eaten immediately (Rudolph, 1982).
 In Florida, where small mammals are scarce and reptiles are abundant, lizards are an
 important component of the diet (Bohall-Wood and Collopy, 1987).  Kestrels forage by
 three different techniques: using open perches from which to spot and attack ground
 prey, hovering in the air to spot ground prey, and  catching insects on the wing (Rudolph,
 1982,1983).

       Molt.  Females begin their molt during incubation and complete it by the end of the
 breeding season. Males, who are responsible for  capturing most of the prey for the family,
 do not begin their molt until near the end of the breeding season (Smallwood, 1988).

       Migration. The American kestrel is a year-round resident over most of the United
 States, but is migratory over the northern-most portions of its range (National Geographic
 Society, 1987). Because of their late molt, males migrate and arrive at the wintering
 grounds later than females or immatures (Smallwood, 1988).

       Breeding activities and social organization.  Adult kestrels are solitary, except during
 the breeding season, and maintain territories even in winter (Brown and Amadon, 1968).
 Kestrels typically build their nests in tree cavities,  but have used holes in telephone poles,
 buildings, or stream banks when tree cavities are  not available (Brown and Amadon,
 1968).  Both parents participate in incubation, but the female performs most of the
 incubation, while the male provides her with food  (Brown and Amadon, 1968).  Following
 hatching, the male brings the majority of the prey  to the nestlings (Brown and Amadon,
 1968).  After fledging, young kestrels remain dependent on their parents for food for at
 least 2 to 4 additional weeks (Lett and Bird, 1987).  Fledglings often perch and socialize
 with their siblings prior to dispersal (Lett and Bird, 1987). In Florida, resident kestrels
 (paulus subspecies) maintain year-round pair bonds and joint territories. The resident pairs
 have a competitive advantage over winter migrants  (sparverius subspecies) in their
 territories (Bohall-Wood  and Collopy, 1986).

       Home range and resources.   Although some investigators have not noted territorial
 defense (e.g., Craighead and Craighead, 1956), Mills (1975)  demonstrated that kestrels
 defend territories by introducing captured birds into  other birds' territories. Winter foraging
territories range from a few hectares in productive areas (e.g., in California) (Meyer and
 Balgooyen, 1987) to hundreds of hectares in less  productive  areas (e.g., Illinois, Michigan)
 (Craighead and Craighead, 1956; Mills, 1975). Summer breeding territories probably
follow the same pattern (Craighead and Craighead, 1956).

      Population density. Although much smaller than red-tailed hawks and bald eagles,
reported kestrel breeding population densities can  be similarly low (e.g., 0.0003 to 0.004
nests per hectare; see table).

      Population dynamics. Kestrels are sexually mature in the first breeding season after
their birth (Carpenter et  al., 1987).  Scarcity of suitable nesting cavities probably limits the
size of kestrel populations in parts of the United States (Cade, 1982). Three to four young
may fledge per nest per  year, but mortality of juveniles in the first year is high (60 to 90
percent) (Craighead and Craighead, 1956;  Henny,  1972). Adult mortality can be low (e.g.,
 12 percent per year) (Craighead and Craighead, 1.956).

                                       2-110                        American Kestrel
-------
Similar species (from general references)

       •      The peregrine falcon (Falco peregrinus], a rare resident of woods, mountains,
             and coasts, preys almost exclusively on birds. Though uncommon, they can
             be found wintering in most states, but rarely breeding. These large falcons
             (38 cm) have been reintroduced in some areas in the United States and have.
             nested in urban environments.

       •      The merlin (Falco columbarius), larger (30 cm) than the kestrel, can be found
             in a variety of habitats but nests in open woods or wooded prairies.
             Wintering along coasts and near cities of the Great Plains, it primarily eats
             birds.

       •      The prairie falcon (Falco mexicanus) also is larger (39 to 50 cm) than the
             kestrel and inhabits dry, open country and prairies. A year-round resident of
             the western United States, prairie falcons prey chiefly on birds and small
             mammals.

General references

       Cade (1982);  Craighead and Craighead (1956); National Geographic  Society (1987);
Brown and Amadon (1968).
                                       2-111
American Kestrel
-------
                                         American Kestrel (Falco sparverius)
Factors
Body Weight
f9>

-•

Metabolic Rate
(kcaf/kg-day)

i
Food Ingestion
Rate ig/g-day]

Water
Ingestion
Rate (g/g-day)
Age/Sex/
Cond./Seas.
Ffall
F winter
Mfall
M winter
F laying/inc.
Ffall
F winter
M incubate
Mfall
M winter
F laying/inc.
Ffall
F winter
M incubate
Mfall
M winter
A F basal
A M basal
A F free-living
A M free-living
A B winter
(vert, prey)
(invert, prey)
A M summer
AF
AM
Mean
115 ± 8.6 SD
132 ± 13 SD
103 ± 6.7 SD
114 ± 7.8 SD
124
127
138
108
111
119
414.4 ± 9.84 SE
368.7 ± 17.0SE
327.2 ± 5.72 SE
337.6 ± 16.8 SE
364.9 ± 26.9 SE
386.4 ± 9.41 SE
134
140
333
345
0.29
(0.18)
(0.11)
0.31
0.11
0.12
Range or
(95% Cl of mean)






(157-706)
(162-733)



Location
California, Imperial Valley
California, Imperial Valley
Utah
Utah
Utah (free-living)
Utah (free-living)

nw California (free-living)
Ohio (seminatural enclosure)

Reference
Bloom, 1973
Bloom, 1973
Gessaman & Haggas, 1 987
Gessaman & Haggas, 1987
Gessaman & Haggas, 1987
Gessaman & Haggas, 1987
estimated
estimated
Koplin et al., 1980
Barrett & Mackey, 1 975
estimated
Note
No.




1
1
2
3
4

5
3
CD
•^

o'
CD
CD

CO
i-t


CD
-------
                                          American Kestrel (Falco sparverius]
Factors
Inhalation
Rate (m3AJay)
Surface Area
(cm2)
Age/Sex/
Cond./Seas,
AF
AM
AF
AM
Dietary
Composition
invertebrates
mammals
birds
reptiles
other
vertebrates
{primarily lizards)
invertebrates
Coleoptera
other invertebrates
frogs {Rana aurora]
other1 herpetofauna
Micratti$,canfornicii$
Sorex vagrans
other mammals
Spring

49
51

Mean
•Q.089
0.079
267
242
Summer



Fall



Range or
#5% Cl of mean)


Winter
32.6
31.7
30.3
1.9
3.5

10.8
14.2
8.0
12.2
30.2
9.4
11.5
Location


Location/Habitat
(measure)
California/open areas, woods
(% wet weight of prey
observed captured)
Florida/dry pine-oak
woodlands (sandhill)
(% wet weight of prey observed
captured)
California/hayfields, pasture
(% wet weight of prey
observed captured)
Reference
estimated
estimated
Reference
Meyer & Balgooyen, 1 987
Bohall-Wood & Collopy,
1987
Collopy & Koplin, 1983
Note
Mo,
6
7
Note
No,



.3
CD
^

o'
Q>
D
CD
co
CD
-------
                                          American Kestrel (Falco sparver/us)
Population
Dynamics
Territory
Size (ha)
Population
Density
Clutch
Size
Clutches/Year
Days
Incubation
Age at
Fledging
Number Fledge
per Active
Nest
Age/Sex
Cond./Seas.
A F winter
A M winter
A B winter
A B summer
A B summer
pairs summer
pairs summer
pairs summer
B B fall
A B winter
A B spring





Mean
31.6 ± 10.7 SD
13.1 ± 2.0 SD
154
202 ± 131 SD
131 ± 100 SD
0.0026 nests/ha
0.0004 nests/ha
0.0035 pairs/ha
birds/ha:
0.0007 ± 0.00004 SD
0.0005 ± 0.0001 SD
0.0010 ± 0.0002 SD
4.3
4 to 5
1
33.7 ± 0.33 SE
29 to 30
27.4 days
3.1
3.8
Range
18.7-42.0
9.7- 14.8
< 452
41 - 500
21 -215
0.0023 - 0.0031
0.0003 - 0.0006
0.0005-0.0012
0.0005 - 0.0006
0.0008-0.0011
3-7

33-35
26 - 30 days

Location/Habitat
California/open areas,
woods
Illinois/agricultural area
Wyoming/grasslands, forests
Michigan/woodlots, fields
Missouri/urban
Missouri/rural
Wyoming/grasslands, forest
s Michigan/fields, woodlots
California/juniper,
sagebrush
NS/NS
Quebec, Canada/captive
Maryland/captive
NS/NS
Maryland/captive
California/juniper,
sagebrush
Wyoming/grasslands, forest
Reference
Meyer & Balgooyen,
1987
Mills, 1975
Craighead & Craighead,
1956
Craighead & Craighead,
1956
Toland & Elder, 1987
Toland & Elder, 1987
Craighead & Craighead,
1956
Craighead & Craighead,
1956
Bloom & Hawks, 1983
Brown & Amadon, 1968
Carpenter et al., 1987
Porter & Wiemeyer,
1972
Brown & Amadon, 1968
Porter & Wiemeyer,
1972
Bloom & Hawks, 1983
Craighead & Craighead,
1956
Note
No.







ro
3
CD
^s
o'
05
13
CD
CO
CD
-------
                                          American Kestrel (Falco sparverius]
Population
Dynamics
Number Fledge
per Successful
Nest
Age at Sexual
Maturity
Annual
Mortality
(percent^
Longevity
Seasonal
Activity^
Mating/
Laying
Hatching
Molt
Migration fall
spring
Age/Sex
Cond./Seas.

B
AB
JB
AB
J B

Begin
early May
mid-April
early April
mid-March
early June
early May
mid-May
early
September
early March
mid-April
Mean
3.7
1 yr
12
88
46.0 ± 4.6 SE
60.7

Peak
late May
late June
early May


Range



up to 9 yrs
End
late June
early June
mid-May
early June
late July
mid-June
mid-September
early November
Location/Habitat
California/juniper,
sagebrush
Quebec, Canada/captive
s Michigan, Wyoming/
open areas, woods
North America/NS
Quebec, Canada/captive
Location
California
central US
northern Utah
Florida
California
northern Utah
central Missouri
northern Utah
northern Utah
south Michigan
Wyoming
Reference
Bloom & Hawks, 1 983
Carpenter et al., 1987
Craighead & Craighead,
1956
Henny, 1972
Carpenter et al., 1987
Reference
Bloom & Hawks, 1 983
Brown & Amadon, 1968
Gessaman & Haggas,
1987
Brown & Amadon, 1 968
Bloom & Hawks, 1 983
Gessamen & Haggas,
1987
Toland & Elder, 1987
Gessaman & Haggas,
1987
Gessaman & Haggas,
1987
Craighead & Craighead,
1956
Craighead & Craighead,
1956
Note
No,




Note
No.




Ol
3
CD
-t

o'
Q)
13

7\
CD
CO
i-»

S
-------
ro
3
CD

5'
Q>
3
7\
CD
                                                    American Kestrel (Falco sparverius}

      1   tnvestigators estimated values from time-activity budget studies of kestrels in the field and rates of energy expenditure during different activities
         measured in the laboratory.
      2   Estimated using equation 3-28 (Lasiewski and Dawson, 1967) and body weights from winter measurements by Gessaman and Haggas (1987).
      3   Estimated using equation 3-37 {Nagy, 1987} and body weights from winter measurements by Gessaman and Haggas (1987).
      4   Authors observed prey captured daily, and estimated total wet-weight prey intake using measured or reported weights for identifiable prey and
         estimated weights for unidentifiable invertebrate prey (also, assumed kestrel weighed 119 g). Also, see Chapters 3 and 4 for methods by
         estimating food ingestion rates.
      5   Estimated using equation 3-15 (Calder and Braun, 1983} and  body weights from winter measurements by Gessaman and Haggas (1987).
      6   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from winter measurements by Gessaman and Haggas (1987).
      7   Estimated using equation 3-21 (Meeh, 1879 and Rubner, 1883, cited in Walsberg and King,  1978) and body weights from winter measurements
         by Gessaman and Haggas (1987).

-------
References (including Appendix)

Barrett, G. W.; Mackey, C. V. (1975)  Prey selection and caloric ingestion rate of captive
       American kestrels. Wilson Bull. 87: 514-519.

Bird, D. M.; Clark, R. G. (1983) Growth of body components in parent- and hand-reared
       captive kestrels. Raptor Res. 17: 77-84.

Bloom, P. H. (1973) Seasonal variation in body weight of sparrow hawks in California.
       Western  Bird Bander 48: 17-19.

Bloom, P. H.; Hawks, S. J. (1983) Nest box use and reproductive biology of the American
       kestrel in Lassen County, California.  Raptor Res. 17: 9-14.

Bohall-Wood, P.; Collopy, M. W. (1986) Abundance and habitat selection of two American
       kestrel subspecies  in north-central  Florida. Auk 103: 557-563.

Bohall-Wood, P. G.; Collopy,  M. W. (1987)  Foraging behavior of southeastern American
       kestrels in relation  to habitat use. Raptor Res. 6: 58-65.

Brown, L; Amadon, D. (1968) Eagles, hawks, and falcons of the world.  New York, NY:
       McGraw  Hill Book Co.

Cade, T. J. (1982) The falcons of the  world. Ithaca, NY: Cornell University  Press.

Calder, W. A.; Braun, E. J. (1983)  Scaling of osmotic  regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Carpenter, J. W.; Gabel, R. R.; Wiemeyer, S. N.; et al. (1987) Captive breeding. In:
       Pendleton, B. A.; Millsap, B. A.; Cline, K. W.; et al., eds. Raptor management
       techniques manual. Washington, DC: National Wildlife Federation; pp. 350-355.

Collopy, M. W. (1973) Predatory efficiency of American kestrels wintering in northwestern
       Califonia. Raptor Res.  7: 25-31.

Collopy, M. W. (1977) Food caching by female American kestrels in winter. Condor 79:
       63-68.

Collopy, M. W.; Koplin, J. R.  (1983) Diet, capture success, and mode of hunting by female
      American kestrels in winter. Condor 85:  369-371.

Craighead, J. J.; Craighead, F. C. (1956) Hawks, owls and wildlife. Harrisburg, PA: The
      Stackpole Co. and Washington, DC: Wildlife  Management Institute.

Duke, G. E.;  Evanson, 0. A.;  Jegers, A. A. (1976) Meal to pellet intervals in 14 species of
      captive raptors. Comp. Biochem. Physiol. 53A: 1-6.
                                      2-117
American Kestrel
-------
Duke, G. E.; Mauro, L; Bird, D. M..(1987) Physiology. In: Pendleton, B. A.; Millsap, B. A.;
       Cline, K. W.; et al., eds. Raptor management techniques manual. Washington, DC:
       Institute for Wildlife Research, National Wildlife Federation; Sci. Tech. Ser. No. 10;
       pp. 262-267.

Enderson, J. H. (1960) A population study of the sparrow hawk in east-central Illinois.
       Wilson Bull. 72: 222-231.

Fischer, D. L.; Ellis, K. L.; Meese, R. J. (1984) Winter habitat selection of diurnal raptors in
       central Utah. Raptor Res. 18: 98-102.

Gessaman, J. A. (1979) Premigratory fat in the American kestrel. Wilson  Bull. 91:
       625-262.

Gessaman, J. A.; Haggas, L. (1987) Energetics of the American kestrel in northern Utah.
       Raptor Res. 6:  137-144.

Henny, C. J. (1972) An analysis of the population dynamics of selected avian species with
       special reference to changes during the modern pesticide era. Washington, DC: Bur.
       Sport. Fish. Wildl.; Wildl. Res. Rep. 1.

King, J. R. (1974) Seasonal allocation of time and energy resources in birds. In: Paynter,
     • R. A., Jr., ed. Avian energetics. Cambridge, MA: Nuttall  Ornithol. Club; pp. 4-70.

Koplin, J. R. (1973) Differential habitat use by sexes of American kestrels wintering in
       northern California. Raptor Res. 7: 39-42.

Koplin, J. R.; Collopy,  M. W.; Bammann, A. R.; et al. (1980) Energetics of two wintering
       raptors. Auk 97: 795-806.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
       variables in resting birds. Resp. Phys. 11: 152-166.

Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation between standard
       metabolic rate and body weight in birds. Condor 69: 12-23.

Lett, D. W.; Bird,  D. M. (1987) Postfledging behavior of American kestrels in southwestern
       Quebec.  Wilson Bull. 99: 77-82.

Meeh,  K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Meyer, R.  L.; Balgooyen, T. G. (1987) A study and implications  of habitat separation by
       sex of wintering American kestrels (Falco sparverius L.).  Raptor Res.  6: 107-123.

Mills, G. S. (1975) A winter population study of the American kestrel in central Ohio.
      Wilson Bull. 87: 241-247.

Mills, G. S. (1976) American kestrel sex ratios and habitat separation. Auk 93: 740-748.

                                       2-118                        American Kestrel
-------
Mueller, H. C. (1987) Prey selection by kestrels: a review. Raptor Res. 6: 83-106.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987) Field guide to the birds of North America.
       Washington, DC: National Geographic  Society.

Porter, R. D.; Wiemeyer, S. N. (1972) Reproductive  patterns in captive American kestrels
       (sparrow hawks). Condor 74: 46-53.

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol. 19: 535-562.

Rudolph, S. G. (1982) Foraging strategies of American kestrels during breeding. Ecology
       63: 1268-1276.

Rudolph, S. G. (1983) Aerial insect-catching by American kestrels. Condor 85: 368-369.

Sferra, N. J. (1984) Habitat selection by  the American kestrel (Falco sparverius) and
       red-tailed hawk (Buteo jamaicensis) wintering in Madison County, Kentucky. Raptor
       Res. 18: 148-150.

Smallwood, J. A.  (1987) Sexual segregation by habitat in American kestrels wintering in
       southcentral Florida: vegetative  structure and responses to differential prey
       availability. Condor 89: 842-849.

Smallwood, J. A.  (1988) A mechanism of sexual segregation by habitat by American
       kestrels (Falco sparverius) wintering in south-central Florida. Auk 105: 36-46.

Sparrowe, R. D. (1972) Prey-catching behavior in the sparrow hawk. J. Wildl. Manage. 36:
       279-308.

Toland, B. R. (1984) Unusual predatory and caching behavior of American kestrels in
       central Missouri. Raptor Res. 18: 107-110.

Toland, B. R. (1987) The effect of vegetative cover  on foraging strategies, hunting
       success and nesting distribution of American kestrels in central Missouri. Raptor
       Res. 21: 14-20.

Toland, B. R.; Elder, W. H.  (1987) Influence of nest-box placement and density on
       abundance and productivity of American kestrels in central Missouri. Wilson Bull.
       99:712-717.

Walsberg, G. E.; King, J. R. (1978) The relationship  of the external surface area of birds to
       skin surface area and body mass.  J. Exp. Biol. 76:  185-189.

Wing, L.; Wing, A. H. (1939) Food consumption of a sparrow hawk. Condor 41: 168-170.

                                       2-119                       American Kestrel
-------
Zar, J. H. (1968) Standard metabolism comparisons between orders of birds. Condor 70:
       278.

Zar, J. H. (1969) The use of the allometric model for avian standard metabolism - body
       weight relationships. Comp. Biochem. Physiol.  29:  227-234.
                                     2-120
American Kestrel
-------
2.1.9.  Northern Bobwhite (quail)

       Order Ga/liformes, Family Phasiadinae. Quail are ground-dwelling birds with short,
heavy bills adapted for foraging on the ground for seeds and insects.  Most species inhabit
brush,  abandoned fields, and open woodlands; some inhabit parklands.  Quail and most
other gallinaceous birds are poor flyers that seldom leave the ground and do not migrate.
All species of this family gather in coveys (i.e., flocks of varying size) during some part of
the year. Quail range in size from Montezuma's quail (22 cm bill tip to tail tip) to the
mountain and Gambel's quail (28 cm); sexes are similar in size but differ in appearance.

Selected species

       The northern bobwhite (Colinus virginianus)  feeds mainly on seeds by gleaning on
the ground and low vegetation.  It ranges from southeastern Wyoming, east to southern
Minnesota and across to southern Maine, south through the central and eastern United
States  to eastern New Mexico in the west and to Florida in the east (American
Ornithologists' Union, 1983).  It is the most widespread of the North American quail and
used to be very common, particularly east of the  Rocky Mountains. Over the past three
decades, however, populations have been declining throughout its range (Brennan, 1991).

       Body size.  Northern bobwhite are average-sized quail (25 cm). Wild bobwhites
typically weigh between 150 and 200 g depending on location and season (see table),
while commercially bred stock usually exceed 200 g and may reach 300 g or more
(Brenner and Reeder, 1985; Koerth and Guthery,  1991). Males and females are similar in
size, and weights tend to increase with latitude and toward the west coast of the United
States  (Hamilton, 1957; Rosene,  1969; Roseberry and Klimstra, 1971). Females are
heaviest in the spring and summer when they are laying eggs; males are lightest at this
time of year (Hamilton,  1957; Roseberry and Klimstra, 1971).  Juveniles tend to weigh
slightly less than adults through winter (Hamilton, 1957; Roseberry and Klimstra,  1971).
Koerth  and Guthery (1987) found both males and females to maintain between 9 and 11
percent body fat (as a percentage of dry  body weight) throughout the year in southern
Texas;  more northern populations may maintain higher body fat ratios, particularly just
prior to breeding (McRae and Dimmick, 1982).

      Habitat.  During the breeding season, grasslands, idle fields, and pastures are the
preferred nesting habitat, and bobwhite often nest in large clumps of grasses (Roseberry
and Klimstra,  1984).  Shade, open herbaceous cover, and green and growing vegetation
are required for suitable nest sites (Lehmann, 1984).  Bobwhites forage in areas with open
vegetation, some bare ground, and light litter (Stoddard, 1931).  Nearby dry powdery soils
are important for dust bathing (Johnsgard, 1988).  Shrubby thickets up to 2 m high are
used for cover during midday (Schroeder, 1985).  Although their range is extensive,
northern bobwhite reproduce poorly in the arid western portions of their range and during
droughts elsewhere (Schroeder, 1985).  During the winter, they require wooded cover
with understory for daytime cover, preferably adjacent to open fields for foraging (Yoho
and Dimmick, 1972). They tend to roost at night in more open habitats with short and
sparse  vegetation (Schroeder, 1985). In  the more northern latitudes, cover and food can
be limited during the winter (Rosene, 1969). Changes in land use, primarily the
                                      2-121
Northern Bobwhite
-------
distribution of farms and farming methods, have eliminated large areas of bobwhite habitat
in the last three decades (Brennan, 1991).

       Food habits. Bobwhites forage during the day, primarily on the ground or in a light
litter layer less than 5 cm deep (Rosene, 1969).  Seeds from weeds, woody plants, and
grasses comprise the majority of the adult bobwhite's diet throughout the year (Handley,
1931; Bent, 1932; Lehmann, 1984), although in winter in the south, green vegetation has
been found to dominate the plant materials in their diet (Campbeil-Kissock et al., 1985).
Insects and other invertebrates can comprise up  to 10 to  25  percent of the adults' diet
during the spring and summer in more  northerly areas and year-round  in the south
(Campbeil-Kissock  et al., 1985; Handley, 1931; Lehmann, 1984).  Insects comprise the
bulk of the chicks' diet; up to 2 or 3 weeks of age  chicks may consume almost 85 percent
insects, the remainder of the diet consisting of berries and seeds (Handley,  1931). Most
insects consumed by bobwhite chicks  are very small, less than 8 mm in length and 0.005
g (Hurst, 1972). Juvenile bobwhite, on the other hand, may consume only 25 percent
insects, the remainder of their diet being fruit and seeds (Handley,  1931).  Quail consume
little grit.  Korschgen (1948) found grit in only 3.4  percent of over 5,000 crops examined,
and agreed with Nestler (1946) that hard seeds can replace grit  as the grinding  agent for
northern bobwhite.

       In some areas, bobwhites apparently can acquire their daily water needs from dew,
succulent plants, and insects (Stoddard,  1931); in more arid  areas or in times of drought,
however, northern  bobwhite need surface water for drinking  (Johnsgard, 1988; Lehmann,
1984;  Prasad and Guthery,  1986).  Females need more water than males during the
breeding season, and both sexes may require more water in the  winter than in the summer
when their diet is more restricted to seeds with low water content (Koerth and Guthery,
1990).  Measurements on captive quail have indicated a daily water requirement of up to
13 percent of their body mass (see table); however, water intake requirements for free-
ranging birds may be higher, perhaps 14 to 21 percent of body mass per day (Koerth and
Guthery, 1990). In the absence of adequate water, females  may fail to reproduce (Koerth
and Guthery, 1991).

       Dustbathing. Quail frequently dustbathe,  although the reason for the behavior is
debated.0 They scratch in dry dirt or dust, toss the dust up into their feathers, rub their
head and sides in the dust, and then shake the dust from  their plumage (Borchelt and
Duncan,  1974). Experiments by Driver et al. (1991) indicate that ingestion of materials
preened from feathers and direct dermal uptake can be significant exposure pathways for
quail exposed to aerial application of pesticides.  Dust bathing might, therefore, provide a
significant exposure route for bobwhites using contaminated  soils.

       Molt.  Juveniles attain adult plumage during  their first fall molt at about 3 to 5
months of age (Hamilton, 1957; Stoddard, 1931).  Adults undergo a complete prebasic
°Stoddard (1931) and others have suggested that dust bathing helps to control ectoparasites;
 Borchelt and Duncan (1974) suggest that dust bathing helps control the amount of oil on the
 quails' feathers.

                                       2-122                     Northern Bobwhite
-------
molt in the late summer and fall into winter plumage; in spring, a limited renewal of
feathers around the head and throat provides the breeding plumage (Bent, 1932).

      Migration.  The northern bobwhite is a year-round resident over its entire range but
may disperse locally to a different cover type or altitude with the changing season
(Lehmann, 1984).  Most winter in wooded or brushy areas, returning to more open
habitats in spring for the breeding season {Lehmann, 1984; Rosene, 1969).  Populations
nesting at higher elevations tend to move to lower ground where the winters are less
severe (Stoddard, 1931). The more southerly populations may be more sedentary; in a
study in Florida, northern bobwhite  were found no further than 1 km from where they
were banded, and 86 percent were  found within 400 m from their banding site over a 1-
to 5-year period (Smith et al., 1982).

      Breeding activities and social organization.  Northern bobwhite build nests on the
ground in  open woodlands or in or around fields used for foraging.  Most nests are
constructed in grassy growth near open ground, often in areas with scattered shrubs and
herbaceous growth  (Klimstra and Roseberry, 1975; Stoddard, 1931).  Both the male and
female scrape out a saucer-shaped ^depression in the ground 2 to 6 cm deep and  10 to 12
cm across, lining it with dead grasses from the previous year's growth (Bent, 1932;
Rosene, 1969). They lay large clutches, 12 to 30 eggs, which one or both parents
incubate for approximately 23 days (Lehmann, 1984; Simpson, 1976). As a general rule,
clutch size and nest success both decrease as the season progresses (Roseberry and
Klimstra, 1984). Family units, consisting of both the male and female as well as the
offspring,  sometimes remain intact through the summer, but more often, one or both ^
parents are lost to predation (some females leave their brood  to the male and begin
another), and other pairs or individual adults may adopt chicks from other broods
(Lehmann, 1984).  By fall, northern  bobwhites of all ages gather in larger coveys for the
fall and winter. The quail remain in  coveys until the next spring, when they disperse as
mating season begins (Lehmann,  1984; Roseberry and Klimstra, 1984).  Coveys of
northern bobwhite tend to average 10 to 12  or 15 birds (up to 30) (Johnsgard, 1988;
Lehmann, 1984; Rosene, 1969).  When roosting in winter, the birds in a covey form a
small circle on the ground under a tree  or in thick brush, with heads facing outward and
their bodies closely packed to conserve heat.

      Home range and resources. In the breeding season, the bobwhite's home range
includes foraging areas, cover, and the nest site and may encompass several hectares.
Mated males and incubating females have the smallest spring and  summer home ranges;
bachelor males and post-nesting males and females have much larger foraging ranges (see
table).  Bobwhite tend to use a portion  of their home range more intensively than the
remainder of the range (Urban, 1972).  In the fall and winter,  the range of each bobwhite
covey must include adequate open foraging areas and cover, typically shrubby or woody
thickets (Rosene, 1969).  Each covey may utilize an area of several hectares, although as
in summer, there tend to be activity centers where the quail spend most of their time
(Yoho and Dimmick, 1972).

      Population density.  Bobwhite density depends on food and cover availability and
varies from year to year as well as from one location to another (Roseberry and Klimstra,
1984). Densities are highest at the  end of the breeding season in the fall.  In the
                          «
                                      2-123                      Northern Bobwhite
-------
southeast, densities may reach values as high as 7.5 birds (adults and juveniles) per
hectare, although average values of 2 to 3 may be more common in these areas (Guthery,
1988; Lehmann, 1984; Smith et a!., 1982).  Winter and spring densities between 0.1 and
0.8 birds per hectare have been recorded in the spring  further north (Roseberry et al.,
1979).

      Population dynamics.  Bobwhites attempt to rear one or two broods per year (up to
three in the south) (Bent, 1932; CKWRI, 1991; Stanford,  1972b).  Bobwhite clutch sizes
are generally smaller in more southerly populations (Roseberry and Klimstra, 1984)  and
smaller as the breeding season progresses in any given locale (Lehmann, 1984; Simpson,
1976). Predation is a major cause of nest loss; once hatched, chicks leave the nest
immediately to follow  both or one parent (Lehmann, 1984; Roseberry and Klimstra, 1984).
Juveniles can survive without parental care after about 6 weeks  of age (Lehmann, 1984).
They reach maturity by 16 weeks of age in the laboratory although they continue to gain
weight through about  20 weeks (Moore and Cain, 1975),  and they may require 8 to 9
months to mature in the wild (Johnsgard, 1988; Jones and Hughes, 1978). Adult
mortality as well as juvenile mortality is high, with 70 to 85  percent of birds surviving less
than 1 year (Brownie et al.,  1985; Lehmann, 1984); thus, the bulk of the population turns
over each year.

Similar species (from general references)

      *      California quail (Callipepla californica), also known  as valley quail, are similar
             in size (25 cm) to the bobwhite and also  gather in coveys during autumn and
     *       winter.  They are common in open woodlands, brushy foothills, stream
             valleys, and suburbs, usually near permanent surface waters; however, their
             range is restricted largely to the western  coastal States and Baja California.

      •      Gambel's quail (Callipepla gambelii) is larger  (28 cm) than the bobwhite, and
             is a resident of the southwestern desert scrublands, usually near permanent
             surface waters. It also gathers in coveys in  winter.

      •      The scaled quail (Callipepla squamata), similar  in size (25 cm) to the
             bobwhite, is restricted to the mesas, plateaus, semidesert scrublands, and
             grasslands mixed with scrub, primarily of western Texas, New Mexico, and
             Mexico.

      «      Mountain quail (Oreortyx pictus) are found in the chapparal, brushy ravines,
             and mountain slopes of the west up to 3,000 m. These also are large quail
             (28 cm). During the fall, they gather in coveys and descend to lower
             altitudes for the winter.
            The Montezuma quail (Cyrtonyx montezumae), formerly known as the
            harlequin quail, is a small (22 cm), secretive resident of the southwest.
            species is usually found in grassy undergrowth of juniper or oak-pine
            woodlands.
             This
                                      2-124
Northern Bobwhite
-------
General references

      Johnsgard (1988); Lehmann (1984); National Geographic Society (1987); Rosene
(1969); Roseberry and Klimstra (1984); Stoddard (1931).
                                     2-125
Northern Bobwhite
-------
                                     Northern Bobwhite (Colinus virginianus]
Factors

Body Weight
to}




•3


-





-
,,


^
v •- r
v I
x -T
Body Fat
\% dry weight)


Body Fat
{% dry weight)
{continued)
-
Age/Sex/
Cond./Seas.
A B fall
A B winter
A B spring
A M winter
A M summer
A F winter
A F summer
A M winter
A M summer
A F winter
A F summer

at hatching
day 6
day 10
day 19
day 32
day 43
day 55
day 71
day 88
day 106
J B fall
A Wi winter
A M spring
A F winter
A F spring
A M winter
A M spring
A F winter
A F spring

Mean
189.9 ± 3.28 SE
193.9 ± 4.56 SE
190.0 ± 4.98 SE
181
163
183
180
161
154
157
157

6.3
9 -10
10- 13
20-25
35-45
55-65
75-85
110- 120
125- 150
140-160
174.0 ± 3.49 SE
15.5 ± 2.8 SD
8.8 ± 3.2 SD
13.8 ± 2.7 SD
12.7 ± 2.4 SD
10.2 ± 0.6 SE
7.9 ± 0.2 SE
10.6 ± 0.8 SE
9.7 ± 0.3 SE
Range or
{95% Cl of mean)











{weight gain:)

(0.5 - 0.75
g/day)

(1.5 g/day)

(1.75 g/day)

(1.75-2.0
g/day)





9.0- 11.9
6.5 - 10.0
8.3- 19.9
7.7- 11.2
Location or
subspecies
Kansas


Illinois



west Rio Grande, Texas




southwest Georgia/both
captive and wild birds
living in farms, woods,
and thickets






Kansas
Tennessee



southern Texas/captive




Reference
Robel, 1969


Roseberry & Klimstra, 1971



Guthery et al., 1988




Stoddard, 1931









Robel, 1969
McRae & Dimmick, 1 982



Koerth & Guthery, 1987



Note
No.































Si
cn
CD
00
o
CT


ir
i-f
CD
-------
                                     Northern Bobwhite (Colinus virgin/anus)
Factors

Egg Wefght
{grams)
Metabolic Rate
(teaf/kg-day)





Food Ingestion
Rate (g/g-dayl


(kcal/kg-day)


Water
Ingestion Rate
(g/g-day) :


Inhalation Rate
(m3/
-------
                                    Northern Bobwhite (Colinus v/rg/nfanus)
Dietary
Composition
adults:
{total plant foods)
misc. seeds
other seeds?
legumes
senna
cultivated plants
grasses
sedges;
mast
Spurges
fruits
forage plants ^' '
(total animal foods) f
•' grasshoppers ^
bugs "f "
, beetles ,*"
adults:
seeds of weeds
seeds of woody
plants
,. seeds of grasses
' cultivated grams, eta •
^ greens
"* insects I
adults:
seeds of forbs
seeds of grasses
seeds/fruits of
woody plants
! unidentified seeds
green vegetation
invertebrates

Spring

(87.2)
21.1

15.2
7.2
2.1
3.1
1.1
14.1
0.1
11.1
12
(12.8)
3.2
2.8
4.6

43.64
4.03
13.2
3.7
27.4
8.03










Summer

(78.7)
6.0

3.9
0.4
2.1
11.3
1.2
0.2
1.2
45.8
0.3
(19.6)
7.5
4.4
6.3

33.7
20.5
24.8
1.9
4.9
14.2


3.5
51.7

9.7
4.6
4.8
25.8

Fall

(79..7)
11.1

10.1
0.2
5.3
26.0
2.4
0.5
5.5
11.3
0.3
(20.3)
16.6
0.6
0.8

30.0
39.7
0.7
8.3
3.4
17.9


19.0
42.9

-
-
1.8
36.2

Winter

(96.8*
2.6

31.5
12.8
2.6
2.3
1.1
28.0
0.4
9.5
5.2
(3.2)
2.4
0.1
0.2

34.3
9.5
7.2
15.4
10.3
23.3


12.0
4.9

1.4
2.3
72.4
6.5
Location/Habitat
(measure)

southeastern United
States/NS

(% volume; crop and gizzard
contents)












south Texas/semi-prairie,
brushland

(% dry volume; crop
contents)



southwest Texas/grasslands
drought conditions

(% wet volume; crop
contents)

„

Reference

Handley, 1931
















Lehmann, 1984







Campbell-Kissock et al., 1 985






Note
No.

































[O
00
CD
•n


CD
O
(T


=r
rt
CD
-------
                                      Northern Bobwhite (Colinus virgin/anus)
Population
Dynamics
Home Range
Size (ha/bJrd} j




(ha/Covey)



Population
Density
(N/ha)




-


Clutch Size
-


Clutches /Year
.Days
Incubation {
Age/Sex/
Cond./Seas.
summer:
AB
A M mated
A M unmated
A F nesting
A F post-nest
winter:
BB

BB
B B fall

B B spring
B B fall
B B spring
B B fall
B B spring
B B winter
B B winter
B B winter


March
August




Mean

3.6
7.6 ± 5.0 SD
16.7 ± 9.5 SD
6.4 ± 4.0 SD
15.6 ± 9.1 SD

6.8 ± 2.9 SD

15.4
0.21 ± 0.0031 SE

0.10 ± 0.0003 SE
0.63 ± 0.24 SD
0.24 ± 0.05 SD
5.0 ± 0.30 SE
2.2 ± 0.21 SE
0.63 ± 0.18 SD
2.25 ± 1.16 SD
3.65 ± 2.22 SD
12.9
13.7 ± 3.28 SD
25.0
9.4
1
23

Range or
{95% Cl of mean)





•

4.0 - 1 1 .7

12.1 - 18.6



0.28 - 0.92
0.18-0.33


0.37 - 0.88
0.6 - 3.9
1.7-7.6
4-33
6-28


0-3
21 -25


Location/Habitat

Iowa/State game area
south Illinois/idle farms
woods, brush, cornfields



Tennessee/woods, old fields
cultivated fields
south lllinois/NS
south Texas/upland
rangeland

south Illinois/agricultural

south Texas/mixed brush
rangeland
South Carolina/farms, woods
Florida/pine woods

south Texas/prairie, brush
Illinois/agricultural
southwest Georgia/pine
woods, farms
NS/NS
south Texas/prairie, brush


Reference

Grim & Seitz, 1972
Urban, 1972




Yoho & Dimmick, 1972

Bartholomew, 1967
Guthery, 1988


Roseberry et al., 1 979

Guthery, 1988

Rosene, 1969
Smith et al., 1 982

Lehmann, 1984
Roseberry & Klimstra, 1984
Simpson, 1976

CKWRI, 1991
Lehmann, 1984

NOW
No*



























(O
I


(O

(O
•2.
O
CD
00
O
cr

rr
-------
                                     Northern Bobwhite (Colinus virginianus]
Population
Dynamics
Percent Nests
Successful
Number Hatch
per
Successful
Nest *
Age at Sexual ,
Maturity
Annual
Mortality Rates
(percent}
t '
Longevity
(months}
Seasonal
Activity
Mating/ Laying
Hatching
Age/Sex/
Cond./Seas.

spring/
summer
March
August
B
B
AM
AF
JM
JF
BB
no hunting
BM
BF
starting:
B November
B October
Begin
March
mid-April
April
mid-March
late April
early May
mid-May
Mean
17.5
32.6 ± 8.1 SD
12.2
20.0
8.4
8-9 months
1 6 weeks
78.8 ± 2.47 SE
85.3 ± 2.72 SE
81.8 ± 2.46 SE
87.2 ± 1.68SE
81
52
56
10.6
8.5
PeaK
May - June
mid-May - July
May - June
May - August
mid-June
June - August
Range or
(95% CI of mean)
15.4-19.0
21.0-52.8


64.7 - 94.8
68.4 - 98.6
73.0 - 93.7
67.9 - 95.8

End
August
mid-August
September
mid-September
October
October
early October
Location/Habitat
southwest Georgia/pine
woods, farms
south Illinois/agricultural
south Texas/semiprairie,
brush
southwest Georgia/pine
woods, farms
NS/NS (wild)
South Carolina/lab
Florida/open woods
Illinois/agricultural
Florida/pine woods
Texas/semiprairie, brush
central Missouri/NS
Location
Florida
south Texas
south Illinois
south Texas
sw Georgia, northern Florida
Missouri
south Illinois
Reference
Simpson, 1976
Roseberry & Klimstra, 1984
Lehmann, 1984
Simpson, 1976
Johnsgard, 1988
Jones & Hughes, 1978
Brownie et al., 1985
Roseberry & Klimstra, 1 984
Pollock et al., 1 989
Lehmann, 1984
Marsden & Baskett, 1958
Reference
Bent, 1932
Lehmann, 1984
Roseberry & Klimstra, 1984
Lehmann, 1984
Stoddard, 1931
Stanford, 1972a
Roseberry & Klimstra, 1 984
Note
No.




9
Note
No.


CO
o
CD
D

CO
o
cr

3;
i-f
CD
-------
                                                 Northern Bobwhite (Colinus virgin/anus}
Seasonal
Activity
Molt fall
spring
Begin
August
early February
Peak
September
March - April
End
October
early June
Location
NS
sw Georgia, northern Florida
Reference
Bent, 1932
Stoddard, 1931
Note
Mo.


ro
_A
w
1   Metabolized energy requirements of farm-raised birds in captivity: (1)7 weeks prior to laying (mean weight of hens = 194 g) and (2) during laying
    (mean weight of hens = 215 g).
2   Estimated using equation 3-28 (Lasiewski and Dawson, 1967) and summer body weights from Roseberry and Klimstra (1971).
3   Estimated using equation 3-37 (Nagy, 1987) and summer body weights from Roseberry and Klimstra (1971).
4   Diet of commercial game food with only 5 to 10 percent water content; maintained at temperature, humidity, and light cycle typical for Texas.
5   Gross energy intake calculated from the average volume of crop contents in shot birds, assuming a 1.5-hour retention period, 2.30 kcal/cm3 for
    the contents, and constant foraging throughout the daylight hours, which is likely to overestimate food intake.
6   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Roseberry and Klimstra (1971).
7   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Roseberry and Klimstra (1971).
8   Estimated using equation 3-21 (Meeh, 1879 and Rubner,  1883, as cited in  Walsberg and King, 1978) and body weights from Roseberry and
    Klimstra (1971).                                      -
9   Expected remaining longevity for those juvenile quail that survived to the month indicated.
CD
ro
o
cr
CD
-------
 References (including Appendix)

 American Ornithologists' Union. (1983) Check-list of North American birds. Lawrence, KS:
       Allen Press, Inc.

 Andrews, T. L; Harms, R. H.; Wilson, H. R. (1973) Protein requirement of the bobwhite
       chick. Poult. Sci. 52: 2199-2201.

 Baldwin, W. P., Jr.; Handley, C. O. (1946) Winter food of the bobwhite quail in Virginia. J.
       Wildl. Manage. 10: 142-149.

 Bartholomew, R. M. (1967) A study of the winter activity of the bobwhite through the use
       of radiotelemetry. Kalamazoo, Ml: Occas. Pap. Adams Ecol. Center, Western  Mich.
       Univ.; 25 pp.

 Bent, A. C. (1932) Life histories of North American  gallinaceous birds. Washington,  DC:
       U.S. Government Printing Office; Smithsonian Inst. U.S. Nat.  Mus., Bull. 162.

 Blem, C. R.; Zara, J. (1980) The energetics of young bobwhite (Colinus virgin/anus).
       Comp. Biochem. Physiol. A: Comp. Physiol. 67: 611-615.

 Borchelt, P. L.; Duncan, L. (1974) Dustbathing and  feather lipid in bobwhite  (Colinus
       virginianus). Condor 76: 471-472.

 Brennan, L. A. (1991) How can we reverse the northern bobwhite decline? Wildl. Soc.
       Bull. 19: 544-555.

 Brenner, F. J.; Reeder, M. (1985) Effect of temperature on energy intake in three strains of
       bobwhite quail (Colinus virginianus). Proc.  Penn. Acad. Sci. 59: 119-120.

 Brownie, C.; Anderson, D. R.; Burnham, K. P.; et  al. (1985) Statistical inference from band
       recovery data - a handbook. Washington, DC: U.S. Fish Wildl. Serv., Resour.  Publ.
       156.

 Buss, I. O.; Mattison, H.; Kozlik, F. M. (1947) The bobwhite  quail in  Dunn County,
       Wisconsin. Wise. Cons. Bull. 12: 6-13.

 Caesar Kleberg Wildlife Research Institute (CKWRI).  (1991) Double broods revisited.  In:
       Quail news from CKWRI No. 14, March 1991. Kingsville, TX:  Texas A&l University;
       p. 6.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Campbell-Kissock, L.; Blankenship, L. H.; Stewart, J. W. (1985) Plant and animal foods  of
       bobwhite and scaled quail in southwest Texas. Southwest. Nat. 30: 543-553.
                                      2-132
Northern Bobwhite
-------
Case, R. M. (1973) Biqenergetics of a covey of bobwhites. Wilson Bull. 85: 52-59.

Case, R. M. (1982) Adaptations of female bobwhites to energy demands of the
      reproductive cycle. Proc. Natl. Bobwhite Quail Symp.  2: 74-78,

Case, R. M..; Robel, R. J. (1974) Bioenergetics of the bobwhite. J. Wildl. Manage. 38:
      638-652.

Craighead, J. J.; Craighead, F. C. (1956) Hawks, owls and wildlife. Harrisburg, PA: The
      Stackpole Co. and Washington, DC: Wildlife Management  Institute.

Crim, L. A.; Seitz, W. K. (1972) Summer range and habitat preferences of. bobwhite quail
      on a southern Iowa State Game Area. Proc. Iowa Acad. Sci. 79: 85-89,

Driver, C. J.; Ligotke, M. W.; Van Voris, P.; et al, (1991) Routes  of uptake and their
      relative contribution to the toxicologic response of northern bobwhite (Colinus
      virginianus) to an organophosphate pesticide. Environ. Toxicol. Chem.  10: 21-33.

Guthery, F. S. (1988) Line transect sampling of bobwhite density on rangeland: evaluation
      and recommendations. Wildl. Soc. Bull. 16: 193-203.

Guthery, F. S.; Koerth, N. E.; Smith, D. S. (1988) Reproduction of northern bobwhites in
      semiarid environments. J. Wildl. Manage. 52:  144-149.

Hamilton, M. (1957) Weights of wild bobwhites in central Missouri. Bird Banding 28:
      222-228.
Handley, C. 0. (1931) The food and feeding habits of bobwhites. In: Stoddard, H. L, ed.
    •  The bobwhite quail: its habits, preservation and increase. New York, NY: Charles
      Scribner's Sons.

Heitmeyer, M. E. (1980) Foods of bobwhites in northeastern Missouri related to land use.
      Trans. Missouri Acad. Sci. 14: 51-60.

Hurst, G. A.  (1972) Insects and bobwhite quail brood habitat management. Proc. Natl.
      Bobwhite Quail Symp. 1: 65-82.

Johnsgard, P. A. (1988) The quails, partridges, and francolins of the world. Oxford,
      England:  Oxford  University Press; pp. 60-68.

Jones, J. E.; Hughes, B. L. (1978) Comparison of growth rate, body weight, and feed
      conversion between Cortunfx D1 quail and bobwhite quail. Poult. Sci. 57:  1471-
      1472.

Judd,  S. (1905) The bob-white and other quails of the United States and their economic
      relations. U.S. Biol. Survey Bull. 21: 1-66.
                                      2-133
Northern Bobwhite
-------
Kellogg, F. E.; Poster, G. L.; Williamson, L. L. (1970) A bobwhite density greater than one
       bird per acre. J. Wildl. Manage. 34: 464-466.

Klimstra, W. D.; Roseberry, J. L. (1975) Nesting ecology of the bobwhite in southern
       Illinois. Wildl. Monogr. 41; 37 pp.

Koerth, N. E.; Guthery, F. S. (1987) Body fat levels of northern bobwhites in south Texas.
       J. Wildl. Manage. 51:  194-197.

Koerth, N. E.; Guthery, F. S. (1990) Water requirements of captive northern bobwhites
       under subtropical  seasons. J. Wildl. Manage.  54: 667-672.

Koerth, N. E.; Guthery, F. S. (1991) Water restriction effects on northern bobwhite
       reproduction. J. Wildl. Manage. 55: 132-137.

Korschgen, L. J. (1948)  Late-fall and early-winter food  habits of bobwhite quail in
       Missouri. J. Wildl. Manage. 12: 46-57.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
       variables in resting birds. Resp. Phys.  11:152-166.

Lasiewski, R. C.; Dawson, W. R. (1967) A reexamination of the relation between standard
       metabolic rate and body weight in birds. Condor 69: 12-23.

Lay, D. W.  (1954) Quail  management for east Texas. Texas Parks Wildl. Dept. Bull. No.
       34.

Lehmann, V. W. (1984) Bobwhites in the Rio Grande plain of Texas. College Station, TX:
       Texas A&M University Press.

Marsden, H. M., Baskett, T. S.  (1958) Annual mortality in a banded bobwhite population.
       J. Wildl. Manage.  22: 414-419.

Martin, A. C.; Zim, H. S.; Nelson, A. L. (1951) American wildlife and plants. New York,
       NY:  McGraw-Hill Book Company, Inc.

McRae, W. A.; Dimmick, R. W. (1982) Body  fat and  blood-serum values of breeding wild
       bobwhites. J. Wildl. Manage. 46: 268-271.

Meeh,  K. (1879) Oberflachenmessungen des  mensclichen Korpers. Z. Biol. 15: 426-458.

Moore, P. E.; Cain, J. R.  (1975) Characterization of bobwhite quail reared for hunting.
       Poult. Sci. 54: 1798.

Nagy, K. A. (1987) Field  metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.
                                      2-134  .
Northern Bobwhite
-------
National Geographic Society. (1987) Field guide to the birds of North America.
      Washington, DC: National Geographic Society.

Nelson, A. L.; Martin, A. C. (1953) Gamebird weights. J. Wildl. Manage. 17: 36-42.

Nestler, R. B. (1946) Mechanical value of grit for bobwhite quail. J. Wildl. Manage. 10:
      137-142.

Nice, M. (1910) Food of the bobwhite. J. Economic Entomology 3: 6-10.

Pollock, K. H.; Moore,  C. T.; Davidson, W. R.; et al. (1989) Survival rates of bobwhite
      quail based on band recovery analyses. J. Wildl. Manage. 53:  1-6.

Prasad, N. L.; Guthery, F. S. (1986) Drinking by northern bobwhites in Texas. Wilson Bull.
      98:485-486.

Reid, V. H.; Goodrum,  P. D. (1960) Bobwhite quail: a product of longleaf pine, forests.
      Trans. North Am. Wildl. Conf. 25: 241-252.

Robel, R. J. (1969) Food habits, weight dynamics and fat content of  bobwhites in relation
      to food plantings in Kansas. J. Wildl. Manage.  38:  653-664.

Robel, R. J.; Bisset, A. R.; Dayton, A. D.; et al. (1979a) Comparative energetics of
      bobwhites on six different foods. J. Wildl. Manage. 43: 987-992.

Robel, R. J.; Bisset, A. R.; Clement, T. M., Jr.;  et al. (1979b) Metabolizable energy of
      important foods of bobwhites in Kansas. J. Wild. Manage. 43: 982-987.

Robel, R. J.; Case, R. M.; Bisset, A. R.; et al. (1974) Energetics of food plots in bobwhite
      management. J. Wildl. Manage. 38: 653-664.

Roseberry, J. L.; Klimstra, W. D. (1971) Annual weight cycles in male and female
      bobwhite quail.  Auk 88: 116-123.             <   '     •   •

Roseberry, J. L; Klimstra, W. D. (1984) Population ecology of the bobwhite. Carbondale
      and Edwardsville, IL: Southern Illinois University Press.
                                                                   „
Roseberry, J. L.; Peterjohn, B. G.; Klimstra, W.  D. (1979) Dynamics of an unexploited
      bobwhite population in deteriorating habitat. J. Wildl. Manage. 43: 306-315.

Rosene, W. (1969) The bobwhite quail, its life and management. New Brunswick, NJ:
      Rutgers Press.

Rubner,  M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und  Kraftweschsel. Z.
      Biol. 19: 535-562.
Schroeder, R. L. (1985) Habitat suitability models index: northern bobwhite. U.S. Fish
      Wildl. Serv. Biol. Rep. 82(10.104).
                                      2-135
Northern Bobwhite
-------
Sermons, W. O.; Speake, D. W. (1987) Production of second broods by northern
       bobwhites. Wilson Bull. 99: 285-286.

Simpson, R. C. (1976) Certain aspects of the bobwhite quails life history in southwest
       Georgia. Atlanta, GA: Georgia Dept. Nat. Resour.; Tech. Bull. WL1.

Smith, G. F.; Kellogg, F. I.; Doster, G. L; et al. (1982) A 10-year study of  bobwhite quail
       movement patterns. Proc. Natl. Bobwhite Quail Symp. 2: 35-44.

Stanford, J. A. (1972a) Bobwhite quail population dynamics: relationships  of weather,
       nesting, production patterns, fall population characteristics, and harvest in Missouri
       quail. Proc. Natl. Bobwhite Quail Symp. 1:  115-139.

Stanford, J. A. (1972b) Second broods in bobwhite quail. Proc. Natl. Bobwhite Quail
       Symp. 1: 21-27.

Stempel, M. E. (1960) Quail hatching  and primary feather moult in adults.  Proc. Iowa
       Acad. Sci. 67: 616-621.

Stoddard, H. L. (1931) The bobwhite quail: its habits, preservation and increase. New
       York, NY: Charles Scribner's Sons.

Tomlinson,  R. E. (1975) Weights and wing lengths of wild Sonoran masked bobwhites
       during fall and winter. Wilson Bull. 87: 180-186.

Urban, D. (1972) Aspects of bobwhite quail mobility during spring through fall months.
       Proc. Natl. Bobwhite Quail Symp. 1: 194-199.

Walsberg, G. E.; King, J. R. (1978) The relationship of the external surface area of birds to
       skin surface area and body mass. J.  Exp. Biol.  76: 185-189.

Wiseman, D. S.; Lewis, J. C. (1981) Bobwhite use of habitat in tallgrass rangeland. Wildl.
       Soc. Bull. 9: 248-255.

Wood, K. N.; Guthery, F. S.; Koerth, N. E. (1986)  Spring-summer nutrition and condition
       of northern bobwhites in south Texas. J.  Wildl.  Manage. 50: 84-88.

Yoho, N. S.; Dimmick, R. W. (1972) Habitat utilization by bobwhite quail during winter.
       Proc. Natl. Bobwhite  Quail Symp. 1:  90-99.
                                      2-136
Northern Bobwhite
-------
2.1.10.  American Woodcock (woodcock and snipe)

      Order Charadriformes, Family Scolooacidae.  These inland members of the
sandpiper family have a stocky build, long bill, and short legs. However, their habitants and
diet are distinct. Woodcock inhabit primarily woodlands and abandoned fields, whereas
snipe are found in association with bogs and freshwater wetlands.  Both species use their
long bills to probe the substrate for invertebrates.  The woodcock and snipe are similar in
length, although the female woodcock weighs almost twice as much as the  female snipe.

Selected species

      The American woodcock (Scolopax minor) breeds from southern Canada to
Louisiana throughout forested regions of the eastern half of North America.  The. highest
breeding densities are found in the northern portion of this range, especially  in the Great
Lakes area'of the United States, northern New England, and southern Canada (Gregg,
1984; Owen et al., 1977). Woodcock winter primarily in the southeastern United States
and are year-round residents in some of these areas. Woodcock are important game
animals over much of their range (Owen et al., 1977).

      Body size.  Woodcock are large for sandpipers (28 cm bill tip to tail tip), and
females weigh more than males (Keppie and Redmond, 1988).  Most young  are full grown
by 5 to 6 weeks after hatching (Gregg,  1984).

      Habitat.  Woodcock inhabit both woodlands and abandoned  fields, particularly those
with rich and  moderately to poorly drained loamy soils, which tend  to support abundant
earthworm populations (Cade, 1985; Owen and  Galbraith, 1989; Rabe et al., 1983a). In
the spring, males use early successional open areas and woods openings, interspersed
with low brush and grassy vegetation, for singing displays at dawn and dusk (Cade, 1985;
Keppie and Redmond, 1985).  Females nest in brushy areas of secondary growth
woodlands near their feeding areas, often near the edge of the woodland or  near a break in
the forest canopy (Gregg, 1984).  During the summer, both sexes use second growth
hardwood or early successional mixed hardwood and conifer woodlands for diurnal cover
(Cade, 1985). At night, they move  into open pastures and early successional abandoned
agricultural fields, including former male singing grounds, to roost (Cade, 1985; Dunford
and Owen, 1973; Krohn, 1970).  During the winter, woodcock use bottomland hardwood
forests, hardwood thickets, and upland mixed hardwood and conifer forests  during  the
day.  At night, they use open areas to some degree, but also forested habitats (Cade,
1985). Diurnal habitat and nocturnal roosting fields need to be in close proximity to be
useful for woodcock (Owen et al., 1977).

      Food habits.  Woodcocks feed primarily on invertebrates found in moist upland soils
by probing the soil with their long prehensile-tipped bill (Owen et al., 1977; Sperry, 1940).
Earthworms are the preferred diet, but when earthworms are not available, other soil
invertebrates are consumed (Miller and Causey, 1985; Sperry, 1940; Stribling and Doerr,
1985). Some seeds and other plant matter  may also be consumed  (Sperry,  1940).  Krohn
(1970) found  that during summer most feeding was done in wooded areas prior to
entering fields at night, but other studies have indicated that a significant amount of food
                                      2-137
American Woodcock
-------
 is acquired during nocturnal activities (Britt, 1971,, as cited in Dunford and Owen, 1973).
 Dyer and Hamilton (1974) found that during the winter in southern Louisiana, woodcock
 exhibited three feeding periods: early morning (0100 to 0500 hours) in the nocturnal
 habitat, midday (1000 to 1300 hours) in the diurnal habitat, and at dusk (1700 to 2100
 hours) again in the nocturnal fields; earthworms and millipedes were consumed in both
 habitat types. Most of the woodcocks' metabolic water needs are met by their food
 (Mendall and Aldous,  1943, as cited in Cade, 1985), but captive birds have been observed
 to drink (Sheldon, 1967).  The chicks leave the nest soon after hatching, but are
 dependent on the female for food for the first week after hatching (Gregg, 1984).

       Molt.  Woodcock molt twice annually. The prenuptial molt  involves body plumage,
 some wing coverts, scapulars, and tertials and occurs in late winter or early spring; the
 complete postnuptial molt takes place in July or August (Bent,  1927).

       Migration.  Fall migration begins in late September and continues through
 December, often following the first heavy frost  (Sheldon, 1967).  The migration may take
 4 to 6 weeks (Sheldon, 1967).  Some woodcock winter in the south Atlantic region, while
 those that breed west of the Appalachian Mountains winter in Louisiana and other Gulf
 States (Martin et al., 1969, as cited in Owen et al., 1977). Woodcock are early spring
 migrants, leaving their wintering grounds in February and arriving on their northern
 breeding grounds in late March to early April (Gregg, 1984; Sheldon, 1967; Owen et al.,
 1977). Dates of woodcock arrival at their breeding grounds vary from year to year
 depending  on the timing of snowmelt (Gregg, 1984). Sheldon (1967) summarizes spring
 and fall migration dates by States from numerous  studies.

       Breeding activities and social organization.  From their arrival in the spring, male
 woodcock  perform daily courtship flights at dawn and at dusk, defending a site on the
 singing grounds in order to attract females for mating (Owen et al., 1977; Gregg, 1984).
 Often several males display on a single singing ground, with each defending his own
 section of the area.  Females construct their nests on the ground, usually at the base of a
 tree  or shrub located in a brushy area adjacent to an opening  or male singing ground
 (Gregg and Hale, 1977; McAuley et al., 1990; Owen et al., 1977). Females are
 responsible for all of the incubation and care of their brood (Trippensee,  1948).  The young
 leave the nest soon  after hatching and can  sustain flight by approximately 18 days of age
 (Gregg, 1984).

       Home range and resources. The home range of woodcocks encompasses both
 diurnal cover areas and nocturnal roosting areas and varies in size depending on season
 and the distribution  of feeding sites and suitable cover. During the day,  movements are
 usually limited until dusk, when woodcock fly to nocturnal roost sites. Hudgins et al.
 (1985) and Gregg (1984) found spring and  summer diurnal ranges  to be only 1  to 10
 percent of the total home range.  Movement on the nocturnal roost sites also is limited;
however, during winter, woodcock are more likely to feed and move  around at night
 (Bortner, pers. comm.). Singing males generally restrict their movements more than non-
 singing males, juveniles, and females (Owen et al., 1977).

       Population density.  The annual singing-ground survey conducted by the United
 States and Canada provides information on  the population trends of woodcock in the
                                      2-138
American Woodcock
-------
northern states and Canada during the breeding season (note from B. Bortner, U.S. Fish
and Wildlife Service, Office of Migrating Bird Management, to Susan Norton, January 9,
1992).  Gregg (1984) summarized results of several published singing-ground surveys and
found estimates to vary from 1.7 male singing grounds per 100 ha in Minnesota (Godfrey,
1974, cited in Gregg, 1984) to 10.4 male singing grounds per 100 ha in Maine (Mendall
and Aldous, 1943, cited in Gregg, 1984). Although this method is appropriate for
assessing population trends, flushing surveys, telemetry, and mark-recapture are better
methods for estimating woodcock densities because there are variable numbers of females
and nonsinging males associated with active singing grounds (Dilworth, Krohn,
Riffenberger, and Whitcomb pers. comm., cited by Owen et al., 1977).  For example,
Dwyer et al. (1988) found 2.2 singing males per 100 ha in a wildlife refuge in Maine, but
with mark-recapture techniques, they found yearly summer densities of 19 to 25 birds per
100 ha in the same area.

      Population dynamics. Woodcocks attempt to raise only a single brood in a given
year but may renest if the initial  clutch is destroyed (McAuley et al., 1990; Sheldon,
1967).  In 12 years of study in Wisconsin, Gregg (1984) found 42 percent of all nests to
be lost to predators and another 11 percent lost to other causes.  Survival of juveniles in
their first year ranges from 20 to 40 percent, and survival of adults ranges from 35 to 40
percent  for males to approximately 40 to 50 percent for females (Dwyer and Nichols,
1982; Krohn et al., 1974).  Derleth and Sepik (1990) found high adult survival rates (0.88
to 0.90  for both sexes) between June and October in Maine, indicating that adult mortality
may occur primarily in the winter and early spring.  They found lower summer survival
rates for young woodcock between fledging  and migration than for adults during the same
months, with most losses of young attributed to predation.

Similar species (from general references)

      ••     The  common snipe (Gallinago gallinago) is similar in length (27 cm) to the
             woodcock,  although lighter in weight. Snipe are primarily found in
             association with bogs and freshwater wetlands and feed on the various
             invertebrates associated with wetland soils. Snipe breed primarily in boreal
             forest regions and  thus are found slightly north of the woodcock breeding
             range, with some areas of overlap in  the eastern half of the continent. The
             breeding range of the snipe, however, extends westward to the Pacific coast
             and throughout most of Alaska, thus occupying a more extensive east-west
             range than the woodcock.

General references

      Cade (1985); Dwyer et al. (1979); Dwyer and Storm (1982); Gregg (1984);
National Geographic Society (1987); Owen et al. (1977); Sheldon (1967); Trippensee
(1948).
                                      2-139
American Woodcock
-------
                                    American Woodcock (Scolopax minor]
Factors
Body Weight
(9!

-• c
A
/•„ ,;,< %- t
'" J\l * jfi »;
Egg Weight (g)
Chick Growth
Bate (g/day)
Metabolic Rate
ikcat/kg-day)


Age/Sex/
Cond./Seas.
AM
AF
A M April
A M May
A M June
A M summer
J M summer
A F summer
J F summer
A M fall
J M fall
A F fall
J F fall
at hatching
at laying
near hatching
M
F
A F basal
A M basal
A F basal
A F free-living
A F nesting
A M free-living
A F free-living
Mean
176
218
134.6 ± 2.9 SE
133.8 ± 5.8 SE
151.2 ± 9.5 SE
145.9
140.4
182.9
168.8
169
164
213
212
13.0
18-19
14- 16
5.1
6.2
115
126
118
315
553
313
296
Range or
(95% Cl of
mean)


127-165
117-152
162-216 -
151 - 192

9- 16




(148-662)
(140-627)
Location
throughout range
Maine
central Massachusetts
Minnesota
Wisconsin
Wisconsin
Maine
s Michigan
s Michigan

Reference ; .....;,
Nelson & Martin, 1953
Dwyer etal., 1988
Sheldon, 1967
Marshall (unpubl.)
Gregg, 1984
Gregg, 1984
Dwyer et al., 1 982
Rabe etal., 1983b
estimated
Rabe etal., 1983b
estimated
Note
No.



1



2
3
4
5
to
I
—x
*>•
o
CD
^t
o'
CD
D
O
O
Q.
O
O
O
-------
                                                    American Woodcock (Scolopax minor]
 Ni
 3
 CD
 "s
 o"
 03
O
o
,0.
o
o
o
                                                            Range or
                                                            05% Cl of
                                                            mean!"
                 Age/Sex/
                 Cond./Seas»
         Food IngestiOn
         Rate fg/g-dayj
                 A B winter
                  (earthworm
                  diet)
                                                                     Louisiana (captive)
  Stickel et al., 1965
         Water
         Ingesttorv
         Rate (g/g-day)
         Inhalation
         Rate (m3/day)
                                                                                                estimated

                                                                                                      I ••!•

                                                                                                estimated
Surface Area
(cm2)
        Dietary
        Composition
                                                                    Location/Habitat
                                                                      (measure)
                                                                                                        Reference
                                                                                                        •	   i

                                                                                                        Sperry, 1940
 earthworms
 Dipter$
 Coteoptera
 Lepidoptera
 other animals
 plants'
                                                                    North America/NS
                                                                            (% volume; stomach
                                                                            contents)
earthworms
beetle larvae
grit (inorganic)
Other organic
                                                                   (% wet weight; mouth
                                                                   esophagus, stomach, &
                                                                   proventriculus contents)
earthworms
other invertebrates
                                                                   N Carolina/soybean fields
                                                                   (% wet weight; digestive
                                                                   tract)
Stribling & Doerr, 1985

———	
Miller & Causey, 1985
        earthworms
        Coleoptera
        Hymertoptera
                                                                           (% volume; esophagus
                                                                           contents)
-------
                                   American Woodcock (Scolopax minor]
Population
Dynamics
Home Range
Size (ha)
Population
Density
(birds/hal
j x
Clutch
Sizfr {
V
Clutches/
Yeaf
Percent Nests
Hatching
Days
incubation
Age at
Fledging
Age/Sex
Cond./Seas.
A M inactive
A M active
A M singing
B B summer
A F with
brood
B B winter
P B winter
B B winter
nests in spring
A M summer
A F summer
J B summer
B B summer
1 st clutch
2nd clutch




Mean
3.1 (median)
73.6 (median)
10.5 (median)
32.4 ± 27.6 SD
4.5
3.38
0.20
0.034
0.21 (nests/ha)
0.035
0.056
0.125
0.223
4
3.8 ± 0.42 SD
3.0 ± 0.67 SD
1 but renest if 1st
lost
about 50
19-21
18-19 days
Range
0.3 - 6.0
38.2-171.2
4.6 - 24.1
7-98
0.026 - 0.046
0.037 - 0.074
0.108-0.143
0.190-0.250
3-5




Location/Habitat
Pennsylvania/mixed forests
with shrubs and fields
Wisconsin/woods, open
areas, brush
North Carolina/agricultural:
untilled soy stubble
untilled corn stubble
rebedded corn fields
Pennsylvania/mixed pine and
hardwoods, open fields
Maine/second growth forest,
meadows, and ponds
throughout range and
habitats
Maine/mixed forests,
agricultural fields
throughout range and
habitats
Maine/mixed forests, fields
NS/NS
Wisconsin/woods, open
areas, brush
Reference
Hudgins etal., 1985
Gregg, 1984
Connors & Doerr, 1 982
Coon et al., 1 982
Dwyer et al., 1 988
Bent, 1927
McAuley etal., 1990
McAuley etal., 1990
McAuley etal., 1990
Mendall & Aldous, 1943;
Pettingill, 1936
Gregg, 1984
Note
No.





11

ro
CD
^t

o'
03
O
o
Q.
O
O
O
-------

                                   American Woodcock (Sco/opax minor]
Population
Dynamics
Age at
Sexual
Maturity
Annual
Mortality
Rates
*•




Seasonal
Activity
Mating/Laying

Hatching

,


Molt


Migration
spring

.fall


Ageteex
Cond./Seas.
M
F

A M east
A M central
J M east
J M central
A F east
A F central
J F east
J F central

Begin
early February
early April
early February
late February
late March
mid-April





mid-February
March
October
late
September

Mean
< 1 year
1 year

65 ± 5.2 SD
60 ± 15 SD
80 ± 4.8 SD
64 ± 12 SD
51 ± 7.3 SD
47 ± 9.6 SD
64 ± 7.7 SD
69 ± 9.4 SD

Peak





early May
mid-May
August to
early
September


April




Range












End
mid-March




early June





early March

December
mid-December


Location/Habitat
throughout range and
habitats

eastern and central United
States/NS







Location
Texas
Maine
Louisiana
Virginia
Connecticut
Massachusetts
Maine
NS/NS



leaving North Carolina
arriving in northern range
arriving North Carolina
leaving Canada

,
Reference
Sheldon, 1967


Dwyer & Nichols, 1 982








Reference
Whiting & Boggus, 1 982
Dwyer et al., 1982
Pettingill, 1936
Pettingill, 1936
Pettingill, 1936
Sheldon, 1967
Dwyer et al., 1982
Owen & Krohn, 1973



Connors & Doerr, 1 982
Gregg, 1984
Sheldon, 1967
Owen etal., 1977

Note
No.











Note
No.


1
1
1


12








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References (including Appendix)

Aldous, C. M. (1938) Woodcock management studies in Maine 1937. Trans. North Am.
      Wildl. Nat. Resour. Conf. 3: 839-846.

Aschoff, J.; Pohl, H. (1970) Rhythmic variations in energy metabolism. Fed. Proc.  29:
       1541-1552.                                                         •

Bent, A. C. (1927) Life histories of North American shore birds. Part 1. Washington, DC:
      U.S. Government Printing Office; Smithsonian Inst. U.S. Nat. Mus., Bull. 142.

Britt, T. L. (1971) Studies of woodcock on the Louisiana wintering ground [master's
      thesis]. Shreveport, LA:  Louisiana State University.

Cade, B. S. (1985) Habitat suitability index models: American woodcock (wintering). U.S.
      Fish Wildl. Serv. Biol. Rep. 82(10.105).

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Connors, J. I.; Doerr, P. D. (1982) Woodcock use  of agricultural fields in coastal North
      Carolina. In: Dwyer, T. J.;  Storm, G. W., tech. coords. Woodcock ecology and
      management. U.S. Fish Wildl. Serv., Wildl.  Res. Rep.  14; pp.  139-147.

Coon, R. A.; Williams, B. K.; Lindzey, J. S.; et al. (1982) Examination of woodcock nest
      sites in central Pennsylvania. U.S. Fish Wildl. Serv., Wildl. Res. Rep. 14; pp. 55-62.

Derleth, E. L.; Sepik, G. F. (1990) Summer-fall survival of the American woodcock in
      Maine. J. Wildl. Manage. 54: 97-106.

Dunford, R. D.;  Owen, R. B. (1973) Summer behavior of immature radio-equipped
      woodcock in central Maine. J. Wildl. Manage. 37: 462-469.

Dwyer, T. J.; Nichols, J. D. (1982) Regional population inferences for the American
      woodcock. In: Dwyer, T. J.; Storm, G. L., tech. coords. Woodcock ecology and
      management. U.S. Fish Wildl. Serv., Wildl.  Res. Rep.  14; pp.  12-21.

Dwyer, T. J.; Storm, G. L., eds. (1982) Woodcock ecology and management. U.S. Fish
      Wildl. Serv,, Wildl. Res.  Rep. 14.

Dwyer, T. J.; Coon, R. A.; Geissler, P. H. (1979) The technical literature on the American
      woodcock 1927-1978.  Laurel, MD: U.S. Fish Wildl. Serv., Migratory Bird and
      Habitat Research Laboratory.

Dwyer, T. J.; Derleth, E. L.; McAuley, D. G. (1982) Woodcock brood ecology in Maine.
      U.S. Fish Wildl. Serv., Wildl. Res. Rep. 14;  pp. 63-70.
                                      2-145
American Woodcock
-------
Dwyer, T. J.; Sepik, G. F.; Derleth, E. L.; et al. (1988) Demographic characteristics of
       Maine woodcock population and effects of habitat management. Washington, DC:
       U.S. Fish Wildl. Serv. Res. Rep. 4.

Dyer, J. M.; Hamilton, R. B. (1974) An analysis of feeding habits of the American
       woodcock (Philohela minor) in southern Louisiana. In: Fifth American woodcock
       workshop proceedings; December 3-5, 1974; Athens, GA. Athens, GA: University
       of Georgia.

Godfrey, G. A. (1974) Behavior and ecology of American woodcock on the breeding range
       in Minnesota [Ph.D. dissertation]. Minneapolis, MN: University of Minnesota.

Greeley, F. (1953) Sex and age studies in fall-shot woodcock (Philohela minor) from
       southern Wisconsin. J. Wildl. Manage.  17: 29-32.

Gregg,' L. (1984) Population ecology of woodcock in Wisconsin. Wis. Dept. Nat. Resour.
       Tech. Bull. No. 144; 51 pp.

Gregg, L. E.; Hale, J. B. (1977) Woodcock nesting habitat in northern Wisconsin. Auk 94:
       489-493.

Hudgins, J. E.; Storm, G. L.; Wakeley, J. S. (1985)  Local movements and diurnal-habitat
       selection by male woodcock in Pennsylvania. J. Wildl. Manage. 49: 614-619.

Johnson, R.C.; Causey, M. K.  (1982) Use of longleaf pine stands by woodcock in southern
       Alabama following prescribed burning.  In: Dwyer, T. J.;  Storm, G. W., tech. coords.
       Woodcock ecology and management. U.S. Fish Wildl. Serv., Wildl. Res. Rep.  14;
       pp. 120-125.

Keppie, D. M.; Redmond, G. W. (1985) Body weight and the possession of territory for
       male American woodcock. Condor 87:  287-290.

Keppie, D. M.; Redmond, G. W. (1988) A review of possible explanations for reverse size
       dimorphism of American woodcock. Can. J. Zool. 66: 2390-2397.

Krohn, W. B. (1970) Woodcock feeding habits as  related to summer field usage in central
       Maine. J. Wildl. Manage. 34: 769-775.

Krohn, W. B.; Martin, F. W.; Burnham, K. P. (1974)  Band-recovery distribtution and
       survival estimates of Maine woodcock.  Proc.  Am. Woodcock Workshop 5: 1-8.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric  analysis of respiratory
      variables in resting birds. Resp. Phys. 11:152-166.

Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation between standard
      metabolic rate and body weight in birds. Condor 69: 12-23.
                                      2-146
American Woodcock
-------
Martin, F. W.; Williams, S. 0.; Newsom, J. D.; et al. (1969) Analysis of records of
      Louisiana-banded woodcock. Proc. Ann. Conf. Southeast. Assoc. Game and Fish
      Comm. 23: 85-96.

McAuley, D. G.; Longcore, J. R.; Sepik, G. F. (1990) Renesting by American woodcock
      (Sco/opax minor) in Maine. Auk 107: 407-410.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.
                                                •
Mendall, H. L; Aldous, C. M. (1943) The ecology and management of the American
      woodcock.  Orono, ME: Maine Coop. Res. Unit, University of Maine; 201 pp.

Miller, D. L.; Causey, M. K. (1985) Food preferences of American woodcock wintering in
      Alabama. J. Wildl. Manage. 49: 492-496.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol.  Monogr.  57: 111-128.

National Geographic Society.*(1987) Field guide to the birds of North America.
      Washington, DC: National Geographic Society.

Nelson, A. L.; Martin, A. C. (1953) Gamebird weights. J. Wildl. Manage. 17: 36-42.

Norris, R. T.; Buele, J. D.; Studholme, A. T. (1940) Banding woodcocks on Pennsylvania
      singing grounds. J. Wildl.  Manage. 4: 8-14.

Owen, R. B.; Galbraith, W. J. (1989) Earthworm biomass in relation  to forest types, soil,
      and land use: implications for woodcock management. Wildl.  Soc. Bull.  17:
      130-136.

Owen, R. B.; Krohn, W. B. (1973) Molt patterns and weight changes of the American
      woodcock.  Wilson Bull. 85: 31-41.

Owen, R. B.; Morgan, J. W. (1975) Summer behavior of adult radio-equipped woodcock in
      central Maine. J. Wildl. Manage. 39: 179-182.

Owen, R. B.; Anderson, J. M.; Artmann, J. W.; et al. (1977) American woodcock. In:
      Sanderson,  G. C., ed. Management of migratory shore and upland game birds in
      North America. Washington, DC: Int. Assoc. Fish Wildl. Agencies; pp. 147-175.

Pettingill, 0. S.,  Jr. (1936) The American woodcock. Boston Soc. Nat. Hist. Mem. 9(2).

Rabe, D. L.; Prince, H. H.; Beaver, D. L. (1983a) Feeding-site selection and foraging
      strategies of American woodcock. Auk 100: 711-716.

Rabe, D. L.; Prince, H. H.; Goodman, E. D. (1983b) The effect of weather on bibenergetics
      of breeding  American woodcock. J. Wildl. Manage. 47:  762-771.
                                     2-147
American Woodcock
-------
Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Bio!. 19: 535-562.

Sheldon, W. G. (1967) The book of the American woodcock. Amherst, MA: University of
       Massachusetts Press.

Sparry, C. (1940) Food habits of a group of shore birds; woodcock, snipe, knot, and
       dowitcher. U.S. Dept. Int., Bur. Biol. Survey, Wildl. Res. Bull. 1; 37 pp.      ,,rli;,
                                •
Stickel, W. H.; Hayne, D. W.;  Stickel, L. F. (1965) Effects of heptachlor-contaminated
       earthworms on woodcocks. J. Wildl. Manage.  29: 132-146.

Stribling, H. L.; Doerr, P. D. (1985) Nocturnal use of fields by American woodcock. J.
       Wildl. Manage. 49: 485-491.

Trippensee, R. E. (1948) American woodcock. Wildlife management. New York, NY:
       McGraw-Hill; pp. 323-332.

Tufts,  R. W. (1940) Some studies in bill measurements and body weights of American
       woodcock (Philohela minor). Can. Field-Nat. 54: 132-134.

Walsberg, G. E.; King, J. R. (1978) The relationship of the external surface area of birds to
       skin surface area and body mass. J. Exp. Biol.  76: 185-189.

Wetherbee, D. K.; Wetherbee, N. S. (1961) Artificial incubation of eggs of various bird
       species and some attributes of neonates. Bird Banding 32: 141-159.

Whiting, R. M.; Boggus, T. G.  (1982) Breeding biology of American woodcock in east
       Texas. In: Dwyer, T. J.; Storm, G. W., tech. coords. Woodcock ecology and
       management. U.S. Fish Wildl. Serv., Wildl. Res. Rep.  14; pp. 132-138.
                                      2-148
American Woodcock
-------
2.1.11.   Spotted Sandpiper (sandpipers)

       Order Charadriiformes, Family Scolooacidae. The family Scolopacidae includes
numerous species of shorebirds, e.g., sandpipers, tattlers, knots, godwits, curlews,
yellowlegs, willets, and dowitchers.  Those known as sandpipers tend to be small with
moderately long legs and bills.  Most sandpipers forage on sandy beaches and mudflats; a
few utilize upland areas.  They feed almost exclusively on small invertebrates, either by
probing into or gleaning from the substrate. Most species are highly migratory, breeding in
arctic and subarctic regions and either wintering along the coasts or in southern latitudes
and the southern hemisphere; therefore, many are only passage migrants throughout  most
of the United States. Scolapids range in size from the least sandpiper (11.5 cm bill tip to
tail tip) to the long-billed curlew (48 cm).

Selected species

       The spotted sandpiper (Actitis macularia) (19 cm) is a very common summer
resident of freshwater and saltwater bodies throughout most of the United States. These
sandpipers are most often encountered singly but may form small flocks. Most winter in
the neotropics.                                           ,

       Body size. Females (approximately  50 g) are significantly larger than males
(approximately 40 g) (Oring and Lank, 1986).

       Habitat.  Spotted sandpipers breed along the edges of bodies of water, usually in
open habitats, from the northern border of the boreal forest across North America, south
to the central United States (Oring and Lank, 1986).  They require open water for bathing
and drinking, semi-open habitat for nesting, and dense vegetation for breeding (Bent,
1929; Oring et al., 1983).

      Food habits.  In coastal areas, spotted sandpipers search the beach and muddy
edges of inlets and creeks, wading  less frequently than most sandpipers; inland they feed
along the shores of sandy ponds and all types of streams, sometimes straying into
meadows, fields, and gardens in agricultural areas (Bent, 1929). Their diet is composed
primarily of terrestrial and, marine insects (Bent, 1929).  While adult flying insects comprise
the bulk of the diet, crustaceans, leeches, molluscs, small fish, and carrion also are eaten
(Oring et al., 1983).  Young feed themselves immediately after hatching, concentrating  on
small invertebrates (Oring and Lank, 1986). During insect outbreaks, sandpipers  will
forage in wooded areas near water, and they have been observed eating eggs  and fish on
occasion (Oring, pers. obs.).

      Molt. Partial prenuptial molt of body plumage occurs in March and April, while the
postnuptial molt begins by August with the body feathers and ends anywhere from
October to April with the  loss of the primary flight feathers (Bent,  1929).

      Migration.  Spotted sandpipers generally migrate in small flocks or solitarily
(National Geographic Society, 1987). They winter from southern United.States to
northern Chile, Argentina, and Uraguay {Oring and Lank, 1986), and breed across North
                                       2-149
Spotted Sandpiper
-------
America, north from Virginia and southern California (National Geographic Society, 1987).
In the spring, females arrive at the breeding grounds earlier than males (in one study, by
about 2 weeks; Oring and Lank, 1982).

       Breeding activities and social organization. The primary consideration for nesting
sites is proximity to water, and spotted sandpipers have been known to build their ground
nests in such diverse conditions as depressions in volcanic rock and strawberry patches
(Bent,  1929).  Spotted sandpipers are polyandrous (i.e., a single female lays eggs for
multiple males), with males supplying most of the incubation and parental care (Oring,
1982).  Thus reproduction is limited by the number of males present (Lank et al., 1985).
Spotted sandpipers lay a determinate clutch of four eggs.  Females may lay several
clutches in a year, often a dozen eggs per season (Maxson and Oring, 1980). Egg laying
begins between late May and early June in Minnesota (Lank et al., 1985), and males
incubate after the third egg is laid (Oring et al., 1986). Females sometimes incubate and
brood when another male is not available (Maxson and Oring,  1980).  Parents brood small
chicks and protect them with warning calls or by distracting or attacking predators (Oring
and Lank, 1986).

       Home range and resources. Although a variety of vegetation types are used, nests
usually are placed in semi-open vegetation near the edge of a lake, river, or  ocean (Oring et
al., unpubl., as cited in Oring et al., 1983; McVey, pers. obs.). The suitability of nesting
habitat varies from year to year in some locations due to levels of precipitation and
predators (Oring et al., 1983).

       Population density.   Spotted sandpiper nesting densities have been studied well at
only one location, on Little  Pelican Island, Leech Lake, Minnesota.  At this location,
densities ranged from  4 to 13 females per hectare and 7 to 20 males per hectare over a
10-year period, depending on weather and other conditions (Oring et al., 1983).

       Population dynamics. Females may lay one to six clutches for different males over
one season {Oring et al., 1984), averaging 1.3 to 2.7 mates per year (Oring et al., 1991b).
Female mating and reproductive success increase with age, but male success does not
(Oring et al., 1991b).  Lifetime reproductive success is most affected by fledging success
and longevity for both males and females (Oring et al., 1991 a).

Similar species  (from general references)

       •      The solitary sandpiper (Tringa solitaria) is usually seen singly in freshwater
             swamps or rivers.  Present over much of the United States during  annual
             migrations, this average-sized sandpiper (18 cm) winters along the southeast
             and Gulf coasts.

       •      The western sandpiper (Calidris mauri) is a small sandpiper (13 cm), common
             on mudflats and sandbars, that winters on both the Atlantic and Pacific
             shores of the United States.
                                       2-150
Spotted Sandpiper
-------
      •      The least sandpiper (Calidris minutilla), the smallest of this group (11 cm), is
             common in winter on salt marshes and muddy shores of rivers and estuaries
             in coastal areas across the United States.

      •      The semipalmated sandpipers (Calidris pusilla) are small birds (13 cm) seen
             in the United States primarily during migration and rarely wintering on Florida
             coasts.

      •      Most other members of the family Scolopacidae forage by gleaning..

General references

      Oring and Lank (1986); Lanket al. (1985); National Geographic Society (1987);
Oring et al. (1991 a, 1991b).
                                      2-151
Spotted Sandpiper
-------
                                      Spotted Sandpiper (Actltis macularia)
Factors
Body Weight
(9)
Metabolic Rate
(kcaT/kg-day)
Food Ingestlon
Rate [g/g-dayj
Water
Ingestion
Rate (g/g-day)
Inhalation
Rate {m3/day}
Surface Area
(cm2)
Age/Sex/
Cond./Seas.
A F spring
A M spring
A F pre-breed
A F laying
A F incubating
A M pre-breed
AM
incubating
A M brooding
A F free-living
A M free-
living

AF
AM
AF
AM
AF
AM
Mean
47.1
37.9
404 - 787
383 - 745
368
440
303
425
436
460

0.16
0.17
0.039
0.033
131
113
Dietary
Composition Spring Summer
mayflies V
midges V
Population
Dynamics
Territory
Size (ha)
Age/Sex
CondJSeas,

Range or
(95% Cl of mean)
43-50
34-41
(202 - 937)
(213-994)




Fall Winter

Mean Range
approx. 0.25
Location
Minnesota island
Minnesota




Location/Habitat
{measure)
Minnesota/island in lake
Location/Habitat
NS/NS
Reference
Maxson & Oring, 1980
Maxson & Oring, 1980
estimated

estimated
estimated
estimated
Reference
Maxson & Oring, 1 980
Reference
Maxson & Oring, 1 980
Note
No.

1
2
3
4
5
6
Note
No.

Note
No.

ro


01
NJ
U)
•o
o
3
CD
o_

U>
Q>
•
CD
-------
                                        Spotted Sandpiper (Actitis macularia)
Population :
Dynamics
Population
Density (N/fta)
Clutch Size
Clutches/Year
Days
Incubation
Age at
Fledging
Number Fledge
per
Nest That
Hatches
Number Fledge
per Successful
Nest
Age at
Sexual
Maturity
Annual
Mortality >
Rates (percent)
Longevity
Seasonal
Activity
Mating
Hatching
Age/Sex ,.
Cond./Seas.
A F summer
A M summer






F
M
F
M
AF
Begin
early May
early June
Mean
10
13.9
4

18 to 24
approximately
1 8 days
1.83
2.58
1 year
1 year
approx. 31
approx. 30
3.7 years
Peak
late May - early
June
late June
Range
3.8 - 12.5
7.5 - 20.0
3-5
1 -6


0.58 - 2.76
1.67-2.91



End


Location/Habitat
Minnesota/island in lake
NS/NS
Minnesota/NS
NS/NS
NS/NS
Minnesota/island in lake
Minnesota/island in lake
Minnesota/island in lake
Minnesota/island in lake
Minnesota/island in lake
Reference
Oring et al., 1983
Bent, 1929; Oring et al., 1983
Oring et al., 1983
Oring, unpublished
Oring et al., 1991 a
Oring et al., 1984
Oring et al., 1984
Oring et al., 1983
Oring et al., 1983; Oring &
Lank, 1982; Oring, unpublished
Oring et al., 1983
Location Reference
Minnesota Lank et al., 1 985
Minnesota Lank et al., 1985
Note \
No.

7








Note
No,


 Ol
 to
 CO
 T5
 O
.3
 CD
 Q.

 CO
 0)
 3
 Q.
 •g.

 •o'
 CD
-------
                                                   Spotted Sandpiper (Actitis macularia)
Seasonal
Activity ;*••
Molt fall
spring
Migration
females
males
Begin
August
late June
early July
Peak
March - April
early - mid-July
mid-July
End
October

Location
NS
Minnesota
Reference
Bent, 1929
Bent, 1929
Lanketal., 1985
Note
No.


to
01
1   Estimated by authors; allometric model not specified.
2   Estimated using equation 3-37 (Nagy, 1987) and body weights from Maxson and Oring (1980).
3   See Chapters 3 and 4 for methods of estimating food ingestion rates; also see Section 4.1.3 and Table 4-4 for sediment ingestion rates for
    sandpipers.
4   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Maxson and Oring (1980).
5   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Maxson and Oring (1980).
6   Estimated using equation 3.-21 (Meeh, 1879 and Rubner,  1883, as cited in Walsberg and King, 1978) and body weights from Maxson and Oring
    (1980).
7   Spotted sandpipers are determinate layers, with a clutch size of four eggs. Clutches with fewer eggs are not complete or have lost eggs; larger
    clutches are the result of more than one female laying in a nest.
in
TJ
CD
Q.
CO

Q.
•
CD
-------
References (including Appendix)

Bent, A. C. (1929) Life histories of North American shore birds. Part 2. Washington, DC:
       U.S. Government Printing Office; Smithsonian !nst. U.S. Nat. Mus., Bull. 146.

Calder, W. A.; Braun, E.  J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Dunning, J. B., Jr. (1984) Body weights of 686 species of North American birds. Western
       Bird Banding Association, Monograph No. 1. Cave Creek, AZ: Eldon Publishing.

Kuenzel, W. J.; Wiegert, R. G. (1973) Energetics of a spotted sandpiper feeding on brine
       fly larvae (Paracoenia; Diptera: Ephydridae) in a thermal spring community. Wilson
       Bull. 85: 473-476.

Lank, D. B.; Oring, L. W.; Maxson, S. J. (1985) Mate and nutrient limitation of egg-laying
       in a polyandrous shorebird. Ecology 66: 1513-1524.

Lasiewski, R.  C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
       variables in resting birds. Resp. Phys. 11: 152-166.

Maxson, S. J.; Oring, L.  W.  (1980) Breeding season time and energy budgets of the
       polyandrous spotted sandpiper. Behaviour 74: 200-263.

Meeh,  K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987)  Field guide to the birds of North America.
       Washington, DC:  National Geographic Society.

Oring,  L. W. (1982) Avian mating systems. In: Farner, D. S.; King, J. R., eds. Avian
       biology, v.  6. New York, NY: Academic Press; pp. 1-92.

Oring,  L. W.; Lank, D.  B. (1982) Sexual selection, arrival times, philopatry and site fidelity
       in the polyandrous spotted sandpiper. Behav. Ecol. Sociobiol. 10: 185-191.

Oring,  L. W.; Lank, D.  B. (1986) Polyandry in spotted sandpipers:  the impact of
       environment and experience. In: Rubenstein, D. I.; Wrangham, R. W.,  eds.
       Ecological aspects of social evolution - birds and mammals; pp.  21-42.

Oring,  L. W.; Lank, D.  B.; Maxson, S. J. (1983) Population studies of the  polyandrous
       spotted sandpiper. Auk 100: 272-285.

Oring,  L. W.; Lank, D.  B.; Maxson, S. J. (1984) Mate and nutrient limitation of breeding in
       the polyandrous spotted sandpiper (abstract only). Am. Zool. 24: 60A.
                                      2-155
Spotted Sandpiper
-------
Oring, L. W.; Fivizzani, A. J.; Halawani, M. E. (1986) Changes in plasma prolactin
      associated with laying and hatch in the spotted sandpiper. Auk 103: 820-8-22.
Oring, L.W.; Colwell, M.A.; Reed, J.M. (1991 a) Lifetime reproductive success in the
      spotted sandpiper (Actitis macu/ar/a): sex differences and variance components.
      Behav. Ecol. Sociobiol. 28: 425-432.

Oring, L.W.; Reed, J.M.; Colwell, M.A.; et al. (1991b) Factors regulating annual mating
      success and reproductive success in spotted sandpipers (Actitis macularia). Behav.
      Ecol. Sociobiol. 28: 433-442.

Palmer, R. S. (1949) Maine birds. Bull. Mus. Comp. Zool. Harvard No. 102.

Poole, E. L. (1938) Weights and wing areas in North American birds. Auk 55: 511-517.

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
      Biol. 19: 535-562.

Walsberg, G. E.; King, J.R. (1978) The relationship of the external surface area of birds to
      skin surface area and body mass. J.  Exp. Biol. 76: 185-189.

Zar, J. H. (1968) Standard metabolism comparisons  between orders of birds. Condor 10:
      278.
                                      2-156
Spotted Sandpiper
-------
2.1.12.   Herring Gull  (gulls)

       Order Charadriiformes, Family Laridae. Gulls are medium- to large-sized sea birds
with long pointed wings, a stout, slightly hooked bill, and webbed feet.  They are
abundant in temperate coastal areas and throughout the Great Lakes. Although gulls may
feed from garbage dumps  and landfills, most take natural prey.  Gulls nest primarily in
colonies, although some of the larger species also nest solitarily. Many populations
migrate annually between  breeding and wintering areas.  North  American gull species
range in size from Bonaparte's gull (33 cm bill tip to tail tip) to the great black-backed gull
(76 cm).

Selected species

       The  herring gull (Larus argentatus) (64 cm) has the largest range of any North
American gull, from Newfoundland south to the Chesapeake Bay along the north Atlantic
and west throughout the Great Lakes into Alaska. Along the Pacific coast, the similar-
sized western gull (L. occidentalism  is the ecological equivalent of the herring  gull.  Both
species take primarily natural foods, especially fish, although  some individuals of both
species forage around fishing operations and landfills  (Pierotti, 1981, 1987; Pierotti and
Annett, 1987). The increase in number of herring gulls  in this century has been attributed
to the increasing abundance of year-round  food supplies found in landfills (Drury, 1965*;
Harris, 1970); however, birds specializing on garbage have such low reproductive success
that they cannot replace themselves in the population (Pierotti and Annett, 1987, 1991).
An alternative explanation  of the species' expansion is that cessation of taking of gulls by
the feather industry in the  late 1800's has allowed gull numbers to return to pre-
exploitation levels (Graham,  1975).

       Body size.  Adult females (800 to 1,000 g) are significantly smaller than males
(1,000 to 1,300 g) in both the herring gull (Greig et al.,  1985) and the western gull
{Pierotti, 1981). Chicks grow from their hatching weight of about 60 to 70 g to 800 to
900 g within 30 to 40 days, after which time their weight stabilizes (Dunn and Brisbin,
1980;  Norstrom et al., 1986; Pierotti, 1982). Norstrom et al. (1986) fitted chick growth
rates to the Gompertz equation as follows:
                         -e(-0.088(t- 14.8))
             BW = 997 e

             BW = ii93e-e(-°-075(t-16-3))
for females, and

for males,
where BW equals body weight in grams and t equals days after hatching.  Adults show
seasonal variation in body weight (Coulson et al., 1983; Norstrom et al., 1986).

      Habitat.  Nesting colonies of herring gulls along the northeastern coast of the
United States are found primarily on sandy or rocky offshore or barrier beach islands
(Kadlec  and Drury, 1968). In the Great Lakes, they are found on the more remote,
secluded, and protected islands and  shorelines of the  lakes and their connecting rivers
(Weseloh, 1989). Smaller colonies or isolated pairs also can be found in coastal marshes
(Burger, 1980a), peninsulas, or cliffs along seacoasts, lakes, and rivers (Weseloh, 1989),
                                       2-157
                     Herring Gull
-------
 and occasionally in inland areas or on buildings or piers (Harris, 1964). Gulls are the most
 abundant seabirds offshore from fall through spring, and are only found predominantly
 inshore during the breeding season in late spring and summer (Powers, 1983; Pierotti,
 1988). Gulls forage predominantly offshore, within  1 to 5 km of the coast (Pierotti,
 1988). In all seasons the number of birds feeding at sea outnumber those feeding inshore
 (data from Powers, 1983; Pierotti, pers. comm.).  Inshore, herring gulls forage primarily in
 intertidal zones but also search for food in wet fields, around lakes, bays, and rock jetties,
 and at landfills in some areas (Burger, 1988). In Florida, herring gull presence at landfills is
 restricted to the winter months (December through April) and may consist primarily of
 first-year birds that migrated from more northerly populations (e.g., from the Great Lakes)
 (Patton, 1988).

       Food habits.  Gulls feed on a variety of foods depending on availability, including
 fish, squid, Crustacea, molluscs,  worms, insects, small mammals and birds, duck and gull
 eggs and chicks, and garbage  (Bourget, 1973;  Burger, 1979a; Fox et al., 1990; Pierotti
 and Annett, 1987).  Gulls forage on open water by aerial dipping and shallow diving
 around concentrations of prey. At sea, such concentrations often are associated with
 whales or dolphins, other seabirds, or fishing boats (McCleery and Sibly, 1986;  Pierotti,
 1988). In the Great Lakes, concentrations of species such as alewife occur seasonally
 (e.g., when spawning) (Fox et al., 1990). Gulls also forage by stealing food from other
 bitds and by scavenging around human refuse sites (e.g., garbage dumps, fish plants,
 docks, and seaside parks) (Burger and Gochfeld, 1981; 1983; Chapman and Parker,
 1985). Individual pairs of gulls may specialize predominantly on a single type of food; for
 example, three quarters of a population of herring gulls in Newfoundland were found to
 specialize either  on blue mussels, garbage, or adults  of Leach's storm-petrel, with 60
 percent of the specialists concentrating on mussels between 0.5 and 3 cm in length
 (Pierotti and Annett, 1987; 1991). Diet choices may change with the age and experience
 of adult birds as well as with availability of prey (Pierotti and Annett, 1987; 1991).
 Females take smaller prey and feed less on garbage than do males (Pierotti, 1981; Greig et
 al., 1985). For example. Fox et al. (1990) found females to feed more on smelt (100 to
 250 mm) and males more on alewife (250 to 300 mm) in the Great Lakes region. Adult
 gulls sometimes attack and eat chicks of neighboring gulls or other species of seabird
 (Brown, 1967; Schoen and Morris, 1984).  Juveniles up to 3 years of age forage less
 efficiently than adults (Greig et al., 1983; MacLean,  1986; Verbeek, 1977).  In the Great
 Lakes, herring gulls' high consumption of alewife during their spawn may result in high
 exposures of the gulls to lipophilic contaminants that biomagnify (Fox et al., 1990).

       Metabolism. Norstrom et  al. (1986) have estimated an annual energy budget for
free-living female herring gulls that breed in the Great Lakes and an annual energy budget
 for free-living juvenile herring gulls in the Great  Lakes in their first year. Between
September and March, the nonbreeding season, they estimate that adult females require
 250 to 260 kcal/day. Following a dip in energy requirements to 210 kcal/day when the
male feeds the female during courtship, the female's needs increase to peak at 280
 kcal/day for egg  production, then fall to approximately  210 kcal/day during incubation.
The energy required to forage for food for the chicks is substantial, rising through July to
 peak in August at 310  to 320 kcal/day, then declining again until September when feeding
chicks has ceased.  These estimates compare well with those derived from Nagy's (1987)
equation to estimate free-living metabolic rates  for seabirds, except that the energy peaks
                                       2-158
Herring Gull
-------
required to produce eggs and to feed chicks are not included in Nagy's model.  Readers
interested in the metabolic rates of first-year herring gulls are referred to Norstrom et al.
(1986). Ellis (1984) provides an overview of seabird energetics and additional discussion
of approaches and models for estimating metabolic rates of free-ranging  seabirds.

       Molt.  Gull chicks are downy gray with dark brown spotting and molt into a dark-
gray or brown mottled juvenile plumage. At the end of the first year, portions of the
plumage have paled, and by the second year, gray plumage develops along the back and
top of wings.  By their third year,  young gulls resemble dirty adults, and  they acquire their
full adult plumage by 4 years (Harrison, 1983; Kadlec and Drury, 1968). Adult gulls, at
least in some populations, begin their primary feather molt during incubation and complete
the molt by mid- to late fall (Coulson et al., 1983). They molt and replace the large body
feathers from mid-summer to early fall  (Coulson et al., 1983).

       Migration. Herring gull populations  along the northeast coast of North America tend
to be migratory, while adult herring gulls of the Great Lakes are year-round residents.
Along the western North Atlantic, most herring gulls arrive on their breeding grounds
between late February and late April. They remain until late August or early September
when they leave for their wintering grounds along the Atlantic and Gulf coasts or well
offshore (Burger, 1982; Pierotti, 1988). Adult and older subadult herring gulls in the Great
Lakes area are essentially nonmigratory (Mineau et al., 1984; Weseloh et al., 1990).
Thus, in contrast to other fish-eating birds  in the Great Lakes system that migrate south in
the winter, herring gulls are exposed to any contaminants that may be in Great Lakes' fish
throughout the year (Mineau et  al., 1984).  Postbreeding dispersal away from breeding
colonies begins in late July and  ends in August, with all ages traveling short distances.
Great Lakes herring gulls less than a year old usually migrate to the Gulf  or Atlantic coast
(Smith, 1959; Mineau et al., 1984), traveling along river systems and the coast (Moore,
1976).

       Breeding activities and social organization.  Gulls nest primarily in colonies on
offshore islands, and nest density is strongly affected by population size (Pierotti, 1981;
1982; 1987).  Typically, males arrive at the breeding grounds first and establish territories.
Both sexes, build the nest of vegetation on  the ground in areas that are sheltered from
wind but may be exposed to the sun (Pierotti, 1981;  1982).  Males feed females for 10 to
15 days prior to the start of egg laying  (Pierotti, 1981). From the laying  of the  first egg
until the chicks are 3 to 4 weeks old, one or both parents will be present at all times
(Tinbergen, 1960).  Males perform most territorial defense, females perform most
incubation, and both parents feed the chicks until they are at least 6 to 7 weeks old
(Burger, 1981;  Pierotti, 1981; Tinbergen, 1960).  All gulls are strongly monogamous; pair
bonds can  persist for 10 or more years and usually only are  terminated by the death of a
mate or failure to reproduce successfully (Tinbergen,  1960).  Males may be promiscuous in
populations with more females than males (Pierotti, 1981).  Herring gull colonies often are
found in association with colonies of other species, including other gulls  (Bourget, 1973;
Brown, 1967).  In some nesting colonies, gulls attack chicks of neighboring gulls and other
species (Brown, 1967; Schoen and Morris,  1984).

       Home range and resources.  During  the breeding season, herring gulls defend a
territory of several tens of square meters around the immediate vicinity of the nest
                                       2-159
Herring Gull
-------
(Burger, 1980b).  Their daily foraging range depends on the availability of prey and on the
foraging strategy, age, and sex of the gull.  Using radiotelemetry on gulls in the Great
Lakes, Morris and Black (1980) demonstrated that some parents with chicks forage at
specific locations within 1 km of the colony whereas other parents make extended flights
to destinations across a lake more than 30 km away.  Similarly, gulls that feed at sea may
range tens of kilometers from their nest whereas gulls from the same colony feeding in the
intertidal zone may travel less than .1 km (Pierotti and Annett, 1987; 1991). Males
typically range farther than females and take larger prey items (Pierotti and Annett,  1987;
1991). At sea during the ngnbreeding season, gijlls may range hundreds of kilometers
during a day (Pierotti, pers. comm.).

      Population density.  As described above, population density is determined by
available nesting space, size of the breeding population, and quality of habitat.  Small
islands with good feeding areas nearby can have several hundred nests per hectare
(Kadlec, 1971; Parsons, 1976b; Pierotti, 1982).  In poor quality habitat, some pairs nest
solitarily without another nest for several kilometers (Weseloh, 1989).

      Population dynamics.  Herring gulls and western gulls usually do not begin breeding
until at least 4 years of age for males and 5 years of age for females (Burger, 1988;
Pierotti, 1981; Pierotti, pers. comm.).  Kadlec and Drury (1968) suggest that in  a given
year, 15 to 30 percent of adults of breeding age do not breed. Most breeding females
produce three-egg clutches, but individuals in poor condition may lay only one or two eggs
(Parsons,  1976a; Pierotti, 1982; Pierotti and Annett, 1987; 1991).  Herring gulls will lay
replacement eggs if all or a portion of their original clutch is destroyed (Parsons,  1976a).
Hatching success appears to be influenced by female diet, with garbage specialists
hatching a smaller percentage of eggs than fish or intertidal (mussel) specialists (Pierotti
and Annett, 1987, 1990, 1991).   Predation, often by gulls of the same or other species,
also contributes to egg losses (Paynter, 1949; Harris, 1964; Davis, 1975).  Many herring
gull chicks that hatch die before fledging, most within the first 5 days after hatching
(Harris, 1964; Kadlec et al., 1969; Brown, 1967). Adult mortality is low (around 10
percent per year), and some birds may live up to 20 years (Brown,  1967; Kadlec and
Drury, 1968).  Subadult birds exhibit higher mortality (20 to 30 percent per year) (Kadlec
and Drury, 1968; Chabrzyk and Coulson, 1976).

Similar species (from general references)

      •      The western gull (Larus occidentalis) (64 cm), found on the Pacific coast of
             the United States, is the ecological equivalent of the herring gull and is
             similar in size (53 cm); males range from 1,000 to 1,300 g and females from
             800 to 1,000 g (Pierotti, 1981).

      •      The glaucous gull (Larus hyperboreus] is larger (69 cm) than the herring gull
             and is the predominant gull breeding in the high arctic.  Birds from  Alaska
             are slightly smaller than birds from eastern Canada.

      •      The glaucous-winged gull (Larus glaucescens) is similar in size to the herring
             gull (66 cm) and is the primary breeding species north of the Columbia River.
             This species hybridizes extensively with the herring gull in Alaska.
                                       2-160
Herring Gull
-------
       •      The California gull (Larus californicus) is smaller (53 cm) than the herring
             gull.  This species breeds primarily in the Great Basin Desert and winters
             along the Pacific coast.

       •      The great black-backed gull (Larus marinus) is the largest species of gull (76
             cm) in North America and breeds from Labrador to Long Island.

       •      The ring-billed gull (Larus delawarensis) is of average size (45 cm) and is the
             most common breeding gull in the Great Lakes and northern prairies.

       •      Franklin's gull (Larus pipixcan) is a small (37 cm), summer resident of the
             Great Plains.

General references

       For general information: Harrison (1983); National Geographic Society (1987);
Tinbergen (1960); Graham (1975). For discussion of diet: Burger (1988); Fox et al.
(1990); Pierotti (1981);  Pierotti and.Annett (1987).
                                       2-161
Herring Gull
-------
                                          Herring Gull (Larus argentatus]
Factors
Body Weight
(9)

-
--"
Chick Growth
Rate fgyday)

£
-------
                                          Herring Gull (Larus argentatus)

Factors
Food Irigestion
Rate (g/g-day)


Water
Ingestion Rate
(g/g-day)
Inhalation Rate
(m3/day)
Surface Area
(cm2)
Age/Sex
Cond./Seas,
A M breeding
A F breeding
A M breeding
A F breeding
AM
AF

"AM
AF
AM
AF
Dietary
Composition
months;

Mytifus edulis
sea urchin
flsh
Oceanodroma
letichorhoa
Fratercula arctica
aduits
Fratercula, Uria
chicks
Larus sj); eggs
Vaccinum
angustjfoiium
Gadus morhua
offef
assorted refuse
-
Mean
0.20
0.21
0.19
0.18
0.055
0.059

0.48
0.41
1,150
1,001

Summer
Mid-May/
Mid-June
30.9
5.8
11.4
22.4

5.8

0.0

3.1
-

12.4

5.8
-
Summer
Mid-June/
Mid-July
0.9
0.0
71.1
7.0

0.0

3.5

0.9
-

1.7

0.9
Range or
(95% Cl of mean}












Summer
Mid-July/
Mid-Aug.
9.1
4.5
18.9
15.9

1.5

9.1

0.8
9.9

14.4

6.8

Summer


















Location ,,
Newfoundland -
diet of mussels
Newfoundland -
• diet of garbage


*




Location/Habitat
(measure]
Newfoundland/island

(% occurrence in
regurgitations and
pellets)

*











Reference
Pierotti & Annett, 1991

Pierotti & Annett, 1991

estimated


estimated

estimated


Reference
Haycock & Threlfal!, 1975
















Note
No.
4

5

6.


7

8

Note
No.

















O)
CO
I
CD
(Q
-------
                                          Herring Gull (Larus argentatus}
Dietary
Composition
year'.
American smelt
alewtfe
other -fish
birds
voles
insects & refuse
laker
fish
insects?
offaK garbage
gulf chicks
adutt birds ;
amphibians;
earthworms , •,
crayfish
snails
crabs !
garbage
; offal
worms f
other inverts.-? *
,fish >>

Summer
1978
46.1
23.1
20.5
2.6
2.6
12.8
Ontario
91.8
5.5
0.5
2.2
1.6
0.5
2.2
0







Population Age/Sex/
Dynamics Cond./Seas.
foraging A M
Radius (kmj A F
Population summer
Density
fftests/ha)
summer

•

Summer
1979
18.4
73.7
0
2.6
2.6
0
Erie
94.1
5.9
2.9
0
0
0
0
0
3
14
27
5
23
28
unknown


Summer

61
1980
.2
16.7
3
13
3
3

75
5
13
1
1
0
11
0
.4
.8
.4
.4
Huron
.8
.6
.6
.0
.0

.6
.5


Mean
10to 15
5 to 10
227


217
75


Summer
1981
57.8
23.4
3.1
6.2
9.4
0
Superior
38.6
42.1
21.0
0
3.5
0
1.7
0








Range
3-50
3-25
138-350





Location/Habitat
(measure)
Lake Ontario

(% occurrence in
regurgitations from and
stomach contents of
incubating adults)

Great Lakes

(% occurrence in boli
regurgitated by chicks)





CA,FL,NY,NJ,TX/
coastal

(% of gulls feeding on items)

offshore feeding on fish was
not included in observations

Location/Habitat
NS/coastal

Massachusetts/coastal
islands

Newfoundland/island - rocky .
Newfoundland/island -
grassy slope

Reference
Foxetal., 1990






Fox et al., 1 990








Burger, 1988







Reference
Pierotti, pers. comm.

Kadlec, 1971


Pierotti, 1982
Pierotti, 1982

Note
No.























Note
No,








[0


en
X
CD
3
CO
-------
                                          Herring Gull (Larus argentatus}
Population
Dynamics
Clutch
Size






Clutches/Year
Days
Incubation
Age at
Fledging
(days}
Number Fledge
per
Active Nest


Number
Fledge per
Successful
Nest
Age at
Sexual
Maturity

Annual
Mortality Rates
(percent)

Age/Sex/
.CondJSeas*














3 colonies

6 colony-yrs
3 colony-yrs
6 colony-yrs
3 colonies



F
M

B
A B

J B
AB

Mean
2.78

2.54

2.38

2.84 ± 0.44 SD

1
30.5
29
51
43

1.42

1.65
1.78
2.19
1.80



5 years
4-5 years

4.3 to 5.8
8

22
7.3

Range
2.51 - 2.90
(over 8 sites)
1 -6
(per nest)
2.3 - 2.8
(over 1 1 years)


1 -2*
28-33

35-44td 56-61
31 to 52

1.40- 1.44

1.40-2.13
1.62- 2.10
2.16-2.25
1.79-1.80






3-8


17-33


Location/Habitat
New Jersey/salt marsh
islands
NE United States/coastal

Maine/coastal islands

Lake Superior, Canada/
islands
(* if first eggs lost)
Holland/NS
Newfoundland/island
Massachusetts/coastal island
New Brunswick/island

New Jersey /coastal

Lake Ontario/lakeshore
Lake Erie/lakeshore
Lake Huron/lakeshore
New Jersey /coastal



throughout range/NS


Scotland/coastal
New England/coastal

Scotland/coastal


Reference
Burger, 1979b

Nisbet & Dairy, 1 984

Hunt, 1972

Meathrel et al., 1 987

Burger, 1979a; Bourget, 1973
Tinbergen, 1960
Pierotti, 1982
Kadlec et al., 1969
Paynter, 1949

Burger & Shisler, 1 980

Mineau et al., 1984
{minimum and maximum are
yearly means)
Burger & Shisler, 1980



Greig et al., 1 983; Pierotti,
pers. comm.

Coulson et al., 1 982
Kadlec & Drury, 1 968

Chabryzk & Coulson, 1976

Note
No,










9




















S3
01
I
CD
(Q

o
c
-------
                                                        Herring Gull (Larus argentatus]
Population
Dynamics
Longevity
Seasonal
Activity
Mating/
Laying
Hatching
Migration
spring
fall
Molt
Age/Sex/
Cond./Seas.
AB
Begin
late April
early May
early May
early May
May
early June
late June
February
August
June
Mean
10
Range
up to 30 years
.-.PeakiB- ;•:;.. .; "-••:
early May
mid-May
mid-May
late May
mid - late May
June
mid-June
late June

July
Ehdl •: ..• ;..;.
early June
early June
mid-June
end May
July
end June
mid-July
late April
September
August
Location/Habitat
NS/NS
Location
ne shore Lake Superior
Maine
New Jersey
Newfoundland
Great Lakes
Massachusetts
Newfoundland
New Brunswick
northwestern Atlantic
populations
Newfoundland
Reference
Pierotti, pers. comm.
Reference . :
Morris & Haymes, 1 977
Bourget, 1973
Burger, 1977, 1979b
Pierotti, 1982
Fox et al., 1990
Kadlec, 1971
Pierotti, 1982, 1987
Paynter, 1949
Burger, 1982
Pierotti, pers. comm.
Note
No.

Note
No.




ro
_A
O)
en
CD
CQ
O
c
1   Weight of chicks from first egg laid in 1978 for the rocky island and in 1977 for the grassy area.  In some years and some locations, chicks from
    the first egg were heavier than the rest, and at other times and locations, the first chick was lighter.
2   Estimated using equation 3-29 (Lasiewski and Dawson, 1967) and body weights from Threlfall and Jewer (1978).
3   Estimated using equation 3-38 (Nagy, 1987) and body weights from Threlfall  and Jewer (1978).
4   Estimated using 11.2 meals of mussel consumed per day per pair, weight of 80 g  per mussel meal of which half is shell and not included in
    ingestion rate, assuming that the female accounts for 46 percent of pair's energy requirement and the male accounts for 54 percent, and using the
    body weights of Threlfall and Jewer (1978).
5   Estimated using 4.2 meals of garbage consumed per day per pair, weight of 100 g per garbage  meal, assuming that the female accounts for 46
    percent of pair's energy requirement and the male accounts for 54 percent, and using the body weights of Threlfall and Jewer (1978).
6   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Threlfall and Jewer (1978).
7   Estimated using equation 3-19 (Lasiewski and Calder, 1971) and body weights from Threlfall and  Jewer (1978).
8   Estimated using equation 3-21  (Meeh, 1879 and Rubner, 1883, as cited in Walsberg and King,  1978) and body weights from  Threlfall and Jewer
    (1978).
9   Beginning with first egg.
-------
References (including Appendix)

Belopol'skii, L. O. (1957) (Ecology of sea colony birds of the Barents Sea). Translated by:
       Israel Program for Scientific Translations, Jerusalem (cited in Dunning, 1984).

Bourget, A. A. (1973) Relation of eiders and gulls nesting in mixed colonies in Penobscot
       Bay, Maine. Auk 90: 809-820.

Brown, R. G. (1967) Breeding success and population growth in a colony of herring gulls
       and lesser black-backed gulls Larus argentatus and L.  fuscus. Ibis 109: 502-515.

Burger, J. (1977) Nesting behavior of herring gulls: invasion into Spartina salt marsh areas
       of New Jersey. Condor 79: 162-169.

Burger, J. (1979a) Competition and predation: herring gulls versus laughing gulls. Condor
       81: 269-277.

Burger, J. (1979b) Colony size: a test for breeding synchrony in herring gull (Larus
       argentatus)  colonies. Auk 96: 694-703.

Burger, J. (1980a) Nesting adaptation of herring gull  (Larus argentatus) to salt marshes
       and storm tides. Biol. Behav. 5: 147-162.

Burger, J. (1980b) Territory size differences in relation to reproductive stage and type of
       intruder in herring gulls (Larus argentatus). Auk 97: 733-741.

Burger, J. (1981) On becoming independent in herring gulls: parent-young conflict. Am.
       Nat. 117: 444-456.

Burger, J. (1982) Herring gull. In: Davis, D. E., ed. CRC handbook of census methods  for
       terrestrial vertebrates. Boca Raton, FL: CRC Press; pp. 76-79.

Burger, J. (1988) Foraging behavior in gulls: differences in method, prey, and habitat.
       Colonial Waterbirds 11: 9-23.

Burger, J.; Gochfeld, M.  (1981) Age-related differences in  piracy behavior of four species
       of gulls, Larus. Behaviour 77: 242-267.

Burger, J.; Gochfeld, M.  (1983) Behavior of nine avian species at a Florida garbage dump.
       Colonial Waterbirds 6: 54-63.

Burger, J.; Shisler, J. (1980) The process of colony formation among herring gulls Larus
       argentatus nesting in New Jersey. Ibis 122: 15-16.

Calder, W. A.; Braun, E.  J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.
                                       2-167
Herring Gull
-------
Chabrzyk, G.; Coulson, J. C. (1976) Survival and recruitment in the herring, gull Larus
       argentatus. J. Anim. Ecol. 45: 187-203.

Chapman, B.-A.; Parker, J. W. (1985) Foraging areas, techniques, and schedules of
       wintering gulls on southeastern Lake Erie. Colonial Waterbirds 8: 135-141.

Coulson, J. C.; Duncan, N.; Thomas, C. (1982) Changes in the breeding biology of the
       herring gull (Larus argentus) induced by reduction in size and density of the colony.
       J. Anim. Ecol. 51: 739-756.

Coulson, J. C.; Monaghan, P.; Butterfield, J.; et al. (1983) Seasonal changes in the herring
       gull in Britain: weight, moult and mortality,, Ardea 71: 235-244.

Davis, J. W. (1975) Age, egg-size and breeding success in the herring gull Larus
       argentatus. Ibis 117: 460-473.

Drury, W. H., Jr. (1965) Clash of coastal nesters. MA: Audubon.

Dunn, E. H. (1976) The development of endothermy and existence energy expenditure in
       herring gull chicks. Condor 78: 493-498.

Dunn, E. H. (1980) On the variability in energy allocation of nestling birds. Auk 1: 19-27.

Dunn, E. H.; Brisbin, I. L. (1980) Age-specific changes in the major body components and
       caloric values of herring gull chicks. Condor 82: 398-401.

Dunning, J. B., Jr. (1984) Body weights of 686 species  of North American birds. Western
       Bird Banding Association, Monograph No. 1. Cave Creek, AZ: Eldon Publishing.

Ellis, H. I. (1984) Energetics of free-ranging seabirds. In: Whittow, G. C.; Rhan, H., eds.
       Seabird energetics. New York, NY: Plenum Press; pp. 203-234.

Erwin, R. M. (1971) The breeding success of two species of sympatric gulls, the herring
       gull and the great black-backed gull. Wilson Bull.  83: 152-158.

Ewins, P. J.; Weseloh, D. V.; Groom, J. H.; et al.  (unpublished 1991) The diet of herring
       gulls (Larus argentatus) during winter and early spring on the lower Great Lakes
       (unpublished manuscript, Canadian Wildlife Service, Burlington, Ontario).

Fox, G. A.; Allan, L. J.; Weseloh, D. V., et al. (1990) The diet of herring gulls during  the
       nesting period in Canadian waters of the Great  Lakes. Can. J. Zool.  68: 1075-
       1085.

Graham, F. (1975) Gulls: a social history. New York, NY: Random House.

Greig, S. A.; Coulson, J. C.; Monaghan, P.  (1983) Age-related differences in foraging
       success in the herring gull (Larus argentatus). Anim. Behav. 31: 1237-1243.
                                       2-168
Herring Gull
-------
Greig, S. A.; Coulson, J. C.; Monaghan, P. (1985) Feeding strategies of male and female
      adult herring gulls Laws argentatus. Behaviour 94: 41-59.

Gross, A. 0. (1940) The migration of Kent Island herring gulls. Bird-Banding 11: 129-155.

Harris, M. P. (1964) Aspects of the breeding biology of the gulls: Lams argentatus, L.
      fuscus, and L. marfnus. Ibis 106: 432-456.

Harris, M. P. (1970) Rates and causes of increases of some British gull populations. Bird .
      Study 17:325-335.

Harrison, P. (1983) Seabirds: an identification guide. Boston, MA: Houghton-Mifflin Co.

Haycock, K. A.; Threlfall, W. (1975) The breeding biology of the herring gull in
      Newfoundland. Auk 92: 678-697.

Hebert,  P. N.; Barclay, R. M. (1986) Asynchronous and synchronous hatching: effect on
      early growth and survivorship of herring gull, Larus argentatus,  chicks. Can. J. Zool.
      64:  2357-2362.

Hebert,  P. N.; Barclay, R. M. (1988) Parental investment in herring gulls: clutch
      apportionment and chick survival. Condor 90: 332-338.

Holley, A. J. (1982) Post-fledging interactions on the territory between parents and young
      herring gulls Larus argentatus. Ibis  124: 198-203.

Hunt, G. L. (1972) Influence of food distribution  and human disturbance on the
      reproductive success of herring gulls. Ecology 53: 1051-1061.

Kadlec,  J. A. (1971) Effects of introducing foxes and raccoons on herring gull colonies. J.
      Wiidl. Manage. 35: 625-636.

Kadlec,  J. A. (1976) A re-evaluation of mortality rates in adult herring  gulls. Bird-Banding
      47:8-12.

Kadlec,  J. A.; Drury, W. H. (1968) Structure of the New England herring gull population.
      Ecology 49: 644-676.

Kadlec,  J. A.; Drury, W. H.; Onion, D. K. (1969) Growth and mortality of  herring gull
      chicks. Bird-Banding 40:  222-233.

Keith, J. A. (1966) Reproduction in a population  of herring gulls (Larus argentatus)
      contaminated by DDT. J. Appl. Ecol. 3(suppl.): 57-70.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis of respiratory
      variables in resting birds. Resp. Phys. 11:  152-166.
                                       2-169
Herring Gull
-------
 Lasiewski, R. C.; Dawson, W. R. (1967) A reexamination of the relation between standard
       metabolic rate and body weight in birds. Condor 69: 12-23.

 Lustick, S.; Battersby, B.; Kelty, M. (1978) Behavioral thermoregulation: orientation
       toward the sun in herring gulls. Science 200: 81-83.

 Lustick, S.; Battersby, B.; Kelty, M. (1979) Effects of insolation on juvenile herring gull
       energetics and behavior. Ecology 60: 673-678.
 *
 Maclean, A. A.  (1986) Age-specific foraging ability and the evolution of deferred breeding
       in three species of gulls. Wilson Bull. 98: 267-279.

 McCleery, R. H.; Sibley, R. M. (1986) Feeding specialization and preference in herring
       gulls. J. Anim. Ecol. 55: 245-259.

 Meathrel, C. E.;  Ryder, J. P.; Termaat, B. M. (1987) Size and composition of herring gull
       eggs: relationship to position in the laying sequence and the body condition of
       females. Colonial Waterbirds 10: 55-63.

 Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol.  15: 426-458.

 Mendall, H. L. (1939) Food habits of the herring gull in relation to freshwater game fishes
       in Maine. Wilson  Bull. 41: 223-226.

 Mineau, P.; Fox, G. A.; Norstrom, R. J.; et al. (1984) Using the  herring  gull to monitor
       levels and effects of organochlorine contamination in the Canadian Great Lakes. In:
       Nriagu, J. O.;  Simmons, M. S., eds. Toxic contaminants in the Great Lakes. New
       York, NY: John Wiley & Sons; pp.  425-452.

 Moore, F. R. (1976) The dynamics of seasonal distribution of  Great Lakes herring gulls.
       Bird-Banding 47:  141-159.

 Morris, R. D.; Black, J. E. (1980) Radiotelemetry and herring gull foraging patterns. J. Field
       Ornithol. 51: 110-118.

 Morris, R. D.; Haymes, G. T. (1977) The breeding biology of two Lake Erie herring gull
       colonies.  Can. J. Zool. 55: 796-805.

 Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987) Field guide to the birds of North America.
       Washington, DC:  National Geographic Society.

Niebuhr, V. (1983) Feeding strategies and incubation behavior of wild herring gulls: an
       experiment using  operant feeding boxes. Anim. Behav. 31: 708-717.
                                       2-170
Herring Gull
-------
Nisbet, I. C.; Drury, W. H. (1984) Super-normal clutches in herring gulls in New England.
      Condor 86: 87-89.

Norstrom, R. J.; Clark, T. P.; Kearney, J. P.; et al. (1986) Herring gull energy requirements
      and body constituents in the Great Lakes.  Ardea 74: 1-23.

Olsson, V. (1958) Dispersal, migration, longevity  and death causes of Strix aluco, Buteo
      buteo, Ardea cinerea and Larus argentatus. A study based on  recoveries of birds
      ringed in Fenno-Scandia. Acta Vertebratica 1: 91-189.

Parsons, J. (1972) Egg size, laying date and incubation period in the  herring gull. Ibis 114:
      536-541.

Parsons, J. (1976a) Factors determining the number and size of eggs laid by the herring
      gull. Condor 78: 481-482.

Parsons, J. (1976b) Nesting  density and breeding success in the herring gull Larus
      argentatus. Ibis 118: 537-546.

Patton, S. R. (1988) Abundance of gulls at Tampa Bay landfills. Wilson Bull. 100:
      431-442.

Paynter, R. A. (1949)  Clutch size and the egg and chick mortality of  Kent Island herring
      gulls. Ecology 30: 146-166.

Pierotti, R. (1981) Male and female parental roles in the western gull  under  different
      environmental conditions. Auk 98: 532-549.

Pierotti, R. (1982) Habitat selection and its effect on reproductive output in the herring gull
      in  Newfoundland. Ecology 63: 854-868.

Pierotti, R. (1987) Behavioral consequences of habitat selection in the herring gull. Studies
      Avian Biol. 10:  119-128.

Pierotti, R. (1988) Associations between marine birds and mammals in the northwest
      Atlantic Ocean. In:  Burger, J., ed. Seabirds and other marine vertebrates. New
      York, NY: Columbia University Press; pp. 31-58.

Pierotti, R.; Annett, C. (1987) Reproductive consequences of dietary  specialization and
      switching in an ecological generalist. In: Kamil, A. C.; Krebs, J.; Pulliam, H. R., eds.
      Foraging behavior. New York, NY: Plenum  Press; pp. 417-442.

Pierotti, R.; Annett, C. A. (1990) Diet and reproductive output in seabirds: food choices by
      individual,  free-living animals can affect survival of offspring. BioSci. 40: 568-574.

Pierotti, R.; Annett, C. A. (1991) Diet choice in the herring gull: constraints imposed by
      reproductive and ecological factors. Ecology 72: 319-328.
                                       2-171
Herring Gull
-------
Poole, E. L. (1938) Weights and wing areas in North American birds. Auk 55: 511-517.

Powers, K. D. (1983) Pelagic distributions of marine birds off the northeastern U.S. NOAA,
       Tech.  Mem. NMFS-F/NED-27: 1-201.

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol. 19: 535-562.

Schoen, R. B.; Morris, R. D. (1984) Nest spacing, colony location, and breeding success in
       herring gulls. Wilson Bull. 96: 483-488.

Sibly, R. M.; McCIeery, R.  H. (1983) Increase in weight of herring gulls while feeding. J.
       Anim.  Ecol. 52: 35-50.

Smith, W. J.  (1959) Movements of Michigan herring gulls. Bird-Banding 30:  69-104.

Threlfall, W.;  Jewer, D. D. (1978) Notes on the standard body measurements of two
       populations of herring gulls (Larus argentatus). Auk 95:  749-753.

Tinbergen, N. (1960) The herring gull's world. New York, NY: Harper and Row, Publishers.

Verbeek, N. A. (1977) Comparative feeding behavior of immature and adult herring gulls.
       Wilson Bull. 89:415-421.

Vermeer, K. (1973) Food habits and breeding range of herring gulls in the Canadian prairie
       provinces. Condor 75: 478-480.

Walsberg, G., E.; King, J. R. (1978) The  relationship of the external surface area of birds to
       skin surface area and body  mass. J. Exp. Biol. 76: 185-189.

Weseloh, D. H. (1989) Herring  gull. In: Cadman, M. D.; Eagles, P. F.; Helleiner, F. M., eds.
       Atlas of the breeding birds of Ontario.  Waterloo, University of Waterloo Press; pp.
       182-183.

Weseloh, D. V.; Mineau, P.; Struger, J.  (1990) Geographical distribution of contaminants
       and productivity measures of herring gulls in the Great Lakes: Lake Erie  and
       connecting channels 1978/79. Sci. Tot. Environ. 91:  141-159.
                                      2-172
Herring Gull
-------
2.1.13.   Belted Kingfisher (kingfishers)

       Order Coraciiformes, Family Alcedinidae.  Kingfishers are stocky, short-legged birds
with large heads and bills. They exist on a diet mostly of fish, which they catch by diving,
from a perch or the air, head first into the water.  They nest jn burrows in earthen banks
that they dig using their bills and feet.

Selected species

       The belted kingfisher (Ceryle a/cyon, formerly Megaceryle alcyon) is a medium-sized
bird (33 cm bill tip to tail tip) that eats primarily fish. It is one of the few species of fish-
eating  birds found throughout inland areas as well as coastal areas.  The belted
kingfisher's range includes most of the North American continent; it breeds from northern
Alaska and central Labrador southward to the southern border of the United States (Bent,
1940). Two subspecies sometimes are recognized: the eastern belted kingfisher (Ceryle
alcyon alcyon), which occupies the range  east of the Rocky Mountains and north to
Quebec, and the western belted kingfisher (Cercyle a/cyon caurina), which occupies the
remaining  range to the west (Bent, 1940).

       Body size. The sexes are similar in size and appearance, although the female tends
to be slightly larger (Salyer and Lagler, 1946). Bent (1940) reported that western
populations are somewhat larger than eastern ones.  Nestlings reach adult body weight by
about 16 days after hatching, but  then may lose some weight before fledging (Hamas,
1981).

       Habitat. Belted kingfishers are typically found along rivers and streams and along
lake and pond  edges (Hamas, 1974).  They are also common on seacoasts and estuaries
(Bent,  1940).  They prefer waters that are free of thick vegetation that obscures the view
of the water and water that is not completely overshadowed by trees (Bent,  1940; White,
1953). Kingfishers also require  relatively clear water in order to see their prey and are
noticeably absent in areas when waters become turbid (Bent, 1940; Davis, 1982; Salyer
and Lagler, 1946). White (1953) suggested that water less than 60 cm deep is preferred.
They prefer stream riffles for foraging sites even when pools are more plentiful because of
the concentration of fish at riffle edges (Davis, 1982).  Belted kingfishers nest in burrows
within  steep earthen banks devoid of vegetation beside rivers, streams, ponds, and lakes;
they also have been found to nest in slopes created by human excavations such as
readouts and landfills (Hamas, 1974). Sandy soil banks, which are easy to excavate and
provide good drainage, are preferred (Brooks and Davis, 1987; Cornwell, 1963; White,
1953). In general, kingfishers nest near suitable fishing areas when possible but will nest
away from water and  feed in bodies of water other than the one closest to home
(Cornwell,  1963).

       Food habits.  Belted kingfishers generally feed on fish that swim near the surface or
in shallow water (Salyer and Lagler, 1946; White, 1953; Cornwell, 1963). Davis (pers.
comm. in Prose,  1985) believes that these kingfishers generally catch fish only in the
upper 12 to 15 cm of  the water column. Belted kingfishers capture fish by diving either
from a perch overhanging the water or after hovering above the water (Bent, 1940). Fish
                                       2-173
Belted Kingfisher
-------
 are swallowed whole, head first, after being beaten on a perch (Bent, 1940).  The average
 length of fish caught in a Michigan study was less than 7.6 cm but ranged from 2.5 to
 17.8 cm (Salyer and Lagler, 1946); Davis (1982) found fish caught in Ohio streams to
 range from 4 to 14 cm in length.  Several studies indicate that belted kingfishers usually
 catch the prey that are most available (White, 1937, 1953; Salyer and Lagler, 1946;
 Davis, 1982). Diet therefore varies considerably among different water bodies and with
 season (see examples in Appendix). Although kingfishers feed predominantly on fish, they
 also sometimes consume large numbers of crayfish (Davis, 1982; Sayler and Lagler,
 1946), and in shortages of their preferred foods, have been known to consume crabs,
 mussels, lizards, frogs, toads, small snakes, turtles, insects, salamanders, newts, young
 birds, mice, and berries (Bent, 1940).  Parents bring surprisingly  large fish to their young.
 White (1953) found that nestlings only 7 to 10 days old were provided fish up to 10 cm
 long, and nestlings only 2 weeks old were provided with fish up  to 13 cm in  length. After
 fledging, young belted kingfishers fed on flying insects for their first 4 days after leaving
 the nest, crayfish for the next week, and by the 18th day post-fledging, could catch fish
 (Salyer and Lagler, 1946).

       Molt.  The juvenile plumage is maintained through the  winter,  and  young birds
 undergo their first prenuptial molt in the spring (between February and April)  involving
 most of the body plumage (Bent, 1940).  Adults have a complete postnuptial molt in the
 fall (August to October) (Bent, 1940).

       Migration.  This kingfisher breeds over most of the area of North America and
 winters in most regions of the continental United States (National Geographic Society,
 1987). Although most northern kingfishers migrate to southern regions during the coldest
 months, some may stay in areas that remain ice-free where fishing is possible (Bent,
 1940).

       Breeding activities and social organization. During the breeding season, pairs
 establish territories for nesting and fishing (Davis, 1982); otherwise, belted kingfishers are
 solitary.  They are not colonial nesters and will defend an unused bank if it lies within their
 territory (Davis, 1982).  In migrating populations, the males arrive before the  females to
 find suitable nesting territories (Davis,  1982).  Kingfishers excavate their burrows in
 earthen banks, forming a tunnel that averages 1  to 2 m in length, although some burrows
 may be as long as 3 to 4 m (Hamas, 1981;  Prose, 1985). The burrow entrance is usually
 30 to 90 cm from  the top of the bank (Bent, 1940; White,  1953) and at least 1.5 m from
 the base  (Cornwell, 1963). Burrows closer to the top may collapse, and burrows too low
 may flood (Brooks and Davis, 1987).  Burrows may be used for more than one season
 (Bent, 1940).  Five to seven eggs are laid on bare substrate or on fish bones within the
 burrow (Hamas,  1981; White, 1953).  Only one  adult, usually the female, spends the night
 in the nest cavity;  males usually roost in nearby  forested areas or heavy cover (Cornwell,
 1963). Both parents incubate eggs and feed the young (Bent, 1940). After fledging, the
 young remain with their parents for 10 to 15 days  (Sayler and Lagler, 1946).

       Home range and resources.  During the breeding season, belted kingfishers require
suitable nesting sites with adequate nearby fishing. During spring and early summer, both
male and female belted kingfishers defend a territory that includes both their nest site and
their foraging area (Davis, 1982).  By autumn, each bird (including the young  of the year)
                                       2-174
Belted Kingfisher
-------
defends an individual feeding territory only (Davis, 1982).  The breeding territories (length
of waterline protected) can be more than twice as long as the fall and winter feeding
territories, and stream territories tend to be longer than those on lakes (Davis, 1982;
Salyer and Lagler, 1946).  Foraging territory size is inversely related to prey abundance
(Davis, 1982).

      Population density.  Breeding densities of between two and six pairs per 10 km of
river shoreline have been recorded, with density increasing with food availability (Brooks
and Davis, 1987; White, 1936).

      Population dynamics.  Kingfishers are sensitive to disturbance and usually do not
nest in areas near human activity (White, 1953; Cornwell,  1963).  Kingfishers typically
breed in the first season after they are born (Bent, 1940).  Fledging success depends on
food availability, storms, floods, predation, and the integrity of the nest burrow but can  be
as high as 97 percent (M. J. Hamas, pers. comm.).  Dispersal of young occurs within  a
month of fledging (White, 1953). No data concerning annual survivorship rates were
found.

Similar species (from general references)

      •      The green kingfisher  (Chloroceryle americana) is smaller (22 cm) than the
             belted kingfisher and is only common in the lower Rio Grande Valley.  It also
             is found in southeastern Arizona and along the Texas coast, usually during
             fall  and winter.

      «      The ringed kingfisher (Ceryle torquata) is larger (41 cm) and resides in the
             lower Rio Grande Valley in Texas and Mexico.

General references
      Bent (1940); Fry (1980); National Geographic Society (1987); Prose (1985); White
(1953).
                                       2-175
Belted Kingfisher
-------
                                             Belted Kingfisher (Cery/e alcyon}
Factors
Body Weight
,
••
: ^ ,;
/'"' •> "
Nestling
Growth Rate
(g/day)
Metabolic Rate -
IkcaJ/kg-dayl
Food Ingestion
Rate (g/g-day)
Water
Ingestion Rate .
fg/g-day]
Inhalation
Bate jffl^/day)
Surface Area \
[CO!2):
Age/Sex/
Cond./Seas.
AB
AB
AB
at hatching
at fledging
at fledging

A B basal
A B free-living
AB
nestlings
AB
AB
AB
Mean
148 ± 20.8 SD
136 ± 15.6 SE
158 ± 11.5 SE
10- 12
148 ± 13.3 SE
169 ± 11.9 SE
5 to 6
132
327
0.50
0.11
0.094
280
Range or
(95% Cl of mean)
125-215





(154-693)
1.0- 1.75



Location or
subspecies
Pennsylvania
Pennsylvania
Ohio
Minnesota
Pennsylvania
Ohio
Pennsylvania, Ohio/streams

northcentral lower Michigan
Nova Scotia



Reference
Powdermill Nature Center
(unpubl.)
Brooks & Davis, 1987
Brooks & Davis, 1 987
Hamas, 1981
Brooks & Davis, 1 987
Brooks & Davis, 1 987
Brooks & Davis, 1987
estimated
estimated
Alexander, 1977
White, 1936
estimated
estimated
estimated
Note
No.
1




2
3
4
5
6
7
8
NJ

vl
05
DO
SL
i-f
CD
Q.
CO
-*J
55'

CD
-------
                                             Belted Kingfisher (Ceryle a/cyon]
X
Dietary Composition
trout
non-trout fish
Crustacea
insects
amphibians
birds and mammals
unidentified
trogt
other game & pan fish
fe,g., perch,
centrarchids)
forage fish (e,g.,
minnow, stickleback.
sculptns)
unidentified fish
crayfish
insects
salmon fry
salmon (1*yrold)
salmon (2-yr-old)
.trout
^sticklebacks
Jcillifish
suckers.
crayfish
cyprinids
. (minnows)
(stonerolters)
{unidentified)
other fish

Spring































Summer
17*
29
5
19
27
1
2
30
13


15


1
41
< 1
11
42
1
15
30
< 1
< 1
13
76
(13)
(38)
(26)
10

Fair































Winter






























:
Location/Habitat (measure)
lower Michigan/lake

(% wet weight; stomach
contents)

*data from spring .and fall
also
Michigan/trout streams

(% wet volume; stomach
contents)






Nova Scotia/riparian -
streams
(% of total number of prey;
fecal pellets)



southwest Ohio/creek

(% of total number of prey
brought to nestlings)



Reference
Alexander, 1977






Salyer & Lagler, 1 946









White, 1 936






Davis, 1982





Note
No.

















v












NJ

_&

vl
03

SL
r-h
CD
Q.

7s

5'
(Q
-h

w'


0
-------
                                            Belted Kingfisher (Ceryle alcyon}
Population
Dynamics
Territory Size
-------
   Ki
   -^
   VI
   (O
 CD
 a
 5
 5'
ca
 3
 4
 5
 6
 7
 8

9
                                                          Belted Kingfisher (Ceryfe alcyon)
            Seasonal
            Activity
                                           Peak
                                           •' '  —.

                                           April to May
                                                      End

                                                      early July

                                                      late July
Location
—-^^-^—
Minnesota
Mating
^•^™w»«^».

Hatching
Reference
	—_
Hamas, 1975
                                           June
                                           early June
                                                                       Minnesota
                                                                       Nova Scotia
                                                                                                         Hamas, 1975
                                                                                                         White, 1936
                     August
                     February
                                                                                                         Bent, 1940
                                                                                                         Bent, 1940
    Migration
     fall departures
                                                           mid-October
                                                           mid-November
                                                           mid-December
                                                                       Maine
                                                                       NY, SD, Wl, NE
                                                                       Massachusetts, New Jersey
                           Bent, 1940
                           Bent, 1940
                           Bent, 1940
           spring arrivals
                late February
                mid-March
                early April
                                                                      PA, Rl, MO
                                                                      NY, CT, IL, Wl
                                                                      Maine, Nova Scotia
                          Bent, 1940
                          Bent, 1940
                          Bent, 1940
            Cited in Dunning (1984).                                              -                i
            Brooks and Davis (1987) reoortPH «** •                                                                                      I


                                                        v wei9hK "°m
                                                                                                                  from Powdermill Nature
                               n 3 „
CD
-------
 References (including Appendix)

 Alexander, G. R. (1974) The consumption of trout by bird and mammal predators on the
       North Branch Au Sable River. Michigan Dept.  Nat. Resources, Dingell - Johnson
       Proj.; F-30-R, Final Report.

 Alexander, G. R. (1977) Food of vertebrate predators on trout waters in north central
       lower Michigan. Michigan Academician 10: 181-195.

 Bent, A. C. (1940) Life histories of North American cuckoos, goat suckers, hummingbirds,
       and their allies. Washington, DC: U.S. Government Printing Office; Smithsonian
       Inst. US Nat. Mus., Bull. 176.

 Brooks, R. P.; Davis, W. J. (1987) Habitat selection by breeding belted  kingfishers (Ceryle
       alcyon).  Am. Midi. Nat.  117: 63-70.

 Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

 Cornwall, G. W. (1963) Observations on the breeding biology and behavior of a nesting
       population of belted kingfishers. Condor 65: 426-431.

 Davis, W. J. (1980) The belted  kingfisher, Megaceryle alcyon: its ecology and territorially
       [master's thesis]. Cincinnati, OH: University of Cincinnati.

 Davis, W. J. (1982) Territory size in Megaceryle alcyon along a stream habitat. Auk 99:
       353-362.

 Dunning, J. B.,  Jr. (1984) Body weights of 686 species of North American birds. Western
       Bird Banding Association, Monograph No. 1. Cave Creek, AZ: Eldon Publishing.

 Fry, C. (1980) The evolutionary biology of kingfishers (Alcedinidae). In:  The living bird,
       1979-80. Ithaca, NY: The Laboratory of Ornithology, Cornell University; pp.
       113-160.

 Hamas, M. J. (1974) Human incursion and nesting sites of the belted kingfisher. Auk 91:
       835-836.

 Hamas, M. J. (1975) Ecological and physiological  adaptations for breeding in the belted
       kingfisher (Megaceryle alcyon)  [Ph.D. dissertation]. Duluth, MN: University of
       Minnesota.

 Hamas, M. J. (1981) Thermoregulatory development  in the belted kingfisher. Comp.
       Biochem. Physiol. A: Comp. Physiol. 69: 149-152.

Lasiewski, R. C.; Calder, W. A. (1971) A preliminary allometric analysis  of respiratory
      variables in resting birds. Resp. Phys. 11: 152-166.
                                       2-180
Belted Kingfisher
-------
Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation between standard
       metabolic rate and body weight in birds. Condor 69: 12-23.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Nagy, K. A. (1987) Field metabolic rate and  food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987) Field guide to the birds of North America.
       Washington,  DC: National Geographic Society.

Poole, E. L. (1938) Weights and wing areas  in North American birds. Auk 55:  511-517.

Prose, B. L. (1985) Habitat suitability index models: belted kingfisher. U.S. Fish Wildl.
       Serv. Biol. Rep. 82(10.87).

Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol. 19: 535-562.

Salyer, J. C.; Lagler, K. F.  (1946) The eastern  belted kingfisher, Megaceryle alcyon alcyon
       (Linnaeus), in relation to fish management. Trans.  Am. Fish. Soc. 76: 97-117.

Walsberg, G. E.; King, J. R. (1978) The relationship of the external surface area of birds to
       skin surface area and body mass. J. Exp. Biol. 76: 185-189.

White, H. C. (1936) The food  of kingfishers  and mergansers on the Margaree River, Nova
       Scotia. J. Biol. Board Can. 2:  299-309.

White, H. C. (1937) Local feeding of kingfishers and mergansers. J. Biol. Board Can. 3:
       323-338.

White, H. C. (1938) The feeding of kingfishers: food of nestlings and effect of water
       height. J. Biol. Board 4: 48-52.

White, H. C. (1953) The eastern belted  kingfisher in the maritime provinces. Fish. Res.
       Board Can. Bull. 97.
                                       2-181
Belted Kingfisher
-------
-------
2.1.14.   Marsh Wren (wrens)

       Order Passer/formes. Family Troalodvtidae.  Wrens are small insectivorous birds
that live in a variety of habitats throughout the United States. They have long, slender
bills adapted for gleaning insects from the ground and vegetation. Most species are
migratory, although some populations are year-round residents.

Selected species

       The marsh wren (Cistothorus palustris) is a common bird inhabiting freshwater
cattail marshes and salt  marshes. Marsh wrens breed throughout most of the northern
half of the United States and in coastal areas as far south as Florida; they winter in the
southern United States and into Mexico,  particularly in coastal areas. Marsh wrens eat
mostly insects, and occasionally snails, which they  glean from the surface of vegetation.
This species was formerly known as the long-billed  marsh wren (Telmatodytes palustris).

       Body size.  Although wrens are small (13 cm bill tip to tail tip; about  10 g body
weight), males tend to be about 10 percent heavier than females (see table).  Body weight
varies seasonally; in Georgia, where marsh wrens are resident throughout the year, they
tend to be heavier in the spring and summer than in the fall and winter (Kale, 1965).

       Habitat. Marsh wrens inhabit freshwater and saltwater marshes, usually nesting in
association with bulrushes, cattails, and sedges or on  occasion in mangroves (Welter,
1935; Bent, 1948; Kale,  1965; Verner, 1965).  Standing water from several centimeters
to nearly a meter is typical of the areas selected (Bent, 1948). Permanent water is
necessary to provide a food supply of insects necessary to maintain the birds and as a
defense against predation (Verner and Engelsen, 1970).  Deeper water and denser
vegetation are associated with reduced predation rates (Leonard and Pieman, 1987).

       Food habits.  Marsh wrens consume aquatic  invertebrates, other insects, and
spiders, which they glean from the water surface, on stems and leaves  of emergent
vegetation, and the marsh floor (Kale, 1965; Welter, 1935).  They sometimes also feed by
flycatching (Welter, 1935). The insect orders most commonly taken include Coleoptera
(both  adults and larvae), Diptera (adults and larvae), Hemiptera (juveniles and adults),
Lepidoptera (larvae most commonly fed to nestlings); and Odonata (newly emerged) (Bent,
1948; Kale, 1964).  When feeding the young, at first the parents bring mosquito adults
and larvae, midges, larval tipulids, and other small insects (Welter, 1935). As the young
mature, the parents bring larger insects such as ground beetles, diving beetles, long-
horned beetles, caterpillars, dragonflies, and sawflies to the nestlings (Welter, 1935). In a
population in Georgia, spiders (usually 1 to 3 mm in size, sometimes 12 to 15 mm), small
crabs  (5 to 7 mm), small snails (1 to 3 mm), and insect eggs also were consumed and fed
to nestlings (Kale, 1965).  Thus, organisms that are aquatic for all or part of their lives are
an important component of the diet of marsh wren adults and nestlings.

       Migration.  Marsh wrens are year-round residents in some southern and coastal
maritime regions where marshes do not freeze.  Most migratory wrens breed throughout
the northern half of the United States through southern Canada  and winter in Mexico and
                                       2-183
Marsh Wren
-------
the southern half of the United States (Bent, 1948; Verner, 1965; American Ornthologists'
Union, 1983; National Geographic Society, 1987).

       Breeding activities and social organization.  Many populations of marsh wren are
polygynous, with some males mating with two, occasionally three, females in a season,
while the remaining males have one mate or remain bachelors.  For example, Leonard and
Pieman (1987) found 5 to 11 percent bachelor males, 41 to 48 percent monogamous
males, 37 to 43  percent bigamous males, and 5 to 12 percent trigamous males in two
marshes in Manitoba, Canada.  Similarly, Verner and Engelsen (1970) found  16 percent
bachelors, 57 percent monogamous, and 25 percent bigamous males in eastern
Washington state.  In contrast. Kale (1965) found most males to be monogamous through
4 years of study in Georgia.

       Males arrive at the breeding marshes before the females to establish territories that
include both nest sites and foraging areas (Kale, 1965; Verner, 1965; Welter, 1935).*
Males build several nests in their territories throughout the breeding season (Kale, 1965;
Verner, 1965).  The female usually only adds lining material to a nest of her choice,
although some may help construct the breeding nest (Kale, 1965). Breeding nests are
oblong in shape, with a side opening, and are woven of cattails, reeds, and grasses and
lashed to standing vegetation, generally 30 cm to  1 m above standing  water or high tide
(Bent, 1948; Verner, 1965)." Incubation lasts approximately 2 weeks, as does the nestling
period (Kale, 1965; Verner, 1965).  After fledging, one or both parents continue to feed
the young for about 12 days (Verner, 1965).  Many populations typically rear two broods
per year, although some may rear three (Kale, 1965; Verner, 1965). In the more
monogamous populations, both parents regularly feed young, but in the more polygynous
ones, the females may provide  most of the food, with males assisting only toward the end
of the nestling period (Leonard  and Pieman, 1988; Verner, 1965).

       Home range and resources. Marshes smaller than 0.40 ha usually are not used by
breeding marsh wrens (Bent, 1948). Average male territory size for a given year and
location can range from 0.006 to 0.17 ha, depending on the habitat and conditions of the
year (see table).  Also, there is  a trend in polygynous populations for polygynous males to
defend larger territories than monogamous males or males that end up as bachelors
(Verner and Engelson, 1970; Verner, 1964; Kale, 1965).

       Population density.  Because the species is  polygynous, there may be  more females
than males inhabiting breeding marshes. Population density varies with the suitability and
patchiness of the habitat. Densities as high as 120 adult birds per hectare have been
recorded (Kale, 1965).

      Population dynamics.  Clutch size and number of clutches per year vary with
latitude and climate (see table). In some populations, marsh wrens commonly destroy
eggs and kill the  nestlings of other pairs of their own species and other marsh-nesting
passerines (Orians and Wilson,  1964; Pieman, 1977; Welter, 1935). Fledging success
depends strongly on nest location; nests over deeper water are less vulnerable to predation
(Leonard and Pieman, 1987). Of nests lost to all causes, Leonard and  Pieman (1987)
found 44 percent due to mammalian predators, 27 percent due to other wrens, 11 percent
due to weather, 8 percent due to  nest abandonment, and 13 percent unknown.  The

                                      2-184                            Marsh Wren
-------
annual mortality of adults is lower than that of first-year birds.  Both sexes of this species
usually commence breeding in the first year following hatching (Kale, 1965).

Similar species

      •      The sedge wren (Cistothorus platensis, formerly known as the short-billed
             marsh wren) nests locally in wet meadows or shallow .sedge marshes and
             hayfields in the northeastern United States, wintering primarily in the
             southeastern United States. It is slightly smaller (11 cm) than the marsh
             wren.

             Note: None of the other wren species inhabit marshes, although all forage
             by gleaning insects from vegetation and other surfaces.  Wrens that inhabit
             moist woodlands and  open areas are listed below.

      •      The house wren (Troglodytes aedon) (12 cm) breeds throughout most of the
             United States, into southern Canada.  It inhabits open habitats with brush
             and shrubs and is found in orchards, farmyards, and urban gardens and
             parks.

      •      The winter wren (Troglodytes troglodytes) (10 cm) breeds in southern
             Canada, where it nests in dense brush, especially along moist coniferous
             woodlands. It winters primarily in the southeastern United States, where it
             inhabits many types of woodlands.

      •      The Carolina wren (Thryothorus ludovicianus) (14 cm) is nonmigratory and
             can be found in both summer and winter in the  eastern United States as far
             north as northern Delaware and as far west as Oklahoma. It inhabits  moist
             woodlands and swamps and wooded suburban  areas,

      •      Bewick's wren (Thryomanes bewickii) (13 cm) is more common in western
             States than the house wren and is declining east of the Mississippi. It is
             found in brushland, stream edges, and open woods.

General references

      Kale (1965); Gutzwiller and Anderson (1987);  Leonard and Pieman (1987); Verner
(1965), National Geographic Society (1987).
                                      2-185
Marsh Wren
-------
                                       Marsh Wren (Cistothorus palustris)

Factors
Body Weight
(9)


^


•
-.
* £ ""
••>-, £
"< , $
5 _, •*
y " i -
Egg Weight (gl
Metabolic Rate
(10-,/kg-day)


Metabolic Rate
(kcal/kg-dayj





>
Age/Sex/
Cond./Seas.
F breeding
M breeding
AF
AM
JB
nestling:
day 1
day 3
day 5
day 7
day 9
day 11
day 13
at fledging

A B basal
A B near basal
A B light
activity
A B basal
A B near basal
A B light
activity
A B free-living
A F free-living
A M free-
living

Mean
10.6 ± 0.99 SD
11.9 ± 0.72 SD
9.4 ± 1.1 SD
10.6 ± 0.7 SD
9.4 ± 1.6 SD

1.1
2.1
4.7
6.8
10.0
10.6
11.3
8.84 ± 0.70 SD
1.14 ± 0.10 SD
91.2
113

169
444
557 ± 115SD

788 ± 115 SD
880 ± 90 SD
1,209
1,174

Range or
(95%' Cl. of mean)
9.0- 13.5
10.5- 13.5






















(571 -2,563)
(554 - 2,486)

Location or
subspecies
New York

Georgia


New York, Minnesota/fresh
marshes






Georgia
Georgia
Georgia (captive)



Georgia (captive)








Reference
Tintle (unpubl.)

Kale, 1965.


Welter, 1935







Kale, 1965
Kale, 1965
Kale, 1965



Kale, 1965
Kale, 1965

Kale, 1965
Kale, 1965
estimated


Note
No.
1

2


3









4
5
6

7
8

9
10
11


to
—X
CO
O)
CD
-------
                                       Marsh Wren (Cistothorus palustris)

Factors
Food Ingestion
Rate
•



Water
Ingestion Rate
(g/g-dayt
Surface Area
(cm2)
Age/Sex/
Cond./Seas.
A B free-living

A B free-living
A F free-living
A M free-
living
AF
AM

AF
AM

Dietary Composition
Hymenoptera
Homoptera
Coleoptera
Lepidoptera
Diptera
Hemiptera
Orthoptera
spiders
other arthropods
(crabs/ amphipods)
molluscs (snails)
other {insect eggs.
undetermined, etc.)

Mean
1,155 ± 130 SD
kcal/kg-day
0.67 g/g-day
0.99 g/g-day
0.96 g/g-day

0.28
0.26

45
48

Spring *














Summer
17.3
13.0
11.6
14.6
8.9
5.4 '
5.6
15.1

1.8
3.5

4.5
Range or
(95% Cl of mean)












Fall














Winter
12.4
40.1
12.6
2.9
7.7
10.0
0.8
6.2

0.9 '
4.0

3.3
Location or
subspecies
Georgia (captive)

Georgia (captive)









Location/Habitat {measure}
Georgia/salt marsh

(% wet volume;
stomach contents)









:
Reference
Kale, 1965

estimated from Kale, 1965
estimated


estimated


estimated


Reference
Kale, 1965












Mote
No.
12

13
14


15


16

Note
No.
17












to
CO
Q>
W
CD
-------
                                        Marsh Wren (Cistothorus palustris)
Population
Dynamics
Territory
Size (ha)




Population
Density





Clutch Size

i

Clutches/Year




Days
Incubation

5
Age/Sex/
Cond./Seas.
A M spring


A M spring

A M spring
spring:
pairs/ha
males/ha


males/ha















Mean
0.0060 ± 0.001 4 SD
0.0156 ± 0.0050 SD
0.0085 ± 0.0042 SD
OJ7 ± 0.021 SE

0.07 ± 0.06 SD

48.3 ± 5.3 SD
8.5
"16.9

3.7 ± 0.5 SD

4.5
6.0 ± 0.19 SD

5.8 + 0.8 SD
1-2
2

2-3

13.1

15.1


Range



0.0242 - 0.360



45.1 - 56.2



3.4-4.3

3-5
4-8


0-3
0-2

0-3

12- 14

13- 16


Location/Habitat
Georgia/salt marsh 1, 1958
Georgia/salt marsh 2, 1 958
Georgia/salt marsh 2, 1 959
west Washington/fresh
mixed-species marsh
Manitoba/fresh cattail marsh

Georgia/salt marsh (4 years)
west Washington/fresh
mixed-species marsh
(2 areas)
Manitoba/fresh mixed-
species marsh (3 years)
Georgia/salt marsh
east Washington/fresh pond-
margin marsh
Manitoba/fresh cattail marsh
Georgia/salt marsh
east Washington/fresh pond-
margin marsh
west Washington/fresh
mixed-species marsh
Georgia/salt marsh

west Washington/fresh
marsh

Reference
Kale, 1965


Verner, 1965

Leonard & Pieman, 1986

Kale, 1965
Verner, 1965


Leonard & Pieman, 1987

Kale, 1965
Verner, 1965

Leonard & Pieman, 1 987
Kale, 1965
Verner, 1965

Verner, 1965

Kale, 1965

Verner, 1965

Note
No.



















*•






fO


CO
00
Q)

W
CD
Z!
-------
                                                  Marsh Wren (Cistothorus palustris)
Population '
Dynamics
Age at
Fledging
Number Pledge
per Active
Nest
Number Pledge
per Successful
Nest
Age at Sexual
Maturity
Annual
Mortality
Rates (percent)
Seasonal
Activity
Mating/Laying
Hatching
Migration fait
spring :
Age/Sex/
Cond./Seas*
B
B


B
B
AB
J B
Begin
April
mid-April
late March
late May
early May
mid-April
September
April
Mean
12- 13
14
3.4 ± 3.4 SD
4.5 ± 1.3 SD
5.1 ± 1.2SD
1 year
1 year
32
70
Peak
May - June
April - May

May
mid-March
(nonmigratory)
Range
10- 15
11 - 16




End
mid-August
early July
mid-July
early August
mid-July
early August
late October
June
Location/Habitat
Georgia/salt marsh
Washington/fresh marshes
Manitoba/fresh mixed marsh
Manitoba/fresh mixed-
species marsh
Manitoba/fresh cattail marsh
Manitoba/fresh marsh
Washington/fresh marsh
Georgia/salt marsh
Location .
Georgia
eastern Washington (Turnbull)
western Washington (Seattle)
New York
eastern Washington (Turnbull)
western Washington (Seattle)
New York, Minnesota
New York, Minnesota
eastern Washington (Turnbull)
western Washington (Seattle)
Reference
Kale, 1965
Verner, 1965
Leonard & Pieman, 1 987
Leonard & Pieman, 1 987
Leonard & Pieman, 1 987
Leonard & Pieman, 1 987
Verner, 1971
Kale, 1 965
Reference
Kale, 1965
Verner, 1965
Verner, 1965
Welter, 1935
Verner, 1965
Verner, 1965
Welter, 1935
Welter, 1935
Verner, 1965
Verner, 1965
Note
No.





Note
No,



to
 I

00
(O
CD
W
CD
      1   As cited in Dunning (1984).
      2   Collection dates not specified.  Resident population; presumably averaged from birds captured throughout the year.
      3   Estimated from Welter's (1935) growth curve based on 50 nestlings.
-------
Ni
_i
CO
O
                                                 Marsh Wren (Cistothorus palustris)

 4   Measured by oxygen respirometry; lowest value of metabolism of postabsorptive wrens resting in the dark (but not at night) at temperatures
     within the thermoneutral zone.
 5   Measured by oxygen respirometry; birds not postabsorptive, but resting in a dark box at temperatures within the thermoneutral zone.
 6   Measured by oxygen respirometry; birds somewhat active in their cage.
 7   Estimated from oxygen consumption, for conditions, see note 3.
 8   Estimated from oxygen consumption, for conditions, see note 4.
 9   Estimated from oxygen consumption, for conditions, see note 5.
10   Estimated from measured daily food intake, excretory losses, assimilation, and respiration for active birds in small cages (173 weekly
     determinations total).  Because of the birds' high activity levels,  Kale (1965) considered the measure representative of free-living birds.
11   Estimated using allometric equation 3-36 (Nagy,  1987) and body weights from Kale (1965).
12   Measured daily food intake of birds in cages and measured caloric content of diet provided.  Because of the birds' high activity levels, Kale (1965)
     considered the measure representative of free-living  birds.
13   Estimated from Kale's  (1965) measured  daily food intake (see note 11) assuming 5.62 kcal/gram  (dry weight) insects, a 70 percent assimilation
     efficiency, and a 67 percent water content  for insects.
14   Estimated from free-living metabolic rate estimated from Nagy's (1987) equation 3-36 (see note 10) assuming the same parameters described in
     note 12.  These predicted food ingestion rates O0.95 g/g-day) for free-living birds exceed the value estimated for Kale's  (1965) caged birds (0.67
     g/g-day);  however, the latter does not include metabolic requirements of searching  for food, reproduction, or unusual thermoregulatory demands.
15   Estimated using equation  3-15 (Calder and  Braun, 1983) and body weights from Kale (1965).
16   Estimated using equation  3-21 (Meeh, 1879 and Rubner, 1883,  as cited in Walsberg and King, 1978) and body weights from Kale (1965).
17   Summer column represents combination of  spring and summer data;  winter column represents combination of fall and winter data. -
w
CD
3
-------
References (including Appendix)

American Ornithologists' Union. (1983) Check-list of North American birds. Lawrence, KS:
      Allen Press, Inc.

Bent, A. C. (1948) Life histories of North American nuthatches, wrens, thrashers, and
      their allies. Washington, DC: U.S.  Government Printing Office; Smithsonian Inst.
      U.S. Nat. Mus., Bull. 195.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Dunning, J. B., Jr. (1984) Body weights of 686 species of North American birds. Western
      Bird Banding Association, Monograph No. 1. Cave Creek, AZ: Eldon Publishing.

Gutzwiller, K. J.; Anderson, S.  H. (1987) Habitat suitability index  models: marsh wren.
      U.S. Fish Wildl. Serv. Biol. Rep. 82(10.139).

Kale, H. W., II (1964) Food  of the long-billed marsh wren, Telmatodytes palustris griseus,
      in the salt marshes of Sapelo Island, Georgia. Oriole 29: 47-61.

Kale, H. W., II. (1965) Ecology and bioenergetics of the long-billed marsh wren
      Telmatoidytes palustris griseus (Brewster) in Georgia salt marshes. Publ. Nuttall
      Ornith. Club No. 5.

Leonard, M.  L.; Pieman, J. (1986) Why are nesting marsh wrens and yellow-headed
      blackbirds spatially segregated? Auk 103: 135-140.

Leonard, M.  L.; Pieman, J. (1987) Nesting mortality and habitat selection by marsh wrens.
      Auk 104: 491-495.

Leonard, M.  L.; Pieman, J. (1988) Mate choice by marsh wrens: the influence of male and
      territory quality. Anim. Behav. 36r 517-528.

Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

National Geographic Society. (1987) Field guide to the birds of North America.
      Washington, DC: National Geographic Society.

Orians, G. H.; Wilson, M. F. (1964) Interspecific territories of birds. Ecology 45:  736-745.

Pieman, J. (1977) Intraspecific  nest destruction in the long-billed marsh wren,
      Telmatodytes palustris plustris. Can. J. Zool. 55: 1997-2003.
                                      2-191
Marsh Wren
-------
Rubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol. 19: 535-562.

Verner, J. (1964) Evolution of polygamy in the long-billed marsh wren. Evolution 18:
       252-261.

Verner, J. (1965) Breeding biology of the long-billed marsh wren. Condor 67: 6-30.

Verner, J. (1971) Survival and dispersal of male long-billed marsh wrens. Bird-Banding 42:
       92-98.

Verner, J.; Engelsen, G. H. (1970) Territories, multiple nest building, and polygamy in the
       long-billed marsh wren. Auk 87: 557-567.

Walsberg, G. E.; King, J. R. (1978) The relationship of the external surface area of birds to
       skin surface area and body mass. J. Exp. Biol. 76: 185-189.

Welter, W. A. (1935) The natural history of the long-billed marsh wren. Wilson Bull. 47:
       3-34.
                                      2-192
Marsh Wren
-------
2.1.15.   American Robin (thrushes)

       Order Passeriformes, Family Muscicaoidae. Subfamily Turdinae.  Thrushes are
common, medium-sized birds that eat worms, insects, and fruit.  They live in a variety of
habitats, including woodlands, swamps, suburbs, and parks.  Most thrushes build nests of
mud and vegetation on the ground or in the crotches of trees or shrubs; bluebirds nest in
holes in trees and posts or in nest boxes.  This group forages primarily on the ground and
in low vegetation by probing and gleaning. Some thrushes are neotropical migrants while
others reside year-round in North America. Thrushes range in size from the eastern and
western bluebirds (18 cm from bill tip to tail tip) to the American robin (25 cm).  Male and
female plumages are similar in most thrushes, although in some species, such as the
bluebirds, the males are more  brightly colored.

Selected species

       The American robin (Turdus migrator/us) occurs throughout most of the continental
United States and Canada during the breeding season and winters in the southern half of
the United  States and in Mexico and Central America.  The breeding range of the robin has
expanded in recent times with the increasing area covered by lawns and other open
habitats (Howell, 1942; Martin et al., 1951; James and Shugart, 1974).

       Body size.  The sexes are  similar in size and appearance. Their size varies slightly
geographically; the smallest robins are found  in the eastern United States  and along the
Pacific coast, and the  largest ones occur in the Rocky Mountains, northern Great Plains,
and northern deserts (Aldrich and James,  1991).d The size of robins tends to increase
with latitude in eastern North America but does not in western North America (Aldrich and
James, 1991).  Fledglings attain  adult size at approximately 6 weeks of age (Howell,
1942).

       Habitat.  Access to fresh water, protected nesting sites, and productive foraging
areas are important requirements for breeding robins (Speirs, 1953). Breeding habitats
include moist forests,  swamps, open woodlands, orchards, parks, and lawns.  Robins
forage on the ground in open areas, along  habitat edges, or the edges of streams; they
also forage above ground in shrubs and within the lower branches of trees (Paszkowski,
1982; Malmborg and Willson,  1988).  Nests in wooded areas are usually near some type
of opening  such as the forest edge or a treefall gap (Young, 1955; Knupp  et. al., 1977).
During the  nonbreeding season, robins prefer moist woods or fruit-bearing trees and shrubs
(Robbins et al., 1983). In the  fall, flocks of migratory robins  are often found along forest
edges or clearings where fruits are most plentiful (Baird, 1980).

       Food habits. Robins forage by hopping along the ground  in search  of ground-
dwelling invertebrates and by searching for fruit and foliage-dwelling insects in shrubs and
low tree branches (Malmborg and Willson, 1988; Paszkowski, 1982). In the months
preceding and during the breeding season, robins feed mainly (greater than 90 percent
volume) on invertebrates and on some fruits;  during the remainder of the year, their diet
dBased on linear measurements of museum study skins.

                                       2-193
American Robin
-------
consists primarily (over 80 to 99 percent by volume) of fruits (Martin et al., 1951;
Gochfeld and Burger, 1984; Wheelwright, 1986). Robins eat a wide variety of both plant
and animal foods; in a compilation of diet records collected throughout the United States
and southern Canada, Wheelwright (1986) found that robins consumed fruits from 51
genera and invertebrates from 107 families.  Commonly eaten fruits include plums,
dogwood, summac, blackberries, blackberries, cherries, greenbriers, raspberries, and juniper
(Martin et al., 1951; Wheelwright, 1986); common invertebrates include beetles,
caterpillars, moths, grasshoppers, spiders, millipedes, and earthworms (Martin et al.,
1951; Wheelwright,  1986; Paszkowski, 1982). Wheelwright (1986) has compiled
seasonal changes in the proportion of plants and invertebrates consumed by robins in three
different sections of the United States (see table). Wheelwright (1986) also has
summarized the average occurrence of fruits of various plant families in the stomachs of
robins by month for these sections. Martin et al. (1951) have summarized the occurrence
of fruits of various plant families in more specific areas of the United States (see
Appendix).

       Wheelwright (1986) found no differences between the sexes in the proportion or
types of invertebrates and fruits eaten.  Very young robins (up to at least 35 days of age)
feed almost entirely on insects and other invertebrates (Howell, 1940).  Older juveniles
tend to eat a higher proportion of fruit and easy-to-capture prey than adults (Gochfeld and
Burger, 1984; Wheelwright, 1986). In a given area, robins often show food preferences:
a population  in  central New York seemed to prefer northern arrowwood and spice bush
fruits over most other plants (Wheelwright, 1988); in Illinois, a group ate predominantly
frost grapes and Virginia creeper in the late summer and fall (Malmborg and Willson,
1988).

       During seasons when fruits dominate the diet, robins may need to consume
quantities in excess of their body weight to meet their metabolic needs each day (see
table).  Robins as well as other fruit-eating birds exhibit a low digestive efficiency for
fruits;  Karasov and Levey (1990) estimated the metabolizable energy coefficient (MEC)
(i.e., the proportion of food energy that actually is assimilated) for robins eating a mixed
fruit diet to be only 55 percent, perhaps  because of the low retention time of the digested
matter in the gut (Levey and Karasov, 1992).  The short retention time might actually be
an adaptation to eating fruit because large quantities of fruit must be processed to obtain
an adequate protein intake. In contrast,  when eating insects, robins (as well as other bird
species) exhibit a higher digestive efficiency of approximately 70 percent (Levey and
Karasov, 1989). Moreover, the energy content of insects tends to be higher than that of
most fruits, particularly on a wet-weight basis (see Chapter 4).  Thus, during the spring
when robins are consuming insects, they should consume a smaller amount relative to
their body weight than when eating fruits (Chapter 4 provides approaches that can be
used to estimate insect ingestion rates for robins).

      Molt.  Postjuvenile and postbreeding (prebasic) molts occur from  late July to
October (Wheelwright, 1986; Sharp, 1990).  During this molt, robins are consuming
largely fruits and other plant materials, which contain limited proteins.  This may
contribute to larger fruit consumption rates at this time. During the prebreeding
(prealternate) molt, robins are feeding  primarily on insects and other invertebrates (letter
                                       2-194
American Robin
-------
from N.T. Wheelright, Department of Biology, Bowdoin College, Brunswick, ME, to Sue
Norton, March 18, 1992).

       Migration.  Most robins nesting  in the northern United States and Canada winter in
the Gulf Coast States and the Carolinas (Speirs, 1953; Dorst, 1962, as cited in Henny,
1972).  Wintering robins are most abundant between 30 and 35 degrees N latitude
(Speirs, 1953). Robin flocks migrate during the day (Bobbins et al., 1983); most northern
robins  leave their breeding grounds from September to November and return between
February and April  (Howell, 1942; Young, 1951; Fuller, 1977)..

       Breeding activities and social organization.  The onset of the breeding season is
later at higher latitudes (approximately 3 days for each additional degree in the east) and
altitudes, but mating and egg laying generally occur in April or  May (James and Shugart,
1974;  Knupp et al., 1977). Males arrive on the breeding grounds before females to
establish territories; females pair with established males, usually for the duration of the
breeding season (Young,  1951). The female primarily builds the nest out of mud, dried
grass, weedy stems, and other materials, constructing it on horizontal limbs, tree-branch
crotches, within shrubs, or on any one of a number of man-made structures with
horizontal surfaces (Howell, 1942;  Klimstra and Stieglitz, 1957). First clutches usually
contain three or four eggs; later clutches tend to contain fewer eggs (Young, 1955).  The
female does all of the incubating, which continues for 10 to 14 days following the laying
of the second egg (Klimstra and Stieglitz, 1957; Young, 1955). Both males and females
feed the nestlings (Young, 1955).   Following fledging, the brood often divides, with the
male and female each feeding half of the fledglings for another 2 weeks (Weatherhead and
McRae, 1990).  Females may start another brood  before the current one is independent,
leaving the male to feed all of the fledglings (Young,  1955).  After reaching independence,
juveniles often form foraging flocks in areas of high food availability (Hirth et al., 1969).

       Early in the breeding season, robins often roost communally.  Males can continue to
use these roosts throughout the breeding season, whereas females stop once they begin
incubating eggs (Howell,  1940; Pitts, 1984).  As fall approaches and their diet turns more
toward fruits, robins in many areas begin to roost communally  again and may join other
species, such as common grackles and European starlings, in large roosts (Morrison and
Caccamise,  1990).

      Home range and resources.  During the breeding season, male robins establish
breeding territories, which the female helps to defend against other robins.  Nonetheless,
the territories of different pairs often overlap where neither pair can establish dominance
(Young, 1951), Most foraging during the breeding season is confined to the territory, but
adults sometimes leave to forage in more productive  areas that are shared with other
individuals (Howell,  1942; Young,  1951; Pitts, 1984).  In some prime nesting areas (e.g.,
dense coniferous forest),  where robin densities are high, territories are small and the birds
might often forage  elsewhere (Howell,  1942).  Adult  robins often return to the same
territory in succeeding years (Young, 1951). During the nonbreeding roosting period,
robins are likely to return to the same foraging sites for many weeks and to join roosts
within  1 to 3 km of these foraging areas (Morrison and Caccamise,  1990).
                                       2-195
American Robin
-------
       Population density.  Nesting population density varies with habitat quality. Densely
forested areas that provide well-protected nest sites have been found to support high
densities of nesting robins; however, the relatively small territories found in these areas
might not be used as much for foraging as those containing open areas (Howell, 1942).  In
the nonbreeding season, robins often join single- or mixed-species roosts that can include
tens of thousands of birds (Morrison and Caccamise, 1990). Wintering robins are most
common in pine or oak pine communities of the southeastern and southcentral United
States, and decrease in abundance in drier, less forested areas westward (Speirs, 1953).

       Population dynamics.  Robins first attempt to breed the year after they hatch
(Henny,  1972) and will raise multiple broods in a season (Howell, 1942). Predation is
often a major source of mortality for both eggs and nestlings (Knupp et al., 1977; Klimstra
and Stieglitz, 1957). Approximately half of the adult birds survive from year to year
(Farner, 1949; Henny,  1972); the average longevity of a robin that survives to its first
January is from  1.3 to  1.4  years (Farner, 1949).

Similar species (from general references)

       •      The wood thrush (Hylocichla mustelina), which is smaller than the robin (18
             cm), co-occurs  with the robin in some woodland habitats but is only present
             in  the eastern United States. This species nests primarily in the interiors  of
             mature forests and has been decreasing in abundance over the past decade
             as forested habitats in North America become increasingly fragmented
             (Bobbins  et al.,  1989; Terborgh, 1989). This species is also primarily a
             summer resident, wintering in Florida and the neotropics.

       •      The hermit thrush (Catharus guttatus) is found in coniferous and mixed
             woodlands at northerly latitudes or high elevations and winters primarily in
             the southern  half of the United States.  This species is also significantly
             smaller (15 cm) than the robin.

       •      Swainson's thrush (Catharus ustulatus) is present in the western and
             northeastern United States during the summer months, wintering in the
             neotropics. It is also smaller than the robin (16 cm).

       •      The varied thrush (Ixoreus naevius) occurs in moist coniferous forests of the
             Pacific Northwest.  This bird is similar in size (21 cm) to the robin.

Genera/ references

       Howell (1942); Young  (1955); National Geographic Society (1987); Robbins et al.
(1983); Sharp (1990).
                                       2-196
American Robin
-------
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•3-
-------
                                       American Robin (Turdus migratorius]

Factors
Surface Area
{cm2)


Age/Sex/
Cond./Seas.
AB
AB

Dietary Composition
nestlings/fledglings:
earthworms
sowbugs
spiders



• millipedes
short-horned {jrass- s
hoppers
beetles
^

lepidopteran larvae , -
ants
unidentified animal
'-, grass (all parts)
mulberries


> honeysuckle seeds
, unidentified plants -,
adults:
fruit
-t invertebrates
adults:
fruit
invertebrates
adults;
fruit
invertebrates




,





Mean
198
182
Spring


7
93

8
92

17
83










Summer

15.0
1.7
2.3
3.1
4.9
11.6
24.7
3.2
5.2
19.5
3.2
2.4
4.2

68
32

41
59

29
71

Range or
{95% Cl of mean)



Pall


92
8

76
24

63
37










Winter













83
17

73
27

70
30
Location or
subspecies


Location/Habitat
(measure) •
south central New
York/forest

(% wet weight; stomach
contents)
(age of robins ranged from 3
to 35 days after hatching;
presence of grass is likely to
be accidental - carried along
with prey)



eastern United States
(% volume;
stomach contents)
central United States
(% volume;
stomach contents)
western United States
(% volume;
stomach contents)

Reference
Walsberg & King, 1978
estimated

t Reference,
Howell, 1942



-







Wheelwright, 1986


Wheelwright, 1986


Wheelwright, 1986


Note
No.
9
10
Note
No.












11


11


11


to
_^
CD
CO
3
CD
^T
o'
Q)
D

JO
O
C7
-------
                                        American Robin (Turdus migrator/us]
Population
Dynamics
Territory
Size (ha)
Foraging Home
"Range (ha)
Population
Density
4pair$/ha)
Clutch Size
Clutches/Year
Days
.Incubation i
Age at
'fledging {daysl
Number Fledge i
per
Breeding Pair
( Number
Fledge per
Successful
Nest
Age/Sex
Cond./Seas.
spring
AB
AB
AB
summer,
adults
feeding:
nestlings
fledglings
spring
AB
AB
AB



B

five areas
Mean
0.42
0.11
0.21
0.15 ± 0.021 SE
0.81 ± 0.13 SE
1.98 ± 0.48 SD
8.6
4.9
3.17
3.45 + 0.59 SD
2
12.5 ± 0.14 SE
13.4 ± 0.1 3 SE
5.6
3:9
1.5 ± 0.45 SE
2.9
2.5 ± 0.15 SD
Flange
0.12-0.84

1.39-2.54
1 -5
1 -5
1 -3
10-14


2.4-3.4
(over 5 areas)
t
Location/Habitat ;
Tennessee/campus
New York/dense conifers
/unspecified forest
Ontario/deciduous forest
Tennessee/campus
New York/dense conifers
/unspecified forest
Illinois/suburban
Wisconsin/park
New York/forest
Wisconsin/park
Wisconsin/park
Wisconsin/park
New York/forest
Ontario/deciduous forest
Wisconsin/park
Maine/forest
Reference
Pitts, 1984
Howell, 1942
Weatherhead & McRae, 1 990
Pitts, 1984
Howell, 1942
Klimstra & Stieglitz, 1957
Young, 1955
Howell, 1942
Young, 1955
V
Young, 1955
Young, 1955
Howell, 1942
Weatherhead & McRae, 1990
Young, 1955
Knupp etal., 1977
Not£
No.
12




13



to
_1
CO
CO
3
CD

5'
0)
3

•33
o
CT
3'
-------
                                                 American Robin (Turdus m/gratorius)
Population
Dynamics
Age at
Sexual
Maturity
Annual
Mortality Rates
(percent!
Longevity
(years)
Seasonal
Activity
Mating/Laying
Hatching
Molt fall
Migration fall
spring
Age/Sex
Cond./Seas.
B
AB
JB
after Jan. 1 of
first year
Begin
early April
late April
early May
early May
early May
mid-May
mid-April
early June

mid-Sept.
February
mid-March
Mean
1 year
51 ± 0.5 SE
78-82
1.3-1.4
Peak
mid-April
late May

July & August
mid-October
Range


up to 9
End
late April
mid-July
early July


early November
early November
March
mid-April
Location/Habitat
NS
North America
North America
Location
Illinois
south central New York
n Maine
west: California, New
Mexico
east: VA, WV, DC, NY
northeast: VT, NH, CT
Kentucky
Colorado
North America
migrating through Minnesota
leaving New York
arriving New York
arriving Wisconsin
Reference
Henny, 1972
Henny, 1972
Farner, 1949
Reference
Klimstra & Stieglitz, 1 957
Howell, 1942
Knupp etal., 1977
James & Shugart, 1 974
James & Shugart, 1974
James & Shugart, 1 974
James & Shugart, 1 974
James & Shugart, 1974
Wheelwright, 1986
Fuller, 1977
Howell, 1942
Howell, 1942
Young, 1951
Note
No.



.Note
No,




ro
to
O
O
3
CD
•^
o'
CD
D
33
O
CT
1   As cited in Dunning (1984).
2   Estimated using equation 3-27 (Lasiewski and Dawson, 1967) and body weights from Clench and Leberman {1978).
3   Hazelton et al. (1984) estimate using Kendeigh's (1969) equations for a 55-g bird.
4   Estimated using equation 3-36 (Nagy, 1987) and body weights from Clench and Leberman (1978).
-------
                                                     American Robin  (Turdus migratorius]

      5   Estimated kcal consumed in feeding trials. Diet consisted of paired offerings of fruit (to test preferences) over a 2-day period,  12 trials per pairing.
          Fruit included strawberries  (2.29 kcal/g), cherries (4.34 kcal/g), green grapes (2.59 kcal/g), and purple grapes (5.85 kcal/g).  Mean weight of the
          birds = 55 g.                                                           *
      6   Based on gizzard contents of robins caught foraging in vineyards; diet 85 percent (wet weight) grapes, 11.5  percent invertebrates, and 4.5
          percent other plants.  Mean weight of the birds = 82.3 g.
      7   Based on same study described in  note 5 and estimated weights of fruits consumed.
      8   Estimated using equation 3-15 (Calder and Braun, 1983) and body weights from Clench and Leberman (1978).
      9   Beak surface area 3.1 cm2; leg surface area  14.0 cm2.
     10   Estimated using equation 3-21 (Meeh, 1879 and Rubner,  1883, as cited in Walsberg and  King, 1978) and body weights from Clench and
          Leberman (1978).
     11   The U.S. Biological  Survey  and U.S. Fish and Wildlife Service records on which this study is based have several limitations:  more birds were
          collected in agricultural and suburban than natural areas; seasons and time of day of collection were convenient to the collectors; quickly digested
          foods such as earthworms  and other soft-bodied insects are underrepresented.
     12   Birds nesting in high densities in dense coniferous forest probably foraged elsewhere more of the time than did birds with larger territories in less
          dense forests.
     13   Also included data from Howell (1942) (Ithaca,  New York) in calculations.
ro
10
o
CD
^
o'
Q>
3
•33
O
CT
-------
References (including Appendix)

Aldrich, J. W.; James, F. C. (1991) Ecogeographic variation in the American robin (Turdus
       migratorius). Auk 108: 230-249.

Armstrong, J. T. (1965) Breeding home range in the nighthawk and other birds: its
       evolutionary and ecological significance. Ecology 46: 619-629.

Baird, J. W. (1980) The selection and use of fruit  by birds in an eastern forest. Wilson
       Bull. 92: 63-73.

Bovitz, P. (1990) Relationships of foraging substrate selection and roosting  in American
       robins and European starlings [master's thesis]. New Brunswick, NJ: Rutgers
       University.

Brackbill, H. (1952) Three-brooded American robin. Bird-Banding 23: 29.

Butts, W. K. (1927) The feeding range of certain birds. Auk 44: 329-350.

Calder, W. A.; Braun,  E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Clench, M.  H.; Leberman, R. C. (1978) Weights of 151 species of Pennsylvania birds
      analyzed by month, age, and sex. Bull. Carnegie Mus. Nat. Hist.

Dorst, J. (1962) The migration of birds. Boston: Houghton Mifflin Co.

Dunning, J. B., Jr.  (1984) Body weights of 686 species of North American birds. Western
      Bird  Banding Association, Monograph No. 1. Cave Creek, AZ: Eldon Publishing.

Farner, D. S. (1945) Age groups and longevity in the American robin. Wilson Bull. 57:
      56-74.
                                                           i
Farner, D. S. (1949) Age groups and longevity in the American robin: comments, further
      discussion, and certain revisions. Wilson Bull. 61: 68-81.

Fuller, P. (1977) Fall robin migration. Loon 49: 239-240.

Gochfeld, M.; Burger, J. (1984) Age differences in foraging behavior of the American robin
      (Turdus migratorius). Behaviour 88: 227-239,,

Hamilton, W. J., Jr. (1940) Summer food of the robin determined by fecal analyses.
      Wilson Bull. 52: 79-82.

Hamilton, W. J., Jr. (1943) Spring food of the robin in central New York.  Auk 60: 273.
                                      2-202
American Robin
-------
Hazelton, P. K., Robel, R. J.; Dayton, A. D. (1984) Preferences and influences of paired
      food items on energy intake of American robins (Turdus migrator/us} and gray
      catbirds (Dumetella carolinensis). J. Wildl. Manage 48: 198-202.

Henny, C. J. (1972) An analysis of the population dynamics of selected avian species with
      special  reference to changes during the modern pesticide era, Washington, DC: Bur.
      Sport. Fish. Wildl., Wildl. Res. Rep. 1.

Hirth, D. H.; Hester, A. E.; Greeley, F. (1969) Dispersal and flocking of marked young
      robins (Turdus m. migrator/us) after fledging. Bird-Banding 40: 208-215.

Howell, J. C. (1940) Spring roosts of the robin. Wilson Bull. 52: 19-23.

Howell, J. C. (1942) Notes on the nesting habits of the American robin (Turdus
      migratorius L.). Am. Midi. Nat. 28: 529-603.

James, F. C.; Shugart, H. H. (1974)  The phenology of the nesting season of the American
      robin (Turdus migratorius) in the United States. Condor 76: 159-168.

Jung, R. E. (1992) Individual variation in fruit choice by American robins  Turdus
      migratorius. Auk 109: 98-111.

Karasov, W. H:; Levey, D.  J. (1990)  Digestive system trade-offs and adaptations of
      frugivorous passerine birds. Physiol. Zool. 63:  1248-1270.

Kendeigh, S. C. (1969) Tolerance of  cold and Bergmann's rule. Auk 86: 13-25.

Klimstra, W. D.; Stieglitz, W. O. (1957) Notes on reproductive activities of robins in Iowa
      and Illinois. Wilson Bull.  69: 333-337.

Knupp, D. M.;  Owen, R.  B.; Dimond, J. B. (1977) Reproductive biology of American robins
      in northern Maine. Auk 94:  80-85.

Lasiewski, R. C.; Dawson, W. R. (1967). A reexamination of the relation  between standard
      metabolic rate and body weight in birds. Condor 69: 12-23.

Levey, D. J.; Karasov, W. H. (1989)  Digestive responses of temperate birds switched to
      fruit or insect diets. Auk 106: 675-686.

Levey, D. J.; Karasov, W. H. (1992)  Digestive modulation in a seasonal frugivore:  the
      American robin Turdus migratorius. Am. J. Physiol. 262: G711-G718.

Malmborg, P. K.; Willson, M. F. (1988) Foraging ecology of avian frugivores and some
      consequences for seed dispersal in an Illinois woodlot. Condor 90: 173-186.

Martin, A. C.; Zim, H. S.; Nelson, A.  L. (1951) American wildlife and plants. New York,
      NY: McGraw-Hill Book Company, Inc.
                                      2-203
American Robin
-------
 Meeh, K. (1879) Oberflachenmessungen des mensclichen Korpers. Z. Biol. 15: 426-458.

 Morrison, D. W.; Caccamise, D. F. (1990) Comparison of roost use by three species of
       communal roostmates. Condor 92: 405-412.

 Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57:  111-128.

 National Geographic Society. (1987) Field guide to the birds of North America.
       Washington, DC: National Geographic Society.

 Paszkowski, C. A. (1982) Vegetation, ground, and frugivorous foraging of the American
       robin Turdus migratorius. Auk 99: 701-709.

 Pitts, T. D. (1984) Description of American robin territories in northwest Tennessee.
       Migrant 55: 1-6.

 Bobbins, C. S.; Bruun,  B.; Zim, H. S.  (1983) A guide to field identification: birds of North
       America. New York, NY:  Golden Press.

 Bobbins, C. S.; Sauer, J. B.; Greenberg, B. S.; efal. (1989) Population declines in North
       American birds that migrate to the neotropics. Proc. Natl. Acad. Sci. USA 86:
       7658-7662.

 Bubner, M. (1883) Uber den Einfluss der Korpergrosse auf Stoff- und Kraftweschsel. Z.
       Biol.  19: 535-562.

 Sharp, M. H. (1990) America's songbird—species profile: American robin (Turdus
      migratorius]. Wild Bird 4: 22-27.

 Skorupa, J.  P.; Hothem, B. L. (1985)  Consumption of commercially-grown grapes by
      American robins (Turdus migratorius):  a field evaluation of laboratory estimates. J.
       Field Ornithol. 56: 369-378.

 Speirs, J. M. (1953) Winter distribution of robins east of the Bocky Mountains. Wilson
       Bull. 65: 175-183.

 Terborgh, J. (1989). Where have all the birds gone? Princeton, NJ: Princeton  University
      Press.

 Walsberg, G. E.; King, J. B. (1978) The relationship of the external surface area of birds to
      skin surface area and  body mass. J. Exp.  Biol. 76: 185-189.

Weatherhead,  P. J.; McBae,  S. B.  (1990) Brood care in American robins: implications for
      mixed reproductive strategies by females. Ariim. Behav. 39: 1179-1188.

Wheelwright, N. T. (1986) The diet of American robins: an analysis of U.S. Biological
      Survey  records.  Auk 103: 710-725.
                                       2-204
American Bobin
-------
Wheelwright, N. T. (1988) Seasonal changes in food preferences of American robins in
      captivity. Auk 105: 374-378.

Young, H. (1951) Territorial behavior of the eastern robin. Proc. Linnean Soc. N.Y. 58-62:
      1-37.

Young, H. (1955) Breeding behavior and nesting of the eastern robin. Am. Midi. Nat. 53:
      329-352.
                                      2-205
American Robin
-------
-------
2.2.  MAMMALS

       Table 2-2 lists the mammalian species described in this section. For range maps,
refer to the general references identified in the individual species profiles. The remainder
of this section is organized by species in the order presented in Table 2-2. The availability
of information in the published literature varies substantially among species, as is reflected
in the profiles.  Some of the selected species include two or more subspecies;  these are
indicated in the profiles when reported by the investigators.  Body lengths of the mammals
are reported for the length of the outstretched animal from the tip of the nose to the base
of the tail.  The tail measurements do  not include the hairs at the tip, but only the tail
vertebrae.  Body weight is reported as fresh wet weight with  pelage, unless otherwise
noted.
                                       2-207
-------
Table 2-2.  Mammals Included in the Handbook
Order
Subfamily
Soricidae
Canidae
Procyonidae
Mustelidae
Mustelinae
Lutrinae
Phocidae
Crlcetidae
Sigmodontinae
Arvieolinae
Leporidae
Common name
short-tailed shrew
red fox
raccoon
mink
river otter
harbor seal
deer mouse
prairie vole
meadow vole
muskrat
eastern cottontail
Scientific name
Blarina brevicauda
Vulpes vulpes
Procyon lotor
Mustela vison
Lutra canadensis
Phoca vitullna
Peromyscus maniculatus
Microtus ochrogaster
Microtus pennsylvanicus
Ondatra zibethicus
Sylvilagus floridanus
Section
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.2.9
2.2.10
2.2.11
                                    2-208
-------
2.2.1.  Short-Tailed Shrew (shrews)

       Order Insectivora. Family Soricidae. Shrews are small insectivorous mammals that
inhabit most regions of the United States.  They have high metabolic rates and can eat
approximately their body weight in food each day.  Most species are primarily vermivorous
and insectivorous, but some also eat small birds and mammals.

Selected species

       The northern short-tailed shrew (Blarina brevicauda) ranges throughout the north-
central and northeastern United States and into southern Canada (George et al.,  1986).  It
eats insects, worms, snails, and other invertebrates and also may eat mice, voles, frogs,
and other vertebrates (Robinson and  Brodie,  1982).  Because they prey on other
vertebrates, shrews can concentrate  DDT (and presumably other bioaccumulative
chemicals) to levels 10 times higher than either Peromyscus and Clethrionomys (Dimond
and Sherburne,  1969).  Shrews are an important component of the diet of many owls
(Palmer and Fowler, 1975; Burt and Grossenheider, 1980) and are also prey for other
raptors, fox, weasels, and other carnivorous  mammals (Buckner, 1966).

       Body size.  Short-tailed shrews are 8 to 10 cm in length with a  1.9 to 3.Q cm tail
(Burt and Grossenheider, 1980). The short-tailed shrew is the largest member of the
genus, with some weighing over 22 g (George et al., 1986; see table).  Some studies have
found little or no sexual dimorphism in size (Choate, 1972), while other reports show that
males are slightly larger than females (George et al., 1986; Guilday,  1957).

       Metabolism. Short-tailed shrews are active for about 1.6 percent of each 24-hour
period  (Martinsen, 1969), in periods of around 4.5 minutes at a time (Buckner, 1964).
The shrew's metabolism is inversely  proportional to the ambient temperature, within the
range of 0 to 25°C (Randolph, 1973). Sleeping  metabolism is half that associated with
normal,'exploring activity (Randolph,  1973).  Randolph (1973) developed a regression
equation for metabolism  (cc O2/g-hour)  during (1) interrupted sleep:8

       (Winter)  Y = 4.754 - 0.0869 (X - 16.4305)
       (Summer)  Y = 5.3448 - 0.1732 (X - 16.2310)

and (2) normal exploring  activity:

       (Winter)  Y = 6.5425 - 0.0516 (X - 12.0600)
       (Summer)  Y = 7.949  - 0^2364 (X - 16.9554)  where X= ambient temperature
                                                  in °C.

Randolph (1973) also developed a regression equation for overall metabolism (cal/animal-
hour) for shrews spending equal amounts of time sleeping and exploring (cal/animal-hour)
as a function of ambient temperature:
Randolph's (1973) equations could be simplified to match that of Deavers and Hudson (1981;
 next page) in form; however, we report the equations as Randolph reported them.

                                      2-209.                     Short-Tailed Shrew
-------
       (Winter)   Y = 583.83 - 7.53 (X - 13.68)
       (Summer)  Y = 544.86 - 20.37 (X - 16.33), where X= ambient temperature in °C.

       Deavers and Hudson (1981) found a linear increase in standard (near basal)
metabolism with decreasing temperature that is similar to that for interrupted sleep
described above (Y = standard metabolism in cc O2/g-hour):

       Y = 8.84 - 0.22  (X)    where X= ambient temperature.

Deavers and Hudson (1981) found that within the thermoneutral zone, the standard
metabolic rate of the short-tailed shrew is approximately 190 percent the metabolic rate
predicted from body weight.

       Habitat. Short-tailed shrews inhabit a wide variety of habitats and are common in
areas with abundant vegetative cover (Miller and Getz, 1977).  Short-tailed shrews need
cool, moist habitats because of their high metabolic and water-loss rates (Randolph,
1973).

       Food habits. The short-tailed shrew is primarily carnivorous.  Stomach analyses
indicate that insects, earthworms, slugs, and snails can make up most of the shrew's
food, while plants, fungi, millipedes, centipedes, arachnids, and small mammals also are
consumed  (Hamilton, 1941; Whitaker and Ferraro, 1963). Small mammals are consumed
more when invertebrates are less available (Allen, 1938; Platt and  Blakeley,  1973, cited in
George et al., 1986). Shrews are able to prey on small vertebrates because they produce
a poison secretion in their salivary glands that is transmitted during biting (Pearson, 1942,
cited in Eadie, 1952).  The short-tailed shrew stores food, especially in the autumn and
winter (Hamilton,  1930; Martin, 1984).  Robinson and Brodie (1982) found that short-
tailed shrews cached most (86.6 percent) of the prey captured; only 9.4 percent was
consumed immediately.  Short-tailed shrews consume approximately 40 percent more food
in winter than in summer (Randolph, 1973).  The shrew must consume water to
compensate for its high evaporative water loss, despite the fact that it obtains water from
both food  and metabolic oxidation (Chew, 1951).  Deavers and Hudson (1981) indicated
that the short-tailed shrew's evaporative  water loss  increases with increasing ambient
temperature even within its thermoneutral zone.  Short-tailed shrews' digestive efficiency
is about 90 percent (Randolph, 1973).

       Temperature regulation and molt.  The short-tailed  shrew does not undergo torpor
but uses nonshivering thermogenesis (NST) to compensate for heat loss during cold stress
in winter (Zegers and Merritt, 1987). The short-tailed  shrew exhibits three molts.  Two
are seasonal molts, the first in October/November replaces summer with winter pelage and
occurs in first- and second-year shrews.  The spring molt  can occur any time from
February to October. The third molt occurs in postjuveniles that have reached adult size
(Findley and Jones, 1956).

       Breeding activities and social organization.  The short-tailed shrew probably breeds
all year, including  limited breeding in winter even in the northern portions of its range
(Blus, 1971).  In Illinois,  males were found to be most  active from January to July,
females from  March to September (Getz, 1989). There are two peak breeding periods, in

                                      2-210                     Short-Tailed Shrew
-------
the spring and in late summer or early fall (Blair, 1940).  The home ranges of short-tailed
shrews in summer overlap both within and between sexes (Blair, 1940), although females
with young do exhibit some territoriality (Platt, 1976). Nomadic shrews are either young
of the year or adults moving to areas with more abundant prey (Platt, 1976).

      Home range and resources. Short-tailed shrews inhabit round, underground nests
and maintain underground  runaways, usually in the top 10 cm of soil, but sometimes as
deep as 50 cm (Hamilton,  1931; and Jameson, 1943, cited in George et al., 1986).
Winter, nonbreeding home ranges can vary from 0.03 to 0.07 ha at high prey densities to
1 to 2.2 ha during low prey densities with a minimum of territory overlap. In the summer,
ranges of opposite sex animals overlap, but same  sex individuals do not; females with
young exclude all others from their area (Platt, 1976).

      Population density.  Population densities vary by habitat and season (Getz, 1989;
Jackson, 1961; Platt, 1968).  In east-central Illinois, population density was higher in
bluegrass than in tallgrass or alfalfa (Getz, 1989). In all three of these habitats, the short-
tailed shrew exhibited annual abundance cycles, with peak densities ranging from 2.5 to
45 shrews per hectare, depending on the habitat (Getz, 1989). The peaks occurred from
July to October (12.9/ha average for all three habitats), apparently just following peak
precipitation levels (Getz, 1989).

      Population dynamics.  Winter mortality up to 90 percent has been reported for the
short-tailed shrew (Barbehenn, 1958; Gottschang, 1965; Jackson, 1961, cited in George
et al., 1986); however, Buckner (1966) suggests that mortality rates in winter may be
closer to 70 percent, which is similar to the average monthly mortality rate he found for
subadult  animals. Several litters, averaging four to five pups, are born each year (George
et al., 1986).                                                                      •

Similar species (from general references)

      •      The masked shrew (Sorex cinereus)  (length 5.1 to 6.4 cm; weight 3 to 6  g)
             is smaller than the short-tailed shrew and is the most common shrew in
             moist forests, open country, and brush of the northern United States and
             throughout Canada and Alaska.  It feeds primarily on insects.

      •      Merriam's shrew (Sorex merriami) (5.7 to 6.4 cm) is found in arid areas and
             sagebrush or bunchgrass of the western United States and is smaller than
             the short-tailed shrew.

      •      The smokey shrew (Sorex fumeus) (6.4 to  7.6 cm; 6 to 9 g), smaller than
             the short-tailed, prefers birch and hemlock  forests with a thick leaf mold on
             the ground to burrow in.  It uses burrows made by small mammals or nests
             in stumps, logs, and among rocks.  Range is limited to the northeast United
             States and east of the Great Lakes in Canada.

      •      The southeastern shrew (Sorex longirostris) (5.1 to 6.4 cm; 3 to 6 g) prefers
             moist areas. Found mostly in open fields and woodlots, its range is limited
                                      2-211
Short-Tailed Shrew
-------
             to the southeastern United States. It nests in dry grass or leaves in a
             shallow depression.

             The long-tailed shrew (Sorex dispar) (7.0 cm; 5 to 6 g) inhabits cool, moist,
             rocky areas in deciduous or deciduous-coniferous forests of the northeast,
             extending south to the North Carolina and Tennessee border.

             The vagrant shrew (Sorex vagrans) (5.9 to 7.3 cm; 7 ± g) inhabits marshy
             wetlands and forest streams.  Its range is confined to the western United
             States, excluding  most of California and Nevada. In addition to insects, it
             also eats plant material.

             The Pacific shrew (Sorex paclficus) (8.9 cm) is slightly larger than the short-
             tailed shrew. It is limited to redwood and spruce forests, marshes, and
             swamps of the northern California and southern Oregon coasts.

             The dwarf shrew  (Sorex nanus) (6.4 cm) is rare throughout its limited range
             in the western United States.

             The least shrew (Cryptotis parva) (5.6 to 6.4 cm; 4 to 7 g) is easily
             distinguished from other shrews by its cinnamon color.  It inhabits grassland
             and marsh; its range is similar to the short-tailed shrew but does not extend
             as far north.

             The desert shrew  (Notiosorex crawfordi) (Gray shrew) (5.1 to 6.6 cm) is
             rarely seen and is  found only in the arid conditions, chaparral slopes, alluvial
             fans, and around low desert shrubs of the extreme southwest.,  It nests
             beneath plants, boards, or debris.
General references
      Burt and Grossenheider (1980); George et al. (1986).
                                       2-212
Short-Tailed Shrew
-------
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                                    2-213
Short-Tailed Shrew
-------
                                      Short-Tailed Shrew (Blarina brevicauda]
Dietary
Composition
earthworms
slugs & snails
misc. animals
Endegon {fungi}
beetles
vegetation
lepidopteran
larvae ' '
chilopoda
other ... ;
fnsects
annelids
vegetable matter
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arachnids ' -
snails
small mammals5
^ Crustacea
tindetermined
Population
Dynamics
Home Range
Size (ha)




Spring



















Age/Sex/
Cond./Seas,
A F summer
A M summer
BBall
B B winter (a)
B B winter (b)

Summer
31.4
27.1
8.1
7.7
5.9
5.4
4.3

1.8
8.6
77.6
41.8
17.1
7.4
6.1
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5.2
3.7
2.4

Fall




















Mean


0.39 ± 0.036 SD



Winter



















Location/Habitat
(measure}
New York/NS

(% volume; stomach
contents)

(June through October
collections combined)



eastern United States
(primarily New York)/NS

(% frequency of
occurrence; stomach
contents)
(all seasons combined)



Range
< 0.1 -0.36
< 0.1 - 1.8

0.03 - 0.07
0.10-0.22

Reference
Whitaker & Ferraro, 1963









Hamilton, 1941









Location/Habitat
s Michigan/bluegrass

s Manitoba/tamarack bog
c New York/old field

-
Reference
Blair, 1940

Buckner, 1966
Platt, 1976

Note
No,



















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                                    2-215
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               2-216
                                                                                  Short-Tailed Shrew
-------
References (including Appendix)

Allen, D. L. (1938) Ecological studies on the vertebrate fauna of a 500-acre farm in
      Kalamazoo County, Michigan. Ecol. Monogr. 8: 347-436.

Barbehenn, K. R. (1958) Spatial and population relationships between Microtus and
      Blarina. Ecology 39: 293-304.

Barrett,  G. W.; Stueck, K. L. (1976) Caloric ingestion rate and assimilation efficiency of
      the short-tailed shrew, Blarina brevicauda. Ohio J. Sci. 76: 25-26.

Blair, W. F. (1940) Notes on home ranges and populations of the short-tailed shrew.
      Ecology 21: 284-288.

Blair, W. F. (1941) Some data on the home ranges and general life history of short-tailed
      shrews, red-backed voles and woodland jumping mice in northern Michigan. Am.
      Midi. Nat. 25: 681-685.

Blus, L.  J.  (1971) Reproduction  and survival of short-tailed shrews (Blarina brevicauda) in
      captivity. Lab. Anim. Sci. 21: 884-891.

Buckner, C. H. (1964) Metabolism, food capacity, and feeding behavior in four species of
      shrews. Can. J. Zool. 42: 259-279.

Buckner, C. H. (1966) Populations and ecological relationships of shrews in tamarack bogs
      of southeastern Manitoba. J. Mammal. 47: 181-194.

Burt, W. H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
      north of Mexico. Boston, MA: Houghton Mifflin Co.

Chew, R. M. (1951) The water exchanges of some small mammals. Ecol. Monogr. 21:
      215-225.

Choate,  J. R.  (1972) Variation within and among populations of short-tailed shrews,
      Blarina brevicauda. J. Mammal. 53: 116-128.

Dapson, R. W. (1968) Reproduction and age structure in a population of short-tailed
      shrews, Blarina brevicauda. J. Mammal. 49: 205-214.

Deavers, D. R.; Hudson, J.  W. (1981) Temperature regulation in  two rodents
      (Clethrionomys gapperi and Peromyscus leucopus) and a shrew (Blarina brevicauda)
      inhabiting  the same environment. Physiol. Zool. 54: 94-108.

Dimond, J. B.; Sherburne, J. A.  (1969)  Persistence of DDT in wild populations of small
      mammals. Nature 221: 486-487.
                                      2-217
Short-Tailed Shrew
-------
Eadie, R. W. (1952) Shrew predation and vole populations on a localized area. J. Mammal.
      33: 185-189.

Findley, J. S.; Jones, J. K., Jr. (1956) Molt of the short-tailed shrew, Blarina brevicauda.
      Am. Midi. Nat. 56: 246-249.

French,  T. W. (1984) Reproduction and age structure of three Indiana shrews. Proc.
      Indiana Acad. Sci. 94: 641-644.

George, S. B.; Choate, J. R.; Genoways, H. H. (1986) Blarina brevicauda. American
      Society of Mammalogists; Mammalian  Species 261.

Getz, L. L. (1989) A 14-year study of Blarina brevicauda populations in east-central Illinois.
      J. Mammal. 70: 58-66.

Gottschang, J. L. (1965) Winter populations of small mammals in old fields of
      southwestern Ohio. J. Mammal. 46: 44-52.

Guilday, J. E. (1957) Individual and geographic variation in Blarina brevicauda from
      Pennsylvania.  Ann. Carnegie Mus. 35:  41-68.

Hamilton, W. J., Jr. (1929) Breeding  habits of the short-tailed shrew, Blarina brevicauda.
      J. Mammal. 10: 125-134.

Hamilton, W. J., Jr. (1930) The food of the Soricidae. J. Mammal. 11: 26-39.

Hamilton, W. J., Jr. (1931) Habits of the short-tailed shrew, Blarina brevicauda (Say). Ohio
      J. Sci. 31: 97-106.

Hamilton, W. J., Jr. (1941) The foods of small forest mammals in eastern United States.
      J. Mammal. 22: 250-263.

Jackson, H. H. T. (1961) Mammals of Wisconsin. Madison, Wl: University of Wisconsin
      Press.

Jameson, E. W., Jr. (1943) Notes on the habits and siphanapterous parasites of the
      mammals of Welland County, Ontario. J. Mammal. 24: 194-197.

Lomolino, M.  V. (1984) Immigrant selection, predation, and the distribution of Microtus
      pennsylvanicus and Blarina brevicauda  on  islands. Am. Nat. 123: 468-483.

Martin, I. G. (1984) Factors affecting food hoarding in the short-tailed shrew  Blarina
      brevicauda. Mammalia 48: 65-71.

Martinsen, D. L. (1969) Energetics and activity patterns of short-tailed shrews (Blarina) on
      restricted diets. Ecology 50: 505-510.
                                      2-218
Short-Tailed Shrew
-------
Miller, H.; Getz, L. L. (1977) Factors influencing local distribution and species diversity of
      forest small mammals in new England. Can. J. Zool. 55: 806-814.

Morrison, P. R. (1948) Oxygen consumption in several small wild mammals. J. Cell. Comp.
      Physiol. 31: 69-96.

Morrison, P. R.; Pierce, M.; Ryser, P. A. (1957) Food consumption and body weight in the
      masked and short-tailed shrews (genus Blarina) in Kansas, Iowa, and Missouri. Ann.
      Carnegie Mus. 51: 157-180.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Mono. 57: 111-128.

Neal, C. M.; Lustick, S. I. (1973) Energetics and evaporative water loss in the short-tailed
      shrew Blarina brevicauda. Physiol. Zool. 46: 180-185.

Palmer,  E. L.; Fowler, H. S. (1975) Fieldbook  of natural history. New York, NY:
      McGraw-Hill Book Co.

Pearson, 0. P. (1942) The cause and nature of a  poisonous action produced by the bite of
      a shrew (Blarina brevicauda). J. Mammal. 23: 159-166.

Pearson, O. P. (1944) Reproduction in the shrew (Blarina brevicauda Say). Am. J. Anat.
      75: 39-93.

Pearson, O. P. (1945) Longevity of the short-tailed shrew. Am.  Midi. Nat. 34: 531-546.

Pearson, O. P. (1947) The rate of metabolism of some small mammals. Ecology 29:
      127-145.

Platt, A. P. (1968) Differential trap mortality as a measure of stress  during times of
      population  increase and decrease. J. Mammal.  49: 331-335.

Platt, W. J. (1974) Metabolic rates of short-tailed shrews. Physiol. Zool.  47: 75-90.

Platt, W. J. (1976) The social organization and territoriality of short-tailed shrew (Blarina
      brevicauda) populations in old-field habitats. Anim. Behav. 24: 305-318.

Platt, W. J.;  Blakeley, N. R. (1973) Short-term effects of shrew predation upon
      invertebrate prey sets in prairie ecosystems. Proc. Iowa Acad. Sci. 80:  60-66.

Randolph, J. C.  (1973) Ecological energetics of a homeothermic predator, the  short-tailed
      shrew. Ecology 54: 1166-1187.

Richardson, J. H. (1973) Locomotory and feeding activity of the shrews, Blarina
      brevicauda and Suncus murinus. Am. Midi. Nat. 90:,224-227.
                                      2-219
Short-Tailed Shrew
-------
Robinson, D. E.; Brodie, E. D. (1982) Food hoarding behavior in the short-tailed shrew
      Blarina brevicauda. Am. Midi. Nat.  108: 369-375.

Schlesinger, W. H.; Potter, G. L. (1974) Lead, copper, and cadmium concentrations in
      small mammals in the Hubbard Brook Experimental Forest. Oikos 25:148-152.

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J: Appl. Physiol. 22:
      453-460.

Whitaker, J. O., Jr.; Ferraro, M. G. (1963) Summer food of 220 short-tailed shrews from
      Ithaca, New York. J. Mammal. 44: 419.

Williams, A. B. (1936) The composition and dynamics of a beech-maple climax
      community. Ecol. Monogr. 6: 317-408.
                                                    V
Zegers, D. A.; Merritt, J. F. (1987) Adaptations of Peromyscus for winter survival in an
      Appalachian montane forest. J. Mammal. 69: 516-523.
                                     2-220
Short-Tailed Shrew
-------
2.2.2.  Red Fox (foxes and coyotes)

       Order Carnivora. Family Canidae. Unlike the more social wolves, foxes and coyotes
tend to hunt alone, although coyotes may hunt larger prey in pairs.  Foxes and coyotes are
primarily carnivorous, preying  predominantly on small mammals, but they also may eat
insects, fruits, berries, seeds,  and nuts. Foxes are found throughout most of the United
States and Canada, including the arctic, as  are coyotes with the exception of the
southeastern United States. Foxes and coyotes are active primarily ,at night.

Selected species

       Red foxes (Vulpes vu/pes) are present throughout the United States and Canada
except in the southeast, extreme southwest, and parts of the central states. Red fox prey
extensively on mice and voles but also feed on other small mammals, insects, hares, game
birds, poultry, and occasionally seeds, berries, and fruits (Palmer and Fowler, 1975).
Twelve subspecies are recognized in North  America (Abies, 1974).

       Body size.  The dog-sized red fox has a body about 56 to 63 cm in length, with a
35 to 41 cm tail (Burt and Grossenheider, 1980).  They weigh from 3 to 7 kg, with the
males usually outweighing the females by about 1 kg (Voigt,  1987; see table).

       Habitat.  As the most widely distributed carnivore in the world, the red fox can live
in habitats ranging from  arctic areas to temperate deserts (Voigt, 1987).  Red  foxes utilize
many types of habitat-cropland, rolling farmland, brush, pastures,  hardwood stands, and
coniferous forests (MacGregor, 1942; Eadie, 1943; Cook and Hamilton, 1944; Abies,
1974).  They prefer areas with broken and-diverse upland habitats  such as occur in most
agricultural areas (Abies, 1974; Samuel and Nelson,  1982; Voigt, 1987). They are rare or
absent from continuous stands of pine forests in the southeast, moist conifer forests along
the Pacific coast, and semiarid grasslands and deserts (Abies, 1974).

       Food habits.  The red fox feeds on both animal and plant material, mostly small
mammals, birds, insects, and fruit (Korschgen,  1959; Samuel and Nelson, 1982).
Meadow voles are a major food in most areas of North America; other common prey
include mice and rabbits (Korschgen, 1959; Voigt, 1987). Game birds (e.g., ring-necked
pheasant and ruffed grouse) and waterfowl  are seasonally important prey in some areas
(Pils and Martin, 1978; Sargeant, 1972; Voigt and Broadfoot, 1983).  Plant material is
most common in red fox diets in summer and fall when fruits, berries, and nuts become
available (Johnson, 1970; Major and Sherburne, 1987). Red foxes often cache food in a
hole for future use (Samuel and Nelson, 1982). They also are noted scavengers on
carcasses or other refuse (Voigt, 1987). Most  activity is nocturnal and at twilight (Nowak
and Paradiso, 1983).

       Temperature regulation and molt. In  winter, foxes do not undergo hibernation or
torpor; instead, they are active year-round.  They undergo one molt per year, which usually
begins in April  and is finished by June.  The winter coat is regrown by October or
November in northern latitudes (Voigt, 1987).
                                      2-221
Red Fox
-------
       Breeding activities and social organization.  Breeding occurs earlier in the south than
 in the red fox's northern ranges (Samuel and Nelson, 1982) (see table).  A mated pair
 maintains a territory throughout the year, with the male contributing more to its defense
 than the female (Preston, 1975).  Pups are born and reared in an underground den, and the
 male  assists the female in rearing young, bringing food to the den for the pups (Samuel
 and Nelson, 1982). Pups first emerge from the den when 4 to 5 weeks old (Samuel and
 Nelson, 1982). Once considered solitary, red foxes now are reported to exhibit more
 complex social habits (MacDonald and Voigt, 1985). A fox family, the basic social unit,
 generally consists of a mated pair or one male and several related females (MacDonald,
 1980; Voigt, 1987). The additional females are usually nonbreeders that often help the
 breeding female (Voigt, 1987).

       Home range and resources. The home ranges of individuals from the same family
 overlap considerably, constituting a family territory (Sargeant, 1972; Voigt and
 MacDonald, 1984). Territories of neighboring red fox families are largely nonoverlapping
 and contiguous, usually resulting in all parts of a landscape being occupied by foxes.
 Territory sizes range from less than 50 to over 3,000 ha (see table). Territories in urban
 areas tend to be smaller than those in rural areas (Abies, 1969).  Adults visit most parts of
 their territory on a regular basis; however, they tend to concentrate their activities near to
 their dens, preferred hunting areas, abundant food supplies, and resting areas (Abies,
 1974; Keenan, 1981). Territory boundaries often conform to physical landscape features
 such as well-traveled roads and streams (Abies, 1974).  Territory defense is primarily by
 nonaggressive mechanisms involving urine scent-marking and avoidance behaviors.  Scent
 marking occurs throughout the territory; there is little patrolling of territory boundaries.
 Each fox or family usually has a main underground den  and one or more other burrows
 within the home range (Nowak and Paradise, 1983). Most dens are abandoned burrows of
 other species (e.g., woodchucks, badgers) (Samuel and  Nelson, 1982). Tunnels are up to
 10 m in length and lead to a chamber 1 to 3 m  below the surface (Nowak and Paradise,
 1983).  Pup-rearing dens are the focal point of fox activity during spring and early
 summer.  Foxes have some rest sites and usually forage away from the den (Voigt,  1987).

      Population density.  One red fox family per 100 to 1,000 ha is typical (Voigt, 1987;
 see table). Red foxes have larger home ranges where population densities are low and  in
 poorer habitats (Voigt,  1987).  Most young foxes, especially males, disperse before the
 age of 1  (Voigt, 1987), usually during September to March, with peaks in dispersal  in
 October and November (Phillips et al., 1972; Storm et al., 1976).

      Population  dynamics. Foxes usually produce pups their first year, except in
 extremely high density areas and in some years in northern portions of their range where
they may delay breeding until the next season (Allen, 1984; Harris, 1979; Storm et al.,
 1976; Voigt and MacDonald, 1984).  Litter size generally averages four to six pups  (see
table). The pups leave the den about 1  month after birth, and they are weaned by about 8
to 10 weeks of age (Abies,  1974). Red foxes incur high mortality rates as a result of
shooting, trapping, disease, and accidents (e.g., roadkills) (Storm et al., 1976). Two
factors that tend to limit red fox abundance are competition with other canids, especially
coyotes, and seasonal limits on food availability (Voigt,  1987).  Fecundity is higher in
areas  of high mortality and low population densities (Voigt, 1987).
                                       2-222
Red Fox
-------
Similar species (from general references)

      •      The arctic fox (Alopex lagopus) is smaller than the red fox (body length
             approximately 51 cm; weight 3.2 to 6.7 kg) and is restricted in its
             distribution to the arctic, found in the United States only in Alaska. This
             species primarily scavenges for food but also eats lemmings, hares, birds,
             and eggs as well as berries in season.

      *      The swift fox (Vulpes ve/ox) is smaller than the red fox (body length 38 to
             51 cm; weight 1.8 to 2.7 kg) and inhabits the deserts and plains of the
             southwest and central United States.  It dens in ground burrows and feeds
             on small mammals and insects.

      •      The kit fox  (Vulpes macrotis) is similar in size to the swift fox and is
             considered  by some to be the same species, although it has noticeably larger
             ears.  It inhabits the southwestern United States and prefers open, level,
             sandy areas and low  desert vegetation.  It feeds on small mammals and
             insects.

      •      The gray  fox (Urocyon cinereoargenteus) is similar in size (body length 53 to
             74 cm; weight 3.2 to 5.8 kg) to the red fox and ranges over most of the
             United States except  the northwest and northern prairies, inhabiting
             chaparral, open forests, and rimrock regions.  Secretive and nocturnal, gray
             foxes will climb trees to evade enemies. They feed primarily on small
             mammals but also eat insects, fruits, acorns, birds, and eggs.

      •      The coyote (Canis latrans) is much larger (body length 81 to 94 cm; weight
             9 to 22 kg) than the red fox and is found throughout most of the United  : >
             States (except possibly eastern), western Canada, and Alaska.  It inhabits
             prairies, open woodlands, brushy and  boulder-strewn areas, and dens in the
             ground. Coyotes share some feeding  habits with the red fox but also
             scavenge and hunt larger prey in pairs.

General references
      Abies (1974); Burt and Grossenheider (1980); Palmer and Fowler (1975); Voigt
(1987).
                                       2-223
Red Fox
-------
                                            Red Fox (Vulpes vutpes}
Factors
Body Weight
{kgK


Pup Growth
Rate fg/day)-
Metabolic Rate
(kcat/kg-dayl

Food Ingestion
Rate (g/g-day)


Water
Ingestion ,
Rate {$g-day}
Inhalation
Rate [m^/day}
Age/Sex/
Cond./Seas.
A M spring
A F spring
A M fall
A F fall
neonate B
at weaning B
birth to
weaning
J summer
A M basal
A F basal
A M free-
living
A F free-living
J 5-8 wks
J 9-1 2 wks
J 13-24 wks
A before
whelp
F after whelp
A nonbreeding
AM
AF
AM
AF
Mean
5.25 ± 0.18SE
4.13 ± 0.11 SE
4.82 ± 0.081 SE
3.94 ± 0.079 SE
0.102 ± 0.12 SD
0.70 .
15.9
193 ± 56 SD
47.9
51.1
161
168
0.16
0.12
0.11
0.075
0.14
0.069
0.084
0.086
2.0
1.7
Range or
(95% CI of
mean)
4.54 - 7.04
3.27 - 4.72
4.13-5.68
2.95 - 4.59
0.071 -0.109


(68 - 383)
(71 -400)





Location
Illinois
Iowa
Wisconsin
North Dakota
North Dakota/lab
Ohio/lab

North Dakota/lab
North Dakota/captive
North Dakota/captive


Reference
Storm etal., 1976
Storm etal., 1976
Storm & Abies, 1 966
Sargeant, 1978
Sargeant, 1978
Vogtsberger & Barrett, 1973
estimated
estimated
Sargeant, 1978
Sargeant, 1978
Sargeant, 1978
estimated
estimated
Note
No.




1
2

3

4
5
NJ

Ni
NJ
33
CD
Q.

Ti
O
X
-------
                                             Red Fox (Vulpes vulpes)
factors
Surface Area
(cm2)
Age/Sex/
Cond./Seas.
AM
AF
Dietary
. Corrtftositioit
rabbits
small mammals
pheasant
other birds
misc.
,rtot accounted for
'mammals
birds
arthropod?
plants
junspecifred/bther
rabbits
mice/rate
,. other mammals
poultry
carrion
livestock
birds
Invertebrates
- plant foods
mammals
- birds
arthropods
plants
wspecified/other
Spring

92.2
2.4
0.2
4.6
0.6
24.8
24.2
4.0
21.0
12.9
9.8
0.6
trace
2.7

Range or
Mean (95% Cl of i
mean]
3,220
2,760
Summer

37.1
43.2
11.6
6.3
1.8
10.7
6.2
1.4
45.0
13.0
0.3
1.2
15.3
6.9

\
Falf

61.7
0.2
4.2
31.1
2.8
36.5
21.3
8.1
16.3
6.5
2.0
1.1
1.6
6.6

Winter
44.4
33.0
8.4
11.2
2.0
1.0
65.0
8.6
<0.1
26.1
0.3
38.7
22.5
8.2
11.6
7.4
5.4
3.8
trace
2.1
81.4
4.8
2.8
7.0
4.0
Location • \

Location/Habitat
{measure)
Nebraska/statewide
(% wet Volume; stomach
contents)
Illinois/farm and woods
(% wet weight; stomach
contents)
Missouri
(% wet volume; stomach
contents)
Maryland/Appalachian
Province (fall & winter)
(% wet weight; stomach
contents)
Reference ,
estimated
Reference
Powell &Case, 1982
Knable, 1974
Korschgen, 1959
Hockman & Chapman, 1983
Note
No.
6
Note
No,




fo
ro
ro
CJI
3J
CD
Q.

-n
o
X
-------
                                           Red Fox (Vulpes vulpes}
Population
Dynamics
Territory size
tta)


,


Population
Density (N/hafr


"• \

Litter
Size


,.
^
\* ,,5
Utters/Year
Days
Gestation
Age at
Weaning
Age at
Sexual
Maturity
Age/Sex/
Cond./Seas.
A B summer
A M summer
A F summer
A F spring

A M all year
A F all year
B B spring

B B spring

BB













F



Mean
1,611
1,967
1,137
699 ± 137SD

717
96
0.001

0.01



5.5

6.8
6.7
4.2
4.1

1
51 -54

8-10 weeks

" 1 0 months



Range
277 - 3,420
514-3,420
277-1,870
596 - 855


57-170




0.046 - 0.077



2- 9
3- 12












Location/Habitat
nw British Columbia/
alpine and subalpine

ec Minnesota/woods, fields,
swamp
Wisconsin/diverse

Canada/northern boreal
forests/arctic tundra
s Ontario, Canada/southern
habitats
"good fox range" in
North America
s Wisconsin/farm, marsh,
pasture
Illinois/farm and woods
Iowa/farm and woods
upper Michigan/NS
North Dakota/prairie
potholes
NS/NS
New York/NS

NS/NS

Illinois, Iowa/farm woods



Reference
Jones &Theberge, 1982


Sargeant, 1972

Abies, 1969

Voigt, 1987

Voigt, 1987

Abies, 1974

Pils& Martin, 1978

Storm et al., 1 976
Storm et al., 1976
Switzenberg, 1950
Allen, 1984

Samuel & Nelson, 1 982
Sheldon, 1949

Abies, 1974

Storm et al., 1976


Note
No.













7

8
7
8
7


9






NJ
O>
3J
CD
Q.
O
X
-------
                                                             Red Fox [Vulpes vulpes}
Population
Dynamics
Annual
Mortality
Rates (percent)



Longevity
Seasonal
Activity
Mating




Parturition
^
Molt
Disperal

Age/Sex/
Cond./Seas*
BB

JM
JF
AF
AB


Begin
early Dec.
late December

late January
February


April
late
September

Mean
79.4

83
81
74
77
< 1 .5 yrs

Peak
late January
Jan. - Feb.



March
late March, April




Range






up to 6 yrs

End
late February
March

early February
March


June
March


Location/Habitat
s Wisconsin/various

Illinois/Iowa/
farms and woods


NS/NS

Location
Iowa
New York

southern Ontario, Canada
northern Ontario, Canada
southern CAN
e North Dakota
NS/NS *
Illinois, Iowa


Reference
Pils& Martin, 1978

Storm et al., 1 976



Storm etal., 1976

Reference
Storm et al., 1 976
Layne & McKeon, 1956;
Sheldon, 1949
Voigt, 1987
Voigt, 1987
Voigt, 1987
Sargeant, 1972
Voigt, 1987
Storm etal., 1976

Note
Wo.







Note
Wo.

9








NJ
ro
KJ
33
CD
Q.
Tl
O
X
1   Estimated using extrapolation equation 3-45 (Boddington, 1978) and body weights from Storm et al. (1976) (Illinois).
2   Estimated using extrapolation equation 3-47 (Nagy, 1987) and body weights from Storm et al. (1976) (Illinois).
3   Food consumption of, an adult pair for 11 days prior to whelping (i.e., parturition) and of the adult female for the first 4 weeks after whelping.
4   Estimated using extrapolation equation 3-17 (Calder and Braun, 1983) and body weights from Storm et al. (1976) (Illinois).
5   Estimated using extrapolation equation 3-20 (Stahl, 1967) and body weights from Storm et al. (1976) (Illinois).
6   Estimated using extrapolation equation 3-22 {Stahl, 1967) and body weights from Storm et al. (1976) (Illinois).
7   Litter size determined from embryo count.  Using placenta! scars generally overestimates litter size, and counting live pups often underestimates
    litter size (Allen,  1983; Lindstrom, 1981).
8   Method of determining  litter size not specified.
9   Cited in Samuel and Nelson (1982).
-------
References (including Appendix)

Abies, E. D. (1969) Home range studies of red foxes (Vulpes vulpes). J. Mammal. 50:
       108-120.

Abies, E. D. {1974} Ecology of the red fox in North America. In: Fox, M. W., ed. The wild
       canids. New York, NY: Van Nostrand Reinhold; pp. 148-163.

Allen, S. H. (1983) Comparison of red fox litter sizes determined from counts of embryos
       and placental scars. J. Wildl. Manage. 47: 860-863.

Allen, S. H. (1984) Some aspects of reproductive performance in the red fox in North
       Dakota. J. Mammal. 65.*246-255.

Allen, S. H.; Guike, J. (1981) The effect of age on adult red fox body weights. Prairie Nat.
       13: 97-98.

Asdell, S. A. (1946) Patterns of mammalian reproduction. Ithaca, NY: Comstock Publ. Co.

Boddington, M. J. (1978) An absolute metabolic scope for activity. J. Theor. Biol. 75:
       443.449.

Burt, W. H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
       north of Mexico. Boston, MA: Houghton Mifflin Co.

Calder, W. A.; Braun, E. J. (1983)  Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Cook, D. B.; Hamilton, W. J., Jr. (1944) The ecological relationship of red fox food in
       eastern New York. Ecology 24: 94-104.

Dalke, P. D.; Sime, P. R. (1938) Home and seasonal ranges of the eastern cottontail in
       Connecticut.  Trans. N. Amer. Wildl. Conf. 3: 659-669.

Dekker, D. (1983) Denning and foraging habits of red foxes, Vulpes vulpes, and their
       interaction with coyotes, Canis latrans, in central Alberta. Can. Field-Nat.  97:
       303-306.

Eadie, W. R. (1943) Food of the red fox in southern New Hampshire. J. Wildl. Manage. 7:
       74-77.

Green, J. S.; Flinders, J. T. (1981) Diets of sympatric red foxes and coyotes in
      southeastern Idaho. Great Basin Nat. 41: 251-254.

Halpin, M. A.; Bissonette, J. A. (1983) Winter resource use by red fox (Vulpes vulpes)
       (abstract only). Trans. Northeast Sect. Wildl. Soc. 40: 158.
                                      2-228
Red Fox
-------
Hamilton, W. J., Jr. (1935) Notes on food of red foxes in New York and New England. J.
      Mammal. 16: 16-21.

Harris, S. (1979) Age-related fertility and productivity in red foxes, Vulpes vulpes, in
      suburban London. J. Zool. (London) 187: 195-199.

Harris, S.; Smith, G. C. (1987) Demography of two urban fox (Vulpes vulpes] populations.
      J. Appl. Ecol. 24: 75-86.

Hockman, J. G.; Chapman, J. A. (1983) Comparative feeding habits of  red foxes (Vulpes
      vulpes) and gray foxes (Urocyon cinereoargentus) in Maryland. Am. Midi. Nat. 110:
      276-285.

Hoffman, R. A.; Kirkpatrick, C. M. (1954) Red fox weights and reproduction in Tippecanoe
      County, Indiana. J. Mammal. 55: 504-509.

Johnson, W. J.  (1970) Food habits of the red fox in Isle Royale National Park, Lake
      Superior. Am. Midi. Nat. 84: 568-572.

Johnson, D. H.; Sargeant, A. B. (1977) Impact of red fox predation on the sex ratio of
      prairie mallards. Washington, DC: U.S. Fish Wildl. Serv.; Wildl. Res. Rep.  6.

Jones, D. M.; Theberge, J. B. (1982) Summer home range and habitat utilization of  the red
      fox (Vulpes vulpes) and gray foxes (Urocyon cinereoargentus) in  Maryland. Am.
      Midi. Nat. 110: 276-285.

Keenan, R. J. (1981) Spatial use of home range among red foxes (Vulpes vulpes) in  south-
      central Ontario. In: Chapman, J. A.; Pursley, D., eds. Worldwide  furbearer
      conference proceedings, August, 1980; Frostburg, Maryland; pp. 1041-1063.

Knable, A. E. (1970) Food habits of the red fox (Vulpes fulva) in Union County,  Illinois.
      Trans. III. State Acad. Sci. 63: 359-365.

Knable, A. E. (1974) Seasonal trends in the utilization of major food groups by the red fox
      (Vulpes fulva) in Union County, Illinois. Trans. III. State Acad. Sci. 66: 113-115.

Korschgen, L. J. (1959) Food habits of the red fox in Missouri. J. Wildl. Manage. 23:
      168-176.

Kuehn, D.  W.; Berg, W. E. (1981) Notes on movements, population statistics, and foods
      of the red fox in north-central Minnesota. Minn. Wildl. Res. Q. 41: 1-10.

Layne, J. N.; McKeon, W. H. (1956) Some aspects of red fox and gray fox reproduction in
      New York. N.Y. Fish and Game J. 3: 44-74.

Lindstrom, E. (1981) Reliability of placental scar counts in the red fox (Vulpes vulpes L.)
      with special reference to fading of the scars. Mammal Rev. 11: 137-49.
                                      2-229
Red Fox
-------
Llewellyn, L. M.; Uhler, F. M. (1952) The foods of fur animals of the Patuxent Research
       Refuge, Maryland. Am. Midi. Nat. 48: 193-203..

MacDonald, D. W. (1980) Social factors affecting reproduction amongst red foxes (Vulpes
       vulpes L. 1758). In: Zimen, E., ed. The red fox, biogeographica: v. 18. The
       Netherlands: W. Junk, The Hague; pp. 123-175.

MacDonald, D. W.; Voigt, D. R. (1985) The biological basis of rabies models. In: Bacon, P.
       J., ed. Population dynamics of rabies in wildlife. London, UK: Academic Press; pp.
       71-107.

MacGregor, A. E.  (1942) Late fall and winter foods of foxes in central Massachusetts. J.
       Wildl. Manage. 6: 221-224.

Major, J. T.; Sherburne, J. A. (1987) Interspecific relationships of coyotes, bobcats, and
       red foxes in western Maine. J. Wildl. Manage. 51: 606-616.

Maurel, D. (1980) Home range  and activity rhythm of adult male foxes during the breeding
       season. In: Amlaner, C. J.; MacDonald, D. W., eds. A  handbook on biotelemetry
       and radio tracking. Edmonds, WA: The Franklin Press;  pp. 697-702.

Nagy, K. A.  (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Mono. 57: 111-128.

Nowak, R. M.; Paradiso, J. L. (1983) Foxes. In: Walker's mammals of the world. 4th ed.
       Baltimore, MD: Johns Hopkins University Press; pp. 932-980.

Palmer, E. L.; Fowler, H. S. (1975) Fieldbook of natural history. New York, NY:
       McGraw-Hill Book Co.

Phillips, R. L.; Andrews, R. D.; Storm, G. L.; et al. (1972) Dispersal and mortality of red
      foxes. J. Wildl. Manage. 36: 237-248.

Pils, C. M.; Martin, M. A. (1978) Population dynamics, predator-prey relationships and
       management of the red foxes in Wisconsin. Madison, Wl: Wise. Dept. Nat. Resour.
      Tech. Bull.  No.  105; 56 pp.

Pils, C. M.; Martin, M. A.; Lange, E. (1981) Harvest, age structure, survivorship,
      productivity of red foxes in Wisconsin.  Madison, Wl: Wise. Dept. Nat. Resour.
      Tech. Bull.  No.  125; 19 pp.

Powell, D. G.; Case, R. M. (1982) Food habits of the red fox in Nebraska. Trans. Nebr.
      Acad. Sci. and Affil. Soc. 10:  13-16.

Preston, E. M. (1975) Home range defense in the red fox, Vulpes vulpes L. J. Mammal.
      56: 645-652.
                                      2-230
Red Fox
-------
Richards, S. H.; Mine, R. L. (1953) Wisconsin fox populations. Madison, Wl: Wise. Cons.
       Dept. Tech. Wildl. Bull. No. 6; 78 pp.

Samuel, D. E.; Nelson, B. B. (1982) Foxes. In: Chapman, J. A.; Feldhammer, G. A., eds.
       Wild mammals of North America. Baltimore, MD: Johns Hopkins University Press;
       pp. 475-490.

Sargeant, A. B. (1972) Red fox spatial characteristics in relation to waterfowl predation. J.
       Wildl. Manage. 36: 225-236.

Sargeant, A. B. (1978) Red fox prey demands and implications to prairie duck production.
       J. Wildl. Manage. 42: 520-527.

Sargeant, A. B.; Pfeifer, W. K.; Allen, S. H. (1975) A spring aerial census of red foxes in
       North Dakota. J. Wildl. Manage. 39: 30-39.

Sargeant, A. B.; Allen, S. H.; Fleskes, J. P. (1986) Commercial sunflowers: food for red
       foxes in North Dakota. Prairie Nat. 18: 91-94.

Sargeant, A. B.; Allen, S. H.; Hastings, J. 0. (1987)  Spatial relations between sympatric
       coyotes and red foxes in North Dakota. J. Wildl. Manage.  51: 285-293.

Sargeant, A. B.; Allen, S. H.; Johnson,  D. H. (1981)  Determination of age and whelping
       dates of live red fox pups.  J. Wildl. Manage. 45: 760-765.

Schoonmaker, W. J. (1938) Notes on mating and breeding habits of foxes in New York
       state. J. Mammal. 19: 375-376.

Scott, T. G. (1943) Some food coactions of the  northern plains red fox. Ecol. Monogr. 13:
       427-480.

Sheldon, W. G. (1949) Reproductive behavior of foxes in New York state. J.  Mammal. 30:
       236-246.

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
       453-460.

Stanley, W. C. (1963) Habits of the red fox in northeastern Kansas. Univ. Kansas Mus.
       Nat. Hist. Misc. Pub.  34: 1-31.

Storm, G. L.; Abies, E. D. (1966)  Notes on newborn  and  Fullterm wild red foxes.  J.
       Mammal. 47: 116-118.

Storm, G. L.; Andrews, R. D.; Phillips, R. L.; et al.  (1976) Morphology, reproduction,'
      dispersal and mortality of midwestern red fox  populations. Wildl. Monogr.  49: 1-82.

Switzenberg, D. F. (1950) Breeding productivity  in Michigan red foxes. J. Mammal. 31:
       194-195.
                                      2-231
Red Fox
-------
Tullar, B. J. (1983) An unusually long-lived red fox. IM.Y. Fish Game J. 30: 227.

Tullar, B. J., Jr.; Berchielli, L. T. (1980) Movement of the red fox in central New York.
       N.Y. Fish Game J. 27: 197-204.

Vogtsberger,  L. M.;  Barrett, G. W. (1973) Bioenergetics of captive red foxes. J. Wild!.
       Manage. 37: 495-500.

Voigt, D. R.; MacDonald, D. W. (1984) Variation in the spatial and social behaviour of the
       red fox, Vulpes vulpes. Acta Zool. Fenn.  171: 261-265.

Voigt, D. R.; Tinline, R. L. (1980) Strategies for analyzing radio tracking data. In: Amianer,
       C. J., Jr.; MacDonald, D. W., eds. A handbook on biotelemetry and radio tracking.
       Oxford, United  Kingdom: Pergamon Press; pp. 387-404.

Voigt, D. (1987) Red fox. In: Novak, M.; Baker, J. A.;  Obbarel, M. E.; et al., eds. Wild
       furbearer management and conservation. Pittsburgh, PA: University of Pittsburgh
       Press;  pp. 379-392.

Voigt, D. R.; Broadfoot, J. (1983) Locating pup-rearing dens of red foxes with
       radio-equipped woodchucks. J. Wildl. Manage.  47: 858-859.
                                      2-232
Red Fox
-------
2.2.3.  Raccoon (raccoons, coatis, ringtails)

       Order Carnivora. Family Procvonidae.  Procyonids are medium-sized omnivores that
range throughout much of North America. Raccoons, coatis, and ringtails feed on insects,
small mammals, birds, lizards, and fruits.  Ringtails are much smaller and more slender
than raccoons and consume a higher proportion of animal matter (Kaufmann, 1982).
Coatis are slightly smaller than racoons and are limited in their distribution in the United
States to just north of the Mexican border.

Selected species

       The raccoon (Procyon lotor) is the  most abundant and widespread medium-sized
omnivore in the North America.  They are found throughout Mexico, Central America, the
United States, except at the higher elevations of the Rocky Mountains, and into southern
Canada (Kaufmann, 1982).  During the last 50 years, raccoon populations in the United
States have increased greatly (Sanderson, 1987).  In suburban areas, they frequently raid
garbage cans and dumps. Raccoons are preyed on by bobcats, coyotes, foxes, and great
horned owls (Kaufmann, 1982).  Twenty-five subspecies are recognized in the United
States and Canada; however, most researchers do not identify the subspecies studied
because different subspecies inhabit essentially nonoverlapping geographic ranges.

       Body size.  Raccoons measure from 46 to 71 cm with a 20 to 30 cm tail. Body
weights vary by location, age, and sex from 3 to 9 kg (Kaufmann, 1982; Sanderson,
1987).  The largest raccoons recorded are from Idaho and nearby states, while the
smallest reside in the Florida  Keys (Lotze and Anderson, 1979).  Juveniles do not reach
adult size until at least the end of their second year (Stuewer, 1943b). In the autumn, fat
reserves account for 20 to 30 percent or more of the raccoon's weight (Whitney and
Underwood, 1952, cited in Kaufmann, 1982).  In Minnesota, Mech et al. (1968) found
that juveniles gained weight almost linearly until mid-November, after which they began to
lose weight until April. Weight loss in adults and yearlings can reach 50 percent during
the 4 months of winter dormancy (e.g., 4.3-kg loss for a 9.1-kg raccoon) (Thorkelson and
Maxwell, 1974; Mech et al.,  1968).  In Alabama, where raccoons are active all year,
winter weight losses are less, 16 to 17 percent on average (Johnson, 1970).

       Habitat.  Raccoons are found near  virtually every aquatic habitat, particularly in
hardwood swamps, mangroves, floodplain forests, and freshwater and saltwater marshes
(Kaufmann, 1982). They are also common in suburban residential areas and cultivated and
abandoned farmlands (Kaufmann, 1982) and may forage in farmyards (Greenwood,  1982).
Stuewer (1943a) stated that  a permanent water supply, tree dens, and available food are
essential.  Raccoons use surface waters for both drinking and foraging (Stuewer, 1943a).

       Food habits. The raccoon is an omnivorous and opportunistic feeder. Although
primarily active from sunset to sunrise (Kaufmann, 1982; Stuewer, 1943a), raccoons will
change their activity period to accommodate the availability of food and water (Sanderson,
1987).  For example,  salt marsh raccoons may become active during the day to take
advantage of low tide (Ivey, 1948, cited in Sanderson, 1987).  Raccoons feed primarily on
fleshy fruits, nuts, acorns, and corn (Kaufmann, 1982) but also eat grains, insects, frogs,
                                      2-233
Raccoon
-------
crayfish, eggs, and virtually any animal and vegetable matter (Palmer and Fowler, 1975).
The proportion of different foods in their diet depends on location and season, although
plants are usually a more important component of the diet. They may focus on a preferred
food, such as turtle eggs, when it is available (Stuewer, 1943a). They also will feed on
garbage and carrion.  Typically, it is only in the spring and early summer that raccoons eat
more animal than plant material. Their late summer and fall diets consist primarily of
fruits. In winter, acorns tend to be the most important food, although raccoons will take
any corn or fruits that are still available (Kaufmann, 1982; Stuewer, 1943a).

       Temperature regulation and molt. From the central United States into Canada,
raccoons undergo a winter dormancy lasting up to 4 months (Stuewer, 1943a).  It is not a
true hibernation, however, and they can be easily awakened {Kaufmann,  1982).  Animals
in the south are active year-round (Goldman, 1950). Snow cover, more than low
temperatures, triggers winter dormancy (Stuewer, 1943a; Mech et al., 1966; Kaufmann,
1982). The raccoon's annual  molt begins  early in spring and lasts about 3 months
(Kaufmann, 1982).

      Breeding activities and social organization. Although solitary, adult raccoons  come
together  for a short time during the mating period (Kaufmann, 1982), which begins earlier
(January to March) in their northern range  than in their southern range (March to June)
(Johnson, 1970; Sanderson, 1987).  Male  and female home ranges overlap freely and each
male may mate with several females during the breeding season (Mech et al., 1966;
Johnson, 1970; Kaufmann, 1982;  Stuewer, 1943a). The most common group of
raccoons is a mother and her young of that year. Further north in their range, a family will
den together for the winter and break up the following spring (Kaufmann,  1982).  Males
are territorial toward one another but not toward females; females are not territorial
(Fritzell, 1978).

      Home range and resources.  The size of a raccoon's home range depends  on its sex
and age,  habitat, food sources, and the season (Sanderson, 1987). Values from a few
hectares  to more than a few thousand hectares have been reported, although home ranges
of a few  hundred hectares appear to be most common (see Appendix). In general, home
ranges of males are larger than those of females, the home range of females with young is
restricted, and winter ranges are smaller than ranges at other times of the year for both
sexes (Sanderson, 1987).  During the  winter, raccoons commonly den in hollow trees;
they also use the burrows of other animals such as foxes, groundhogs, skunks, and
badgers.  These sites are used for sleeping during warmer periods.  After wintering in one
den, the female will choose a new den in which to bear her young (Kaufmann,  1982).
Schneider et al. (1971) found that once the cubs leave the den, the family will  not use it
again that year.

      Population density.  Population  density depends on  the quality and quantity of food
resources and den sites. Values between 0.005 and 1.5 raccoons per hectare  have  been
reported, although 0.1 to 0.2 per hectare is more common (see Appendix). Populations
exceeding one raccoon per hectare have been reported in residential areas (Hoffman and
Gottschang, 1977).  Although  raccoons may prefer tree dens over ground  dens,
particularly  for raising young (Stuewer, 1943a), Butterfield (1954) found high raccoon
densities  in an area with few tree dens but numerous ground dens.

                                      2-234                               Raccoon
-------
      Population dynamics.  Males generally are not sexually mature by the time of the
first regular breeding season following their birth, but they may mature later that summer
or fall (Johnson, 1970; Sanderson, 1951).  Females may become pregnant in their first
year (Johnson,  1970).  In a review of several studies, Kaufmann (1982) found that up to
60 percent of both wild and captive females mate and produce litters in their first year.  In
Illinois and Missouri, Fritzell et al. (1985) found pregnancy rates of yearlings from 38 to 77
percent.  After their first year, almost all females breed annually (Fritzell et al., 1985).
Females produce only one litter each year, and the female alone cares for the young
(Sanderson,  1987; Stuewer,  1943a, 1943b). With some exceptions  (Bissonnette and
Csech, 1937), larger litter sizes usually occur in the raccoon's northern range (Lotze and
Anderson, 1979).  Some juveniles of both sexes disperse from the areas where they were
born during the fall or winter of their first year, while others stay and  raise young within
their parents' home range (Stuewer, 1943a).  The highest mortality rates occur within the
first 2 years; the age structure of populations in Alabama suggests that mortality is higher
for subadults than for juveniles (Johnson, 1970).

Similar species (from general references)

      •      The coati (Nasua nasua) is slightly smaller than the raccoon  (4 to 6 kg) but
             with a much longer tail (51 to 64 cm).  Ranging throughout  Central America
             from Panama to Mexico (Kaufmann, 1982), the coati is rare in the United
             States where it inhabits open forests of the southwest, near the Mexican
             border. It forages primarily for grubs and tubers but also feeds on fruits,
             nuts, bird eggs, lizards, scorpions, and tarantulas. Coatis roll arthropods  on
             the ground to remove wings and scales.

      •      The ringtail (Bassariscus astutus) is smaller (36 to 41 cm; 0.9 to 1.13 kg)
             than the raccoon, with a tail equal to its body length.  It ranges throughout
             the southwestern United States into northern California and  Oregon,
             inhabiting chaparral, rocky ridges, and cliffs near water.  Ringtails are
             omnivorous like the raccoon but consume a higher proportion of animal
             matter, feeding mainly on  small mammals, insects, birds, and lizards as well
             as fruits.  They den in caves or crevices along cliffs, hollow  trees, under
             rocks, and in unused buildings.  Although ringtails sometimes live in
             colonies, mated pairs are more common.  More nocturnal than the raccoon,
             the ringtail is only active at dawn and dusk (Kaufmann, 1982).

Genera/ references

      Burt and Grossenheider (1980); Goldman (1950); Johnson (1970);  Kaufmann
(1982); Palmer and Fowler (1975); Sanderson (1987).
                                      2-235
Raccoon
-------
                                             Raccoon (Procyon lotor]
Factors
Body Weight
.(kg)


. /
Pup Growth
Rate fg/day)
•)'..
Metabolic
Hate
{TOa/kg-day}
Metabolic Rate
Ikcaf/kg-day)

Food Ingestion
Rate te/g-dayl
Age/Sex/
Cond./Seas.
AM
A F parous
A F nulliparous
JM
JF
AM
AF
AM
AF
neonate
birth to 7 days
8 to 1 9 days
20 to 30 days
31 to 40 days
41 to 50 days
birth to 6 wks
6 to 9 wks
1 0 to 16 wks
Winter
15-35°C
JB
A M basal
A F basal
A M free-living
A F free-living

Mean
7.6
6.4
6.0
5.1
4.8
6.76
5.74
4.31
3.67
0.075
17
21
11
12
23
17.8
3.9
29.5
9.36 ± 1.68
SD
304
44.8
46.8
183
187

Range
or (95% Ci)
7.0 - 8.3
5.6 - 7.1
5.1 -7.1
4.6 - 5.7
4.2 - 5.3
»
up to 8.8
up to 5.9





(83 - 400)
(85 - 408)

Location
we Illinois
Missouri
Alabama
w New York/captive
w New York
NS/lab
Washington, DC/National
Zoo
Ohio/lab


Reference
Sanderson, 1984
Nagel, 1943
Johnson, 1970
Hamilton, 1936
Hamilton, 1936
Montgomery, 1969
Mugaas et al., 1984
Teubner & Barrett, 1983
estimated
estimated

Note
No.







1
2
3
to
N3
CO
O>
3J
CD
O
O
O
O
3
-------
                                           Raccoon (Procyon /otor]

Factors
Water
Ingestion Rate
(g/g-day)
Inhalation
Rate (m3/day)
Surface Area
fern2)
Age/Sex/
Cond./Seas.
AM
AF

AM
AF
AM
AF
Dietary
Composition
crayfish
snails
insects
reptiles/amphibians
fish
rodents
corn
Smilax
acorns
pokeberry
wild cherry
blackberries
grapes
persimmon

Mean
0.082
0.083

2.47
2.17
3,796
3,414

Spring
37
5
40
6
3
7
0
0
0
0
0
0
0
0

Summer
8
5
39
5
2
2
1
trace
trace
trace
17
16
trace
0
Range
or J9596 CO
•







Fall
3
3
18
3
trace
trace
2
trace
5
17
2
trace
23
11

Winter
9
6
12
7
2
8
19
6
17
2
0
0
8
7

Location







Location/Habitat
(measure)
Maryland/forested
bottomland

(% wet volume; digestive
tract)










Reference
estimated

.
estimated

estimated


Reference
Llewellyn & Uhler, 1 952













Note
No.
4


5

6

Note
No.














ro
oo
30
Q>
o
o
o
o
3
-------
                                            Raccoon (Procyon lotor]
Dietary
Composition
frogs
fish
birds
mammals
othetfunspecified
persimmon
corn
grapes
pokeberry
acorns
sugar hackbefry
cherry • ,
insects j _
crayfish <
MoIIusca
(mussels and oysters)
Crustacea (shrimp &
crabs)
Pisces (goby
& cabezon) \
"Annelida
* (marine worms)
Eehiurida (worm)
frufts
Jnsects
mammals *
grains f$.g. corn)
-earthworms
amphibians
vegetation
reptiles :
molluscs ; 'a-
birds ' , -5
carrion s " ""
unspecified

Spring
8.1
1.2
trace
1.7
7.8
0
57.6
0
0
0
0
0
22.0
1.6






















Summer
trace
0
0
0
6.7
35.8
0
trace
20.5
0
0
29.5
3.5
4.0
44

25

9

20

1
37.9
8.2
14.3
14.7
7.2
4.4
6.1
3.0
1.9
1.5
1.5
0.2

Fall
0
0
trace
1.4
1.8
57.3
10.0
10.2
4.5
5.4
5.5
0
2.4
1.5






















Winter
0
0
8.4
0
7.2
27.4
25.9
0
0
4.2
18.4
0
trace
1.4














•






Location/Habitat
(measure]
Tennessee/NS

(% wet volume; digestive
tract)










sw Washington/tidewater
mudflats

(% wet volume; stomach
contents)




New York/NS

(% wet volume; stomach
contents)









Reference
Tabatabai & Kennedy, 1988













Tyson, 1950








Hamilton, 1951

f









Note
No.























7











ro

ro
CO
03
3J
0)
o
o
o
o
-------
                                                  Raccoon (Procyon lotor]
               Age/Sex/
               CondJSeas.
                                                                              Reference
                                                                                   •
                                                                              Fritzell, 1978
Population
Dynamics
                                                                   Location/Habitat
                                                                  North Dakota/prairie
                                                                  potholes
                                 670 - 4,946
                                 229-1,632
                A M spr./sum
                A F spr./sum.
Home
Range
Size
ma)
                                                                                              Stuewer, 1943a
                                                                   Michigan/riparian
                                 18.2-814
                                 5.3 - 376
               A M May - Dec
               A F May - Dec ,
                                                                   Georgia/coastal island
                                65 ± 18 SE
                                39 ± 16 SE
A M all year
A F all year
                                                                                               Hoffman & Gottschang, 1977
                                                                   Ohio/residential woods
Population
Density (N/ha>
                                                                               Urban, 1970

                                                                               Dorney, 1954
                                                                               —.   i
                                                                               Fritzell et al., 1985
                                                                    Lake Erie, Ohio/
                                                                      Sandusky Bay, marsh
                                                                    Wisconsin/marsh
                1 to 3 yrs
                4 yrs +
                                                                                               Johnson, 1970
                                                                    Alabama/bottomlands,
                                                                    marsh
                                                                                                Sanderson, 1987
                                                                    most of range/NS
                                                                                                Hamilton, 1936; Sanderson
                                                                                                1987; Stuewer, 1943b
                                                     North America/NS
 Days
 Gestation
                                                                                                Montgomery, 1969
 Age at
 Weaning
 (days)
                                                                                                Johnson, 1970

                                                                                                Fritzell et al., 1985
                                                                                                __————^—
                                                                                                Sanderson,  1951

                                                                                                Clark etal., 1989
                                                     Alabama/NS

                                                     IL, MO/NS
                                                          	•—
                                                     Missouri/NS

                                                     sw Iowa/agricultural
  Age at
  Sexual
  Maturity
   Annual
   Mortality
   Rates
   (percent)
-------
                                                           Raccoon (Procyon fotor)
Population
Dynamics
Longevity
Seasonal
Activity
Mating
% Parturition
Molt
Torpor
Age/Sex/
Cond./Seas.
AB
AB
Begin
February
January
April
April

late November
Mean
3.1 years
1.8 years
Peak
March
February
early April
May
summer

Range

End
August
March
May
October

March/April
Location/Habitat
Alabama/NS
Missouri/NS
Location
sw Georgia, nw Florida
n United States
Michigan
sw Georgia, nw Florida
northern latitudes
ec Minnesota
Reference
Johnson, 1970
Sanderson, 1951
Reference
McKeever, 1958
Johnson, 1970
Stuewer, 1943b
McKeever, 1958
Goldman, 1950
Whitney & Underwood, 1 952
Note
No.
11
Note
No,



12
ro
ro
      1   Estimated using equation 3-43 (Boddington, 1978} and body weights from Nagel (1943).
      2   Estimated using equation 3-45 (Nagy, 1987) and body weights from Nagel (1943).
      3   See Chapters 3 and 4 for methods for calculating food ingestion rates from free-living metabolic rate and diet.
      4   Estimated using equation 3-17 (Calder and Braun, 1983) and body weights from Nagel (1943).
      5   Estimated using equation 3-20 (Stahl, 1967) and body weights from Nagel (1943).
      6   Estimated using equation 3-22 (Stahl, 1967) and body weights from Nagel (1943).
      7   Collections from April through October.
      8   Measured from April through July.
      9   Based on radiotracking.
     10   Average of three methods of estimating density.
     11   Hunted population.
     12   Cited in Schneider et al. (1971).
Q>
O
O
O
O
-------
References (including Appendix)

Alexander, G. (1977) Food of vertebrate predators on trout waters in north central lower
      Michigan. Michigan Academician 10: 181-195.

Arthur, S. C. (1928) The fur animals of Louisiana. Louisiana Dept. Conserv.; Bull. No. 18.

Asdell, S. A. (1964) Patterns of mammalian reproduction.  Ithaca, NY: Comstock Publ. Co.

Bailey, V. (1936) The mammals and life zones of Oregon.  U.S. Dept. Agr., Bur. Biol.
      Survey, North Am. Fauna 55: 1-416.

Bissonnette, T. H.; Csech, A. G. (1937) Modification of mammalian sexual cycles. Part 7,
      fertile matings of raccoons in December instead of February induced by increasing
      daily periods of light. Proc. R. Soc. London, ser. B 827: 246-254.

Boddington, M. J. (1978) An absolute metabolic scope for activity. J. Theor. Biol. 75:
      443-449.

Brown, C. E. (1936) Rearing wild animals in captivity, and gestation periods. J. Mammal.
      17: 10-13.

Burt, W.  H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
      north of Mexico. Boston, MA: Houghton Mifflin Co.

Butterfield, R. T. (1944) Populations, hunting pressure, and movement of Ohio raccoons.
      Trans. North Am. Wildl. Conf. 9: 337-344.

Butterfield, R. T. (1954) Some raccoon and groundhog relationships. J. Wildl. Manage. 18:
      433-437.

Cagle, F. R. (1949) Notes on the raccoon, Procyon lotor megalodous Lowery. J. Mammal.
      30: 45-47.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol.  244: R601-R606.

Cauley, D. L.; Schinner, J. R. (1973) The Cincinnati raccoons. Nat. Hist.  82: 58-60.

Clark, W. R.; Hasbrouck, J. J.; Kienzler, J. M.; et al. (1989) Vital statistics and  harvest of
      an Iowa raccoon population. J. Wildl. Manage. 53: 982-990.

Cowan, W. F. (1973) Ecology and life history of the raccoon (Procyon lotor hirtus Nelson
      and Goldman) in the northern part of its range [Ph.D. dissertation]. Grand Forks,
      ND: University of North Dakota.
                                      2-241
Raccoon
-------
Cunningham, E. R. (1962) A study of the eastern raccoon, Procyon lotor (L.), on the
       Atomic Energy Commission Savannah River Plant [master's thesis]. Athens, GA:
       University of Georgia.

Dew, R. D. (1978) Biology of the raccoon, Procyon lotor; I. Genie variation. II. Population
       age structure and average litter size [master's thesis]. Memphis, TN: Memphis State
       University.

Dorney, R. S. (1954) Ecology of marsh raccoons. J.  Wildl. Manage. 18: 217-225.

Eisenberg, J. F. (1981) The mammalian radiations; an analysis of trends in evolution,
       adaptation, and behavior. Chicago, IL: University of Chicago Press,

Ewer, R. F. (1973) The carnivores. Ithaca, NY: Cornell University Press.

Flower, S. S. (1931) Contributions to our knowledge of the duration of life in vertebrate
       animals. V. Mammals. Zool. Soc. London. Proc. (part 1): 145-234.

Fritzell, E. K. (1978) Habitat use by prairie raccoons  during the waterfowl breeding season.
       J. Wildl. Manage. 42: 118-127.

Fritzell, E. K.; Hubert,  G. F., Jr.; Meyen, B. E.; et al.  (1985) Age-specific reproduction in
       Illinois and Missouri raccoons. J. Wildl. Manage 49: 901-905.

Goldman,  E. A. (1950) Raccoons of North and Middle America. Washington, DC: U.S. Fish
       Wildl. Serv.; North Am. Fauna 60.

Greenwood, R. J. (1982)  Nocturnal activity and foraging of prairie raccoons (Procyon lotor)
       in North Dakota. Am. Midi. Nat. 107: 238-243.

Hamilton,  W. J., Jr. (1936) The food and breeding habits of the raccoon. Ohio J. Sci. 36:
       131-140.

Hamilton,  W. J., Jr. (1940) The summer food of minks and raccoons on the Montezuma
       Marsh, New York.  J. Wildl. Manage. 4: 80-84.

Hamilton,  W. J., Jr. (1951) Warm weather foods of the raccoon  in New York state. J.
       Mammal. 32: 341-344.

Hoffman, C. O.; Gottschang, J. L. (1977) Numbers,  distribution,  and movements of a
       raccoon population in a suburban residential community. J. Mammal. 58: 623-636.

Ivey, R. D. (1948) The raccoon in the salt marshes of northeastern Florida. J. Mammal.
       29:290-291.

Johnson, A. S. (1970) Biology of the raccoon (Procyon lotor varius Nelson and Goldman)
       in Alabama.  Alabama Cooperative Wildlilfe Research Unit;  Auburn Univ. Agric. Exp.
       Stn. Bull. 402.
                                      2-242
Raccoon
-------
  Kaufmann, J. H. (1982) Raccoon and allies. In: Chapman, J. A.; Feldhamer, G. A., eds.
        Wild mammals of North America. Baltimore, MD: Johns Hopkins University Press;
        pp. 567-585.

  Llewellyn, L. M.; Uhler, F. M. (1952) The foods of fur animals of the Patuxent Research
        Refuge,  Maryland. Am. Midi. Nat. 48: 193-203.

  Lotze, J.-H. (1979) The raccoon (Procyon lotor) on St. Catherines Island, Georgia. 4.
        Comparisons of home ranges determined by livetrapping and radiotracking. New
        York, NY: American Museum of Natural History; Rep. No. 2664.
                                                 *
,  Lotze, J.-H.; Anderson, S. (1979) Procyon lotor. American Society of Mammalogists;
        Mammalian Species No. 119.

  Lowery, G. H.,  Jr.  (1936) A preliminary report on the distribution of the mammals of
        Louisiana. Louisiana Acad. Sci. Proc. 3: 1-39.

  McComb, W. C. (1981) Effects of land use upon food habits, productivity, and
        gastrointestinal parasites of raccoons. In: Chapman, J. A.; Pursley, D.,  eds.
        Proceedings worldwide furbearer conference: v. 1,  August 1980; Frostburg, MD;
        pp. 642-651.

  McKeever, S. (1958) Reproduction in the raccoon  in the southeastern United States. J.
        Wildl. Manage. 22: 211.

  Mech, L. D.; Tester, J. R.; Warner, D. W. (1966) Fall daytime resting habits of raccoons as
        determined  by telemetry. J. Mammal. 47: 450-466.

  Mech, L. D.; Barnes, D. M.; Tester, J. R. (1968) Seasonal weight changes, mortality, and
        population structure of raccoons in Minnesota. J. Mammal. 49: 63-73.

  Montgomery, G. G. (1969) Weaning of captive raccoons. J. Wildl. Manage. 33: 154-159.

  Moore, D. W.; Kennedy, M. L. (1985) Weight changes and population structure of
        raccoons in  western Tennessee. J. Wildl. Manage. 49: 906-909.

  Mugaas, J. N.;  Mahlke, K. P.; Broudy, E.; et al. (1984) Metabolism of raccoons, Procyon
        lotor, in  winter  and summer (abstract only). Am. Zool.  24: 89A.

  Nagel, W. O. (1943) How big is a 'coon. Missouri Conservationist 6-7.

  Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
        birds. Ecol.  Mono.  57:  111-128.

  Palmer, E. L.; Fowler, H. S. (1975) Fieldbook of natural history.  New York, NY:
        McGraw-Hill Book  Co.
                                       2-243
Raccoon
-------
Sanderson, G. C. (1951) Breeding habits and a history of the Missouri raccoon population
       from 1941 to 1948. Trans. North Am. Wildl. Conf. 16: 445-461.

Sanderson, G. C. (1984) Cooperative raccoon collections. III. Nat. Hist. Survey Div.;
       Pittman-Robertson Proj. W-49-R-31.

Sanderson, G. C. (1987) Raccoon. In: Novak, M.; Baker, J. A.; Obbarel, M. E.; et al., eds.
       Wild furbearer management and conservation. Pittsburgh, PA: University of
       Pittsburgh Press; pp. 487-499.

Sanderson, G. C.; Hubert, G. F. (1981) Selected  demographic characteristics of Illinois
       (U.S.A.) raccoons (Procyon lotor). In: Chapman, J. A.; Pursley, D., eds. Worldwide
       furbearer conference proceedings: v.  1. August 1980; Frostburg, Maryland.

Sanderson, G. C.; Nalbandov, A. V. (1973) The reproductive cycle of the raccoon in
       Illinois. Illinois Nat. Hist. Surv. Bull. 31: 29-85.

Schneider, D. G.; Mech, D.  L.; Tester, J. R. (1971) Movements of female raccoons and
       their young as determined by radio-tracking. Anim. Behav. Monogr. 4:  1-43.

Schoonover, L. J.; Marshall, W. H. (1951) Food habits of the raccoon (Procyon lotor
       hirtus) in north-central Minnesota. J. Mammal. 32: 422-428.

Seton, E. T. (1929)  Lives of game animals. Garden City,  NJ: Doubleday, Doran and
       Company.

Sherfy, F. C.; Chapman, J. A. (1980) Seasonal home range and habitat utilization of
       raccoons in Maryland. Carnivore 3: 8-18.

Slate, D. (1980) A study of New Jersey raccoon  populations—determination of the
       densities, dynamics and incidence of disease in raccoon populations in  New Jersey.
       N.J. Div. Fish, Game, and Wildl.; Pittman-Robertson Proj. W-52-R-8, Final Rep.

Sonenshine, D. E.; Winslow, E. L. (1972) Contrasts in distribution of raccoons in two
       Virginia localities. J. Wildl. Manage. 36: 838-847.

Stahl, W. R. (1967)  Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
       453-460.

Stains, H. J. (1956) The raccoon in Kansas: natural history, management, and economic
       importance. Univ. Kansas Mus. Nat. Hist,,, Misc. Publ. 10: 1-76.

Stuewer, F. W. (1943a) Raccoons: their habits and management in Michigan.  Ecol.
       Monogr. 13:  203-257.

Stuewer, F. W. (1943b) Reproduction of raccoons in Michigan. J. Wildl. Manage. 7:
       60-73.
                                      2-244
Raccoon
-------
Tabatabai, F. R.; Kennedy, M. L. (1988) Food habits of the raccoon (Procyon lotor) in
      Tennessee. J. Tenn. Acad. Sci. 63: 89-94.

Tester, J. R. (1953) Fall food habits of the raccoon in the South Platte Valley of
      northeastern Colorado. J. Mammal. 34: 500-502.

Teubner, V. A.; Barrett, G. W. (1983) Bioenergetics of captive raccoons. J. Wildl. Manage.
      47: 272-274.

Thorkelson, J.; Maxwell, R. K. (1974) Design and testing of a heat transfer model of a
      raccoon (Procyon lotor) in a closed tree den. Ecology 55: 29-39.

Tyson, E. L.  (1950) Summer food habits of the raccoon in southwest Washington. J.
      Mammal. 31: 448-449.

Urban, D. (1970) Raccoon populations, movement patterns, and predation on a managed
      waterfowl marsh. J. Wildl. Manage. 34: 372-382.

VanDruff, L. W. (1971) The ecology of the raccoon and opossum, with emphasis on their
      role as waterfowl nest predators [Ph.D. dissertation]. Ithaca, NY: Cornell University.

Whitney, L. F.; Underwood, A. B. (1952) The raccoon. Orange, CT: Practical Science Publ.
                                                                      •
Wood, J. E. (1954) Food habits of furbearers of the upland post oak region in Texas. J.
      Mammal. 35: 406-415.

Yeager, L. E.; Rennels, R.  G. (1943) Fur yield and autumn foods of the raccoon in Illinois
      river bottom lands. J. Wildl. Manage. 7: 45-60.
                                      2-245
Raccoon
-------
-------
2.2.4.  Mink (mink, weasels, ermine)

       Order Carnivora. Family Mustelidae. Although varied in size, most members of this
family have long, slender bodies and short legs. Throughout the family, the male is usually
larger than the female. The more terrestrial species feed primarily on small mammals and
birds.  Mustelids that live around lakes and streams feed on aquatic prey such as fish,
frogs, and invertebrates (Burt and.Grossenheider,  1980).

Selected species

       The mink (Mustela vison) is the most abundant and widespread carnivorous
mammal in North America.  Mink are distributed throughout North America, except in the
extreme north of Canada, Mexico, and arid areas of the southwestern United  States.  It is
common throughout its range but often overlooked because of its solitary nature and
nocturnal activity.  Mink are particularly sensitive to PCBs and similar chemicals, and have
been found to accumulate PCBs in subcutaneous fat to 38 to 200 times dietary
concentrations, depending on the PCB congener (Hornshaw et al., 1983).

       Body size.  Body size varies greatly throughout the species' range, with males
weighing markedly more than females (in some populations, almost twice as much, see
table). Males measure from 33 to 43 cm with a 18 to 23 cm tail. Females measure from
30 to 36 cm with a 13 to 20 cm tail (Burt and Grossenheider, 1980).  Farm-raised mink
tend to be larger than  wild mink (letter from  R.J. Aulerich, Department of Animal Science,
Michigan State  University, East Lansing, Ml, to Susan Norton, January 7, 1992).

       Metabolism.  Harper et al. (1978) evaluated the energy requirements of growing
farm-raised male mink during a 21-day period when about 20 percent of their total growth
would  occur. They expressed food intake on the basis of metabolic body size (MBS)
instead of body weight (BW) where MBS  = BW(kg)0-73. Metabolizable energy (ME)
requirements were 147.8 ± 6.06 (kcal/kgMBS-day). Accounting for assimilation efficiency,
this corresponded to a gross energy (GE)  intake of approximately 203 (kcal/kgMBS-day).

       Iversen (1972) found that basal metabolic rate for mink and other mustelids
weighing 1 kg or more could be expressed by the  equation:

                   BMR =  84.6Wt°'78{±0.15),
                                                                 e
where BMR = basal metabolic  rate in kcal/day and Wt =  body weight in kilograms.  This
model reflects the finding that the larger mustelids have a slightly (10 to 15 percent)
higher  basal metabolic rate than expected for mammals in general.f  Free-living metabolic
rates would be expected to be three to five times higher (see table).

       Habitat.  Mink are found associated with aquatic habitats of all kinds, including
waterways such as rivers, streams, lakes, and ditches, as well as swamps, marshes, and
fMustelid species much smaller than 1 kg (i.e., the stoat and weasel) have much higher basal
 metabolic rates than predicted for mammals in general.

                                       2-247            ,                      Mink
-------
backwater areas (Linscombe et al., 1982). Mink prefer irregular shorelines to more open,
exposed banks (Allen, 1986).  They also tend to use brushy or wooded cover adjacent to
the water, where cover for prey is abundant and where downfall and debris  provide den
sites (Allen, 1986).

       Food habits. Mink are predominantly nocturnal hunters, although they are
sometimes active during the day.  Shorelines and emergent vegetation are the mink's
principal hunting areas (Arnold, 1986, cited in Eagle and Whitman,  1987). Mink are
opportunistic feeders, taking whatever prey is abundant (Hamilton,  1936, 1940; Errington,
1954; Sargeant et al., 1973).  Mammals are the mink's most important prey year-round in
many parts of their range (Eagle and Whitman, 1987), but mink also hunt aquatic prey
such as fish, amphibians, and crustaceans and other terrestrial prey such as bird, reptiles,
and insects, depending on the season (Linscombe et al., 1982). In  marsh habitats in
summer, muskrats can be an important food source depending  on their population density
and vulnerability (e.g., health) (Hamilton, 1940; Sealander, 1943; Errington,  1954). Mink
diet also can depend on marsh water level; Proulx et al. (1987) found that with high water
levels, mink captured predominantly crayfish and meadow voles, but during  periods of low
water, the mink preyed on aquatic birds and muskrats deeper in the marsh.  Similarly,
Errington (1939) found that mink predation on muskrats in the  prairie pothole region can
increase dramatically in times of drought as the muskrat burrows become more exposed.
Also in this region, ducklings and molting adult ducks that frequent shorelines are
particularly vulnerable to mink predation (Arnold and  Fritzell, 1987;  Sargeant et al., 1973).
In winter, mink often supplement their diet with fish  (Eagle and Whitman, 1987). Females
tend to be limited to smaller  prey than males, who  are able to hunt  larger prey such as
rabbits and muskrats more successfully (Birks and  Dunstone, 1985; Sealander, 1943).

       Temperature regulation and molt.  In winter, mink do not undergo hibernation or
torpor; instead, they are active year-round. Mink replace their summer coat  in mid to late
fall with a darker more dense coat and molt again in the spring  (Eagle and Whitman, 1987;
Linscombe et al.,  1982).

       Breeding activities and social organization.  Mating occurs in  late winter to early
spring  (Eagle and Whitman, 1987). Variation in the length of mating season with different
subspecies reflects adaptations to different climates (Linscombe et al., 1982).  Ovulation is
induced by mating, and implantation is delayed (Eagle and  Whitman, 1987).  Parturition
generally occurs in the late spring, and the mink kits are altricial (helpless) at birth
(Linscombe et al., 1982). Mink.are generally solitary, with females  only associating with
their young of the year.  Female home ranges generally do not overlap with the home
ranges of other females, nor  do the home ranges of males  overlap with each other (Eagle
and Whitman, 1987).  The home range of a male may overlap the home range  of several
females, however, particularly during the breeding season (Eagle and Whitman,  1987).

       Home range and resources. The home range of mink encompasses both their
foraging areas around waterways and their dens. When denning, mink use bank burrows
of other animals, particularly muskrats, as well as cavities in tree roots, rock or brush
piles, logjams, and beaver lodges (Melquist et al., 1981; Birks and Linn, 1982; Eagle and
Whitman, 1987).  Individual mink may use several different dens within their home range,
males more so than females (Birks and Linn, 1982). Melquist et al.  (1981) found that  den

                                       2-248                                  Mink
-------
sites in Idaho were 5 to 100 m from the water, and they never observed mink more than
200 m from water.  The shape of mink home ranges depends on habitat type; riverine
home ranges are basically linear, whereas those in marsh habitats tend to be more circular
(Birks and Linn, 1982; Eagle and Whitman, 1987). Home range size depends mostly on
food abundance, but also on the age and sex of the mink, season, and social stability
(Arnold, 1986; Birks and Linn, 1982; Eagle and Whitman, 1987; Linn and Birks, 1981;
Mitchell,  1961).  In winter, mink spend more time near dens and use a smaller portion of
their home range than  in summer (Gerell, 1970, cited in Linscombe et al., 1982). Adult
male home ranges are  generally larger than adult female home ranges (Eagle and Whitman,
1987), particularly during the mating season when males may range over  1,000 ha
(Arnold, 1986).

      Population density.  Population  density depends on available cover  and prey.
Population densities typically range from 0.01 to 0.10 mink per hectare (see table). In
riverine environments,  it can be more meaningful to measure densities in terms of number
of mink per unit length of shoreline covered rather than in terms of number per hectare.

      Population dynamics. Mink reach sexual maturity at 10 months to a year and may
reproduce for 7 years,  possibly more (Enders, 1952;  Ewer, 1973).  Female mink can
reproduce once per year and usually give birth to their first litters at the age of 1 year
(Eagle and Whitman, 1987). Females  often live to the age of 7 years in captivity (Enders,
1952).

Similar species (from general references)

      •      The long-tailed weasel (Mustela frenata) is smaller (males 23 to 27 cm, 200
             to 340 g; females 20 to  23 cm, 85  to 200 g) than the mink. It is considered
             beneficial in agriculture because it kills  small rodents, but it does not harm
             poultry.  Although it does not range as far north as the mink, the  long-tailed
             weasel does inhabit parts of the southwest.

      •      The least weasel (Mustela nivalis) is smaller than the mink (males 15 to 17
             cm, 39 to 63 g;  females 14 to 15 cm,  38 to 40 g) and inhabits meadows,
             fields, and wooded areas.  The least weasel feeds extensively on  mice and
             insects.  Its habitat is limited to the  north central United States and Canada.

      •      The ermine (Mustela erminea), or shorttail weasel, is smaller (males 15 to 17
             cm, 71 to 170 g; females 13 to 19  cm, 28 to 85 g) than the mink.  The
             ermine inhabits woody areas near water and feeds primarily on small
             mammals. The ermine's range is limited to the northern and western United
             States and Canada.

      •      The black-footed ferret (Mustela nigripes) is larger  (36 to 46 cm; up to 1.1
             kg) than  the mink and inhabits western prairies in the United States,
             although it now is an endangered species.  It feeds on prairie dogs and other
             small animals.
                                      2-249
Mink
-------
General references

      Burt and Grossenheider (1980); Eagle and Whitman (1987); Hall (1981); Linscombe
etal. (1982); Palmer and Fowler (1975).
                                     2-250
Mink
-------
                                             Mink [Mustela vison]
factors
WeigM



-"
Pup Growth
Rate (g/day)

Age/Sex/
Cond./Seas»
AM
AM
A M spring
A F spring
A M summer
J M summer
A M fall
J M fall
A F summer
J F summer
A F fall
J F fall
neonate
neonate
0-30 days; M
31-90d; M
91-120 d;M
121-150 d; M
151-1 80 d; M
0-30 days; F
31-90 d; F
91-120d;F
121-150d;F
151-1 80 d; F
Mean

1,734 ± 350 SD
974 ± 202 SD
1,040
777
1,233
952
550
533
586
582
8.3 ± 1.54SD
7.0
21
15
9.0
4.3
6.5
13
6.7
1.7
0.6
Range or
<95% Cl of
mean)
< 2,300
< 1,400



6-10


Location
western races
eastern races
Michigan (farm-raised)
Montana
Montana
NS
Michigan (farm-raised)
NS/(farm-raised)

Reference
Harding, 1934
Harding, 1934
Hornshaw et al., 1983
Mitchell, 1961
Mitchell, 1961
Eagle & Whitman, 1987
Hornshaw et al., 1983
Wehr et al. (unpublished)

Note
NO,
1
1




2

to

to
or
-------
                                              Mink (Mustela v/'son)


Factors
Metabolic Rate
(kcal/kg-day]



.Food Ingestion
, Rate (g/g-day]

I '

Vv'ater ,
Ingestion
Rate (g/g-day)
Inhalation
Rate (m3/day)
Surface Area
(cm2)


Age/Sex/
Cond./Seas.
A F basal
A M basal
A F ranch cage
A F free-living
A M free-living
A M summer


A M winter
A F winter
A M yr-round
AF
AM
AF
AF
AM
AF
AM
Dietary
Composition
ducks
other birds ,
eggs
muskrats
ground squirrels
other mammals
insects











Mean
96
84
258
258
236
0

0
0
0
.13

.12 ± 0.0048 SE
.16 ± 0.0075 SE
.22
0.11
0
.099
0.028
0.33
0.55
743
1

Spring
5.2
18.8
3.3
42.0
14.2
15.5
1.0
,120

Summer
32.5
21.6
14.5
2.1
0.5
25.3
3.5
Range or
{95% Cl of
mean)



(110-507)
(121 -550)













Fall








Wfnter









Location


(farm-raised)


(captive)

Michigan (farm-raised)




(farm-raised)




Location/Habitat
(measure)
Manitoba, Can/aspen
parklands of prairie
potholes

(% dry weight in scats;
male mink only)



Reference
estimated

Farrell &Wood, 1968b
estimated

Arnold & Fritzell, 1987

Bleavins & Aulerich, 1981

estimated
estimated

Farrell & Wood, 1968c
estimated

estimated


Reference
Arnold & Fritzell, 1987







Note
No.
3


4

5

6

7
8

9


11

Note
No.







CJ1
10
-------
                                              Mink (Mustela vison]
Dfetary
Composition
(habitat/season)
trout
non-trout fish
unidentified fish
crustaceans \
amphibians
birds/mammals
vegetation
unidentified
(sex of mink)
muskrat
cottontail
smatt mammals
targe birds '••
small birds
snakes
frogs
fish
crayfish
frogs
mice & rats
fish
rabbits
crayfish
birds
fox squirrels
mu$krats
other
-.
Spring

Summer
(stream; year-round)
52
6
3
11
2
5
17
4







































Fall

Winter
(river; year-round)
56
26
3
4
3
6
1
1



















(M) (F)
43 14
16 12
5 17
18 11
trace
2 2
10 37
5 4
1 3
24.9
23.9
19.9
10.2
9.3
5.6
2.2
1.3
2.7
Location/Habitat
{measure}
Michigan/stream, river

(% wet weight; stomach
contents)





Michigan/NS

(% volume; stomach
contents)






Missouri/statewide


(% dry volume; stomach
contents)




,
Reference
Alexander, 1977








Sealander, 1943









Korschgen, 1958








Note
No.









12


















KJ

ro
01
oo
7?
-------
                                            Mink (Mustela v/son]
Population
Dynamics
Home Range
Size








Population
Density
•f

Utter
Size

Utters
/Year
Days
Gestation
Age at
Weaning

Age at
Sexual
Maturity
Longevity

Age/Sex/
Cond./Seas.


AM


AF
AF
AM
J M
AF


A F winter
A F winter







eat meat
fully,
homeothermic
B
B


F

Mean


770 ha




2.63 km
1.23 km
1.85 km
0.03 - 0.085 N/ha

0.006 N/ha
0.6 N/km river
4.2
4

1


5"1
37 days

7 weeks
1 0 months
1 year


7

Range
259 - 380 ha




7.8 ha
20.4 ha
1.8 -5.0 km
1.1 - 1.4km
1.0 -2.8 km





2-8
4-10


39-76
40 - 75






maximum 1 0 years
maximum 1 1 years

Location/Habitat
North Dakota/prairie
potholes
Manitoba, Canada/prairie
potholes
Montana/riverine:
heavy vegetation
sparse vegetation
Sweden/stream


Montana/river

Michigan/river

Michigan/(farm-raised)
Montana/river
North America/NS
North America/NS

North America/NS
United States/ffarm-raised)
Louisiana/NS

NS/NS
United States/(farm-raised)
NS/NS

NS/zoo
NS/(farm-raised)

Reference
Eagle (unpublished)

Arnold & Fritzell, 1987

Mitchell, 1961


Gerell, 1970


Mitchell, 1961

Marshall, 1936

Hornshaw et al., 1983
Mitchell, 1961
Hall & Kelson, 1959
Hall & Kelson, 1959

Hall & Kelson, 1959
Enders, 1952
Svilha, 1931

Kostron & Kukla, 1 970
Enders, 1952
Ewer, 1973

Eisenberg, 1981
Enders, 1952
Note
No.
13






1




14








14

14

15



NJ
OI
-------
                                                              Mink (Mustela vison)
Seasonal
Activity
' Mating
Parturition
Molt
Begin

April

'Peak
April
March
fall

mid- to late fall
End

June

Location
Alaska
Montana
Florida, Cypress Swamp
most areas (except south)
NS
Reference , ,
Burns, 1964
Mitchell, 1961
Humphrey & Zinn, 1 982
Eagle & Whitman, 1 987
Eagle & Whitman, 1 987
Note :
No. \
14


NJ
10
U1
O1
 1   Cited in Linscombe et al. (1982).
 2   Cited in NRC (1982).
 3   Estimated using Iversen's (1972) model and summer body weights from Mitchell (1961); equation 3-43 (Boddington, 1978) and body weights
     from Mitchell (1961) yield  slightly lower estimates (see text).
 4   Estimated using equation 3-47 (Nagy 1987) and body weights from Mitchell (1961).
 5   Arnold  and Fritzell (1987) estimated that mink require 180 g of prey per day by assuming a male body mass of 1,420 g and using the model of
     Cowan et al. (1957) derived from measures of prey requirements for captive mink.
 6   Diet of whole chicken (20  percent), commercial mink cereal (17 percent), ocean fish scraps (13 percent), and beef parts, cooked eggs, and
     powdered milk.  Moisture content of feed = 66.2 percent.
 7   Estimated using equation 3-47 (Nagy, 1987), summer body weights from Mitchell (1961), and dietary composition of Alexander (1977). See
     Chapter 4, Figure 4-7 for the calculations.
 8   Estimated using equation 3-17 (Calder and Braun, 1983) and  body  weights from Mitchell (1961).
 9   Diet contained 65 percent  water.
10   Estimated using equation 3-20 (Stahl, 1967) and body weights from Mitchell (1961).
11   Estimated using equation 3-22 (Stahl, 1967) and body weights from Mitchell (1961).
12   Collected from fur buyers.
13   Cited in Allen (1986).
14   Cited in Eagle and Whitman (1987).
15   Cited in Eisenberg (1981).
z
3
-------
References (including Appendix)

Alexander, G. (1977) Food of vertebrate predators on trout waters in north central lower
       Michigan. Michigan Academician 10: 181-195.

Allen, A. W. (1986) Habitat suitability index models: mink. U.S. Fish Wildl. Serv. Biol. Rep.
       82(10.127).

Arnold, T. W. (1986) The ecology of prairie mink during the waterfowl breeding season
       [master's thesis]. Columbia, MO: University of Missouri.

Arnold, T. W.; Fritzell, E. K. (1987) Food habits of prairie mink during the waterfowl
       breeding season. Can. J. Zool. 65: 2322-2324.

Birks, J. D.; Dunstone,  N. (1985) Sex-related differences in the diet of the mink Mustela
       vison. Holarctic Ecol. 8: 245-252.

Birks, J. D.; Linn,  I. J. (1982) Studies of home range of the feral mink, Mustela vison.
       Symp. Zool. Soc. Lond. 49: 231-257.

Bleavins, M. R.; Aulerich, R. J.  (1981) Feed consumption and food passage in mink
       (Mustela vison) and European ferrets (Mustela putorius  furo). Lab. Anim. Sci. 31:
       268-269.

Boddington, M. J. (1978) An absolute metabolic scope for activity. J. Theor. Biol. 75:
       443-449.

Burgess, S. A.;  Bider, J. R. (1980) Effects of stream habitat improvements on
       invertebrates, trout populations, and mink activity.  J. Wildl. Manage. 44: 871-880.

Burns, J. J. (1964) The ecology, economics, and management of mink in the
       Yukon-Kuskokwim Delta, Alaska [master's thesis]. Anchorage, AK: University of
       Alaska.

Butt, W. H.; Grossenheider, R. P.  (1980) A field guide to the mammals of North America
       north of Mexico. Boston, MA: Houghton  Mifflin Co.               »

Calder, W. A.; Braun, E. J. (1983) Scaling  of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Chanin, P. R.; Linn, I. (1980) The diet of the feral mink (Mustela vison) in southwest
       Britain. J. Zool. (London) 192: 205-223.

Cowan, I. M.; Wood, A. J.; Kitts, W. D. (1957)  Feed requirements of deer, beaver, bear,
       and mink for growth and maintenance. Trans. North Am. Wildl. Conf. 22: 179-188.
                                      2-256
Mink
-------
Cowan, W. F.; Reilly, J. R. (1973) Summer and fall foods of mink on the J. Clark Salyer
       National Wildlife Refuge. Prairie Nat. 5: 20-24.

Eagle, T. C.; Whitman, J. S. (1987) Mink. In: Novak, M.; Baker, J. A.; Obbarel, M. E.; et
       al., eds. Wild furbearer management and conservation. Pittsburgh, PA: University of
       Pittsburgh Press; pp. 615-624.

Eberhardt, L. E. (1974) Food habits of prairie mink (Muste/a vison)  during the waterfowl
       breeding season [master's thesis]. St. Paul, MN: University of Minnesota.

Eisenberg, J. F. (1981) The mammalian radiations. Chicago, IL: University of Chicago
       Press.

Enders, R. K. (1952) Reproduction of the mink (Mustela vison). Proc. Am. Philos. Soc. 96:
       691-755.

Errington, P. L. (1939) Reactions of muskrat populations to drought. Ecology 20: 168-186.

Errington, P. L. (1954) The special responsiveness of minks to epizootics in muskrat
       populations. Ecol. Monogr. 24: 377-393.

Ewer, R. F. (1973) The carnivores. Ithaca, NY: Cornell University Press.

Farrell, D. J.; Wood, A. J. (1968a) The nutrition of the female mink (Mustela vison).  I. The
      metabolic rate of the mink. Can. J. Zool. 46: 41-46.

Farrell, D. J.; Wood, A. J. (1968b) The nutrition of the female mink (Muste/a vison).  II.
      The energy requirement for maintenance. Can. J. Zool. 46: 47-52.

Farrell, D. J.; Wood, A. J. (1968c) The nutrition of the female mink (Muste/a vison).  III.
      The water requirement for maintenance. Can. J. Zool. 46: 53-56.

Gerell,  R. (1970) Home ranges and movements of the mink Muste/a vison Schreber in
      southern Sweden. Oikos 20: 451-460.

Gilbert, F. F.; Nancekivell, E. G. (1982) Food habits of mink (Muste/a  vison) and otter
      (Lutra canadensis) in northeastern  Alberta. Can. J. Zool.  60: 1282-1288.

Guilday, J. E. (1949) Winter food of Pennsylvania mink. Pennsylvania Game News 20:
       12-32.

Hall, E. R. (1981) The mammals of North  America. 2nd ed. New York, NY: John  Wiley and
      Sons.

Hall, E. R.; Kelson, K. R. (1959) The mammals of North America. 1st ed. New York, NY:
      The Ronald Press Co.

Hamilton, W. J., Jr. (1936) Food habits of the mink in New York. J. Mammal. 17: 169.

                                      2-257                                  Mink
-------
Hamilton, W. J., Jr. (1940) The summer food of minks and raccoons on the Montezuma
       Marsh, New York. J. Wildl. Manage. 4: 80-84.

Hamilton, W. J., Jr. (1959) Foods of mink in New York. N.Y. Fish and Game J. 6: 77-85.

Harding, A. R. (1934) Mink trapping. Columbus, OH: A. R. Harding.

Harper, R. H.; Travis, H. F.; Glinsky; M. S. (1978) Metabolizable energy requirement for
       maintenance and body composition of growing farm raised male mink (Mustela
       vfson). J. Nutr.  108: 1937-1943.

Hornshaw, T. C.; Aulerich, R. J.; Johnson, H. E. (1983) Feeding Great Lakes fish to mink:
       effects on mink and accumulation and elimination of PCBs by mink. J. Toxicol.
       Environ.  Health 11: 933-946.

Humphrey, S. R.; Zinn, T. L. (1982) Seasonal habitat use by river otters and everglades
       mink. J.  Wildl. Manage. 46: 375-381.

Iversen, J. A. (1972) Basal energy metabolism of mustelids. J.  Comp. Physiol. 81:
       341-344.

Korschgen, L. J. (1958) December food habits of mink in Missouri. J. Mammal. 39:
       521-527.

Kostron, K.; Kukla, F. (1970) Changes in thermoregulation in mink kits within the 45 days
       of ontogenesis.  Acta Univ. Agric., Facultas Agronomica, Sbornik Vysoke Skoly
       Zemedelske (Brunn)  (rada A) 18: 461-469.

Linn, I. J.; Birks, J. D. (1981) Observations on the home ranges of feral American mink
       (Mustela vfson) in Devon, England, as revealed by radio-tracking. In:  Chapman,
       J. A.; Pursley, D., eds. Proceedings worldwide furbearer conference: v. 1. August
       1980;  Frostburg, MD; pp. 1088-1102.

Linscombe, G.;  Kinler, N.; Aulerich, R. J. (1982) Mink. In: Chapman, J. A.; Feldhammer,
       G. A.,  eds. Wild mammals of North America. Baltimore, MD: Johns Hopkins
       University Press; pp. 329-643.

Marshall, W. H.  (1936) A study of the winter activities of the mink. J. Mammal. 17:
       382-392.

McCabe, R. A. (1949) Notes on live-trapping mink. J.  Mammal. 30: 416-423.

McDonnell, J. A.; Gilbert, F. F. (1981) The responses of muskrats ('Ondatra  zibethicus) to
      water level fluctuations at Luther Marsh, Ontario. In: Chapman, J. A.; Pursley, D.,
      eds. Proceedings worldwide furbearer conference: v. 1. August 1980; Frostburg,
      MD; pp.  1027-1040.
                                      2-258
Mink
-------
Melquist, W. E.; Whitman, J. S.; Hornocker, M. G. (1981) Resource partitioning and
      coexistence of sympatric mink and river otter populations, in: Chapman, J. A.;
      Pursley, D., eds. Proceedings worldwide furbearer conference: v.  1. August 1980;
      Frostburg,  MD; pp.  187-220.

Mitchell, J. L. (1961) Mink movements and populations on a Montana river. J. Wildl.
      Manage. 25: 48-54.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

National Research Council (NRC) (1982) Nutrient requirements of mink and foxes. In:
      Nutrient requirements of domestic animals series. No. 7. Washington, DC: National
      Academy of Sciences, National Academy Press.

Palmer, E. L.; Fowler, H. S. (1975) Fieldbook of natural history. New York, NY:
      McGraw-Hill Book Co.

Pendleton,  G. W. (1982) A selected annotated bibliography of mink behavior and ecology.
      Brookings,  SD: South Dakota State University; Tech. Bull. No. 3.

Perel'dik, N. S.; Milovanov, L. V.; Erin, A. T. (1972) Feeding fur bearing animals.
      Washington, DC: Translated from Russian by the Agricultural Research Service,
      U.S. Department of Agriculture and the National Science Foundation.

Proulx, G.;  McDonnell, J. A.; Gilbert, F, F. (1987) The effect of water level fluctuations on
      muskrat. Ondatra zibethicus, predation by mink, Mustela vison. Can. Field-Nat.
      101:89-92.

Sargeant, A. B.; Swanson, G. A.; Doty, H. (1973) Selective predation  by mink, Mustela
      vison, on waterfowl. Am. Midi. Nat. 89: 208-214.

Sealander, J. A. (1943) Winter food habits of mink in southern Michigan. J. Wildl.
      Manage. 7: 411-417.                        „

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
      453-460.

Svilha, A. (1931) Habits of the Louisiana mink (Mustela  vison vulgivagus). J. Mammal. 12:
      366-368.
                      »
Williams, T. M. (1980) A comparison of running and swimming energetics in the mink
      (abstract). Am. Zool. 20: 909.

Williams, T. M. (1983) Locomotion in the North American mink, a semi-aquatic mammal. I.
      Swimming  energetics and body drag. J. Exp. Biol. 103: 155-168.
                                      2-259
Mink
-------
-------
2.2.5.  River Otter

       Order Carnivore, Family Mustelidae. Mustelids have long, slender bodies, short
legs, and anal scent glands.  Throughout the family, the male is usually larger than the
female. The more terrestrial species of this family occupy various habitats and feed
primarily on small mammals and birds. Mustelids that live around lakes and streams feed
primarily on aquatic species such as fish, frogs, and invertebrates (Palmer and Fowler,
1975; Burt and Grossenheider, 1980).

Selected species

       The northern river otter (Lutra canadensis) historically lived in or near lakes,
marshes, streams, and seashores throughout much of the North American continent (Hall,
1981).  Currently, many populations along the coastal United States and Canada are stable
or increasing, but this species is rare or extirpated throughout much of the midwestern
United States (Toweill and Tabor,  1982).  The river otter dens in banks and hollow logs.
Individuals  range over large areas daily, feeding primarily on fish. Although otters have
few natural predators, while on land, they may be taken by coyotes, fox, or dogs (Melquist
and Hornocker, 1983). Otters clean themselves frequently by rubbing and rolling in any
dry surface (Toweill and Tabor, 1982). Otters appear to undergo bradycardia while
submerged and can stay underwater for up to  4 minutes (Melquist and Dronkert, 1987).
Because of its piscivorous diet and high trophic level, the river otter is a noteworthy
indicator of bioaccumulative pollution in aquatic ecosystems  (Melquist and Dronkert,
1987).

       Body size. River otters measure 66 to 76 cm with a 30 to 43 cm tail. Sexual
dimorphism in size is seen among all subspecies (Harris, 1968; van Zyll de Jong, 1972,
cited in Toweill and  Tabor, 1982), and adult males (5 to 10 kg) outweigh females (4 to 7
kg) by approximately 17 percent (Melquist and Hornocker, 1983; see Table).  Full adult
weight generally is not attained until sexual maturity after 2 years of age (Melquist and
Hornocker, 1983). Along the Pacific Coast, there is some evidence that size decreases
from north  to south (Toweill and Tabor, 1982).

       Metabolism.  Iversen (1972) found that basal metabolic rate of otters and other
mustelids weighing  1 kg or more could be expressed by the equation:

                   BMR = 84.6Wt°'78 (±0.15),

where BMR = basal metabolic rate in kcal/day and Wt = body weight in kilograms. Free-
living  metabolic rates would be expected to be three to five times higher (see table).

       Habitat.  Almost exclusively aquatic, the river otter is  found in freshwater,
estuarine, and some marine environments all the way from coastal areas to mountain lakes
{Toweill and Tabor,  1982).  They are found primarily in food-rich coastal areas, such as
the lower portions of streams and  rivers,  estuaries, nonpolluted waterways, the lakes and
tributaries that feed rivers, and areas showing  little human impact (Mowbray et al., 1979;
Tabor and Wight, 1977).
                                       2-261
River Otter
-------
       Food habits. Otters usually are active in the evening and from dawn to
midmorning, although they can be active any time of day (Melquist and Hornocker, 1983).
The bulk of the river otter's diet is fish; however, otters are opportunistic and will feed on
a variety of prey depending on availability and ease of capture.  River otters take different
fish species according to their availability and how well the fish can escape capture
(Loranger,  1981).  Depending on availability, otters also may consume crustaceans
(especially crayfish), aquatic insects (e.g., stonefly nymphs, aquatic beetles), amphibians,
insects, birds (e.g., ducks), mammals (e.g., young beavers), and turtles (Burt and
Grossenheider, 1980; Lagler and Ostenson,  1942; Liers, 1951b; Melquist and Hornocker,
1983; Palmer and  Fowler, 1975; Toweill and Tabor, 1982).  Gilbert and  Nancekivell
(1982) observed that otters consume more waterfowl in the northerly latitudes than in the
south, probably because of the ease of capturing the waterfowl during their molt in the
north. Otters probe the bottoms of ponds or streams for invertebrates and may ingest
mud or other debris in the process (Liers, 1951b). Otters in captivity required 700-900 g
of food daily (Harris, 1968, cited in Toweill and Tabor,  1982).

       Temperature regulation and molt. Seasonal patterns in otters are not well
understood. Otters are active throughout the year (Toweill and Tabor, 1982), with the
most intense activity levels during the  winter (Larsen, 1983; Melquist and Hornocker,
1983). They undergo a gradual molt in spring and fall (Melquist and Dronkert,  1987).

       Breeding activities and social organization. Adult males are usually solitary; an
adult female and two or three pups make up a typical family group  (Melquist and Dronkert,
1987). River  otters breed in  late winter or early spring over a  period of 3 months or more.
Birth of a litter follows mating by about 1 year; however, implantation is delayed for
approximately  10 months, and active gestation lasts only 2 months (Pearson and Enders,
1944, cited in Toweill and Tabor, 1982; Melquist and Dronkert, 1987).  Newborn otters
are born blind but fully furred  and depend on their mother for milk until 3 to 5 months of
age (Johnstone,  1978; Liers,  1951b).  Family groups disperse about 3 months after the
pups are weaned {Melquist and Hornocker, 1983).

       Home range and resources. The river otter's home  range encompasses the area
needed for foraging and reproduction (Melquist and Dronkert, 1987). The shape of the
home range varies  by habitat type; for example, near rivers or coastal areas, it may be a
long strip along the shoreline (measured in kilometers), but in marshes or areas  with many
small streams, the  home range may resemble a polygon (measured  in hectares; Melquist
and Dronkert, 1987).  All parts of a home range are not used equally; instead, several
activity centers may be interconnected by a  stream or coast (Melquist and Hornocker,
1983). Food has the greatest influence on habitat use, but adequate shelter in  the form of
temporary dens and resting sites also plays a role (Anderson and Woolf,  1987a; Melquist
and Hornocker, 1983). River otters use dens dug by other animals  or natural shelters such
as hollow logs, logjams, or drift piles (Toweill and Tabor, 1982; Melquist and Dronkert,
1987). Beaver bank dens and lodges accounted for 38 percent of resting sites  used by
radio-tracked otters in Idaho (Melquist and Hornocker, 1983).  River otters appear to prefer
flowing water habitats (e.g., streams) over more stationary water (e.g., lakes, ponds)
(Idaho study; Melquist and Hornocker,  1983).
                                       2-262
River Otter
-------
       River otters maintain distinct territories within their home ranges: females maintain
a feeding area for their families, males for breeding purposes (Toweill and Tabor, 1982).
Individuals tend to avoid confrontation through mutual avoidance (Melquist and Hornocker,
1983).  Home ranges are most restricted for lactating females (Melquist and Dronkert,
1987).  Adult and subadult males have larger, more variable home ranges than females.

       Population density. River otter populations show variable spacing in relation to prey
density and habitat (Hornocker et al., 1983).  This characteristic, along with their secretive
habits and use of several den sites, makes it difficult to estimate river otter populations
(Melquist and Dronkert, 1987).  Population density of otters often is expressed in terms of
number per kilometer of waterway or coastline because of their dependence on aquatic
habitats. Densities between one otter every kilometer to one  otter every 10 km of river or
shoreline are  typical (see table).

       Population parameters.  Otters generally are not sexually mature until 2 years of
age (tiers, 1951b; Hamilton and Eadie, 1964; Tabor and Wight, 1977; Lauhachinda,
1978).  Adult females appear to reproduce yearly in Oregon (based on a pregnancy rate of
almost 100 percent; Tabor and Wight, 1977), but Lauhachinda (1978) concluded that they
breed every other year in Alabama and Georgia. Litters usually consist of two to three
pups, although litters as large as six pups occur (see table). As adults, river otter mortality
rates are low, between 15 and 30 percent per year  (Lauhachinda,  1978; Tabor and Wight,
1977).

Similar species (from general references)

       «     The sea otter (Enhydra lutris) (76 to 91 cm body and 28 to 33 cm tail;
             weight 13 to 38 kg) inhabits kelp beds and rocky shores from the Aleutian
             Islands to California.  Its diet includes  fish, abalones, sea urchins, and other
             marine animals.

General references

       Burt and Grossenheider (1980); Melquist and Dronkert  (1987);  Palmer and Fowler
(1975); Toweill and Tabor (1982).
                                       2-263
River Otter
-------
                                           River Otter (Lutra canadensis}
Factors
Weight



Pup Growth
Rate (g/day)
Metabolic Rate
(kcal/kg-day)

Food Ingestion
Rate [g/g-dayj
Water
Ingestion
Rate (g/g-day)
Inhalation
Rate (m3/day)
Surface Area
(cm2)
Age/Sex/
Cond./Seas.
AB
AM
AF
YM
YF
AM
AF
YM
YF
neonate
neonate
1 0 to 20 days
A F basal
A M basal
A F free-living
A M free-living

AF
AM
AF
AM
AF
AM
Mean

8.13 ± 1.15SD
6.73 ± 1.00SD
6.36 ± 0.98 SD
5.83 ± 1.82SD
9.20 ± 0.6 SE
7.90 ± 0.2 SE
7.90 ± 0.4 SE
7.20 ± 0.1 SE
0.132
0.140 to 0.145
26.7
44.8
42.6
183
178

0.082
0.080
2.5
2.9
3,785
4,280
Range or
(95% Cl of
mean)
5.0-15
5.84- 10.4
4.74 - 8.72
4.41 - 8.31
3.75 - 7.01




(83 - 400)
(81 -391)




Location
throughout range
Alabama, Georgia
we Idaho
New York
Alabama, Georgia
NS






Reference
Melquist & Dronkert, 1987
Lauhachinda, 1978
Melquist & Hornocker, 1983
Hamilton & Eadie, 1 964
Hill & Lauhachinda, 1981
Liers, 1951 a
estimated
estimated

estimated
estimated
estimated
Note
No.
1



2
3
4
5
6
7
8
Ni

NJ
CD
-T

o
3
CD
-------
                                             River Otter (Lutra canadensis)
Dietary
Composition
fish
(sucker)
(sculpins!
(squawflsh) ' -
(perch!
(whltefish)
Invertebrates
birds
mammals
reptiles
invertebrates
(aquatic insects)
(fr water shrimp)
fishes
(trout)
(sculpln!
(sunfish)
frog
salamander
snake
birds
mammals

fish
(sunfish)
(minnow/carp)
(herring)
(bass!
frogs
crayfish
dragonfly nymphs
birds

Spring
100
(52)
(40)
(5)
(22)
(21)
2
<1
1
0
41.6
19.6
14.3
91.4
23.7
20.5
47.1
19.6
0.3
0.2
6.7
8.1

97
(31)
(52)
(49)
(26)
3
12
2
4

Summer
93
(47)
(31)
(4)
(3)
(10)
7
12
4
1
44.2
19.2
8.9
92.9
9.8
20.9
72.8
19.2
0.7
0.7
4.1
5.3

69
(31)
(0)
(38)
(0)
6
50
0
13
r
Fall
97
(17)
(38)
( D
(7)
(24)
10
1
3
0
33.3
10.7
10.7
100
33.3
21.3
60.0
10.7
1.3
—
1.3
2.7

98
(80)
(17)
(10)
(5)
11
8
6
3
-
Winter
99
(30)
(42)
(6)
(9)
(66)
12
<1
1
0
26.3
4.0
4.0
100
29.3
25.3
33.3
9.1
-
—
1
4.0

99
(52)
(44)
(40)
(14)
16
7
2
1
location/Habitat
(measure)
we Idaho/mountain streams
and lakes

(percent frequency of
occurrence in scats)

(most of the fish were
longer than 30 cm)


nw Montana/
lakes and streams

(percent frequency of
occurrence in scats)








nw Illinois/Mississippi River

(percent frequency of
occurrence in scats)






Reference
Melquist & Hornocker, 1 983









Greer, 1955












Anderson & Woolf , 1987b








Note
No*
































10

O>

CJ1
CD
-^


o
rt-
r-h
CD
-------
                                             River Otter (Lutra canadensis)
Dietary
Composition
game & pan fish
forage fish
fish remains
amphibians
other invertebrates
Population
Dynamics
Home Range
Size {ha or fcm
river)






Population
Density
(N/ha or N/km
shoreline}





Spring
32
17.6
3.0
16.1
25.8
Age/Sex/
Corid./Seas.
AB

AB
AM
AF





yearling M
yearling F
adult F
B B
BB



A F breeding
A M breeding
yearling B
BB
BB

AB






Summer






*
Fall Winter






Mean ' .









400 ha
295 ha
43
32
31
28
± 20 SD km
± 6.2 SD km
± 9.2 SD km
± 7.5 SD km
0.26/km
0.05/km
0.019/km
0.071 /km
0.85/km






0.0025/ha

Range
400- 1,900 ha

2,900 - 5,700 ha


10-78 km
25 - 40 km
23 - 50 km
15-39 km
0.17 -0.37/km




0.0094-0.014
/ha

Location/Habitat
{measure)
Michigan/habitat NS

(% volume; stomach
contents)


Location/Habitat
Missouri/marsh, streams

Colorado (fall-spr)/NS
se Texas/coastal marsh

we Idaho/river drainage
{no trends seen with season)


we Idaho/river drainage



se Alaska/coastal - island
se Texas/coastal marsh

Missouri/marsh, streams

Reference
Lagler & Ostenson, 1 942




••
Reference"
Erickson et al., 1 984

Mack, 1985
Foy, 1984

Melquist & Hornocker, 1 983



Melquist & Hornocker, 1 983



Woolington, 1984
Foy, 1984

Erickson et al., 1984 *
Note
No.





Note
No.
9

9
9









9
9

9
ro
ro
en
o>
CD



O
r-f
i-f
CD
-------
                                            River Otter (Lutra canadensis)
Population
Dynamics
Litter
"Size
Litters
/Year
Days
Gestation
Age at
Weaning
Age at
Sexual
Maturity
Annual
Mortality
Rates {percent}
Longevity
Age/Sex/
Cond./Seas,
1 yr old
2 yr old
3 yr old
4 yr old
5 to 1 2 yrs
old

total
active
)
F
M
birth - 1 yr .
1 - 2 yrs
2 - 1 1 yrs
AM
AF
AB
Mean
2.73 ± 0.77 SD
2.68 ± 0.71 SD
2.1 ± 0.7 SD
0.53 ± 0.91 SD
0.87 ± 0.96 SD
1.60 + 1.42SD
2.29 ± 1.25 SD
2.67 ± 1.40SD
1
60-63

2 yrs
2 yrs
32
54
27
17.8
20.3

Range
1 -4
1 -4
0-3
0-3
0-4
1 -5
0-6

290 - 380
> 90 days


< 15 yrs
Location/Habitat
Maryland/wetlands
Alabama, Georgia/NS
New York/NS
Maine/NS
NS
Wisconsin/captive
NS
NS
New York/NS
Oregon/NS
Alabama, Georgia/riverine
Alabama, Georgia/riverine
Reference
Mowbray et al., 1 979
Hill & Lauhachinda, 1981
Hamilton & Eadie, 1964
Docktor etal., 1987
Trippensee, 1953
Liers, 1951b
Lancia & Hair, 1 983
Harris, 1968
Hamilton & Eadie, 1964
Tabor & Wight, 1977
Lauhachinda, 1978
Lauhachinda, 1978
Note
No,
10
11-

12
•13




O)
;o

<"
CD
—t


O
i-h
r-h
CD
-------
                                                        River Otter (Lutra canadensis]
Seasonal
Activity
Mating
Parturition
Dispersal
Begin
January
March
winter
mid-March
late March
late January

Peak
March to April
late winter

April to May
End
May
April
spring
mid-May
early April
May

Location
Michigan
New York
AL, FL, GA
Maryland, Chesapeake Bay
we Idaho
Alabama
we Idaho
Reference
Hooper & Ostenson, 1 949
Hamilton & Eadie, 1964
Lauhachinda, 1978
Mowbray et al., 1979
Melquist & Hornocker, 1983
Lauhachinda, 1978
Melquist & Hornocker, 1 983
Note
No.
14

15
fO
to
O)
00
 1   Summary of studies discussed by Hall (1981) and Woolington (1984).
 2   Cited in Toweill and Tabor (1982).
 3   Estimated using equation 3-43 (Boddington,  1978) and adult body weights from Lauhachinda (1978).
 4   Estimated using equation 3-47 (Nagy, 1987) and adult body weights from Lauhachinda (1978).
 5   See Chapters 3 and 4 for methods of estimating food ingestion rates.
 8   Estimated using equation 3-17 (Caider and Braun, 1983) and adult body weights from Lauhachinda (1978).
 7   Estimated using equation 3-20 (Stahl, 1967) and adult body weights from Lauhachinda (1978).
 8   Estimated using equation 3-22 (Stahl, 1967) and adult body weights from Lauhachinda (1978).
 9   Cited in Melquist  and Dronkert (1987).
10   Determined from  implanted embryo counts.
11   Determined from  corpora lutea counts.
12   Total gestation period (including preimplantation).
13   Active  gestation period (postimplantation), cited in Melquist and Dronkert (1987).
14   Cited in Toweill and Tabor (1982).
15   Dispersal at age 12 to 13 months.
2
CD
*^
O
i-f
CD
-------
References (including Appendix}

Alexander, G. (1977) Food of vertebrate predators on trout waters in north central lower
       Michigan. Michigan Academician 10: 181-195.

Anderson, K. L. (1981) Population and reproduction characteristics of the river otter in
       Virginia and tissue concentrations of environmental contaminants [master's thesis].
       Blacksburg, VA: Virginia Polytechnic Institute.

Anderson, K. L.; Scanlon, P. F. (1981) Reproduction and population characteristics of river
       otters in Virginia. Virginia J. Sci. 32: 87.

Anderson, E. A.; Woolf, A. (1987a) River otter habitat use in northwestern Illinois. Trans.
       Illinois Acad. Sci. 80: 107-114.

Anderson, E. A.; Woolf, A. (1987b) River otter food habits in northwestern Illinois. Trans.
       Illinois Acad. Sci. 80: 11 5-118.

Boddington, M. J. (1978) An absolute metabolic scope for activity. J. Theor. Biol. 75:
       443-449.

Burt, W. H.; Grossenheider, R*. P. (1980) A field guide to the mammals of North America
       north of Mexico. Boston, MA:  Houghton Mifflin Co.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic  regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Chabreck, R. H.; Holcombe, J. E.; Linscombe, R. G.; et al. (1982) Winter foods of river
       otters from saline and fresh environments in Louisiana. Proc. Annu. Conf.
       Southeast Assoc. Fish Wildl. Agencies 36: 473-483.

Docktor, C. M.; Bowyer, T. R.; Clark, A.  G. (1987) Number of corpora lutea as related to
       age and distribution of river otter in Maine. J. Mammal.  68: 182-185.

Eisenberg, J. F. (1981) The mammalian radiations; an analysis  of trends  in evolution,
       adaptation, and behavior. Chicago, IL: University of Chicago Press.

Erickson, D. W.; McCullough, C. R.; Porath, W. R.  (1984) River otter investigations in
       Missouri.  Missouri Dept. Conserv.; Pittman-Robertson Proj. W-13-R-38, Final
       Report.

Foy, M. K. (1984) Seasonal movement, home range, and habitat use of river otter in
       southeastern Texas [master's thesis]. College Station, TX: Texas  A&M University.

Gilbert, F. F.; Nancekivell, E. G. (1982) Food habits of mink (Mustela vison) and otter
       (Lutra canadensis) in northeastern Alberta. Can. J. Zool. 60: 1282-1288.
                                       2-269
River Otter
-------
Greer, K. R. (1955) Yearly food habits of the river otter in the Thompson Lakes region,
       Northwestern Montana, as indicated  by scat analyses. Am. Midi. Nat. 54: 299-313.

Greer, K. R. (1956) Fur resources and investigations: study of the otter food habits along a
       segment of the Gallatin River. Montana Fish and Game Dept.; Job Comp. Rep.
       W-049-R-06:35-59.

Grenfell, W. E., Jr. (1974) Food habits of the river otter in  Suisin Marsh, central California
       [master's thesis]. Sacramento, CA: California State  University.

Grinnell, J.; Dixon, J. S.; Linsdale, J. M. (1937) Fur-bearing mammals of California.
       Berkeley, CA: University of California Press.

Hall, E. R. (1981) The mammals of North America. 2nd ed.  New York,  NY: John Wiley and
       Sons.

Hall, E. R.; Kelson, K. R. (1959) The mammals of North America. 1st ed.  New York, NY:   *
       The Ronald Press Co.

Hamilton,  W. J., Jr. (1961) Late fall, winter  and early spring foods of 141  otters from  New
       York. N. Y. Fish and Game J. 8: 106-109.
                                                      •
Hamilton,  W. J., Jr.; Eadie, W. R. (1964) Reproduction in the otter, Lutra canadensis.  J.
       Mammal. 45: 242-252.

Harris, C.  J. (1968) Otters: a study of the recent Lutrinae.  London,  U.K.: Weidenfield &
       Nicolson.

Harris, J. (1969) Breeding the Canadian otter Lutra c. canadensis in a private collection.
       Int. Zoo Yearbook 9: 90-91.

Hill, E. P.;  Lauhachinda, V. (1981) Reproduction in river otters from Alabama and Georgia.
       In:  Chapman, J. A.; Pursley, D., eds.  Proceedings worldwide furbearer conference:
       v. 1. August 1980; Frostburg, MD.

Hooper, E. T.; Ostenson,  B. T.  (1949) Age groups in Michigan otter. Ann Arbor, Ml:
       University of Michigan; Mus. Zool. Occas. Pap.  518.

Hornocker, M. G.; Messick, J. P.;  Melquist, W. E. (1983) Spacial strategies in three
       species of Mustelidae. Acta Zool. Fenn. 174: 185-188.

Humphrey, S. R.; Zinn, T. L. (1982) Seasonal habitat use by river otters and  Everglades
       mink. J. Wildl. Manage. 46: 375-381.

Iversen, J. A. (1972) Basal energy metabolism of Mustelids. J. Comp. Physiol. 81:
       341-344.
                                      2-270
River Otter
-------
Johnstone, P. (1978) Breeding and rearing the Canadian otter (Lutra canadensis) at Mole
       Hall Wildlife Park, 1966-1977. Int. Zoo Yearbook 18: 143-147.

Knudsen, G. J.; Hale, J. B. (1968) Food habits of otters in the Great Lakes region. J. Wildl.
       Manage. 32: 89-93.

Lagler, K. F.; Ostenson, B. T. (1942) Early spring food of the otter in Michigan. J. Wildl.
       Manage. 6: 244-254.

Lancia, R. A.; Hair, J. D. (1983) Population status of bobcat (Felis rufus) and river otter
       (Lutra canadensis) in North Carolina. Raleigh, NC: North Carolina State Univ., Proj.
       E-1;65pp.

Larsen, D. N. (1983) Habitats, movements, and  foods of river otters in coastal
       southeastern Alaska [master's thesis]. Fairbanks, AL: University of Alaska.

Larsen, D. (1984) Feeding habits of river otters in coastal southeastern Alaska. J. Wildl.
       Manage. 48: 1446-1452.

Lauhachinda, V. (1978) Life history of the river otter in Alabama with emphasis on food
       habits [Ph.D. dissertation]. Auburn, AL: University of Alabama.

Liers, E. E.  (1951 a) My friends the land otters. Nat. Hist. 60: 320-326.

Liers, E. E.  (1951b) Notes on the river otter (Lutra canadensis). J. Mammal. 32: 1-9.

Liers, E. E.  (1966) Notes on  breeding  the Canadian otter Lutra canadensis in captivity and
       longevity records of beavers Castor canadensis. Int.  Zoo  Yearbook 6:  171-172.

Loranger, A. J.  (1981) Late fall and early winter foods of the river otter (Lutra canadensis)
       in Massachusetts, 1976 - 1978. In: Chapman, J. A.; Pursley, D., eds. Worldwide
       furbearer conference proceedings, v 1; August 3-11, 1980; Frostburg, MD; pp.
       599-605.

MacFarlane, R.  (1905) Notes on mammals collected and observed in the northern
       Mackenzie River District. Proc. U.S. Natl. Mus. 23: 716-717.

Mack, C. M. (1985) River otter restoration in Grand County, Colorado [master's thesis].
       Fort Collins, CO: Colorado State University.

McDaniel, J. C. (1963) Otter population study. Proc. Annu. Conf. Southeast. Assoc. Game
       and  Fish Comm. 17: 163-168.

Melquist, W. E.; Dronkert, A. E. (1987) River otter. In: Novak, M.; Baker, J. A.; Obbarel,
       M. E.; et al., eds. Wild furbearer management and conservation. Pittsburgh, PA:
       University of Pittsburgh Press;  pp. 627-641.
                                       2-271
River Otter
-------
Melquist, W. E.; Hornocker, M. G. (1983) Ecology of river otters in west central Idaho. In:
       Kirkpatrick, R. L., ed. Wildlife monographs: v. 83. Bethesda, MD: The Wildlife
       Society; 60 pp.

Melquist, W. E.; Whitman, J. S.; Hornocker, M. G. (1981) Resource partitioning and
       coexistence of sympatric mink and river otter populations. In: Chapman, J. A.;
       Pursley, D., eds. Worldwide furbearer conference proceedings, v 1; August 3-11,
       1980; Frostburg, MD; pp. 187-220.

Modafferi, R.; Yocom, C. F. (1980) Summer food of river otter in north coastal California
       lakes. Murrelet 61: 38-41.

Mowbray, E. E.; Pursley,  D.; Chapman, J. A. (1979) The status, population characteristics
       and harvest of the river otter in Maryland.  Waverly Press; Maryland Wildl. Admin.,
       Publ. Wildl. Ecol. 2; 16 pp.

Nagy, K. A.  (1987) Field metabolic rate and food  requirement scaling in mammals and
       birds. Ecol. Mono. 57: 111-128.

Palmer, E. L; Fowler, H. S. (1975) Fieldbook of natural history. New York, NY:
       McGraw-Hill Book Co.

Pearson, O.  P.; Enders, R. K. (1944) Duration of pregnancy in certain Mustelids. J. Exp.
      Zool. 95: 21-35.

Pierce, R. M. (1979) Seasonal feeding  habits of the river otter (Lutra canadensis) in ditches
       of the Great Dismal Swamp [master's thesis]. Norfolk, VA: Old Dominion
       University.

Reid, D. G. (1984) Ecological interactions of river otters and beavers in a boreal ecosystem
       [master's thesis]. Calgary, Canada: University of Calgary.

Ryder, R. A. (1955) Fish predation by the otter in Michigan. J.  Wildl. Manage. 19: 497-
      498.

Scheffer, V. B. (1958) Long life of a river otter. J. Mammal. 39:  591.

Sheldon, W. G.; Toll, W. G. (1964) Feeding habits of the river otter in a reservoir in central
      Massachusetts. J. Mammal. 45: 449-455.

Shirley, M. G. (1985) Spring food habits of river otter in southwestern Louisiana (abstract
      only). Proc. La. Acad. Sci. 48: 138.

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
      453-460.

Stenson, G.  B.; Badgero, G. A.; Fisher, H. D.  (1984) Food habits of the river otter Lutra
      canadensis in the marine environment of British Columbia. Can. J. Zool. 62: 88-91.
                                       2-272
River Otter
-------
Tabor, J. E.; Wight, H. M. (1977) Population status of river otter in western Oregon. J.
       Wildl. Manage. 41: 692-699.

Toll, W. G. (1961) The ecology of the river otter (Lutra canadensis) in the Quabbin
       Reservation of central Massachusetts [master's thesis]. Amherst,  MA: University of
       Massachusetts.

Toweill, D. E. (1974) Winter food habits of river otters in western Oregon. J. Wildl.
       Manage. 38: 107-111.

Toweill, D. E.; Tabor, J. E. (1982) River otter. In: Chapman, J. A.; Feldhammer, G. A.,
       eds. Wild mammals of North America. Baltimore,  MD: Johns Hopkins University
       Press; pp. 688-703.

Trippensee, R. E. (1953) Wildlife management: fur  bearers,  waterfowl, and  fish. New
       York, NY: McGraw-Hill.

Tumlison, R.; Shalaway, S. (1985) An annotated bibliography on the North  American river
       otter Lutra canadensis. Stillwater, OK: Okla. Fish  Wildl. Res. Unit & Dept. Zool.,
       Oklahoma State University.

van Zyll de Jong, C. G. (1972) A systematic review of the  nearctic  and neotropical river
       otters (Genus Lutra, Mustelidae, Carnivora).  Ontario, Canada: R. Ontario Mus.,  Life
       Sci. Contr. 80.

Wilson, K. A. (1959) The otter in North Carolina. Proc. Southeast. Assoc. Fish and Game
       Comm. 13: 267-277.

Wilson, K. A. (1985) The role of mink and otter as  muskrat  predators in northeastern
       North Carolina. Proc. Annu. Conf. Southeast. Assoc. Game Fish Comm. 18:
       199-207.

Woolington, J. D. (1984) Habitat use and movements of river otters at Kelp Bay, Baranof
       Island, Alaska [master's thesis]. Fairbanks, AK: University of Alaska.
                                      2-273
River Otter
-------
-------
2.2.6.  Harbor Seal (hair seals)

       Order Carnivora. Family Phocidae.  Seals, sea lions, and walruses are collectively
referred to as pinnipeds (Latin for wing-footed).  Pinnipeds are divided into three families:
otarids (sea  lions and fur seals); phocids (hair seals, also called true seals or earless seals);
and walruses.  Most pinnipeds feed on marine species such as fish, squid, and other
invertebrates (Burt and Grossenheider, 1980). Unlike fur seals, which are protected from
the cold marine environment by a dense layer of underfur, phocids rely only on a thick
blubber layer for insulation (Pierotti and Pierotti,  1980).  Phocids include both the smallest
(ring seals) and the largest (elephant seals) of the pinnipeds.  The geographic range of
most phocid species is from the arctic Atlantic and Pacific south to the coasts of Canada
and Alaska,  although some do inhabit warmer water (Burt and Grossenheider, 1980).
Most phocids, with the exception of the elephant seal, do not exhibit the large disparity in
size between the sexes, which is characteristic of otarids (sea lions and fur seals)  (Burt
and Grossenheider,  1980).

Selected species

       In North America, harbor seals (Phoca vitulina) range from Alaska to Baja California,
Mexico, along  the Pacific coast (subspecies richardsi; Hoover, 1988), and from
Newfoundland to eastern Long Island along the Atlantic coast (subspecies concolor, Payne
and Selzer, 1989). They are one of the most commonly seen pinniped  species, in part due
to their tendency to inhabit coastal areas (Hoover, 1988).  Harbor seals can be found along
the Pacific coast on a year-round basis (except during stormy periods in winter), but
Atlantic populations winter offshore when coastal ice has formed in their usual haul-out
areas (Boulva and McLaren, 1979). The recent increases in harbor seal populations in New
England waters appear to be due to a southward  dispersal of seals from rookeries  in Maine
following the termination of a Massachusetts bounty on harbor seals (1962) and the
passage of the Marine Mammal Protection Act (1972) (Payne and Schneider, 1984).

       The spotted or largha seal (Phoca largha) is a closely related species that until
recently was considered a subspecies of the harbor seal. It is similar in size, appearance,
and feeding  habits to the Pacific harbor seal, but it tends to inhabit colder waters along  the
Pacific coasts  (Ashwell-Erickson and Eisner, 1981). In North America,  it seldom ventures
further south than the northern coast of Alaska (Ashwell-Erickson and Eisner, 1981).  The
spotted seal requires ice for breeding haul-outs and gives birth about 2  months earlier than
the Pacific harbor seal (Ashwell-Erickson and Eisner,  1981; Boulva and  McLaren, 1979).
The harbor seal, in contrast, breeds on land (Boulva and McLaren, 1979).

       Body size.  The length and weight of harbor seals vary geographically, but sexually
mature adults tend to be about 1.5 m in length and weigh from 65 to 90 kg (Ashwell-
Erickson and Eisner, 1981; Pitcher and Calkins, 1979).  Harbor seals exhibit some sexual
dimorphism, the male being larger (Pitcher and Calkins, 1979).  Body length usually is used
to measure size because weight can vary substantially with factors such as season, food
availability, and molting (Ronald et al., 1982).  Newborn pups are around  80 cm long and
weigh from 8.6 to almost 15 kg, with females often weighing less than males (Newby,
1973; Pitcher and Calkins, 1979; Rosen, 1989).  Harbor seal pups are highly precocial and
                                       2-275
Harbor Seal
-------
are able to swim within hours of birth (Boulva and McLaren, 1979; Lawson and Renouf,
1987). Seal milk consists of about half fat, and the pups more than double their weight
before they are weaned at approximately 30 days (Bigg, 1969a, as cited in Pitcher and
Calkins, 1979).  Harbor seals continue to grow  with age for several years beyond the age
of sexual maturity (Boulva and McLaren, 1979; Pitcher and Calkins, 1979).  Body fat
varies seasonally with food intake, while total body weight and lean body mass increase
with age (Ashwell-Erickson and Eisner, 1981).  Harbor seals, unlike many other pinnipeds,
do not fast for extended periods during the molting period or breeding season (Boulva and
McLaren,  1979; Pierotti and Pierotti, 1980).

       Habitat.  Harbor seals inhabit a variety of environments and are able to tolerate a
wide  range of temperatures and water salinities {Boulva and McLaren, 1979; Hoover,
1988). In  its eastern range, the harbor seal inhabits inlets, islets, reefs,  and sandbars
(Boulva and McLaren, 1979).  In western North America, the harbor seal inhabits tidal  mud
flats,  sand bars, shoals, river deltas, estuaries,  bays, coastal rocks, and  offshore islets
(Johnson and Jeffries, 1977), even ranging up rivers into freshwater areas in search of
food (Roffe and  Mate, 1984).  Harbor seals also inhabit some freshwater lakes (Power and
Gregoire, 1978). Habitats used for haul-outs include cobble and sand beaches, tidal mud
flats,  offshore rocks and reefs, glacial and sea ice, and man-made objects such as piers
and log booms (Hoover, 1988).

       Food habits.  Harbor seals' diet varies seasonally and includes bottom-dwelling
fishes (e.g., flounder, sole, eelpout), invertebrates (e.g., octopus), and species that can be
caught in periodic spawning aggregations (e.g., herring, lance, squid) (Everitt et al., 1981;
Lowry and Frost, 1981; Pitcher and Calkins, 1979; Roffe and Mate, 1984).g Harbor seals
are opportunistic, consuming different prey in relation to their availability and ease of
capture (Pitcher  and Calkins,  1979; Pitcher, 1980; Shaffer, 1989). They may move into
rivers on a seasonal basis in pursuit of prey (e.g.,  eulachon in the Columbia River during
winter; Brown et al., 1989). They hunt alone or in small groups  (Hoover, 1988).  Fish
species consumed range between 40 and 280 mm, with mean values  of between 60 and
180 mm (Brown and Mate, 1983).  Recently weaned pups tend to feed  on prey that are
more  easily captured than fish, such as shrimp or  other crustaceans (Hoover, 1988;
Pitcher and Calkins, 1979).  During  the breeding and  molting seasons, when harbor seals
spend more time on land, adults rely on their blubber layer as  an additional source of
energy (Ashwell-Erickson and Eisner, 1981).  During this time, they may be more
susceptible to lipophilic contaminants  (e.g., PCBs) that may have accumulated in their
blubber (Hoover, 1988).
8Studies of harbor seal diet often rely on counts of fish sagittal otoliths found in scats or stomach
 contents.  These otoliths can be identified to the level of species, annul! on the otoliths counted to
 determine age, and fish weights and lengths estimated from otolith dimensions.  However, partial
 or complete digestion of otoliths, particularly of small fish species, may result in significant
 underestimates of the proportion of these prey in seal diets, particularly from scat analysis (da
 Silva and Neilson, 1985; Harvey, 1989).  Studies of stomach contents of stranded seals also may
 present a biased picture of dietary composition due to extended periods of fasting prior to
 stranding (Selzer et al., 1986).
                                       2-276
Harbor Seal
-------
       In general, food consumption by adult seals is highest in winter and lowest in the
summer (Ashwell-Erickson and Eisner, 1981; Ashwell-Erickson et al., 1979).  Innes et al.
(1987) estimated allometric equations for maintenance food ingestion rates (IR; wet-
weight biomass) with body weight (BW, kg) for phocids:
       IRmaint(kg/day) = 0.079 BW(kg)0-71

       IRmaint(kg/day) = 0.032 BW(kg)1-00

       IRmaint(kg/day) = 0.068 BW(kg)0-78
                                adult (N  = 11; r2 = 0.84);

                                juveniles (N =  19; r2 = 0.68); and

                                both adults and juveniles (N = 30; r2  =
                                0.68).
       Allometric equations for food ingestion rates of growing animals (IR; wet-weight
biomass) with body weight (BW, kg) for phocids also have been estimated (Innes et al.,
1987):

       IRgrowth(kg/day) = 0.0919 BW(kg)0-84   adult (N =  11; r2 = 0.84); and
       IR
:h(kg/day) = 0.0547 BW(kg)0-84   juveniles (N = 19; r2 = 0.68).
        growtl

Innes et al. (1987) found that growing juvenile phocid seals ingested 1.7 times more
biomass per day than a similar-sized growing adult and 1.4 times more than juvenile
phocids that were not growing.

       Boulva and McLaren (1979) estimated a relationship between body weight and daily
food ingestion for harbor seals from eastern Canada:
       IRfree-living
-------
southern latitudes, but within populations, breeding is synchronized (Hoover, 1988; Slater
and Markowitz, 1983).  Harbor seals may form large breeding aggregations on land in
areas where food resources are plentiful (Slater and Markowitz, 1983); however, pupping
activities are not restricted to large, discrete rookeries (Pitcher and Calkins, 1979). Mating
occurs soon after weaning, which is 3 to 6 weeks after birth (Ashwell-Erickson and Eisner,
1981).  It is likely that harbor seals are promiscuous (Pierotti and Pierotti, 1980), although
there is some evidence that they are mildly polygynous, with males defending territories at
the haul-out sites (Boulva and McLaren, 1979; Perry, 1989; Slater and Markowitz, 1983).
Following mating, implantation is delayed for 1.5 to 3 months, during which time the
female molts (Bigg, 1969a; Hoover, 1988; Pitcher and Calkins, 1979). At other times of
the year, harbor seals also can be found in groups of 30 to 80 in some haul-out areas
(Hoover, 1988).

      Home range and resources.  Harbor seals generally inhabit highly productive coastal
areas, with upwelling ocean currents that bring nutrients to the surface supporting
abundant marine life (e.g., the California current system, the Gulf of Alaska, and the Gulf
of Maine; Ronald et al., 1982).  Harbor seals also require adequate places to haul out, and
their distribution is influenced by the availability of suitable sites (Boulva and McLaren,
1979).  In general, seals stay near particular haul-out sites with only local movements
(Brown  and Mate,  1983; Pitcher and Calkins,  1979; Slater and Markowitz, 1983).  Haul-
out patterns are determined by several factors, including weather, tidal pattern, time of
day, season, and human proximity (Slater and Markowitz, 1983). Harbor seals are
considered fairly sedentary, with individuals showing year-round site fidelity, although
some seasonal movement  associated with pupping and long-distance movements are
recorded (Pitcher and Calkins, 1979; Slater and Markowitz, 1983).  Data on likely daily or
monthly foraging distances are lacking.

      Population density.   Harbor seals are found principally in coastal areas within 20 km
of shore; they tend to concentrate in estuaries and protected waters (Hoover, 1988).
Their distribution is highly  patchy, and local population densities in haul-out areas with
favorable food resources nearby can be quite high (Pitcher and Calkins, 1979).

      Population dynamics. Females are sexually mature by 3 to 5 years of age, whereas
males are sexually mature  later, at 4 to 6 years of age (Boulva and McLaren, 1979; Pitcher
and Calkins, 1979).  Females only produce one pup per year (Hoover, 1988). Three major
causes of preweaning pup mortality  are stillbirth, desertion by the mother, and shark kills
(Boulva  and McLaren, 1979).  Mortality from birth to 4 years of age was estimated to be
74 percent for females and 79 percent for males in one study, after which it remained at
about 10 percent per year  (Pitcher and Calkins, 1979). Life expectancy for harbor seals is
about 30 years (Newby, 1978).

Similar species (from general references)

      •     The ringed seal (Phoca hispida) is smaller (1.4 m length; weight to 90 kg)
             than the harbor seal and inhabits colder waters. It feeds mainly on marine
             invertebrates.
                                       2-278
Harbor Seal
-------
      •      The harp seal (Phoca groenlandicus) (1.8 m; weight to 180 kg) inhabits
             deep, icy water.  It ranges from the Arctic Atlantic south to Hudson Bay; it
             is only rarely found further south.  It feeds on macroplankton and fish.

      •      The largha or spotted seal (Phoca largha) (1.5 m) is a closely related species
             that until recently was considered a subspecies of the harbor seal.  Its
             characteristics are compared with those of the harbor seal under Selected
             species.

      •      The ribbon seal (Phoca fasciata) (1.6 m; males to 90 kg, females to 76 kg)
             lives near pack ice in the Bering Sea and feeds on bottom invertebrates, fish,,
             and octopus and squid.

General references

      Ashwell-Erickson and Eisner (1981); Burt and Grossenheider (1980); Hoover
(1988); Pitcher and Calkins (1979); Ronald et al. (1982).
                                      2-279
Harbor Seal
-------
                                             Harbor Seal (Phoca v/tulina]


Factors
Body Weight
(kg)













'

^
,i
Pup Growth
Rate fg/day)


Metabolic
Rate
(lOg/kg-day)

Age/Sex/
Cond./Seas.
A M {> 7 yrs)
A F {> 7 yrs)
J M 2 yrs
J M 4 yrs
J M 6 yrs
A M 8 yrs
A M 1 2 yrs
A M 1 6 yrs
A M 24 yrs
J F 2 yrs
J F 4 yrs
J F 6 yrs
A F 8 yrs
A F 1 2 yrs
A F 1 6 yrs
A F 24 yrs
neonate M
neonate F
at weaning B
birth to
weaning
M
F
J B resting
A F resting



Mean
84.6 ± 11.3 SD
76.5 ± 17.7 SD
49
70
84
95
110
120
124
40
56
67
76
90
101
112
12.0 ± 0.51 SE
11.5 ± 0.31 SE
24.0


520
790
7.3
6.6

Range or
(95%Ctof
mean]




























Location •*';..
Gulf of Alaska

Aleutian Ridge and Pribilof
Islands, Bering Sea, Alaska












Alaska

British Columbia, Canada
Gulf of St. Lawrence/island
marine


California/lab




Reference^
Pitcher & Calkins, 1 979

Ashwell-Erickson & Eisner,
1981












Pitcher & Calkins, 1979

Bigg, 1969a
Rosen, 1989



Davis et al., 1 985



Note
No.


1















2




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«3
-------
                                             Harbor Seal (Phoca vitulina]
Dietary
Composition
walleye pollock
English sole
shiner perch
Pacific herring
Pacific cod
rex sole
Pacific tomcod
'rockfish
Dover sole
Petrafe sole
other fish '
octopus
salmon
capelirt
Pacific cod
walleye pollock
Pacific sandlance
squid & octopus
shrimp, crabs
herring
saimonids
josmerids
'cod, torofcod,
watfeye, pollock
other

Spring
3.7
37.0
0.0
0
0
37
3.7
3.7
3.7
7.4
3.8















Summer
27.3
0.0
0.0
54.6
0
9.1
0
0
0
0
9.0
17.6
5.4
20.3
6.8
12.2
4.1
20
3.7
6.4
4.4
22.5
26.0

14.1

Fait
32.2
27.0
0.5
3.9
10.1
2.9
4.7
4.7
3.4
1.8
8.8
17.7
0.0
4.8
8.1
9.7
21.0









Winter
1.3
0
63.6
28.6
0
0
0
0
2.6
.0
3.9
30.4
0.0
5.4
10.7
14.3
0.0




•



Location/Habitat
(measure)
Washington/
coastal island

(% of total otoliths
recovered from scat
samples)





Kodiak Island, Alaska/
coastal marine

{% frequency of occurrence;
stomach contents)

Gulf of Alaska/
coastal marine

(% wet volume; stomach
contents)

all seasons combined


Reference
Everitt et al., 1981



.






Pitcher & Calkins, 1 979





Pitcher, 1980







Note
No.

























to

to
00
to
I
Q>
CD
Q>
-------
                                              Harbor Seal (Phoca vitu/ina)
Population
Dynamics \
Foraging
Radius (knrtj
Population
Density {N/ha}
Litter
Size i
Utters
/Year
Months
Gestation
Age at
Weaning
Age at"
Sexual
Maturity
• (years)
Annual
Mortality
Rates (percent)
longevity
Age/Sex/ -
Cond./Seas.
AB
AB
summer



B
B
F
M
F
M
AB
birth to 4 yrs
4 to 5 yrs old
7 to 14 yrs old
>. 20 yrs old
AB
AM
AF
Mean
5km
30 to 55 km
0.0305
1
1
10.5 to 11
30 days
35 days
5.5 ± 0.23 SE
3 to 4
6
17.5
77/4 yrs
11/yr
8 to 9/yr
14/yr

Range
unknown
unknown
0.00394-0.0611
highly clumped
distrib.




4-9
5-7

< 30
< 26
< 31
Location/Habitat
California/Bay
Washington/Columbia River
Maine/coastal marine
throughout range and
habitats
throughout range and
habitats
throughout range and
habitats
NS/NS
e Canada/marine
c California/coastal marine
Gulf of Alaska/coastal
marine
e Canada/marine
e Canada/marine
Gulf of Alaska/coastal
marine
e Pacific/NS
Gulf of Alaska/coastal
marine
Reference
Stewart et al., 1989
Beach et al., 1 985
Richardson, 1981
Pitcher and Calkins, 1979
Hoover, 1988
Hoover, 1988
FAO Adv. Comm., 1976
Boulva & McLaren, 1979
Slater & Markowitz, 1983
Pitcher & Calkins, 1 979
Boulva & McLaren, 1 979
Boulva & McLaren, 1979
Pitcher & Calkins, 1979
Newby, 1978
Pitcher & Calkins, 1 979
Ndts
No.
9
10



11


12

ro
ro
CO
to
I
Q)
-^
CT
O
-t

CD
CD
CO
-------
                                                          Harbor Seal (Phoca vitulina]
Seasonal
Activity
Mating
Parturition
5
3
•/
Molt -
Begin
early April
mid-May
late April
early February
late June
May
August
early June
late June
Peak
February
July
mid-June

early June
late July
End
July
late June
early May
September
June
September
early September
September/October
Location
Nova Scotia, Canada
Mexico
Bering Sea
Tugidak Island, Alaska
c California
Mexico
Canada
Washington
Washington, Puget Sound
Scotland
Gulf of Alaska
Reference
Boulva & McLaren, 1 979
Bigg, 1969b
Bigg, 1969b
Pitcher & Calkins, 1979
Riedman, 1990
Johnson & Jeffries, 1983
Thompson & Rothery, 1 987
Pitcher & Calkins, 1 979
Note
No.
13
13



14
to
to
CO
X
05
5-
O
-^
to
CD
0)
 1   Estimated from graph of growth curve.
 2   Cited in Boulva and McLaren (1979).  Weight doubled from birth.
 3   Juvenile is a yearling; weight 33 kg. Adult female weight 63 kg.
 4   Estimated using equation 3-43 (Boddington, 1978) and  body weights from Pitcher and Calkins (1979).  Caution must be used, however, because
     pinnipeds were not included in the data set from which the allometric model was derived.
 5   Estimated using equation 3-47 (Nagy, 1987) and body weights from Pitcher and Calkins (1979). Caution must be used, however, because
     pinnipeds were not included in the data set from which the allometric model was derived.  Mean values are somewhat higher than is consistent
     with food ingestion rate estimates and data from the spotted seal (see Appendix).
 6   Estimated using equation 3-17 (Calder and Braun, 1983) and body weights from Pitcher and Calkins (1979).  Caution must be used, however,
     because pinnipeds were not included in the data set from which the allometric model was derived.
 7   Estimated using equation 3-20 (Stahl, 1967) and body weights from Pitcher and Calkins (1979). Caution must be used, however, because
     pinnipeds were not included in the data set from which the allometric model was derived.
 8   Estimated using equation 3:22 (Stahl, 1967) and body weights from Pitcher and Calkins (1979). Caution must be used, however, because
     pinnipeds were not included in the data set from which the allometric model was derived.
 9   Satellite telemetry of one seal.  Foraging radius depends on distribution and abundance of prey.
10   Seventy-five percent of 58 seals radio-tagged in the Columbia River were relocated at haul-out sites 30 to 55 km away. Cited in Hoover (1988).
11   Cited in Ronald et al. (1982).
12   Postweaning mortality.
13   Cited in Hoover (1988).
14   Nineteen to 33 days to complete molt.
-------
References (including Appendix)

Allen, S. G.; Huber, H. R.; Ribic, C. A.; et al. (1989) Population dynamics of harbor seals
      in the Gulf of the Farallones, California. Calif. Fish Game 75: 224-232.

Angell-James, J. E.; Eisner, R.; de Burgh Daly, M. (1981) Lung inflation: effects on heat
      rate, respiration, and vagal afferent activity in seals. Am. J. Physiol. 240:
      H190-H198.

Ashwell-Erickson, S.; Eisner, R. (1981) The energy cost of free existence for Bering Sea
      harbor and spotted seals. In: Hood, D. W.; Calder, J. A., eds. The Eastern Bering
      Sea shelf: oceanography and resources, v. 2. Washington, DC: Department of
      Commerce;  pp. 869-899.

Ashwell-Erickson, S.; Eisner, R.; Wartzol, D. (1979) Metabolism and nutrition of Bering
      Sea harbor and spotted seals.  Proc. Alaska Sci. Conf. 29: 651-665.

Beach, R.J.; Geiger, A.; Jeffries, S. J., et al. (1985) Marine mammals and their
      interactions  with fisheries of the Columbia River and adjacent waters, 1980-1982.
      Seattle, WA: Third Ann. Rept. to U.S. Dept. Commerce, NOAA, Natl. Mar. Fish.
      Serv.

Bigg, M. A. (1969a) The harbour seal in British Columbia. Fish. Res. Board Can.; Bull. 172.

Bigg, M. A. (1969b) Clines in the pupping season of the harbour seal, Phoca vitulina. J.
      Fish. Res. Board Can. 26: 449-455.

Boddington, M. J. (1978) An absolute metabolic scope for activity. J. Theor. Biol. 75:
      443-449.

Boulva,  J.; McLaren, I. A. (1979) Biology of the harbor seal, Phoca vitulina, in eastern
      Canada. Quebec, Canada: Fish. Res. Board Can. Bull. 200.

Brown, R.  F.; Mate, B. R.  (1983) Abundance, movements, and feeding habits of harbor
      seals, Phoca vitulina, at Nearts and Tillamook Bays, Oregon. U.S. Natl.  Mar. Fish.
      Serv. Fish. Bull. 81: 291-301.

Brown, R.  F.; Jeffries, S. J.; Harvey,  J. T. (1989) Seasonal abundance and winter feeding
      ecology of harbor seals in the  Columbia River (abstract). In: 8th Biennial Conference
      on the Biology of Marine Mammals; December 7-11, 1989; Pacific Grove, CA; p. 9.--

Bryden,  M. M. (1972) Growth  and development of marine mammals. In: Harrison, R. J.,
      ed.  Functional anatomy of marine mammals. New York, NY: Academic Press; pp.
      2-79.

Burt, W. H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
      north of Mexico. Boston,  MA:  Houghton Mifflin  Co.
                                      2-285
Harbor Seal
-------
Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J.'Physiol. 244: R601-R606.

Craig, A. B., Jr.; Pasche, A. (1980) Respiratory physiology of freely diving harbor seals
       (Phoca vitulina). Physiol. Zool. 53: 419-432.

da Silva, J.; Neilson, J. D. (1985) Limitations of using otoliths recovered in scats to
       estimate prey consumption in seals. Can. J. Fish. Aquat. Sci. 42: 1439-1442.

Davis,  R. W.; Williams, T. M.; Kooyman, G. L. (1985) Swimming metabolism of yearling
       and adult harbor seals (Phoca vitulina). Physiol. Zool. 58: 590-596.

Depocas, F.; Hart, J. S.; Fisher, H. D. (1971) Sea water drinking and water flux in starved
       and in fed harbor seals,  Phoca vitulina. Can. J. Physiol. Pharmacol.  49: 53-62.

Everitt, R. D.; Gearin, P. J.;  Skidmore, J. S.; et al. (1981) Prey items of harbor seals and
       California sea lions in Puget Sound, Washington. Murrelet 62: 83-86.

Food and Agriculture Organization (FAO) of the United Nations, A. C. on Marine Resources
       Research. (1976) Mammals in the seas. Ad Hoc  Group III on seals and marine
       otters, draft report. In: Symposium: Scientific consultation on marine mammmals;
       August 13 to September 9, 1976; Food and Agric. Advis. Comm. Mar. Resour.
       Res., Mar. Mammal,  Sci. Consult. Organ, of U.N., Bergen, Norway.

Harkonen, T. J. (1988) Food-habitat relationship of harbour seals and black cormorants in
       Skagerrak and Kattegat. J. Zool.  (London) 214: 673-681.

Harvey, J. T. (1989) Assessment of errors associated with harbour seal (Phoca vitulina)
       faecal sampling. J. Zool. (Lond.) 219: 101-111.

Hoover, A. A. (1988) Harbor seal, Phoca vitulina.  In: Lentfer, J. W., ed. Selected marine
       mammals of Alaska: species accounts with research and management
       recommendations. Washington, DC: Marine Mammal Commission; pp. 125-157.

Innes, S.; Lavigne, D. M.; Earle, W. M.; et al. (1987) Feeding rates of seals and whales. J.
       Anim. Ecol. 56: 115-130.

Irving,  L. (1972) Arctic life of birds and mammals  including man. New York, NY:
       Springer-Verlag.

Johnson, M. L.; Jeffries, S.  J. (1977) Population evaluation of the harbour seal (Phoca
       vitulina richardii) in the waters of the state  of Washington. U.S.  Mar. Mammal
       Comm.; Rep. MMC-75/05.

Johnson, M. L.; Jeffries, S. J. (1983) Population biology evaluation of the  harbor seal
       (Phoca vitulina richardii)  in the waters of the State of Washington:  1976-1977.
      Tacoma, WA: University of Puget Sound; MMC-76/25.
                                      2-286
Harbor Seal
-------
Jones, R. E. (1981) Food habits of smaller marine mammals from northern California. Proc.
       Calif. Acad. Sci. 42: 409-433.

Klinkhart, E. G. (1967) Birth of a harbor seal pup. J. Mammal. 48: 677.

Lawson, J. W.; Renouf, D. (1987) Bonding and weaning in harbor seals, Phoca vitulina. J.
       Mammal. 68: 445-449.

Ling, J. K. (1970) Pelage and molting in wild animals with special reference to aquatic
       forms. Q. Rev. Bio. 45: 16-54.

Ling, J. K. (1974) The integument of marine mammals. In: Harrison, R. J., ed. Functional
       anatomy of marine mammals: v. 2. New York, NY: Academic Press; pp. 1 -44.

Lowry, L. F.; Frost, K. J. (1981) Feeding and trophic relationships of phocid seals and
       walruses in the Eastern Bering Sea. In:  Hood, D. W.; Calder, J. A., eds. The Eastern
       Bering Sea shelf: oceanography and resources: v. 2. Washington, DC: Department
       of Commerce; pp. 813-824.

Nagy, K. A.  (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Mono. 57: 111-128.

Newby, T. C. (1973) Observations on the breeding behavior of the harbor seal in the State
       of Washington.  J. Mammal. 54:  540-543.

Newby, T. C. (1978) Pacific harbor seal. In: Haley, D., ed. Marine mammals of eastern
       north Pacific and arctic waters. Seattle, WA: Pacific Search Press; pp. 184-191.

Payne, P. M.; Schneider, D. C. (1984) Yearly changes in abundance of harbor seals, Phoca
       vitulina, at  a winter haul-out site in Massachusetts. Fish. Bull. 82: 440-442.

Payne, P. M.; Selzer, L. A. (1989) The distribution, abundance and selected prey of the
       harbor seal, Phoca vitulina concolor, in  southern New England. Mar. Mammal. Sci.
       5: 173-192.

Perez, M. A. (1990) Review of marine mammals population and prey information for Bering
       Sea ecosystem studies. Washington, DC: U.S. Dept. Commerce, Nat. Oceanic Atm.
      Admin., Nat. Mar. Fish. Serv.; NOAA Tech. Mem. NMFS F/NWC-186.

Perry, E. (1989) Evidence for polygyny in  harbour seals, Phoca vitulina. In: 8th Biennial
      conference on the biology of marine mammals; December; Pacific Grove, CA.

Pierotti, R.; Pierotti, D. (1980) Effects of cold climate on the evolution of pinniped breeding
      systems. Evolution 34: 494-507.

Pitcher, K. W. (1977) Population productivity and food habits of harbor seals in the Prince
      William Sound-Copper  River Delta area, Alaska. Final report to U. S. Marine
      Mammal Commission No. MMC-75103. USDC NTIS. PB-226 935.
                                      2-287
Harbor Seal
-------
Pitcher, K. W. (1980) Food of the harbor seal, Phoca vitulina richardsi, in the Gulf of
       Alaska. U.S. Natl. Mar. Fish. Serv. Fish. Bull. 78: 544-549.

Pitcher, K. W.; Calkins, D. G. (1979)  Biology of the harbor seal, Phoca vitulina richardsi, in
       the Gulf of Alaska.'Final report. Outer Continental Shelf Environmental Assessment
       Program Research Unit 229, Contract No. 03-5-002-69.

Pitcher, K. W.; McAllister, D. C. (1981) Movements and haulout behavior of radio-tagged
       harbor seals, Phoca vitulina. Can. Field-Nat. 95:292-297.

Power, G.; Gregoire, J. (1978) Predation by freshwater seals on the fish community of
       lower Seal Lake, Quebec. J. Fish. Res. Board Can. 35: 844-850.

Renouf, D. (1989) Weight increases in harbour seals in spite of reduced food intake and
       heightened thermal demands: adjustable metabolism? In: 8th Biennial Conference
       on the Biology of Marine Mammals; December; Pacific Grove, CA.

Richardson, D. T. (1973) Distribution  and abundance of harbor and gray seals in Acadia
       National Park. Final report to National  Park Service and Maine Department of Sea
       and Shore Fisheries. State of Maine Contract No. MM4AC009.

Richardson, D. T. (1981) Feeding habits and  population studies  of Maine's harbor and gray
       seals. Natl. Geogr. Soc.  Res. Rep. 13: 497-502.

Riedman, M. (1990) The pinnipeds: seals, sea lions, and walruses. Berkeley, CA:
       University of California Press.

Roffe, T. J.; Mate, B. R. (1984) Abundances  and feeding habits of pinnipeds in the Rogue
       River, Oregon. J. Wildl. Manage. 48: 1262-1274.

Ronald, K.; Selley, J.; Healey, P. (1982) Seals.  In: Chapman, J.  A.; Feldhammer, G. A.,
       eds. Wild mammals of North America. Baltimore, MD: Johns Hopkins University
       Press; pp. 769-827.

Rosen, D. A. (1989)  Neonatal growth rates and behaviour in the Atlantic harbour seal,
       Phoca vitulina (abstract). In: 8th Biennial Conference on the Biology of Marine
       Mammals; December 7-11, 1989; Pacific Grove, CA; p. 57.

Scheffer, V. B.; Slipp, J. W. (1944) The harbor seal in Washington state. Am. Midi. Nat.
       32:373-416.

Schneider, D. C.; Payne, P. M. (1983) Factors affecting haul-out of harbor seals at a site in
      southeastern Massachusetts. J. Mammal. 64: 518-520.

Selzer, L. A.; Early, G.; Fiorelli,  P. M.; et al. (1986) Stranded animals as indicators of prey
      utilization by harbor seals, Phoca vitulina concolor, in southern New England. Fish.
      Bull. 84: 217-220.
                                       2-288
Harbor Seal
-------
Shaffer, K. E. (1989) Seasonal and size variations in diets of harbor seals, Phoca vitulina
       (abstract). In: 8th Biennial Conference on the Biology of Marine Mammals;
       December 7-11, 1989; Pacific Grove, CA; p. 62.

Slater, L. M.; Markowitz, H. (1983) Spring population trends in Phoca vitulina richardi\r\
       two central California coastal areas. Calif. Fish Game 69: 217-226.

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
       453-460.

Stewart, B. S.; Leatherwood,  S.; Yochem, P. K.; et al. (1989)  Harbor seal tracking and
       telemetry by satellite. Mar. Mamm. Sci. 5: 361-375.

Stutz, S. S. (1966) Moult and pelage patterns in the Pacific harbor seal, Phoca vitulina
       [master's thesis]. Vancouver, Canada: University of British Columbia.

Thompson, P; Rothery, P. (1987) Age and sex differences in the timing of moult in the
       common seal, Phoca vitulina.  J. Zool. (London) 212: 597-603.

Wilson, S. C. (1978) Social organization and behavior of harbor seals Phoca vitulina
       concolor in Maine.  Final report to Marine Mammal Commission, Contract No.  GPO
       PB 280-3188. NTIS PB 280 188.
                                      2-289
Harbor Seal
-------
-------
2.2.7.  Deer Mouse (deer and white-footed mice)

       Order Rocfentia, Family Muridae (Genus Peromyscus).^ New world mice (family
Muridae) are small, ground-dwelling rodents that live in a large variety of habitats including
woodlands,  prairies, rocky habitats, tundra, and deserts.  All are nocturnal and are preyed
on by owls, hawks, snakes, and carnivorous mammals.  Most species eat primarily seeds,
but some also regularly eat small invertebrates. Many species store food. The genus
Peromyscus is the most widespread and geographically variable of North American rodents
(MacMillen and Garland, 1989).

Selected species

       The deer mouse (Peromyscus maniculatus} is primarily granivorous and has the
widest geographic distribution of any Peromyscus species (Millar, 1989; Brown and Zeng,
1989).  It is resident and common in nearly every dry-land habitat within its range,
including alpine tundra, coniferous and deciduous forest, and grasslands as well as
deserts.  There are many recognized subspecies or races of the deer mouse  associated
with different locations or insular habitats,  including artemisiae, austerus, bairdii,
balaclavae, blandus, borealis, carli, cooledgei, gambelii, gracilis, labecula, maniculatus,
oreas, nebrascensis, nubiterrae, rufinus, and sonoriensis (MacMillen and Garland,  1989;
Millar,  1982)

       Body size.  Deer mice range from 7.1 to 10.2 cm in length, with a 5.1 to 13 cm
tail, and adults weigh from 15 to 35 g (Burt and Grossenheider, 1980; see table).  Body
size varies somewhat among populations and subspecies throughout .the species'  range.
Body weight also  varies seasonally, being lower in autumn and winter and a few grams
higher in spring and summer (Zegers and Merritt, 1988).  There may (Fleharty et al., 1973)
or may not (Millar and Schieck, 1986) be seasonal differences in fat content.

      Habitat. Deer mice inhabit nearly all types of dry-land habitats within their range:
short-grass prairies, grass-sage communities, coastal sage scrub,  sand dunes, wet prairies,
upland mixed and cedar forests, deciduous  forests, ponderosa pine forests, other
coniferous forests, mixed deciduous-evergreen forests, juniper/pinon forests, and  other
habitats (Holbrook, 1979; Kaufman and Kaufman, 1989; Ribble and Samson, 1987; Wolff
and Hurlbutt, 1982). Few studies have found  microhabitat features that distinguish the
deer mouse, and some studies have come to different conclusions regarding habitat
structure preferences (Ribble and Samson,  1987).  For example, Vickery (1981) found that
deer mice appeared to prefer areas with moderate to heavy ground and mid-story  cover to
more open ground areas, whereas others have found more deer mice in more open than in
more vegetated areas (see Kaufman and Kaufman, 1989).

      Food habits.  Deer mice  are omnivorous and highly opportunistic, which leads to
substantial regional and seasonal  variation in their diet. They eat  principally  seeds,
arthropods, some  green vegetation, roots, fruits, and fungi as available (Johnson,  1961;
Menhusen,  1963; Whitaker, 1966). The nonseed plant materials  provide a significant
^Peromyscus is considered a member of the family Cricetidae by some mammalogists.

                                       2-291                             Deer Mouse
-------
proportion of the deer mouse's daily water requirements (MacMillen and Garland, 1989).
Food digestibility and assimilation for most of their diet have been estimated to be as high
as 88 percent (Montgomery, 1989).  Deer mice may cache food during the fall and winter
in the more northern parts of their range (Barry, 1976; Wolff, 1989).  They are nocturnal
and emerge shortly after dark to forage for several hours (Marten, 1973).

       Temperature regulation. The de.er mouse has a metabolic rate  about 1.3 times
higher than the other species in the genus (MacMillen and  Garland, 1989; Morris and
Kendeigh, 1981; see table).  Its metabolic rate is substantially higher in winter than in
summer (Morris and Kendeigh, 1981; Stebbins, 1978; Zegers and Merritt, 1988). Outside
the thermoneutral zone (25 to 35°C), metabolic rate varies according  to the following
equation:

            V02 = 0.116 - 0.003(Ta)  + 0.0304 (V0-5)

where VO2 = volume oxygen consumed (ml/g-min); Ta = ambient temperature; and V =
wind speed (Chappell and Holsclaw, 1984).  Deer mice can enter torpor (body
temperature, 19 to 30°C) to reduce metabolic demands in the winter  and also  in  response
to brief food shortages (Tannenbaum and Pivorun,  1988, 1989). The deer mouse uses
nonshivering thermogenesis (NST) to quickly awaken from torpor and  to maintain body
temperature during the winter (Zegers and Merritt, 1987).  The deer mouse may burrow in
soils to assist thermoregulation; one study measured the burrow dimensions to be 24 cm
deep (range 13 to 50 cm) and 132 cm long  (range 30 to 470 cm)  (Reynolds and
Wakkinen, 1987).

      Breeding activities and social organization.  The duration of the reproductive season
varies with latitude and longitude according  to the regression equation:

            Y = -33.0 + 2.79 X + 0.0748 Z - 0.0370 X2

where Y = duration of the breeding season  in weeks, X = latitude, and Z = longitude (r
= 0.58; Millar, 1989).  Lactating females have longer gestation periods than nonlactating
females.  Newborn deer mice are highly altricial (Layne, 1968).  Several studies have
indicated that daily food consumption increases over 15 percent during early pregnancy
and more than doubles during lactation (Glazier, 1979; Millar, 1975, 1978, 1979, 1982,
1985; Millar and  Innes, 1983; Stebbins,  1977).  Deer mice are promiscuous; in one study,
19 to 43 percent of litters resulted from  multiple inseminations (Birdsall and Nash, 1973,
as cited in Millar, 1989).

      Home range and resources.  Deer mice tend to occupy more than one nest site,
most frequently in tree hollows up to 8 m from the ground  (Wolff and  Durr, 1986) but also
among tree roots and under rocks and logs (Wolff and Hurlbutt,  1982; Wolff, 1989). At
low densities, home ranges are maintained by mutual avoidance, but at higher  densities,
females may defend a core area or territory (Wolff, 1989).  The home  range of female deer
mice encompasses both their foraging areas and their nests.  Male home ranges are larger
and overlap the home ranges of many females (Cranford, 1984; Taitt,  1981; Wolff,
1985a, 1986; Wolff et al., 1983).
                                      2-292
Deer Mouse
-------
      Population density.  Population density varies considerably over space and time and
is often positively correlated with food abundance (Taitt, 1981; Wolff, 1989), moisture
content of plants (Bowers and Smith, 1979), and vegetative cover (van Home, 1982) as
well as season (Montgomery, 1989; Taitt, 1985). Interspecific competition also can play a
role in determining  population densities (Kaufman and Kaufman,  1989).

      Population dynamics. Although laboratory and field studies have demonstrated that
females can produce their first litter by 3 months of age, females of the more northern
populations do not  mature under natural conditions until the spring after the year of their
birth.  First litters are consistently smaller than subsequent litters (Millar, 1989), and
latitude and elevation explain a significant amount of the variation in litter size among P.
maniculatus populations (Smith and McGinnis,  1968, as cited in Millar, 1989). Millar
(1989) estimated the relationship between litter size and latitude and longitude to be

             Y =  -1.62 +  0.0103X '+ 0.106Z  +  0.0004X2 - 0.0005Z2
                        " *
where Y is the mean litter size; X, the latitude; and Z, the longitude.  The largest litters are
produced in northwestern North America. Pups wean within about 3 weeks, and females
may have up to four litters per year in the more southern parts of the species' range
(Millar, 1989).  Mortality rates are highland most deer mice live for less than 1 year
(Millar and Innes, 1983).

Similar species (from general references}

      «      The cactus mouse (Peromyscus eremicus), almost the same size as the deer
             mouse (8.1 to 9.1 cm; 17 to 40  g), is found  only in low deserts of the
             extreme southwest and Mexico.  It may feed on green vegetation, seeds,
             and berries and can climb trees for food.

      •      The California mouse (Peromyscus  californicus) (9.6 to 11.7 cm; 42 to 50 g)
             is found in southwestern California and lives  among oaks and dense
             chaparral.  It stores acorns in nests made of twigs  and sticks.

      •      The canyon mouse (Peromyscus-crinitus)  (7.6 to 8.6 cm) is limited to the
             western United States.  It lives in rocky canyons and on lava-covered slopes,
             nesting among rocks.

      •      The oldfield mouse (Peromyscus polionotus),  smaller than the deer mouse
             (4.1 to 6.1 cm), is limited to the  extreme  southeastern United States,  where
             it inhabits sandy beaches and fields and feeds on seeds and berries.
             Females may be territorial during the breeding season.

      •      The white-footed mouse (Peromyscus leucopus) is approximately the same
             size as the deer mouse (9.1 to 10.7 cm;  14 to 31 g).  Its range extends
             north into Canada and west to Arizona but does not extend as far north and
             west as the deer mouse's range. Like the deer mouse, the white-footed
             mouse's diet consists mainly of arthropods, seeds, and other vegetation, and
             it usually nests off the ground. It is most abundant in habitat that includes a
                                      2-293
Deer Mouse
-------
             canopy, such as brushy fields and deciduous woodlots in northern regions
             and riparian areas and ravines in prairie and semidesert regions.

       •      The cotton mouse (Peromyscus gossypinus) (9.1 to 11.7 cm; 28 to 51  g) is
             found in the southeastern United States where it inhabits wooded areas,
             swampland, stream banks, and field edges. This tree climber nests in trees,
             under logs, and in buildings.

       •      The brush mouse (Peromyscus boylii) (9.7 to 10.7 cm; 22 to 36 g) is limited
             to chaparral and rocky areas of the arid and semiarid west and southwest
             United States. A good climber, it lives under rocks and debris and in
             crevices. It feeds on pine nuts, acorns, seeds, and berries.

General references

       Burt and Grossenheider (1980); Kirkland and  Lane (1989); Millar (1985, 1989);
Wolff (1989).
                                      2-294
Deer Mouse
-------
                                   Deer Mouse (Peromyscus maniculatus]
-
/
Factors
Body Weight
($ 1


'

,
-


\



Pup Growth i
Rate (g/day) \


Metabolic "
RO^/kg-day)




Age/Sex
Cond./Seas^
AM
AF
AM
AF
AM
AF
AB
A F nonbreed.
A F gestat.
A F lactat.
neonate
neonate
at weaning
at weaning
B

M
F
F resting
M avg daily:
winter
spring
summer

'
Mean * ^
22
20
15.7
14.8
22.3
21.1
19.6 ± 0.71 SE
20.3 ± 0.42 SE
31.5 ± 0.43 SE
24.5 ± 0.37 SE
1.8
1.7 ± 0.02 SE
8.8
9.3 ± 0.1 OSE
0.38 ± 0.01 SE

0.27 ± 0.06 SE
0.22 ± 0.05 SE
50

138 ± 5.3 SE
102 ± 7.2 SE
75 ± 3.4 SE
Range or
(95% Cl of
mean}










1.6-2.8

7.7- 11.2

0.30 - 0.95



40-61




-

Location (subspecies)
North America

NS (austerus)

NS (blandus)

New Hampshire
NS (borealis) lab


North America
Alberta, Canada
North America
Northwest Territories, Canada
Alberta, Canada (nebrascensis)

Alberta, Canada (borealis)

North America

Alberta, Canada lab



'
Reference
Millar, 1989

Fordham, 1971

Dewsbury et al., 1980

Schlesinger & Potter, 1 974
Millar & Innes, 1 983


Millar, 1989
Millar, 1989
Millar, 1989
Millar, 1979
Millar, 1985

Millar & Innes, 1 983

MacMillen & Garland, 1 989

Stebbins et al., 1 980



Mots
No,


1

1











2



3


ro
to
CO
en
D
CD
(D
O

V)
(D
-------
                                 Deer Mouse (Peromyscus manfculatus}


Factors
Metabolic Rate
(kcaf/kg-day)


f
-. .-
..
, ,
*
Food
Ingestion
Rate
(g/g-day)
•*
!i
j
*
| * ,-' ;
$ - -I y "
| »j,l ^;
•, ^ 1-
•j v^J" \£ "
; * A •;
Water
Ingestion
Rate (g/g»day);

Inhalation
Rate [TO%ayJ
Surface Area
{cm2}

Age/Sex
Cond./Seas.
M avg daily:
winter
spring
summer
B free-living:
winter
summer
A M free-living
A F free-living
A F nonbreed.

A F nonbreed.


A F lactating

A F lactating


A F nonbreed.
A M nonbreed.

JM
AB
AB
JM

AM
AF
AM
AF


Mean

668 ± 25 SE
623 ± 35 SE
360 ± 17 SE

790
592
547
574
0.19

0.18


0.45

0.38


0.19
0.22

0.21 ± 0.01 SE
0.19
0.19
0.34 ± 0.02 SE
0.15
0.025
0.023
91
86
Range or
(95% Cl of
mean)







(259- 1,153)
(271 -1,212)















0.123-0.287








Location (subspecies)
Alberta, Canada lab



Illinois lab




Manitoba, Canada
(maniculatus) lab
Alberta, Canada
(borealis) lab

Manitoba, Canada
(maniculatus) lab
Alberta, Canada
(borealis) lab

Virginia lab


South Dakota lab
(sonoriensis) lab
Illinois (bairdii) lab
South Dakota lab







Reference
Stebbins et al., 1 980



Morris & Kendeigh, 1981


estimated

Millar, 1979

Millar & Innes, 1983


Millar, 1979

Millar & Innes, 1 983


Cronin & Bradley, 1 988


Nelson & Desjardins, 1987
Ross, 1930
Dice, 1922
Nelson & Desjardins, 1987
estimated
estimated

estimated


Note
No,
3



4


5

6
7

6
7

8


9




10
11
12
13
14

15

ro

M
CD
D
CD
CD
o

co
CD
-------










I
4?
wyscus manicu
P
V.
0)
s
V
V)
3

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2-297
Deer Mouse
-------
                                  Deer Mouse (Pefomyscus maniculatus]
Population
Dynamics
Home Range
Size (ha)

-'- ! :•
J •' ' :":
Population
Density
IN/ha]
• •!•
: ;,- -~ -
Utter
Size ..
Litters/Year
Age/Sex/
Cond./Seas.
A M summer
A F summer
A M winter
A F winter
BM
BF
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AF
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BB
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B B summer
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AB
BB


Mean
0.039 ±0.0054 SD
0.027 ±0.0047 SD
0.019 ±0.0065 SD
0.014 ±0.0050 SD
0.058 ± 0.006 SE
0.061 ± 0.005 SE
0.10 ± 0.0063 SE
0.075 ±0.0063 SE
0.128 ± 0.012 SE
0.094 ±0.001 3 SE
0.19
2.8

12 ± 6.7 SD
3.4
4.4 *
5.1 ± 0.14 SE
2.4
1.9 ± 0.1 SE
Range

0.054 - 0.065
0.054 - 0.072



12.8-22.4
3.4 - 8.4
12.7-45.5
3.9 - 28
3.0 - 6.4
1 -8

Location (subspeclesl/Habitat
Utah/subalpine meadow
snowfree
Utah/subalpine meadow
snowbound
Virginia/mixed deciduous forest
Oregon/ponderosa pines
\dahol(artemisiae-sarcobatus)
desert
Arizona/desert
Coiorado/subalpine meadows
Utah/subalpine meadow
British Columbia, Canada/burnt
slash
Montana/understory near river
Virginia (nubiterrae]/NS
'average for North America/NS
Alberta, Canada
(nebrascens!s)INS
average for North America/NS
Alberta, Canada
(6orea//s)/various alpine
Reference
Cranford, 1984
Cranford, 1984
Wolff, 1985a
Bowers & Smith, 1 979
Bowers & Smith, 1 979
Brown & Zeng, 1 989
Vaughn, 1974
Cranford, 1984
Sullivan, 1979
Metzgar, 1979
Wolff, 1985b
Millar, 1989
Millar, 1985
Millar, 1989
Millar & Innes, 1 983
Note
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                                     2-299
Deer Mouse
-------
                                                 Deer Mouse (Peromyscus maniculatus]
ro
w
o
o
Seasonal
Activity
Torpor
Begin

Peak
winter
End

Location {subspecies}
northern parts of range
Reference
Tannenbaum & Pivorun, 1989
Note
No.

 1   Cited in Montgomery (1989).
 2   Growth rate of "newly emerged" pups, soon after leaving the nest.
 3   Temperatures during winter averaged -17.7°C (-6 to -22°C); during spring averaged 14.5°C (8 to 22°C); during summer 20.6°C (14 to 32°C).
 4   Estimated by authors from laboratory-derived model assuming no reproduction, molt, or weight change and assuming summer temperatures
     averaged 17.5°C above ground and 20.2°C in burrows and winter temperatures averaged -3°C above ground and 10.7°C in burrows.
 5   Estimated using equation 3-48 (Nagy, 1987) and body weights from Millar (1989).
 6   Diet of rat chow with 3 percent water content and 4.5 kcal/g dry weight.
 7   Diet of Purina lab chow no. 5001; composition not specified.
 8   Diet of lab chow; composition not specified.
 9   Diet of lab chow with 8 to 10 percent water content.
10   Mean varied by subspecies; sonoriensis, eremicus, gambelii, and fraterculus tested. Dry diet prepared in lab, probably less than 10 percent water
     content; air temperature 21 to 24° C.
11   Dry air at 32 to 34°C; diet of wheat and peanuts, about 10 percent water content.
12   Temperature 20°C ± 2°C; diet of lab chow with 8 to 10 percent water content.
13   Estimated using equation 3-17 (Calder and Braun, 1983) and body  weights from Millar (1989).
14   Estimated using equation 3-20 (Stahl, 1967) and body weights from Millar (1989).
15   Estimated using equation 3-22 (Stahl, 1967) and body weights from Millar (1989).
16   Cited in Millar  (1989).
D
CD
CD
O

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CD
-------
References (including Appendix)

Abbott, K. D. (1974) Ecotypic and racial variation in the water and energy metabolism of
      Peromyscus maniculatus from the western United States and Baja California,
      Mexico [Ph.D. dissertation]. Irvine, CA: University of California.

Agnew, W. J.; Uresk, D. W.; Hansen, R. M.; et al. (1988) Arthropod consumption by small
      mammals on prairie dog colonies and adjacent ungrazed mixed grass prairie in
      western South Dakota. In: Uresk, D. W.; Schenbeck, G. L; Cefkin, R., tech.
      coords. Eighth Great Plains wildlife damage control workshop proceedings; April
      28-30, 1987; Rapid City, South Dakota. Fort Collins, CO: U.S. Dept. Agr., Forest
      Serv., Rocky Mountain Forest and Range Experiment Station; pp. 81-87.

Barry, W. J. (1976) Environmental effects on food hoarding in deermice (Peromyscus). J.
      Mammal.  57: 731-746.

Birdsall, D. A.; Nash, D. (1973) Occurrence of successful multiple insemination of females
      in natural  populations of deer mice (Peromyscus maniculatus). Evolution 27:
      106-110.

Blair, W. F. (1940) A study of prairie deer mouse populations  in southern Michigan. Am.
      Midi.  Nat. 24: 273-305.
                                                                   »
Blair, W. F. (1958) Effects of x-irradiation of a natural population of deer-mouse
      (Peromyscus maniculatus). Ecology 39: 113-118.

Bowers, M. A.; Smith, H. D. (1979) Differential habitat utilization by sexes of the
      deermouse, Peromyscus maniculatus. Ecology 60: 869-875.               ,

Brower, J. E.; Cade, T. J. (1966) Ecology and physiology of Napaeozapus insignis (Miller)
      and other  woodland mice. Ecology 47: 46-63.

Brown, J. H.; Zeng, Z. (1989) Comparative  population ecology of eleven species of
      rodents in the Chihuahuan Desert. Ecology 70: 1507-1525.

Burt, W. H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
      north of Mexico. Boston,  MA: Houghton Mifflin Co.

Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
      Am. J. Physiol. 244: R601-R606.

Chappell, M. A.;  Holsclaw, D. S., Ill (1984)  Effects of wind on thermoregulation and
      energy balahce in deer mice (Peromyscus maniculatus). J. Comp. Physiol. B
      Biochem. Syst. Environ. Physiol. 154: 619-625.
                                      2-301
Deer Mouse
-------
 Cook, J. C.; Topping, M. S.; Stombaugh, T. A. (1982) Food habits of Microtus
       ochrogaster and Peromyscus maniculatus in sympatry. Trans. Missouri Acad. Sci.
       16:17-23.

 Cranford, J. A. (1984) Population ecology and home range utilizations of two subalpine
       meadow rodents (Microtus longicaudus and Peromyscus maniculatus). In: Merrit, J.
       F., ed. Winter ecology of small mammals: v. 10. Spec. Publ. Carnegie Mus. Nat.
       Hist.; pp. 1-380.

 Cronin, K. L; Bradley, E. L. (1988) The relationship between food intake, body fat and
       reproductive inhibition in prairie deermice (Peromyscus maniculatus bairdii). Comp.
       Biochem. Physiol. A Comp. Physiol. 89: 669-673.

 Deavers, D. R.; Hudson, J. W. (1981) Temperature regulation in two rodents
       (Clethrionomys gapperi and Peromyscus leucopus) and a shrew (Blarina brevicauda)
       inhabiting the  same environment. Physiol. Zool. 54: 94-108.

 Dewsbury,  D. A.; Baumgardner, D. J.; Evans, R. L.; et al. (1980) Sexual dimorphism for
       body mass in  13 taxa of muroid rodents under laboratory conditions.  J. Mammal.
       61:  146-149.

 Dice, L. R.  (1922) Some factors affecting the distribution of the prairie vole, forest deer
       mouse, and prairie deer mouse. Ecology 3: 29-47.
              *
 Drickamer,  L. C.  (1970) Seed preferences in wild caught Peromyscus maniculatus bairdii
      and  Peromyscus leucopus noveboracensis. J.  Mammal. 51: 191-194.

 Drickamer,  L. C.  (1976) Hypothesis linking food habits and habitat selection in
      Peromyscus. J. Mammal. 57: 763-766.

 Drickamer,  L C.  (1978) Annual reproduction patterns in populations of two sympatric
      species of Peromyscus. Behavior. Biol.  23: 405-408.

 Drickamer,  L. C.; Bernstein, J. (1972) Growth in two subspecies of Peromyscus
      maniculatus. J. Mammal. 53: 228-231.

 Dunmire, W. W. (1960) An altitudinal  survey of reproduction in Peromyscus maniculatus.
      Ecology 41: 174-182.

Eisenberg, J. F. (1981) The mammalian radiations. Chicago, IL: University of Chicago
      Press.

Fairbairn, D. J. (1977) The spring decline in deer mice: death or dispersal? Can. J. Zool.
      55: 84-92.

Fairbairn, D. J. (1978) Dispersal of deer mice, Peromyscus maniculatus:  proximal causes
      and effects on fitness. Oecologia 32: 171-193.
                                      2-302
Deer Mouse
-------
Flake, L. D. (1973) Food habits of four species of rodents on a short-grass prairie in
      Colorado. J. Mammal. 54: 636-647.

Fleharty, E. D.; Krause, M. E.; Stinnett, D. P. (1973) Body composition, energy content,
      and lipid cycles of four species of rodents. J. Mammal. 54: 426-438.

Fordharh,  R. A. (1971) Field populations of deermice with supplemental food. Ecology 52:
      138-146.

Glazier,  D. S. (1979) An energetic and ecological basis for different reproductive rates in
      five species of Peromyscus (mice) [Ph.D. dissertation]. Ithaca, NY:  Cornell
      University.

Green, D.  A.; Millar, J. S. (1987) Changes in gut dimensions and capacity of Peromyscus
      maniculatus relative to diet quality and energy needs. Can. J. Zool. 65:  2159-2162.

Gyug, L. W. (1979) Reproductive and developmental adjustments to breeding season
      length in Peromyscus [master's thesis]. London, Ontario: University of Western
      Ontario.

Gyug, L. W.; Millar, J. S. (1980) Fat levels in a subarctic population of Peromyscus
      maniculatus. Can. J. Zool. 58: 1341-1346.

Halford, D. K. (1987) Density, movement, and transuranic tissue inventory of small
      mammals at a liquid radioactive waste disposal  area. In: Pinder,  J. E., Ill; Alberts, J.
      J.;  McLeod, K. W., et al., eds. Environmental research on actinide elements;
      November 7-11, 1983; Hilton Head, South Carolina.  U.S. Department of Energy,
      Office of Scientific and Technical Information. Rep. No. CONF-841142
      (DE86008713); pp. 147-156.

Halfpenny, J. C. (1980)  Reproductive strategies: intra  and interspecific comparison within
      the genus Peromyscus [Ph.D. dissertation]. Fort Collins, CO: University  of Colorado.

Hamilton,  W. J., Jr. (1941) The foods of small forest mammals in eastern United States.
      J. Mammal. 22: 250-263.

Harris, J. H. (1986) Microhabitat segregation in two desert rodent species: the relation of
      prey availability to diet. Oecologia (Berl.) 68:  417-421.

Hayward,  J. S. (1965) Metabolic rate and its temperature-adaptive significance in six
      geographic races of Peromyscus. Can. J. Zool. 43: 309-323.

Hock, R. J.;  Roberts, J. C. (1966)  Effect of altitude on oxygen consumption  of deer mice:
      relation of temperature and  season. Can. J. Zool. 44: 365-376.

Holbrook,  S. J. (1979) Habitat utilization, competitive interactions, and coexistence of
      three species of cricetine rodents in east-central Arizona. Ecology 60: 758-769.
                                      2-303
Deer Mouse
-------
Howard, W. E. (1949) Dispersal, amount of inbreeding, and longevity of a local population
       of prairie deer mice on the George Reserve, southern Michigan. Contr. Lab. Vert.
       Biol., University of Michigan 43:1-52.

Johnson, D. R. (1961) The food habits of rodents in range lands of southern Idaho.
       Ecology 42: 407-410.

Kantak, G. E. (1983) Behavioral, seed preference, and habitat selection experiments with
       two sympatric Peromyscus species. Am. Midi. Nat. 109: 246-252.

Kaufman, D. W.; Kaufman, G. A. (1989) Population biology. In: Kirkland, G. L; Lane, J.
       N., eds. Advances in the study of Peromyscus (Rodentia). Lubbock, TX: Texas Tech
       University Press.

King, J. A.; Deshaies, J. C.; Webster, R. (1963) Age of weaning of two subspecies of
       deer mice. Science 139: 483-484.

Kirkland, G. L.; Lane, J. N., eds. (1989) Advances in the study of Peromyscus (Rodentia).
       Lubbock, TX: Texas Tech University Press.

Layne, J. N. (1968) Ontogeny.  In: Biology of Peromyscus (Rodentia). Spec. Publ., Amer.
       Soc. Mammal. 2:  1-593.

Linzey, A. V.  (1970) Postnatal growth and development of Peromyscus maniculatus
       nubiterrae. J. Mammal. 51: 152-155.

MacMillen, R. E.; Garland, T. J. (1989) Adaptive physiology. In: Kirkland, G. L.; Lane, J.
       N., eds. Advances in the study of Peromyscus (Rodentia). Lubbock, TX: Texas Tech
       University Press.

Marinelli, L.; Millar, J. S. (1989) The ecology of beach-dwelling Peromyscus maniculatus
       on the Pacific coast. Can. J. Zool. 67: 412-417.

Martell, A. M.; MacAuley, A. L. (1981) Food habits of deer mice (Peromyscus
       maniculatus) in northern Ontario. Can. Field Nat. 95: 319-324.

Marten, G. G. (1973) Time patterns of Peromyscus activity and  their correlations with
       weather. J. Mammal. 54: 169-188.

May, J. D. (1979) Demographic adjustments to breeding season length in Peromyscus
       [master's thesis].  London, Ontario: University of Western Ontario.

McCabe, T. T.; Blanchard, B. D. (1950) Three species of Peromyscus,  Santa Barbara, CA:
       Rood Associates.

McLaren, S. B.; Kirkland, G. L., Jr. (1979) Geographic variation in litter size of small
       mammals in  the central Appalachian region. Proc. Pennsylvania  Acad. Sci. 53:
       123-126.
                                      2-304
Deer Mouse
-------
McNab, B. K.; Morrison, P. (1963) Body temperature and metabolism in subspecies of
      Peromyscus from arid and mesic environments. Ecol. Monogr. 33: 63-82.

Menhusen, B. R. (1963) An investigation on the food habits of four species of rodents in
      captivity. Trans. Kansas Acad. Sci. 66: 107-112.

Metzgar, L. H. (1973a) Exploratory and feeding home ranges in Peromyscus. J.  Mammal.
      54: 760-763.

Metzgar, L. H. (1973b) Home range shape and activity in Peromyscus leucopus. J.
      Mammal. 54: 383-390.

Metzgar, L. H. (1979) Dispersion patterns in a Peromyscus population.  J. Mammal. 60:
      129-145.
                               •   . . • •            .•                      '    -
Metzgar, L. H. (1980) Dispersion and numbers in Peromyscus populations. Am.  Midi. Nat.
      103: 26-31.

Meyers, P.; Master, L.  L.;  Garrett, R. A. (1985) Ambient temperature and rainfall:  an effect
      on sex ratio and litter size. J. Mammal. 66: 289-298.

Millar, J. S. (1975) Tactics of energy partitioning in breeding Peromyscus. Can.  J. Zool.
      53: 967-976.

Millar, J. S. (1978) Energetics  of reproduction in Peromyscus leucopus: the cost of
      lactation. Ecology 59: 1055-1061.

Millar, J. S. (1979) Energetics  of lactation \nPeromyscus maniculatus.  Can. J. Zool. 57:
      1015-1019.

Millar, J. S. (1982) Life cycle characteristics of  northern Peromyscus maniculatus  borealis.
      Can. J. Zool. 60: 510-515.

Millar, J. S. (1985) Life cycle characteristics of  Peromyscus maniculatus nebrascensis.
      Can. J. Zool. 63: 1280-1284.

Millar, J. S. (1989) Reproduction and development.  In: Kirkland, G. L.;  Lane, J. N., eds.
      Advances in the study of Peromyscus (Rodentia). Lubbock, TX:  Texas Tech
      University Press; pp. 169-205.

Millar, J. S.; Innes, D. G. (1983)  Demographic and life cycle characteristics of montane
      deer mice. Can. J. Zool. 61: 574-585.

Millar, J. S.; Schieck, J. O. (1986) An annual lipid cycle  in a montane population of
      Peromyscus maniculatus. Can. J. Zool. 64: 1981-1985.

Millar, J. S.; Willie, F. B.; Iverson, S. L.  (1979) Breeding  by Peromyscus in seasonal
      environments. Can. J. Zool. 57: 719-727.
                                      2-305
Deer Mouse
-------
Montgomery, W. I. (1989) Peromyscus and Apodemus: patterns of similarity in ecological
       equivalents. In: Kirkland, G. L.; Lane, J. N., eds. Advances in the study of
       Peromyscus (Rodentia). Lubbock, TX: Texas Tech University Press; pp. 293-366.

Morris, J. G.; Kendeigh, C. S. (1981) Energetics of the prairie deer mouse Peromyscus
       maniculatus bairdii. Am. Midi. Nat. 105: 368-76.

Morrison, P. R. (1948) Oxygen consumption in several small wild mammals. J. Cell. Comp.
       Physiol. 31: 69-96.

Morrison, P.; Dieterich, R.; Preston, D. (1977) Body growth in sixteen rodent species and
       subspecies maintained in laboratory colonies. Physiol. Zool. 50: 294-310.

Murie, M. (1961) Metabolic characteristics of mountain, desert and coastal populations of
       Peromyscus. Ecology 42: 723-740.            ,

Myers, P.; Master, L. L. (1983) Reproduction by Peromyscus maniculatus: size and
       compromise. J. Mammal. 64: 1-18.

Myers, P.; Master, L. L.; Garrett, R. A. (1985) Ambient temperature and rainfall: an effect
       on sex ratio and litter size in deer mice. J. Mammal. 66: 289-298.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

Nelson, R. J.; Desjardins,  C. (1987) Water availability affects reproduction in deer mice.
       Biol. Reproduc. 37: 257-260.

Reynolds, T. D.; Wakkinen, W. L. (1987) Characteristics of the burrows of four species of
       rodents in undisturbed soils in southeastern Idaho. Am. Midi. Nat. 118: 245-250.

Ribble, D. 0.; Samson, F.  B. (1987) Microhabitat associations of small mammals in
       southeastern Colorado, with special emphasis on Peromyscus (Rodentia).
       Southwest. Nat. 32: 291-303.

Rood, J.  K. (1966) Observations on the reproduction of Peromyscus in captivity. Am. Midi.
       Nat. 76: 496-503.

Ross, L. G. (1930) A comparative study of daily water-intake among certain taxonomic
       and geographic groups within the genus Peromyscus.  Biol. Bull. 59: 326-338.

Sadleir, R. M. (1970) Population dynamics and breeding of the deermouse (Peromyscus
      maniculatus) on Burnaby Mountain, British Columbia. Syesis 3: 67-74.

Schlesinger, W. H.; Potter, G. L. (1974) Lead, copper, and cadmium concentrations in
      small mammals in the Hubbard Brook Experimental Forest. Oikos 25:  148-152.
                                      2-306
Deer Mouse
-------
Sieg, C. H.; Uresk, D. W.; Hansen, R. M. (1986) Seasonal diets of deer mice on bentonite
      mine spoils and sagebrush grasslands in southeastern Montana. Northwest Sci. 60:
      81-89.

Smith, M. H.; McGinnis, J. T. (1968) Relationships of latitude, altitude and body size to
      litter size and mean annual production of offspring in Peromyscus. Res. Pop. Biol.
      10: 115-126.

Stahl, W. R.  (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22: 453-
      460.

Stebbins, L. L. (1977) Energy requirements during reproduction of Peromyscus
      maniculatus. Can. J. Zool. 55: 1701-1704.

Stebbins, L. L. (1978) Some aspects of overwintering in Peromyscus maniculatus. Can. J.
      Zool. 56: 386-390.

Stebbins, L. L.; Orich, R.;  Nagy, J.  (1980) Metabolic  rates of Peromsyscus maniculatus in
      winter,  spring, and summer. Acta. Theriol. 25: 99-104.

Sullivan, T. P.  (1979) Repopulation of clear-cut habitat and conifer seed predation by deer
      mice. J. Wildl. Manage. 43: 861-871.

Svendsen, G. (1964) Comparative reproduction and development in two species of mice in
      the genus Peromyscus. Trans. Kansas Acad. Sci. 67: 527-538.

Svihla, A. (1932) A comparative life history study of  the mice of the genus Peromyscus.
      Misc. Publ. Mus. Zool., Univ. Michigan 24: 1-39.

Svihla, A. (1934) Development and growth of deermice (Peromyscus maniculatus
      artemisiae).  J. Mammal. 15: 99-104.

Svihla, A. (1935) Development and growth of the prairie deer mouse,  Peromyscus
      maniculatus bairdii. J. Mammal. 16: 109-115.

Taitt, M.  J. (1981) The effect of extra food on small  rodents populations: deer mice
      (Peromyscus maniculatus). J. Anim. Ecol. 50:  111-124.

Taitt, M.  J. (1985) Cycles and annual fluctuations: Microtus townsendii and Peromyscus
      maniculatus. Acta.  Zool. Fenn. 173:41-42.

Tannenbaum, M. G.; Pivorun, E. B. (1988) Seasonal study of daily torpor in southeastern
      Peromyscus maniculatus and Peromyscus leucopus from mountains and foothills.
      Physiol. Zool. 61: 10-16.

Tannenbaum, M. G.; Pivorun, E. B. (1989) Summer torpor in montane Peromyscus
      maniculatus. Am. Midi.  Nat. 121: 194-197.
                                      2-307
Deer Mouse
-------
Thomas, B. (1971) Evolutionary relationships among Peromyscus from the Georgia Strait,
       Gordon, Goletas, and Scott Islands of British Columbia, Canada [Ph.D. dissertation].
       Vancouver, BC: University of British Columbia.

Tornasl, T. E. (1985) Basal metabolic rates and thermoregulatory abilities in four small
       mammals. Can. J. Zool. 63: 2534-2537.

van Home, B. (1982) Niches of adult and juvenile deer mice (Peromyscus maniculatus) in
       serai stages of coniferous forest. Ecology 63: 992-1003.

Vaughn, T. A. (1974) Resource allocation in some sympatric subalpine rodents. J.
       Mammal.  55: 764-795.

Vickery, W. L. (1981) Habitat  use by northeastern forest rodents. Am. Midi.  Nat. 106:
       111-118.

Whitaker, J. O., Jr. (1966) Food of Mus muscu/us, Peromyscus maniculatus bairdi, and
       Peromyscus leucopus in Vigo County, Indiana. J. Mammal. 47: 473-486.

Wolff, J. O. (1985a) The effects of density, food, and interspecific interference on home
       range size in Peromyscus leucopus and Peromyscus maniculatus. Can. J. Zool. 63:
       2657-2662.

Wolff, J. 0. (1985b)  Comparative population ecology of Peromyscus leucopus and
       Peromyscus maniculatus. Can. J. Zool. 63:  1548-1555.

Wolff, J. O. (1986) The effects of food on midsummer demography of white-footed mice,
       Peromyscus leucopus. Can. J. Zool. 64: 855-858.

Wolff, J. O. (1989) Social behavior. In: Kirkland, G. L.; Lane, J. N., eds. Advances in the
       study of Peromyscus (Rodentia). Lubbock, TX: Texas Tech. University Press; pp.
       271-291.

Wolff, J. O.; Durr, D. S. (1986) Winter nesting behavior of Peromyscus leucopus and
       Peromyscus maniculatus. J. Mammal. 67: 409-412.

Wolff, J. O.; Hurlbutt, B. (1982) Day refuges of Peromyscus leucopus and Peromyscus
       maniculatus. J. Mammal. 63: 666-668.

Wolff, J. O.; Freeberg, H.; Dueser, R. D. (1983) Interspecific territoriality in two sympatric
       species of Peromyscus  (Rodentia: Cricetidae). Behav. Ecol. Sociobiol.  12: 237-242.

Wolff, J. O.; Dueser,  R. D.; Berry, D. S. (1985) Food habits of sympatric Peromyscus
       leucopus and Peromyscus maniculatus. J. Mammal. 66: 795-798.

Zegers, D. A.; Merritt, J. F. (1987) Seasonal changes in  non-shivering thermogenesis of
       three small mammals (abstract only). Bull. Ecol. Soc. Am. 68: 455.
                                      2-308
Deer Mouse
-------
Zegers, D. A.; Merritt, J. F. (1988) Adaptations of Peromyscus for winter survival in an
      Appalachian montane forest. J. Mammal. 69: 516-523.
                                     2-309
Deer Mouse
-------
-------
2.2.8.  Prairie Vole (voles)

       Order Rodentia Family Muridae (subfamily Arvicolinae).  New world voles are small,
herbivorous rodents that reside in all areas of the United States where good grass cover
exists. Their presence is characterized by narrow runways through matted grasses.
Microtus species are adapted to underground, terrestrial, and sometimes semiamphibious
habitats (Johnson and Johnson, 1982). They are active by day and night and feed mainly
on shoots, grasses, and  bark (Johnson and Johnson, 1982). Voles are prey for snakes,
raptors, and mammalian predators such as short-tailed shrews, badgers, raccoons,
coyotes, and foxes (Eadie, 1952; Johnson and Johnson, 1982; Martin, 1956).

Selected species

       The prairie vole (Microtus ochrogaster) represents the ground-burrowing members
of this group.  This vole  is found  in the north and central plains of the United States and in
southern Canada, usually in dry places such as prairies and along fencerows and railroads.
Its range has expanded eastward to West Virginia as a result of clear-cutting of forests
(Jones et al., 1983). Voles are active by day or night (Johnson and Johnson, 1982).
Although prairie and meadow voles usually occupy different  habitats, where they coexist
their population densities tend to be negatively correlated (Klatt, 1985; Krebs, 1977).

       Body size. The prairie vole measures from 8.9 to 13 cm in length and has a 3.0- to
4.1-cm tail (Burt and Grossenheider, 1980).  After reaching sexual maturity, voles
continue to grow for several months (Johnson and Johnson, 1982).  Adults weigh from 30
to 45 g (see table). Prairie_voles  maintain a relatively constant proportion of their body
weight as fat (15 to 16 percent on a dry-weight basis) throughout the year (Fleharty et al.,
1973).

       Habitat. The prairie vole inhabits a wide variety of prairie plant communities and
moisture regimes, including  riparian, short-grass, or tall-grass communities (Kaufman and
Fleharty, 1974).  Prairie voles prefer areas of dense vegetation, such as grass, alfalfa, or
clover (Carroll  and  Getz, 1976); their presence in a habitat depends on suitable cover for
runways (Kaufman and Fleharty,  1974).  They will tolerate sparser plant cover than the
meadow vole because the prairie vole usually nests in burrows at least 50 mm
underground or in grass nests under logs or boards (Klatt and Getz, 1987).

       Food Habits. Meadow voles, as other voles, are largely herbivorous, consuming
primarily green succulent vegetation but also roots, bark, seeds, fungi, arthropods, and
animal matter  (Johnson and Johnson, 1982;  Lomolino,  1984; Stalling, 1990).  Voles have
masticatory and digestive systems that allow them to digest fibrous grasses such as
cereals (Johnson and Johnson, 1982). Diet varies by season and  habitat according to
plant availability, although meadow and other voles show a preference for young, tender
vegetation (Johnson and Johnson,  1982; Martin, 1956).  Voles can damage pastures,
grasslands, crops such as hay and grain, and fruit trees (by eating bark and roots)
(Johnson and Johnson, 1982).
                                       2-311
Prairie Vole
-------
       Temperature regulation and molt.  Unlike some other mammals, prairie voles do not
hibernate or exhibit torpor (Johnson and Johnson, 1982). They overwinter without using
their lipid reserves, finding food to meet their metabolic requirements year-round (Fleharty
et al., 1973).  Prairie voles use burrows, runways, nests, and snow cover to help maintain
their body temperature.  They also modify when they are active to avoid excessively hot or
cold temperatures (Johnson and Johnson, 1982). Voles undergo three molts (juvenile,
subadult, and adult), and molting may occur at any time during the year (Jameson, 1947,
as cited in Stalling,  1990). The subadult-to-adult molt occurs between 8 and 12 weeks of
age (Martin, 1956).

      Breeding activities and social organization.  Prairie voles are monogamous; a mated
pair occupies the same home  range (Thomas and Birney, 1979).  Reproduction occurs
throughout\he year, and gestation lasts approximately 3 wk (Martin, 1956; Keller, 1985;
Nadeau,  1985).  Both sexes care for the young; paternal activities include runway
construction, food caching, grooming, retrieving, and brooding the young (Thomas and
Birney, 1979). The young are weaned by about 3 weeks of age (Thomas and Birney,
1979).  Reproductive activity  peaks from May to October, coinciding with high moisture
availability (Martin, 1956; Keller,  1985).  Monogamous family units apparently defend
territories against other family groups (Ostfeld et al.,  1988; Johnson and Johnson,  1982;
Thomas and Birney, 1979).

      Home range and resources.  Prairie voles excavate underground  nests that are  used
as nurseries, resting areas, and as shelter from severe weather (Klatt and Getz, 1987).
They spend very little time away from this nest (Barbour, 1963). In thick vegetation,
prairie voles move about in surface runways, and the number of runways is proportional to
population density (Carroll and Getz, 1976). Female home range size decreases with
increasing prairie vole density  according to the following  regression equation (Gaines and
Johnson, 1982):
      Y=  -0.23X + 20.16
where Y= home range length in meters and X =
minimum number alive per 0.8 ha grid.
Abramsky and Tracy (1980) found a similar correlation using both sexes according to the
equation:
      Y=  -0.20X + 27.12
where Y= home range length in meters and X = number
of individuals per hectare.
      Population dynamics.  Female prairie voles can reach sexual maturity in about 35 d,
males in 42 to 45 d (Gier and Cooksey, 1967, as cited in Stalling, 1990).  Martin (1956)
found in Kansas that females mature within about 6 wk in the summer, but may require 15
wk or more to mature if born in the fall.  Male prairie voles tend to disperse from their
natal site; approximately twice as many females as males mature near their birthplace
(Boonstra et al., 1987).  Populations tend to fluctuate with available moisture (Gier, 1967,
as cited in Stalling, 1990). Mortality rates in prairie vole postnestling juveniles and young
adults are similar and higher than adult mortality rates; nestlings have the lowest mortality
rate (Golley, 1961). Average life expectancy in the field is about 1 yr (Martin, 1956).
                                      2-312
                                        Prairie Vole
-------
Similar species (from general references)

      •      The pine vole (Microtus pinetorum) (7 to 11 cm), despite its name, usually
             inhabits deciduous forest floors, among a thick layer of duff, where it
             tunnels through loose soil near the surface.  It is found in the eastern half of
             the United States, except Florida; in the south, it inhabits pine forests. In
             addition to feeding on bark, it burrows for bulbs,  tubers, and corms.

      •      See also similar species listed for the meadow vole in this chapter.

General references

      Burt and Grossenheider (1980);  Johnson and Johnson (1982); Stalling (1990);
Tamarin (1985).
                                       2-313
Prairie Vole
-------
                                          Prairie Vole (Microtus ochrogaster}
Factors

Body Weight
g>



v

, , , , -
Metabolic Rate
l(02/kg-d}
•'
Metabolic Rate
tkcal/kg-d)
•*
Food Ingestion
Rate [g/g-d)
Water
Ingestion Rate
fe/s-d)


Inhalation
Rate [fli /d)
Surface Area
Age/Sex/
Cond./Seas.
AB
A B summer
A B fall
A B winter
A B spring
AM
AF
neonate B
A winter

A summer
A B basal

A B free-living
A B at 21 °C
A B at 28°C
AB

AB
AB
AB
AB

AB

Mean
41.6
41.9
44.2
39.0
41.3
31.3 ± 0.35 SE
33.3 ± 0.30 SE
2.8 ± 0.4 SD
51.8 ± 8.2 SD

41.8 ± 4.8 SD
177

399
0.13-0.14
0.09-0.10 '
0.37

0.29 ± 0.02 SE
0.21
0.14
0.043

139
Range or
{95% CI of mean)













(190-8331





0.1 5 to 0.26





Location
ne Colorado
ne Colorado



s Indiana

ne Kansas
NS/lab





Illinois/lab

NS/lab

Kansas/lab
Illinois/lab





Reference
Abramsky & Tracy, 1 980
Abramsky & Tracy, 1980



Myers & Krebs, 1971

Martin, 1956
Wunderetal., 1977


estimated

estimated
Dice, 1922

Chew, 1951

Dupre, 1983
Dice, 1922
estimated
estimated

estimated
Note
No.











1

2
3

4

5
6
7
8

9
Ni
CO
T)
S
-V
5'

o_
CD
-------
                                        Prairie Vole (Microtus ochrogaster]
Pie&ry
Composition

..
Sporobalus asper
Kochiff $eoparid

Boutelaua gracilis
Bro/nus japon1cti$
Rumex crispus
Tritlcum ae&tivun
Carex sp»
other
' (grasses]
(forbsl ..

7
.,



Festuca arundinacea
Dactylis glomerata
Phleum pratense
Tridens flavus
Setar/a viridis



Taraxacum officinale
Lamiurft arnpJexicaule
Bmmus teetotum
Setaria faberi

CapseHa bursa-pasL
Trifolium stotonifera
arthropods
animal material
other
-Population
Dynamics
Home
Range
Size (ha)
v





5
Spring










20.5
6.7
8.3
17.1
6.7
5.8
3.9
2.8
5.6
2.7
2.4
0.2 .
0
3.9
Age/Sex/
Cond./Seas.
A B all yr

A M all yr
A F all yr
AM
AF

Summer
19.5
22.5
6.5
8.5
9.2
3.4
2.0
28.3
(53.5)
(46.5)
25.0
1.7
2.0
11.1
6.2
4.8
2.9
4.7
3.9
1.2
0.8
0.3
0.2
1.4
-
Fall










10.6
1.1
2.1
1.9
1.7
3.9
5.2
2.5
0.7
0.5
0.5
0.0
0.2
1.5

Mean
0.098 ± 0.01 2 SE

0.037 ± 0.0029 SE
0.024 ± 0.001 8 SE
0.011
0.0073

Winter










28.9
4.2
5.3
11.0
6.2
1.5
3.4
4.8
21.0
0.6
1.4
0.1
0.0
0.9
Location/Habitat
{measure)
Kansas/forb and grass field

(% volume; stomach
contents)

(Items less than 2% of
volume were combined as
"other")


Missouri/old field

(mean number of food
items; stomach contents)

(Plant parts consumed: leaf,
stem, and seeds of Festuca
and Bromus; leaf and stem
of Tridens and Setaria faberi;
leaf and seeds of Dactylis
and Seteria viridis; and
leaves only of all other plant
species)


Range Location/Habitat
Illinois/bluegrass

Kansas/NS

ne Colorado/short-grass
prairie

Reference
Fleharty & Olson, 1 969









Cook et al., 1982










<



• Reference
Jike etal., 1988

Swihart & Slade, 1 989

Abramsky & Tracy, 1 980

Note
No*
























Note
Mo.






ro
CO
o,
CD
-------
                                          Prairie Vole (Microtus ochrogaster)
Population
Dynamics
Population
Density
{N/ha)


Utter
.Size
Utters/Year
Days
Gestation
Pup Growth
Rate (g/d)

Age at
Weaning
Age at
Sexual
Maturity
Annual
Mortality
longevity
Age/Sex/
Cond./Seas.
summer
winter
spring
summer
summer
winter
spring
fall



days 1 to 10
days 1 1 to 30
> 30 d until
growth stops

F
M

B
B
Mean
25-35
12
78-118
81 - 104
168-234
160-197
203 - 247
94- 123
3.18 ± 0.24 SD
3.4
4.25
several
21
21
0.6
1.0
0.5
(highly variable)
21 days
35 days

93%
1 yr
Range



1 -7



'

42 to 45 d


up to 1 .8 yr
Location/Habitat
w Nebraska/xeric prairie
Illinois/alfalfa field
ne Kansas/grassland

ne Kansas/grassland
Kansas/NS
lllinois/NS
NS/NS
ne Kansas/grassland
NS/NS
ne Kansas/grassland

NS/lab
NS/NS

ne Colorado/short-grass
prairie
ne Kansas/grassland
Reference
Meserve, 1971
Carroll & Getz, 1976
Martin, 1956 «

Martin, 1956
Jameson, 1947
Cole &Batzli, 1978
Johnson & Johnson, 1982
Martin, 1956
Keller, 1985
Martin, 1956

Thomas & Birney, 1 979
Gier & Cooksey, 1 967

Abramsky & Tracy, 1 980
Martin, 1956
Note
No.



10
11
12





13



ro
to
en
S2.
cb"
o_
CD
-------
                                                    Prairie Vole (Microtus ochrogaster]
Seasonal
Activity
Mating
Parturition
Molt
Begin



Peak *
May to Oct
May to Oct
any time
End '-



Location
NS
NS
NS
Reference
Keller, 1985; Martin, 1956
Keller, 1985; Martin, 1956
Jameson, 1947
Note
No,


13
fo
to
 1 Estimated using equation 3-43 (Boddington,  1978) and body weights (summer) from Abramsky and Tracy (1980).
 2 Estimated using equation 3-48 (Nagy, 1987) and body weights (summer) from Abramsky and Tracy (1980).
 3 Estimated from ingestion rate for diet of oats (74 to 78 percent of total weight of diet) and dry grass, assuming 31 to 34 g body weight. Diet was
   low in water (probably less than 10 percent).
 4 Measured water drunk from water bottles; diet consisted of rolled oats with sunflower seeds; temperature 28°C.
 5 Measured water drunk; diet of dry food.
 6 Temperature 21 °C; dry air.
 7 Estimated using equation 3-17 (Calder and Braun, 1983) and body weights (summer) from Abramsky and Tracy (1980).
 8 Estimated using equation 3-20 (Stahl, 1967) and body weights (summer) from Abramsky and Tracy (1980).
 9 Estimated using equation 3-22 (Stahl, 1967) and body weights (summer) from Abramsky and Tracy (1980).
10 Determined from pup count, which may underestimate litter size at birth.
11 Cited in Keller (1985); embryo or pup count.
12 Cited in Keller (1985); embryo or placental scar count.
13 Cited in Stalling (1990).
— \
CD'
CD
-------
References (including Appendix)

Abramsky, Z.; Tracy, C. R. (1980) Relation between home range size and regulation of
       population size in Microtus ochrogaster. Oikos 34: 347-355.

Agnew, W. J.; Uresk, D. W.; Hansen; et al. (1988) Arthropod consumption by small
       mammals on prairie dog colonies and adjacent ungrazed mixed grass prairie in
       western South Dakota. In: Uresk, D. W.; Schenbeck, G. L.; Cefkin, R., tech. coord.
       Eighth Great Plains wildlife damage control workshop proceedings; April 28-30,
       1987; Rapid City, South Dakota. Fort Collins, CO: U.S. Department of Agriculture,
       Forest Service, Rocky Mountain Forest and Range Experiment Station; pp.  81-87.

Barbour, R. W. (1963) Microtus: a simple method of recording time spent in the nest.
       Science 141: 41.

Boddington, M. J. (1978) An absolute metabolic scope for activity. J. Theor.  Biol. 75:
       443-449.

Boonstra,  R.; Krebs, C.  J.; Gaines, M. S.; et al. (1987) Natal philopatry and breeding
       systems in voles (Microtus spp.). J. Anim. Ecol. 56:  655-673.

Bradley, S. R. (1976) Temperature regulation and bioenergetics of some microtine rodents
       [Ph.D. dissertation]. Ithaca, NY: Cornell University.

Burt, W. H.; Grossenheider,  R. P. (1980) A field guide to the mammals of North America
       north of Mexico. Boston,  MA: Houghton Mifflin Co.

Calder, W. A.; Braun, E. J. (1983)  Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244:  R601-R606.

Carroll, D.; Getz, L. L. (1976) Runway use and population density in Microtus ochrogaster.
       J. Mammal.  57:  772-776.

Chew, R. M. (1951) The water exchanges of some small mammals.  Ecol. Monogr. 21:
       215-225.

Cole, F. R.; Batzli, G. O. (1978) Influence of supplemental feeding on a vole population. J.
       Mammal. 59: 809-819.

Colvin, M. A.; Colvin, D. V.  (1970) Breeding and fecundity of six species of voles
       (Microtus). J. Mammal. 51:  417-419.

Cook, J. C.; Topping, M. S.; Stombaugh, T. A. (1982) Food habits of Microtus
       ochragaster  and Peromyscus maniculatus in sympatry. Trans. Missouri Acad. Sci.
       16: 17-23.
                                      2-318
Prairie Vole
-------
Corthum, D. W., Jr. (1967) Reproduction and duration of placenta! scars in the prairie vole
       and the eastern vole. J. Mammal. 48: 287-292.

Dice, L. R. (1922) Some factors affecting the distribution of the prairie vole, forest deer
       mouse, and prairie deer mouse. Ecology 3: 29-47.

Dupre, R. K. (1983) A comparison of the water relations of the hispid cotton rat,
       Sigmodon hispidus, and the prairie vole, Michrotus ochrogaster. Com p. Biochem.
       Physiol. 75A: 659-663.

Eadie,  R. W. (1952) Shrew predation and vole populations on a localized area. J. Mammal.
       33:185-189.

Fitch, H. S. (1957) Aspects of reproduction and development in the prairie vole (Microtus
       ochrogaster). Univ. Kansas Publ., Mus. Nat. Hist. 10: 129-161.

Fleharty, E. D.; Olson, L. E. (1969) Summer food habits of Michrotus ochrogaster and
       Sigmodon hispidus. J. Mammal. 50: 475-486.

Fleharty, E. D.; Krause, M. E.; Stinnett, D. P. (1973) Body composition, energy content,
       and lipid cycles of four species of rodents. J. Mammal.  54: 426-438.

Gaines, M. S.; Johnson, M. L. (1982) Home range size and population dynamics in the
       prairie vole, Microtus ochrogaster. Oikos 39: 63-70.

Gaines, M. S.; Rose, R. K. (1976) Population dynamics of Microtus ochrogaster in eastern
       Kansas. Ecology 57: 1145-1161.

Getz, L. L.; Hofmann, J. E.; Klatt, B. J.; et al. (1987) Fourteen years of population
       fluctuations of Microtus ochrogaster and M. pennsylvanicus in east central Illinois.
       Can. J. Zool. 65: 1317-1325.

Gier, H. T. (1967) The Kansas small mammal census: terminal report. Trans. Kansas Acad.
       Sci. 70: 505-518.

Gier, H. T.; Cooksey, B. F., Jr. (1967) Michrotus  ochrogaster in the laboratory. Trans.
       Kansas Acad. Sci. 70: 256-265.

Golley, F. B. (1961) Interaction of natality, mortality and movement during one annual
       cycle in a Microtus population.  Am. Midi. Nat. 66: 152-159.

Harvey, M. J.; Barbour, R. W. (1965) Home range of Microtus ochrogaster as determined
       by a modified minimum area method. J. Mammal. 46: 398-402.

Jameson, E. W., Jr. (1947) Natural history of the prairie vole (mammalian genus
       Michrotus). Misc. Publ. Mus. Nat. Hist. Univ.  Kansas  1: 125-151.
                                      2-319
Prairie Vole
-------
Jike, L.; Batzli, G. O.; Getz, L. L. (1988) Home ranges of prairie voles as determined by
       radiotracking and by powdertracking. J. Mammal. 69: 183-186.

Johnson, M. L.; Johnson, S. (1982) Voles (Microtus species). In: Chapman, J. A.;
       Feldhamer, G. A., eds. Wild mammals of North America. Baltimore, MD: Johns
       Hopkins University Press; pp. 326-353.

Jones, J. K. Jr.; Armstrong,  R. S.; Hoffman, R. S.; et al. (1983) Mammals of the Great
       Northern Plains. Lincoln,  NE: University of Nebraska Press.

Kaufman, D. W.; Fleharty, E. D. (1974) Habitat selection by nine species of rodents in
       north-central Kansas.  Southwest. Nat.  18: 443-451.

Keller, B. L. (1985) Reproductive patterns. In:  Tamarin, R.  H., ed. Biology of new world
       Microtus. American Society of Mammalogists; Special Publication No. 8; pp.
       725-778.

Keller, B. L.; Krebs, C. J. (1970) Microtus population biology.  III.  Reproductive changes in
       fluctuating populations of M. ochrogaster and M. pennsylvanicus in southern
       Indiana, 1965-1967.  Ecol. Monogr. 40: 263-294.

Kenney, A. M.; Evans, R. L.; Dewsbury, D. A. (1977) Postimplantation pregnancy
       disruption in Microtus orchogaster, Microtus pennsylvanicus, and  Peromyscus
       maniculatis. J. Reprod. Pert. 49: 365-367.

Klatt, B. J.  (1985) The role of habitat preference and interspecific competition in
       determining the local distribution of Microtus pennsylvanicus and M.  ochrogaster in
       central  Illinois (abstract).  Bull. Ecol. Soc. Am. 66: 209.

Klatt, B. J.; Getz, L. L. (1987) Vegetation characteristics of Microtus ochragaster and M.
      pennsylvanicus habitats in east-central Illinois. J. Mammal. 68:  569-577.

Krebs, C. J. (1977) Competition  between Microtus pennsylvanicus  and Microtus
       ochragaster. Am. Midi. Nat. 97: 42-49.

Kruckenberg, S. M.; Gier, H.  T.; Dennis, S. M. (1973)  Postnatal development of the prairie
       vole, Microtus ochrogaster. Lab. Anim.  Sci. 23: 53-55.

Lomolino, M. V. (1984) Immigrant selection, predation, and the distribution  of Microtus
      pennsylvanicus and Blarina brevicauda on islands. Am.  Nat.  123: 468-483.

Martin, E. P. (1956) A population study of the prairie vole (Michrotus ochragaster) in
       northeastern Kansas.  Univ. Kansas Publ. Mus. Nat.  Hist. 8: 361-416.

Martin, E. P. (1960) Distribution of native mammals among the communities of the mixed
       prairie.  Fort Hays Stud. N. S. Sci. Ser. 1: 1-26.
                                       2-320
Prairie Vole
-------
Meserve, P. L. (1971) Population ecology of the prairie vole, Microtus ochrogaster, in the
       western mixed prairie of Nebraska. Am. Woodl. Nat. 86: 417-433.

Morrison, P. R.; Dieterich, R.; Preston, D. (1976) Breeding and reproduction of fifteen wild
       rodents maintained as laboratory colonies. Lab. Anim. Care 26: 237-243.

Myers, J. H.; Krebs, C. J. (1971) Genetic, behavioral, and reproductive attributes of
       dispersing field voles Microtus pennsylvanicus and Michrotus ochrogaster. Ecol.
       Monogr. 41: 53-78.

Nadeau, J.  H. (1985) Ontogeny. In: Tamarin, R. H., ed. Biology of new world Microtus.
       Spec. Publ.  Amer. Soc. Mammal.  8; pp. 254-285.

Nagy, K. A. (1987) Field metabolic rate an'd food requirement scaling in mammals and
       birds. Ecol.  Monogr. 57: 111-128.

Ostfeld, R.  S.; Pugh, S. R.; Seamon, J. O.;  et al. (1988)  Space use and reproductive
       success in a population of meadow voles. J. Anim. Ecol. 57: 385-394.

Quick, F. W. II (1970) Small  mammal populations in an old field community [Ph.D.
       dissertation]. Louisville, KY: University of Louisville.

Richmond,  M. E. (1967) Reproduction of the vole, Microtus orchogaster [Ph.D.
       dissertation]. Columbia, MO: University of Missouri.

Richmond,  M. E.; Conaway,  C. H. (1969) Management,  breeding and reproductive
       performance of the vole, Microtus ochrogaster in  a laboratory colony. Lab. Anim.
       Care 19: 80-87.

Rolan, R. G.; Gier,  H. T. (1967) Correlation of embryo and placental scar  counts of
       Peromyscus maniculatis and Microtus orchogaster. J. Mammal. 48: 317-319.

Rose, R. K.; Gaines, M. S. (1978) The reproductive cycle of Microtus orchogaster in
       eastern Kansas. Ecol.  Monogr. 48: 21-42.

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl.  Physiol. 22:
       453-460.

Stalling, D.  T. (1990) Microtus ochrogaster. American Society of  Mammalogists;
       Mammalian  Species No. 355;  9 pp.

Swihart, R. K.; Slade, N. A. (1989) Differences in home-range size between sexes of
       Microtus ochrogaster. J. Mammal. 70: 816-820.

Tamarin, R. H. (1985) Biology of new world Microtus. Spec. Publ. Amer.  Soc. Mammal. 8.

Thomas, J. A.; Birney, E. C.  (1979) Parental care and mating system of the prairie vole,
       Microtus ochrogaster. Behav.  Ecol. Sociobiol. 5: 171-186.
                                      2-321
Prairie Vole
-------
Wooster, L. D. (1939) An ecological evaluation of predatees on a mixed prairie area in
      western Kansas. Trans. Kans. Acad. Sci. 42: 515-517.

Wunder, B. A. (1985) Energetics and thermoregulation. In: Tamarin, R. H., ed. Biology of
      new world Microtus. Spec. Publ. Amer. Soc. Mammal. 8; pp. 812-844.

Wunder, B. A.; Dobkin, D. S.; Gettinger, R. D. (1977) Shifts of thermogenesis in the
      prairie  vole (Microtus ochrogaster), strategies for survival in a seasonal
      environment. Oecologia (Berl.) 29: 11-26.

Zimmerman, E. G. (1965) A comparison of habitat and food of two species of Microtus. J.
      Mammal. 46: 605-612.
                                      2-322
Prairie Vole
-------
2.2.9.  Meadow Vole (voles)

       Order Rodentia Family Muridae (subfamily Arvicolinae).  New world voles are small,
herbivorous rodents that reside in all areas of Canada and the United States where there is
good grass cover. Their presence is characterized by narrow runways through matted
grasses.  Microtus species are adapted to underground, terrestrial, and sometimes
semiamphibious habitats (Johnson and Johnson, 1982), They are active by day and night,
feeding mainly on shoots, grasses, and bark. Voles are prey for hawks and owls as well
as several mammalian predators such as short-tailed shrews, badgers, and foxes (Johnson
and Johnson, 1982; Eadie, 1952).

Selected species                                               -•..-..-,

       The meadow vole (Microtus pennsylvanicus) makes its burrows  a|ong surface
runways in grasses or other herbaceous vegetation.  It is the most widely distributed small
grazing herbivore in North America and is found  over most of the northern half of the
United States. Meadow voles have been used in bioassays to indicate the presence of
toxins  in their foods (Kendall and Sherwood, 1975, cited in Reich, 1981; Schillinger and
Elliot, 1966).  Although primarily terrestrial, the meadow vole also is a strong  swimmer
(Johnson and Johnson, 1982).

       Body size. The meadow vole measures 8.9 to 13 cm in length (head and body) and
has a 3.6- to 6.6-cm tail. They weigh between 20 and 40 g depending on age, sex, and
location (see table).  Mature males are approximately 20 percent heavier than females
(Boonstra and Rodd, 1983). Meadow voles lose weight during the winter, reaching a low
around February, then regain weight during spring and summer, reaching a high around
August in many populations (see table; Iverson and  Turner, 1974).

       Habitat.  The meadow vole inhabits grassy fields, marshes, and bogs (Getz,
1961 a). Compared with the prairie  vole, the meadow vole prefers fields with more grass,
more cover, and fewer woody plants (Getz, 1985; Zimmerman, 1965). The meadow vole
also tends to inhabit moist to wet habitats, whereas the prairie vole is relatively
uncommon in sites with standing water (Getz, 1985).

       Food habits. Meadow voles consume green succulent vegetation, sedges, seeds,
roots, bark, fungi, insects, and animal  matter (see table).  They are agricultural pests in
some areas, feeding on  pasture, hay, and grain (Johnson and Johnson, 1982; Burt and
Grossenheider, 1980).  At high population  densities, the meadow vole has been known to
girdle trees, which can damage orchards (Byers,  1979, cited in Reich, 1981).  In seasonal
habitats, meadow voles favor green vegetation when it is available and consume other
foods more when green vegetation is less available (Johnson and Johnson,  1982;  Riewe,
1973;  Getz, 1985). Although Zimmerman (1965) found some evidence of food selection,
he found that meadow voles generally ate the most common plants in their habitat.
Meadow voles living on prairies consume more seeds and fewer dicots and  monocots than
voles in a bluegrass habitat (Lindroth and Batzli,  1984). The meadow vole's large  cecum
allows  it to have a high  digestive efficiency of 86 to 90 percent (Golley, 1960).
                                      2-323
Meadow Vole
-------
Coprophagy (eating of feces) has been observed in this species (Ouellete and Heisinger,
1980).

       Temperature regulation and molt.  In winter, Microtus species do not undergo
hibernation or torpor; instead, they are active year round (Didow and Hayward, 1969;
Johnson and Johnson, 1982).  Behaviors that help meadow voles to maintain their body
temperature include the use of burrows, runways, nests, and  snow cover for insulation.
They also can change when they are active; when temperatures exceed 20°C, meadow
voles are most active at night (Getz, 1961b; Johnson and Johnson,  1982).  In winter,
meadow voles increase their brown fat content (a major site of thermoregulatory heat
production).  Mature individuals average 0.5 percent brown fat in summer, increasing to
1.7 percent in early winter; juveniles average 1.0 percent in the summer,  increasing to  2.3
percent in the winter (Didow and Hayward, 1969). Voles undergo three molts: juvenile,
postjuvenile, and adult. The timing varies by species (Johnson and Johnson, 1982). Adult
Arvicolinae also undergo winter and summer rnolts (Johnson and Johnson, 1982).

      Breeding activities and social organization.  Meadow voles are polygynous (McShea,
1989).  Males form a hierarchy in which the most dominant male voles breed (Boonstra
and Rodd, 1983).  Voles produce litters throughout the breeding season, the number of
litters per season increases with decreasing latitude (Johnson and Johnson,  1982).

      Home range and resources. The area encompassed by a meadow vole's home
range depends on season,  habitat, population density, and the age and sex of the animal.
Summer ranges tend to be larger than winter ranges, and ranges in marshes tend to be
larger than ranges in meadows (Getz, 1961c; Reich, 1981).  Home range  size also declines
with increasing population  density (Getz, 196'lc;  Tamarin, 1977a).  Female meadow voles
defend territories against other females, whereas male home ranges are larger and overlap
with home ranges of both sexes (Madison, 1980; Ostfeld et al., 1988; Wolff, 1985).
Meadow voles build runways in grasses and  vegetation at the ground's surface and use
the runways for foraging about 45 percent of the time, depending on weather and other
factors (Gauthier and Bider, 1987).  The meadow vole exhibits daytime activity where
dense cover is available and becomes more crepuscular with less cover (Graham, 1968,
cited in  Reich, 1981).  All Microtus species apparently do some burrowing, excavating
underground nests that are used as nurseries, resting areas, and as shelter from severe
weather (Johnson and Johnson, 1982). Nests are built with the use of dead grass in
patches of dense, live grass; widened spaces, called forms, are used off main runways
(Ambrose, 1973).

      Population density.  Meadow vole population densities  fluctuate widely from season
to season and year to year, sometimes crashing to near zero before recovering in a few
years to densities of several hundred per hectare (Boonstra and Rodd,  1983; Lindroth and
Batzli, 1984; Getz et al., 1987; Myers and Krebs, 1971; Taitt and Krebs,  1985).  Krebs
and Myers (1974) noted population  cycles of 2 to 5 yr, whereas Tamarin (1977b) reported
3- to 4-year population cycles in southeastern Massachusetts. However, Getz et al.
(1987) found no indication of multiannual abundance cycles in their three  habitat study
(i.e., bluegrass, tallgrass prairie, and alfalfa) in east central Illinois. Meadow voles avoid
short-tailed shrews (Fulk, 1972), and the vole population density decreases as the number
of short-tailed shrews in the area increases (Eadie, 1952).
                                      2-324
Meadow Vole
-------
      Population dynamics.  Voles reach sexual maturity usually within several weeks
after birth, with females maturing before males, but still continue to grow for several
months (Johnson and Johnson, 1982).  Innes (1978) reported that litter size is
independent of latitude or elevation. However, summer litters were, on average, 14
percent larger than litters produced during other seasons, and larger females produced
larger litters (Keller and Krebs, 1970). Young from the spring and  early summer litters
reached adult weight in about 12 wk (Brown, 1973). Mortality rates are highest in
postnestling juveniles and young adults and lowest in nestlings (ages 1 to 10 d) (Golley,
1961). Dispersing  meadow voles (predominantly young males) tend to weigh less than
resident meadow voles (Boonstra et al., 1987; Myers and Krebs, 1971; Boonstra and
Rodd, 1983; Brochu et al., 1988).

Similar species (from general references)

      •     The California vole (Microtus californicus) is larger than the meadow vole  (12
            to  14 cm head and body) and is found throughout California and southern
            Oregon.  It inhabits freshwater and saltwater marshy areas, wet meadows,
            and grassy hillsides from the seashore to the mountains and feeds on green
            vegetation.

      •     Townsend's vole (Microtus townsend/i) usually is found near water in moist
            fields, sedges, tules, and meadows (from tidewater to alpine meadows).  Its
            range is limited to extreme northwestern California, western Oregon and
            Washington, and southern British Columbia  (inhabits several islands off the
            coast of Washington and British Columbia).  It is easily distinguished by its
            large size (12 to 16 cm) and black-brown color.

      •     The montane vole (Microtus montanus) (mountain vole) is slightly larger (10
            to  14 cm) than the meadow vole and is found in valleys of  the mountainous
            Great Basin area of the western and northwestern United States.

      •     The long-tailed vole (Microtus longicaudus) (tail 5 to  9 cm)  is slightly larger
            (11 to 14 cm) than the meadow vole. It is found in the western United
            States and Canada to Alaska and lives along streambanks,  in mountain
            meadows, sometimes in dry situations, and in brushy areas during winter. In
            addition to grasses and bark, it feeds on bulbs.  It nests above ground  in
            winter and burrows in summer.

      •     The creeping vole (Microtus  oregoni)  (Oregon vole) (10 to 11 cm)  is an
            inhabitant of western Oregon and Washington and extreme northwest
            California. Seldom above ground, it spends most of  its time burrowing
            through forest floor duff or grass roots. It lives in forests, brush, and grassy
            areas.

      *     The sagebrush vole (Lagurus curtatus) (9.7 to 11 cm) lives  in loose soil and
            arid conditions and feeds on green vegetation, especially sagebrush. It also
            burrows around sagebrush; a vole found living in sagebrush is almost
            certainly this species.
                                      2-325
Meadow Vole
-------
General references

      Burt and Grossenheider (1980); Reich (1981); Johnson and Johnson (1982);
Tamarin (1985).
                                    2-326
Meadow Vole
-------
                                   Meadow Vole (Microtus pennsy/van/cus]


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                                                Meadow Vole  (Mlcrotus pennsylvanicus]
Population
Dynamics
Longevity
Seasonal
Activity
Mating
Dispersal
Age/Sex/
Cond./Seas.

Mean
2-3 mo
Begin
early April

.Peak
Oct. - Nov.
April - June
fall/winter
summer (females)
winter (males)
Range
< 24 mo
End
mid-October

Location/Habitat
NS
NS
. Location
Manitoba, Canada
Michigan (fall-winter peak)
Michigan (spring-summer
peak)
Indiana/grassland
Massachusetts/coastal field
Reference
Beer & MacLeod, 1961
Johnson & Johnson, 1 982
Reference
Mihok, 1984
Getz, 1960
Getz, 1960
Myers & Krebs, 1971
Tamarin, 1977b
Note
No.
9
Mote
No,
15
15

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to
00
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O
 1   Cited in Reich (1981) and Johnson and Johnson (1982).
 2   Cited in Nadeau (1985).
 3   Body weight 35.6 g; temperature not specified; cited in Deavers and Hudson (1981).
 4   Temperature 15 to 25°C; weight 26.2 to 32 g.
 5   Estimated using equation 3-43 (Boddington, 1978) and body weights from Anderson et al. (1984).
 6   Estimated using equation 3-48 (Nagy, 1987) and body weights from Anderson et al. (1984).
 7   Cited in Johnson and Johnson (1982).
 8   Short-day photoperiod = 10 h of light, 14 of dark; long-day photoperiod =  14 h of light, 10 of dark.
 9   Cited in Reich (1981).
10   Estimated using equations 3-17 (Calder and Braun, 1983) and 3-18 and body weights from Anderson et al. (1984).
11   Estimated using equation 3-20 (Stahl, 1967) and body weights from Anderson et al. (1984).
12   Estimated using equation 3-22 (Stahl, 1967) and body weights from Anderson et al. (1984).
13   Cited in Keller (1985).
14   Cited in Johnson and Johnson (1982).
15   Cited in Getz (1961 b).
O_
CD
-------
References (including Appendix)

Ambrose, H. W., III. (1973) An experimental study of some factors affecting the spatial
      and temporal activity of Microtus pennsylvanicus. J. Mammal. 54: 79-100.

Anderson, M.; Prieto, J.; Rauch, J. (1984) Seasonal changes in white and brown adipose
      tissues in Clethrionomys gapperi (red-backed vole) and in Microtus pennsylvanicus
      (meadow vole). Comp. Biochem. Physiol. A Comp. Physiol. 79: 305-310.

Bailey, V. (1924) Breeding, feeding and other life habits of meadow mice (Microtus). J.
      Agric.  Res. 27: 523-526.

Barbehenn, K. R. (1955) A field study of growth in Microtus pennsylvanicus. J. Mammal.
      36: 533-543.

Beer, J.  R.; MacLeod, C. F. (1961) Seasonal reproduction in the meadow vole. J. Mammal.
      42: 483-489.

Benton,  A. H. (1955) Observations on the life history of the northern pine mouse. J.
      Mammal. 36: 52-62.

Boddington, M. J. (1978)  An absolute metabolic scope for activity. J. Theor. Biol. 75:
      443.449.                             •

Boonstra, R.;  Rodd, F. H. (1983) Regulation of breeding density in Microtus
      pennsylvanicus. J.  Anim. Ecol. 52: 757-780.

Boonstra, R.;  Krebs, C. J.; Gaines, M. S.; et al. (1987) Natal philopatry and breeding
      systems in voles (Microtus spp.). J. Anim. Ecol. 56: 655-673.

Bradley, S. R. (1976) Temperature regulation and bioenergetics of some microtine rodents
      [Ph.D.  dissertation]. Ithaca, NY: Cornell University.

Brochu,  L.; Caron, L.; Bergeron, J.-M. (1988) Diet quality and body condition of dispersing
      and resident voles (Microtus pennsylvanicus). J. Mammal. 69: 704-710.

Brooks,  R. J.; Webster, A. B. (1984)  Relationships of seasonal  change to changes in age
      structure and body size in Microtus pennsylvanicus. Carnegie Mus. Nat. Hist. Spec.
      Publ. No. 10; pp. 275-284.

Brown, E. B.,  III. (1973) Changes in patterns of seasonal growth of Microtus
      pennsylvanicus. Ecology 54: 1103-1110.

Burt, W. H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
      north of Mexico. Boston, MA:  Houghton Mifflin Co.

Byers, R. E. (1979) Meadow vole control  using anticoagulant baits. Hort. Sci. 14: 44-45.
                                      2-331
Meadow Vole
-------
Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

Corthum,  D. W., Jr. (1967) Reproduction and duration of placental scars in the prairie vole
       and the eastern vole. J. Mammal. 48: 287-292.

Dark, J.; Zucker, I. (1986) Photoperiodic regulation of body mass and fat reserves in the
       meadow vole. Physiol.  Behav. 38: 851-854.

Dark, J.; Zucker, I.; Wade, G.  N. (1983) Photoperiodic regulation of body mass, food
       intake, and reproduction in meadow voles. Am. J. Physiol. 245: R334-R338.

Deavers, D. R.; Hudson, J. W. (1981) Temperature regulation in two rodents
       (Clethrionomys gapperi and Peromyscus leucopus) and a shrew (Blarina brevicauda)
       inhabiting the same environment. Physiol. Zool. 54: 94-108.

Didow, L.  A.; Hayward, J. S. (1969) Seasonal variations in the mass and composition of
       brown adipose tissue in the meadow vole, Microtus pennsylvanicus. Can. J. Zool.
       47: 547-555.

Dieterich,  R. A.; Preston, D. J. (1977) The meadow vole (Microtus pennsylvanicus) as a
       laboratory animal. Lab.  Anim. Sci. 27: 494-499.

Douglass,  R. J. (1976) Spatial interactions and microhabitat selections of two locally
       sympatric voles, Microtus montanus and Microtus pennsylvanicus. Ecology 57:
       346-352.

Dueser, R. D.; Wilson, M.; Rose, R. K. (1981) Attributes of dispersing meadow voles in
       open-grid populations. Acta Theriol. 26: 139-162.

Eadie, R. W. (1952) Shrew predation and vole populations on a localized area. J. Mammal.
       33: 185-189.

Ernst, C. H. (1968) Kidney efficiencies of three Pennsylvania mice. Trans. Kentucky Acad.
       Sci. 29: 21-24.

Fulk, G. W. (1972) The effect  of shrews on the space utilization of voles. J.  Mammal.  53:
      461-478.

Gauthier, R.; Bider, J. R. (1987) The effects of weather on runway use by rodents. Can. J.
      Zool. 65: 2035-2038.

Getz, L. L.'(1960) A population study of the vole, Microtus pennsylvanicus. Am. Midi.  Nat.
       64: 392-405.

Getz, L. L. (1961 a) Factors influencing the local distribution oi Microtus and  Synaptomys
      in southern Michigan. Ecology 42: 110-119.
                                      2-332
Meadow Vole
-------
Getz, L. L. (1961b) Responses of small mammals to live-trap and weather conditions. Am.
      Midi. Nat. 66: 160-170.

Getz, L. L. (1961c) Home ranges, territoriality, and  movement of the meadow vole. J.
      Mammal. 42: 24-36.

Getz, L: L. (1985) Habitat. In: Tamarin, R. H., ed. Biology of new world Microtus. Spec.
      Publ. Amer. Soc. Mammal. 8; pp. 286-309.

Getz, L. L.; Hofmann, J. E.; Klatt, B. J.; et al. (1987) Fourteen years of population
      fluctuations of Microtus ochrogaster and M.  pennsylvanicus in east central Illinois.
      Can. J. Zool. 65: 1317-1325.

Coin, O. B. (1943) A study of individual variation in Microtus pennsylvanicus
      pennsylvanicus. J. Mammal. 24: 212-223.

Golley, F. B. (1960) Anatomy of the digestive tract of Microtus. J.  Mammal. 41: 89-99.

Golley, F. B. (1961) Interaction of natality, mortality and movement during one annual
      cycle in a Microtus population. Am. Midi. Nat. 66: 152-159.

Graham, W. J. (1968) Daily activity patterns in the meadow vole, Microtus pennsylvanicus
      [Ph.D. dissertation]. Ann Arbor, Ml: University of Michigan.

Hamilton, W. J., Jr. (1937) Growth and life span of the field mouse. Am. Nat. 71:
      500-507.

Hamilton, W. J., Jr. (1941) Reproduction of the field mouse (Microtus pennsylvanicus).
      Cornell Univ. Agric. Exp. Sta. Mem. 237: 3-23.

Harris, V. T.  (1953) Ecological relationships of meadow voles and rice rats in tidal
      marshes. J. Mammal. 34: 479-487.
Innes, D. G. (1978) A reexamination of litter sizes in some North American microtines.
      Can. J. Zool.  56: 1488-1496.

Innes, D. G.; Millar, J. S. (1979) Growth of Clethrionomys gapperi and Microtus
      pennsylvanicus in captivity. Growth 43: 208-217.

Innes, D. G.; Millar, J. S. (1981) Body weight, litter size, and energetics of reproduction in
      Clethrionomys gapperi and Microtus pennsylvanicus. Can. J. Zool. 59: 785-789.

Iverson, S. L.; Turner, B. N. (1974) Winter weight dynamics in Microtus pennsylvanicus.
      Ecology 5,5: 1030-1041.

Iverson, S. L.; Turner, B. N. (1976) Small mammal radioecology:  natural reproductive
      patterns of seven species. Pinawa, Manitoba: Whiteshell Nuclear Research
      Establishment; AECL-5393; 53 pp.
                                      2-333
Meadow Vole
-------
Johnson, M. L.; Johnson, S. (1982) Voles (Microtus species). In: Chapman, J. A.;
       Feldhamer, G. A., eds. Wild mammals of North America; pp. 326-353.

Keller, B. L. (1985) Reproductive patterns. In: Tamarin, R. H., ed. Biology of new world
       Microtus. Spec. Publ. Amer. Soc. Mammal. 8; pp. 812-844.

Keller, B. L.; Krebs, C. J. (1970) Microtus population biology. III. Reproductive changes in
       fluctuating populations of M. ochrogaster and M. pennsylvanicus in southern
       Indiana, 1965-1967. Ecol. Monogr. 40: 263-294.

Kendall, W. A.; Sherwood, R. T. (1975) Palatability of leaves of tall fescue and reed
       canary-grass and some of their alkaloids to meadow voles. Agron. J.  67: 667-671.

Kenney, A. M.; Evans, R. L.; Dewsbury, D. A. (1977) Postimplantation pregnancy
       disruption in Microtus orchogaster, Microtus pennsylvanicus, and Peromyscus
       maniculatis. J. Reprod. Pert. 49: 365-367.

Kott, E.; Robinson, W. L. (1963) Seasonal variation in litter size of the meadow vole in
       southern Ontario. J. Mammal. 44:  467-470.

Krebs, C. J. (1977) Competition between Microtus pennsylvanicus and Microtus
       ochragaster. Am.  Midi. Nat. 97: 42-49.

Krebs, C. J.; Myers, J. H. (1974) Population cycles in small mammals. Adv.  Ecol. Res. 8:
       267-399.

Lee, C.; Horvath, D. J. (1969) Management of the meadow vole (Microtus
      pennsylvanicus). Lab. Anim. Care 19: 88-91.

Lindroth, R. L.; Batzli, G. O. (1984) Food habits of the meadow vole (Microtus
      pennsylvanicus) in bluegrass and prairie habitats. J. Mammal. 65:  600-606.

Lomolino, M. V. (1984) Immigrant selection, predation, and the distribution of Microtus
      pennsylvanicus and Blarina brevicauda on islands. Am. Nat. 123: 468-483.

Madison, D. M. (1978) Movement indicators of reproductive events among female
      meadow voles as-revealed by radio-telemetry. J. Mammal. 59:  835-843.

Madison, D. M. (1980) Space use and social structure in meadow voles, Microtus
      pennsylvanicus. Behav. Ecol. Sociobiol.  7: 65-71.

McShea, W. J. (1989) Reproductive synchrony and home range size in a territorial
      microtine. Oikos 56: 182-186.

McShea, W. J.; Madison, D. M. (1989) Measurements of reproductive traints (litter size,
      pup growth, and birth interval) in a field population of meadow voles. J.  Mammal.
      70: 132-141.
                                      2-334
Meadow Vole
-------
Mihok, S. (1984) Life history profiles of boreal meadow voles (Microtus pennsylvanicus).
      Carnegie Mus. Nat. Hist. Spec. Publ. No. 10; pp. 91-102.

Mihok, S.; Brian, T. N.; Iverson, S. L. (1985) The characterization of vole population
      dynamics. Ecol. Monogr. 55: 399-420.

Millar, J. S. (1987) Energy reserves in breeding small rodents. Symp. Zool. Soc. Lond. 57:
      231-240.

Morrison, P.; Dieterich, R.; Preston, D.  (1977) Body growth in sixteen rodent species and
      subspecies maintained in laboratory colonies. Physiol. Zool. 50: 294-310.

Morrison, P. R. (1948) Oxygen consumption in several small wild  mammals. J. Cell.  Comp.
      Physiol. 31: 69-96.

Myers, J. H.; Krebs, C. J. (1971) Genetic, behavioral, and reproductive attributes of
      dispersing field voles Microtus pennsylvanicus and Michrotus ochrogaster. Ecol.
      Monogr. 41: 53-78.

Nadeau, J. H. (1985) Ontogeny. In: Tamarin, R. H., ed. Biology of new world Microtus.
      Spec. Publ. Amer. Soc. Mammal. 8; pp. 254-285.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
      birds. Ecol. Monogr. 57: 111-128.

Ognev, S. I. (1950) Mammals of the U.S.S.R. and adjacent countries. Translated from
      Russian by: Israel Program for Scientific Translations (1964), Jerusalem; 626 pp.

Ostfeld, R. S.; Pugh, S. R.; Seamon, J. O.; et al. (1988) Space use and reproductive
      success in a population of  meadow voles. J. Anim. Ecol. 57: 385-394.

Ouellette, D. E.; Heisinger, J. F. (1980) Reingestion of feces by Microtus pennsylvanicus.
      J. Mammal. 61: 366-368.

Pearson, O. P. (1947) The rate of metabolism of some small mammals. Ecology 29:
      127-145.                                                    .

Reich, L. M. (1981) Microtus pennsylvanicus. Mammalian species. The American Society
      of Mammalogists; Species No. 159; 8 pp.

Riewe, R. R. (1973) Food habits of insular meadow voles, Microtus pennsylvanicus
      terraenovae (Rodentia: Cricetidae), in Notre Dame Bay, Newfoundland. Can.
      Field-Nat. 87: 5-13.

Schillinger, J. A., Jr.; Elliott, F. C. (1966) Bioassays for nutritive value of individual alfalfa
      plants. Q. Bull. Michigan Agric. Exp. Sta. 48: 580-590.
                                      2-335
Meadow Vole
-------
Schwartz, B.; Mihok, S. (1983) Body composition of meadow voles contrasted during
       annual and multiannual population fluctuations (abstract). Bull. Ecol. Soc. Am. 64:
       102.

Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
       453-460.

Taitt, M. J.; Krebs, C. J. (1985) Population dynamics and cycles. In: Tamarin, R. H., ed.
       Biology of new world Microtus. Spec. Publ. Amer. Soc. Mammal. 8; pp. 567-620.

Tamarin, R. H. (1977a) Dispersal in island and mainland voles. Ecology 58: 1044-1054.

Tamarin, R. H. (1977b) Demography of the beach vole (Microtus breweri) and the meadow
       vole (M. pennsy/vanfcus) in southern Massachusetts. Ecology 58: 1310-1321.

Tamarin, R. H. (1984) Body mass as a criterion of dispersal in voles: a critique. J.
       Mammal. 65: 691-692.

Tamarin, R. H., ed. (1985) Biology of new world Microtus. Spec. Publ. Amer. Soc.
       Mammal. 8.

Townsend, M. T. (1935) Studies on some of the small animals of central New York.
       Roosevelt Wildl. Ann. 4: 1-20.

Van Vleck, D. B. (1969) Standardization of Microtus home range calculation. J. Mammal.
       50: 69-30.

Wiegert, R. (1961) Respiratory energy loss and activity patterns in the meadow vole,
       Microtus pennsylvanicus pennsylvanicus. Ecology 42:  245-253.

Wolff,  J. 0. (1985) Behavior. In: Tamarin, R. H., ed. Biology of New World Microtus,
       Spec. Publ. Am. Soc. Mammal. 8; pp. 340-372.

Wunder, B. A.  (1985) Energetics and thermoregulation. In: Tamarin, R. H., ed. Biology of
       new world Microtus. Spec. Publ. Amer. Soc. Mammal. 8; pp. 812-844.

Zimmerman, E. G. (1965) A comparison of habitat and food of two species of Microtus. J.
       Mammal. 46:  605-612.
                                     2-336
Meadow Vole
-------
2.2.10.  Muskrat (water rats and muskrats)

      Order Rodentia Family Muridae.  Water rats and muskrats are the most aquatic of
this family of rodents, with most of their lives spent in or near bogs, marshes, lakes or
streams. These two rodents feed mostly on aquatic vegetation.  Only one species exists
in each genus (Burt and Grossenheider, 1980).

Selected species

      The muskrat (Ondatra zibethicus) is indigenous and common throughout  most of
the United States (except in the extreme southeast, central Texas, and most of California)
and Canada (except in the extreme north) (Burt and Grossenheider, 1980). Muskrats feed
primarily on aquatic plants.  They are prey for hawks, minks, otters, raccoons, owls, red
fox, dogs, snapping turtles,  and water snakes (Bednarik, 1956; Errington, 1939a; Wilson,
1985), and are more vulnerable to predation during times of drought when low water
levels leave their dens or lodges more exposed (Errington,  1939a). Many vertebrates use
muskrat homes for shelter or to find food (Kiviat, 1978).  The muskrat is one of the most
valuable fur animals in North America (Dozier, 1953; Perry, 1982). Including the
Newfoundland muskrat, formerly Ondatra obscurus, 16 recognized subspecies of O.
zibethicus exist in North America (Perry, 1982).  Of these, O. z. zibethicus (eastern United
States, southeastern Canada), O. z. osoyoosensis (Rocky Mountains, southwestern
Canada), and O. z. rfvalfcius (southern Louisiana, coasts of Mississippi, western Alabama,
and eastern Texas) are most often studied.

      Body size.  The muskrat measures 25 to 36 cm (head and body) with  a 20- to 25-
cm tail (Burt and Grossenheider, 1980), and adult weights can range from 0.5 kg to over 2
kg (see Appendix).  Willner et al. (1980) reported no sexual dimorphism, whereas Dozier
(1950),  Parker and Maxwell (1984), and others (see Appendix) reported that males are
slightly heavier than females.  Muskrats tend to be larger and heavier in northern latitudes
(Perry, 1982), although the smallest muskrats are found in  Idaho (Reeves and Williams,
1956).  Fat levels in adult males increase from spring through fall, and subsequently
decrease from winter to spring (Schacher and  Pelton,  1975).  In nonpregnant females, fat
levels decrease from winter through summer; in pregnant females, body fat increases from
spring to summer (Schacher and Pelton, 1975).

      Habitat.  Muskrats inhabit saltwater and brackish marshes and freshwater creeks,
streams, lakes, marshes, and ponds (Dozier, 1953; Johnson, 1925; Kiviat, 1978; O'Neil,
1949).  Muskrats that live along the banks or shores of waterways generally  excavate
dens in the banks, whereas muskrats living  in  ponds with ample plant material construct
lodges (Johnson, 1925; Perry, 1982).  When available, bank dens seem preferred over
constructed lodges (Johnson, 1925).

      Food habits. Muskrats are primarily herbivorous, but some populations are more
omnivorous (Dozier, 1953; Errington, 1939b). Muskrats usually feed at night, diving to
gnaw on aquatic vegetation  growing near their houses (Dozier, 1953; Johnson,  1925;
Perry, 1982). The roots and basal portions of aquatic plants make up most of the
muskrat's diet, although shoots, bulbs, tubers, stems, and leaves  also are eaten (Dozier,
                                      2-337
Muskrat
-------
 1950, 1953; Willner et al., 1980; Svihla and Svihla, 1931).  Marsh grasses and sedges
 (Svihla and Svihla, 1931) and cattails (Johnson, 1925; Willner et al., 1975) seem to be
 important muskrat foods; in Maryland, green algae is also important (Willner et al., 1975).
 Although muskrats forage near their dens or lodges, they show preferences for some plant
 species (e.g., cattails, bulrushes) over others (Bellrose, 1950). Muskrats are a major
 consumer of marsh grasses (Kiviat, 1978). They also dig for food on lake and pond
 bottoms (Bailey, 1937; Dozier, 1953; Hanson et al., 1989).  Among the animals that
 muskrats consume are crayfish, fish, frogs, turtles, and young birds (Errington, 1939b;
 Johnson, 1925; Willner et al., 1980).  Molluscs are an important component of the diet of
      pspujatlons (Cerway st al., 1iSii Nevis and Odom,  1i89; Pamrtalaa, 1i8i; Willnar
 et al., 1980),  Young muskrats feed more on bank vegetation than do adults (Warwick,
 1940, cited in Perry, 1982).

       Temperature regulation and molt. Active year-round (Kiviat, 1978), muskrats
 usually begin their annual molt in the summer, with fur reaching its minimum density
 during August (Willner et al., 1980). Muskrats use their dens or lodges to insulate
 themselves from summer heat and winter cold (O'Neil, 1949; Willner et al., 1980). During
 extreme cold, muskrats may freeze to death if they are unable to plug their den entrances
 {Errington, 1939a).

      Breeding activities and social organization. Muskrats are solitary or form breeding
 pairs that remain in a home range exclusive of other pairs (Errington, 1963; Proulx and
 Gilbert,  1983). They are territorial, particularly during peak reproductive activity, with
 their houses usually spaced at least 8 m apart (Johnson, 1925; Sather, 1958; Trippensee,
 1953).  In southern parts of their range, muskrats breed throughout the year, with late fall
 and  early spring peaks {O'Neil, 1949; Svihla and Svihla, 1931; Wilson, 1955).  In  northern
 latitudes, breeding occurs only in the spring and  summer, with first litters born in late April
 er early May (Mathiak, 1366; Beer, 1950; Errington, 1937b; Gashwiler, 1950).  Errington
 (1937b) found that postpartum estrus occurs in the muskrat, and suggested that the
 period between litters is about 30 d. Neonates are almost hairless but  by age 2 wk are
 covered with fur and able to swim (Errington, 1963).

      Home range and resources.  Muskrats have  relatively small home ranges that vary
 in configuration depending on the aquatic habitat (Perry, 1982; Willner et al., 1980).  They
 build two different types of houses:  a main dwelling and a feeding house (feeder) that is
 smaller than the main house (Dozier, 1953; Johnson, 1925; Sather, 1958). The feeder
 provides protection from the elements and predators when feeding in prime foraging areas,
 as well as access to oxygen during frozen conditions.  The house provides a dry nest and
 stable temperatures.  Muskrats usually forage within 5 to 10 m of a house (Willner et al.,
 1980). Using radiotelemetry, MacArthur (1978) found  muskrats within 15 m of their
 primary dwelling 50 percent of the time and  only rarely more than 150  m.  Mathiak (1966)
 reported other experiments showing that muskrats remain close to their dwellings.

      In the winter, muskrats build pushups, which are cavities formed in 30 to 46 cm
 high piles of vegetation pushed up through holes in the ice  of a marsh (Perry, 1982).
 Muskrats use pushups as resting  places during frozen conditions to minimize their
 exposure to  cold water (Fuller, 1951).  In the summer, muskrats often change the use of
their home range in response to water levels; during droughts they will  move if the area

                                       2-338                               Muskrat
-------
around the house dries up, which can lead to intense aggression in the more favorable
habitat (Errington, 1939a).  Usually only a minor proportion of drought-evicted muskrats
can find new homes (Errington, 1939a). In the winter, droughts can result in severe
mortality (Errington,  1937a).

      Population density. Bellrose and Brown (1941, cited in Perry, 1982) concluded that
cattail communities support more muskrat houses than other plant types in the Illinois
River valley.  Cattail communities also support high densities  of muskrats in other areas
(Errington,  1963; Dozier, 1950). In pond and lake habitats, shoreline length is a more
important factor than overall habitat area in determining muskrat density (Glass,  1952,
cited in Perry, 1982). Many investigators estimate muskrat densities by counting the
number of houses or push-ups and multiplying by a factor ranging from  2.8 (Lay, 1945,
cited in Boutin and Birkenholz, 1987) to 5.0 (Dozier et al., 1948), although this method is
questionable  (Boutin and Birkenholz, 1987).

      Population dynamics. The age at first breeding varies  but usually occurs during the
first spring  after birth (Errington, 1963; Perry, 1982). Southern populations produce more
litters but with fewer pups in each than do northern populations (Boyce, 1977; Perry,
1982; see table). Muskrats in lower quality habitats have both smaller litter sizes and
fewer litters than muskrats in better quality areas (Neal, 1968). They disperse in the
spring to establish breeding territories or to move into uninhabited areas (Errington, 1963).
Muskrat population cycles of 5, 6, and  10 y have been reported (Butler, 1962; Willner et
al., 1980);  Perry (1982) summarized several studies that reported cycles ranging from 10
to 14 yr or more. Butler (1962) found that muskrats follow a 10-yr cycle in most parts of
Canada.

Similar species (from general references)
                                                                       •3 .
      •      The Florida water rat (Neofiber alleni) is much smaller (20 to 22 cm)  than
             the muskrat, with a rounded tail (11 to 17 cm)  to distinguish it further. The
             Florida water rat inhabits  bogs, marshes, weedy lake borders, and savanna
             streams, though its range is limited to Florida.  It feeds on aquatic plants and
             crayfish.

General references

      Boutin and Birkenholz (1987);  Burt and Grossenheider  (1980); Perry (1982); Willner
etal. (1980).
                                       2-339
Muskrat
-------
                                          Muskrat (Ondatra zibethicus]
Factors
Body Weight

'
I :
<\..^
Pup Growth
Rate tg/d}
s
Metabolic
' (10.,/ka-d) ' > !
Metabolic Rate
(kcal/kg-d)

Age/Sex/
Cond./Seas.
B M winter
B F winter
B M winter
B F winter
B M winter
B F winter
A M spring
A F spring
neonate
neonate
at weaning
at weaning
0 to 30 d
weaning to 1st
fall; M
F
floating
swimming
floating
swimming
A M basal
A F basal
A M free-living
A F free-living
Mean
1,480
1,350
1,326 ± 45.9 SE
1,221 ± 54.2 SE
1,180
1,090
909
837
21.3
200
5.4
7.5
7.1
21 ± 7.9 SE
38
101
182
71.6
213
216
Range or
(95% Cl of mean)
1,400-1,520
1,300-1,400

730- 1,550
770- 1,450
16-28
20-25
112- 184
4.3-5.6


(90 - 505}
(91 -513}
Location
New York
e Tennessee
Nebraska, nc Kansas
Idaho
Iowa
New York
Iowa
New Brunswick, Canada
Iowa/marsh
New Brunswick, Canada/
marsh
lab (water temperature
25°C)
lab (water temperature
25°C)

Reference
Dozier, 1950
Schacher & Pelton, 1978
Sather, 1958
Reeves & Williams, 1 956
Errington, 1939b
Dean, 1957
Errington, 1939b
Parker & Maxwell, 1984
Errington, 1939b
Parker & Maxwell, 1 980
Fish, 1982
Fish, 1982
estimated
estimated
Note
No.







1
2
Ni

00
co
7T

3
-------
                                        Muskrat (Ondatra zibethicus]

Factors
Food
Ingestion
Rate (g/g-d)
Water
Ingestion
Rate (g/g-d)
Inhalation
Rate (m3/d)
Surface Area
(cm2)
Dietary
Composition
cattail
bulrush
burreed
waterstarwort
pondweed
arrowhead
corn
cattail
rush
millet
algae
grass
cord grass
seeds
other
Age/Sex/
CondJSeas-
greens
greens & corn

AM
AF

AM
AF
AM
AF

Spring
















Mean
0.34
0.26

0.97
0.98

0.61
0.57
1,221
1,159

Summer







59
17
8
5
4
4
2
3
Range or
(95% Cl of mean)











Fall
















Winter
25-50
10-25
5-10
2- 5
2- 5
2- 5
2-5









Location
Louisiana, captive (rivalicius)









Location/Habitat
(measure)
ne United States/NS

(rough approximation of %
diet; stomach contents)



Somerset Co., MD/brackish
marsh

(% of diet; stomach
contents)




Reference
Svihla &Svihla, 1931


estimated


estimated

estimated


Reference
Martin et al., 1951






Willner et al., 1975







Note
No.
3


4


5

6

Note
No.















K)
I

to
c
w
Q>
-------
                                          Muskrat (Ondatra zibethicus)
Dietary
Composition
green algae
3-square rush
switch grass
soft rush
water willow
grass:
other'
Population
Dynamics
Home Range
Size (ha) >

\
"• <•
Population
Density :
*•
,1
*j i
4 \

*-

"•' , t :
' ^',
Utter
Size

*

Spring








Summer
77
8
8
4
2
1
<1
Age/Sex/
Cond./Seas,
summer
early summer
late summer
BM
BF
A B spring
A B summer
A B fall
BM
BM
BB

B B summer

B B summer






Fait







,
Mean
0.17 ± 0.0078 SD
0.048 ± 0.024 SD
0.11 ± 0.084 SD
0.17
0.17
9.3 ± 1.3 SE/ha
2.6 ± 0.3 SE/ha
6.3 ± 1.1 SE/ha
18.7/ha
2.1 /ha
28.3/ha

23/km river

48/km river

3.46
4.65
7.1 ± 0.2 SE
7.3

Winter







-'
Range










1 -74






3-6

1 - 12
Location/Habitat
(measure)
Montgomery Co., MD/
freshwater

(% of diet; stomach
contents)


•'.- ,
Location/Habitat
Ontario, Canada/marsh
Ontario, Canada/bay

Iowa/marsh

ne Iowa/open water riverine


Virginia/fringe marsh
Virginia/marsh
Louisiana/Sc/rpus olneyi
marsh
Pennsylvania/riverine (little
vegetation)
Massachusetts/wetland,
river (sedges)
Louisiana/marsh
Virginia/marsh
Iowa/riverine
Wisconsin/marsh

Reference
Willner et al., 1975







Refefence %
Proulx & Gilbert, 1983
Proulx & Gilbert, 1 983

Neal, 1968

Clay & Clark, 1985


Halbrook, 1990

O'Neil, 1949

Brooks & Dodge, 1986

Brooks & Dodge, 1986

O'Neil, 1949
Halbrook, 1990
Clay & Clark, 1 985
Mathiak, 1966
Note
No.







Note
No,




















ro

CO
^
10
(0
7T

3
-------
                                         Muskrat (Ondatra zibethicus]
Population \
Dynamics ' ;
Utters/Year \
Days
Gestation
Age at
Weaning
Age at
Sexual
Maturity
Annual
Mortality
- Rates
(%}
Longevity
Season?!
Activity
Mating
Parturition
Dispersal
Age/Sex/
Cond,/Seas»


B

adult
juvenile
juvenile

Begin
year-round
late April
early May
late May

Mean
1.7
2.1
5-6
29-30
28 d
6 mo
87
90
67

Peak
winter
spring-summer
June
early July
fall
spring
Range - , ;
< 7-8
> 22 - 23
21 -30d


< 5 yr
End •',

late August
late August
mid-August

Location/Habitat
Idaho/marsh
Maine/wildlife refuge - NS
Louisiana/NS
nw Iowa/marsh
Maine/wildlife refuge - NS
Iowa/marsh
Louisiana/marsh
ne Iowa/riverine
Missouri/NS
Ontario, Canada/marsh
',
Location
southern latitudes
northern latitudes
Iowa
Maine
Idaho
Ontario, Canada
Iowa
Reference
Reeves & Williams, 1956
Gashwiler, 1950
O'Neil, 1949
Errington, 1937b
Gashwiler, 1950
Errington, 1939b
Svihla & Svihla, 1931
Clay & Clark, 1985
Schwartz & Schwartz, 1 959
Proulx & Gilbert, 1983
Reference
O'Neil, 1949; Svihla & Svihla,
1931
Chamberlain, 1951;
Gashwiler, 1950; Reeves &
Williams, 1956
Errington, 1937b
Gashwiler, 1950
Reeves & Williams, 1956
McDonnell & Gilbert, 1981
Errington, 1963
Note
No.




7

Note
No,



to
4^
to
M
/T

3
-------
N)
00
                                                       Muskrat (Ondatra zibethicus]

      1   Estimated using equation 3-43 (Boddington, 1978} and body weights from Sather (1958).
      2   Estimated using equation 3-46 {Nagy, 1987) and body weights from Sather (1958).
      3   Based on wet weight of food; greens included Panicum hemitomum, P. virgatum, and Spartina patens.
      4   Estimated using equation 3-17 (Calder and Braun, 1983) and body weights from Sather (1958).
      5   Estimated using equation 3-20 (Stahl, 1967) and body weights from Sather (1958).
      6   Estimated using equation 3-22 (Stahl, 1967) and body weights from Sather (1958).
      7   Cited in Perry (1982.)
co
-------
References (including Appendix)

Arthur, S. C. (1931) The fur animals of Louisiana. Louis. Dept. Conserv. Bull. 18 (revised).

Asdell, S. A. (1964) Patterns of mammalian reproduction. Compstock Publishing Co,

Bailey, V. (1937) The Maryland muskrat marshes. J. Mammal. 18: 350-354.

Bednarik, K. (1956) The muskrat in Ohio Lake Erie marshes. Columbus, OH: Ohio Division
      of Wildlife Department of Natural Resources; 67 pp.

Beer, J. R. (1950) The reproductive cycle of the muskrat in Wisconsin.  J. Wildl. Manage.
       14: 151-156.

Bellrose, F. C. (1950) The relationship of muskrat populations to various marsh and
      aquatic plants. J. Wildl. Manage. 14: 299-315.

Bellrose, F. C.; Brown, L. G. (1941) The effect of fluctuating water levels on the muskrat
      population of the Illinois  River valley. J. Wildl. Manage. 5: 206-212.

Beshears, W. W., Jr. (1951) Muskrats in relation to farm ponds. Proc. Annu. Conf.
      Southeast. Assoc. Game and Fish Comm. 5: 1-8.

Beshears, W. W.; Haugen, A. O. (1953) Muskrats in farm ponds. J. Wildl. Manage. 17:
      540-456.

Boddington, M.  J. (1978) An absolute metabolic scope for activity. J. Theor. Biol. 75:
      443-449.

Boutin, S.; Birkenholz,  D. E. (1987) Muskrat and round-tailed muskrat. In: Novak, M.;
      Baker, J. A.; Obbarel, M. E.; et al., eds. Wild furbearer management and
      conservation; pp. 316-324.

Boyce, M. S. (1977) Life histories in variable environments: applications to geographic
      variation  in the muskrat (Ondatra zibethicus) [Ph.D. dissertation]. New Haven, CT:
      Yale University.

Brooks, R. P.; Dodge, W. E.  (1986) Estimation of habitat quality and summer population
      density for muskrats on a watershed basis. J. Wildl. Manage. 50: 269-273.

Burt, W. H.; Grossenheider, R. P. (1980) A field guide to the mammals of North America
      north of Mexico. Boston, MA: Houghton Mifflin Co.

Butler,  L. (1940) A quantitative study of muskrat food. Can. Field-Nat. 54: 37-40.

Butler,  L. (1962) Periodicities in the annual muskrat population figures for the province of
      Saskatchewan.  Can. J. Zool. 40: 1277-1286.
                                      2-345
Muskrat
-------
 Calder, W. A.; Braun, E. J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol. 244: R601-R606.

 Chamberlain, J. L. (1951) The life history and management of the muskrat on Great
       Meadows Refuge [master's thesis]. Amherst, MA: University of Massachusetts.

 Clay, R. T.; Clark, W. R. (1985) Demography of muskrats in the upper Mississippi River. J.
       Wildl.  Manage. 49: 883-890.

 Convey, L. E.; Hanson, J. M.; MacKay, W. C. (1989) Size-selective predation on  unionid
       clams by muskrats. J. Wildl. Manage. 53: 654-657.

 Dean, F. C. (1957) Age criteria and kit growth of central New York muskrats [Ph.D.
       dissertation]. NY: State University of New York, College of Forestry.

 Dibblee, R. L. (1971) Reproduction, productivity and food habits of muskrats on Prince
       Edward Island [master's thesis]. Wolfville, Nova Scotia, Canada: Acadia University.

 Dilworth, T. G. (1966) The life history and ecology of the muskrat. Ondatra zibethicus
       zibethicus, under severe water level fluctuations [master's thesis]. Fredericton, New
       Brunswick, Canada: University of New Brunswick.

 Donohoe,  R. W. (1961) Muskrat production in areas of controlled and uncontrolled
       water-level units [Ph.D. dissertation]. Columbus, OH: Ohio State University.

 Dorney, R. S.; Rusch, A. J. (1953) Muskrat growth and litter production. Wise. Conserv.
       Dept. Tech. Wildl. Bull. 8; 32 pp.

 Dozier, H. L. (1948) Estimating muskrat populations by house counts. Trans. North Amer.
       Wildl. Conf. 13: 372-392.

 Dozier, H. L. (1950) Muskrat trapping on the Montezuma National Wildlife Refuge, New
       York, 1943-1948. J. Wildl. Manage. 14: 403-412.

 Dozier, H. L. (1953) Muskrat production and management. U.S. Fish Wildl. Serv.  Circ. 18;
       42  pp.

Dozier, H.  L.; Markley, M. H.; Llewellyn, L. M. (1948) Muskrat investigations on the
       Blackwater National Wildife Refuge, Maryland, 1941-1945. J. Wildl. Manage. 12:
       177-190.

Erickson, H. R. (1963) Reproduction, growth, and movement of muskrats inhabiting small
      water areas in New York state. N.Y. Fish Game J. 10: 90-117.

Errington,  P. L. (1937a) Habitat requirements of stream-dwelling muskrats. Trans. North
      Amer. Wildl. Conf. 2: 411-416.
                                      2-346
Muskrat
-------
Errington, P. L. (1937b) The breeding season of the muskrat in northwest Iowa. J.
       Mammal.  18: 333-337.

Errington, P. L. (1939a) Reactions of muskrat populations to drought. Ecology 20:
       168-186.

Errington, P. L. (1939b) Observations on young  muskrats in Iowa. J. Mammal. 20:
       465-478.

Errington, P. L. (1948) Environmental control for increasing muskrat production. Trans.
       North Amer. Wildl. Nat. Resour. Conf. 13: 596-609.

Errington, P. L. (1963) Muskrat populations. Ames, IA: Iowa State University Press.

Fish, F. E. (1982) Aerobic energetics of surface  swimming in the muskrat Ondatra
       zibethicus. Physiol. Zool. 55: 180-189.

Fish, F. E. (1983) Metabolic effects of swimming velocity and water temperature  in the
       muskrat (Ondatra zibethicus). Comp. Biochem.'Physiol. A Comp. Physiol. 75:
       397-400.

Fuller,  W. A. (1951) Measurements and weights of northern muskrats. J.  Mammal. 32:
       360-362.

Gashwiler, J. S. (1948) Maine muskrat investigations. Maine Dept. Inland Fish. Game Bull.;
       38 pp.

Gashwiler, J. S. (1950) A study of the reproductive capacity of Maine muskrats. J.
       Mammal. 31: 180-185.

Glass,  B. P. (1952) Factors affecting the survival of the plains muskrat Ondatra zibethica
       cinnamomina in Oklahoma. J. Wildl. Manage.  16: 484-491.

Godin,  A. J. (1977) Wild mammals of New England.  Baltimore, MD: Johns Hopkins
       University Press; 304 pp.

Halbrook, R. S. (1990) Muskrat populations in Virginia's Elizabeth River: Influence of
       environmental contaminants [Ph.D. dissertation].  Blacksburg, VA: Virginia
       Polytechnic Institute and State University.

Hall, E. R. (1981) The mammals of North America. 2nd ed. New York, NY: John Wiley and
       Sons; 181 pp.

Hanson, J. M.; Mackay, W. C.; Prepas, E. E. (1989) Effect of size-selective predation by
       muskrats (Ondatra zibethicus) on a population of unionid  clams (Anodonta grandis
       Simpson/ana). J. Anim. Ecol.  58: 15-28.
                                      2-347
Muskrat
-------
Harris, V. T. (1952) Muskrats on tidal marshes of Dorchester County. Maryland Board Nat.
       Resour., Chesapeake Bio. Lab., Dept. Res.  Education Publ. 91; 36 pp.

Johnson,  C. E. (1925) The muskrat in New York:  its natural history and economics.
       Roosevelt Wildl. Bull. 3: 205-321.

Kiviat, E. (1978) The muskrat's role in the marsh ecosystem: a qualitative synthesis
       (abstract). Bull. Ecol. Soc. Am. 59: 124.

Lay, D. W. (1945) Muskrat investigations in Texas. J. Wildl. Manage. 9: 56-76.

MacArthur, R. A. (1978) Winter movements and home range of the muskrat. Can.
       Field-Nat. 92: 345-349.

MacArthur, R. A.; Krause, R. E. (1989) Energy requirements of freely diving muskrats
       (Ondatra zibethicus). Can. J. Zool. 67: 2194-2200.

Martin, A. C.; Zim, H. S.; Nelson, A. L. (1951) American wildlife and plants. New York:
       McGraw-Hill.

Mathiak, H. A. (1966) Muskrat population studies at Horicon Marsh.  Tech. Bull. Wisconsin
       Conserv. Dept. 36: 1-56.

McDonnell, J. A.; Gilbert, F. F. (1981) The responses of muskrats (Ondatra zibethicus) to
       water level fluctuations at Luther Marsh, Ontario. In: Chapman, J.  A.; Pursley, D.,
       eds. Proceedings worldwide furbearer conference: v. 1. August 1980; Frostburg,
       MD; pp. 1027-1040.

McLeod, J. A.; Bondar, G. F. (1952) Studies on the biology of the muskrat in Manitoba.
       Part I. Oestrus cycle and breeding season. Can. J. Zool. 30: 243-253.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

Neal, T. J. (1968) A comparison of two muskrat populations. Iowa State J. Sci. 43:
       193-210.

Neves, R.  J.; Odom, M. C. (1989) Muskrat predation on endangered freshwater mussels in
      Virginia. J. Wildl. Manage. 53: 934-941.

O'Neil, T.  (1949) The muskrat in the Louisiana coastal marshes (A study of the ecological,
      geological, biological, tidal, and climatic factors governing the  production and
      management of the muskrat industry in Louisiana).  New Orleans, LA: Louis. Dept
      Wildl. Fish., Fed. Aid  Sect. Fish and Game Div.;  152 pp.

O'Neil, T.; Linscombe, G.  (1976) The fur animals,  the alligator, and the fur industry in
      Louisiana. New Orleans, LA: Louisiana Wildl. and Fish. Comm. Wildl. Education Bull.
      106; 66 pp.
                                      2-348
Muskrat
-------
Olsen, P. F. (1959) Muskrat breeding biology at Delta, Manitoba. J. Wildl. Manage. 23:
       40-53.

Parker, G. R.; Maxwell, J. W. (1980) Characteristics of a population of muskrats (Ondatra
       zibethicus zibethicus) in New Brunswick. Can. Field-Nat. 94; 1-8.

Parker, G. R.; Maxwell, J. W. (1984) An evaluation of spring and autumn trapping seasons
       for muskrats. Ondatra zibethicus, in eastern Canada. Can. Field-Nat. 98: 293-304.

Parmalee, P. W. (1989) Muskrat predation on softshell turtles. J. Tenn. Acad. Sci. 64:
       225-227.
Perry, H. R., Jr. (1982) Muskrats. In: Chapman, J. A.; Feldhamer, G. A., eds. Wild
      mammals of North America: biology, management and economics. Baltimore, MD:
      Johns Hopkins University Press; pp. 282-325.

Proulx, G.; Gilbert, F. F. (1983) The ecology of the muskrat Ondatra zibethicus at Luther
      Marsh, Ontario. Can. Field-Nat. 97: 377-390.

Reeves, H. M.; Williams, R. M. (1956) Reproduction, size, and mortality in Rocky Mountain
      muskrat. J. Mammal. 37: 494-500.

Sather, J. H. (1958) Biology of the Great Plains muskrat in Nebraska. Wildl. Monogr. 2. 35
      PP-

Schacher, W. H.; Pelton, M. R. (1975) Productivity of niuskrats in east Tennessee. Proc.
      Annu. Conf. Southeast. Assoc. Game and  Fish Comm. 29: 594-608.

Schacher, W. H.; Pelton, M. R. (1978) Sex ratios, morphology and condition parameters of
      muskrats in east Tennessee. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl.
      Agencies 30: 660-666.

Schwartz, C. W.; Schwartz, E. R. (1959) The wild mammals of Missouri. Columbia, MO:
      University of Missouri Press and Missouri Conservation Commission.

Seamans, R. (1941) Lake Champlain fur survey. Vermont Fish Game Bull.  3-4.

Smith, F. R.  (1938) Muskrat investigations in Dorchester County, Maryland, 1930-34.  U.S.
      Dept. Agr. Circ. 474; 24 pp.

Smith, H. R.; Jordan, P. A. (1976). An exploited population of muskrats with unusual
      biomass, productivity, and body size. Conn. Dept. Environ. Prot. Rep. Invest. No.  7;
      16pp.

Smith, H. R.; Sloan,  R. J.; Walton, G. S. (1981) .Some management implications  between
      harvest rate and population resiliency of the muskrat (Ondatra zibethicus). In:
      Chapman, J. A.;  Pursley, D., eds. Proceedings worldwide furbearer conference: v.
      1. August 1980; Frostburg, MD; pp. 425-442.
                                      2-349
Muskrat
-------
Stahl, W. R. (1967) Scaling of respiratory variables in mammals. J. Appl. Physiol. 22:
      453-460.

Stevens, W. E. (1953) The northwestern muskrat of the Mackenzie Delta, Northwest
      Territories, 1947-48. Can. Wildl. Sen/., Wildl. Manage. Bull., Ser. 8; 55 pp.

Stewart, R. W.; Bider, J. R. (1974) Reproduction and survival of ditch-dwelling muskrats in
      southern Quebec. Can. Field-Nat. 88: 420-436.

Svihla, A. (1931) The field biologist's report. In: Arthur, S. C., compil. The fur animals of
      Louisiana. New Orleans, LA: Louisiana Dept. Conserv., Bull. 18 (rev.);  439 pp.

Svihla, A.; Svihla, R. D.  (1931) The Louisiana muskrat. J. Mammal. 12: 12-28.

Trippensee, R. E. (1953) Muskrats. In: Wildlife management: fur bearers, waterfowl, and
      fish: v. 2. New York, NY: McGraw-Hill; pp. 126-139.

Walker, E. P.; et al. (1975) In: Paradise, J. L., ed. Mammals of the world:  v. 2. 3rd ed.
      Baltimore, MD: Johns Hopkins University Press;  pp. 645-1500.

Warwick, T. (1940) A contribution to the ecology of the muskrat (Ondatra zibethica) in the
      British Isles. Proc. Zool. Soc. London, Ser. A 110: 165-201.

Willner, G. R.; Chapman, J. A.; Goldsberry, J. R. (1975) A study and review of muskrat
      food habits with special reference to Maryland. Maryland Wildl. Adm. Publ. Wildl.
      Ecol.  1; 25 pp.

Willner, G. R.; Feldhamer, G. A.; Zucker, E. E.; et al. (1980) Ondatra zibethicus.
      Mammalian species. No. 141. Amer. Soc. Mammal.; 8 pp.

Wilson,  K. A. (1954) Litter production of coastal North  Carolina muskrats. Proc. Annu.
      Conf. Southeast.  Assoc. Game and Fish Comm.  8: 13-19.

Wilson,  K. A. (1955) A compendium of the principal data on muskrat reproduction.
      Raleigh, NC: North Carolina Wildl. Resour. Comm., Game Div.; Fed. Aid Wildl.
      Restoration Proj. W-6-R.

Wilson,  K. A. (1956) Color, sex ratios, and weights of North Carolina muskrats. Raleigh,
      NC: North Carolina Wildl. Resour. Comm.; Fed. Aid in Wildl. Restoration Proj.
      W-6-R-15; 20 pp.

Wilson,  K. A. (1985) The role of mink and otter as muskrat predators in northeastern
      North Carolina. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies  18:
      199-207.
                                       2-350
Muskrat
-------
2.2.11.   Eastern Cottontail (rabbits)

       Order Laaomoroha Family Leooridae. Rabbits and hares are medium-sized grazing
herbivores found throughout North America.  Most species are nocturnal and crepuscular.
Many are social, travelling in small groups. Rabbits are prey for large carnivorous birds and
mammals.  Most species also are important game animals.

Selected species

       The eastern cottontail (Sylvi/agus floridanus) is the most widely distributed of the
medium-sized rabbits (Chapman et al., 1982). It is found over most of the eastern half of
the United States and  southern Canada and has been widely introduced into the western
United States (Chapman et al., 1980).  North of Mexico, 14 subspecies are recognized
(Chapman et al., 1982). The eastern cottontail feeds on green vegetation in summer and
bark and twigs in winter. The cottontail is active from early evening to late morning and is
preyed on by owls, hawks, and carnivorous mammals (Palmer and Fowler,  1975;  Burt and
Grossenheider, 1980).

       Body size. The eastern cottontail measures 35 to 43 cm in length and weighs 0.7
to 1.8 kg (Lord, 1963; see table) with females slightly larger than the males (Nowak and
Paradiso, 1983; see table). Cottontail body weight varies seasonally, increasing during
spring and summer and declining during winter in some areas; different patterns occur in
other areas (Chapman et al., 1982; Pelton and Jenkins, 1970).

       Habitat.  The eastern cottontail is unique to the genus because of the large variety
of habitats that it occupies; including glades and woodlands, deserts, swamps, prairies,
hardwood forests, rain forests, and boreal forests (Nowak and Paradiso, 1983). Open
grassy areas generally are used for foraging at night, whereas dense, heavy cover typically
is used for shelter during the day (Chapman et al., 1982).  During winter, cottontails rely
more on woody vegetation for adequate cover (Allen, 1984).

       Food habits.  During the growing season, cottontails eat herbaceous plants (e.g.,
grasses, clover, timoth, alfalfa). During the winter in areas where herbaceous plants are
not available, they consume woody vines, shrubs, and trees (e.g., birch, maple, apple)
(Chapman et al., 1982). In Ohio, bluegrass and other grasses made up a large portion of
the eastern cottontail's diet,  except during snow cover (Chapman et al., 1982). During
the winter in Connecticut,  the principle diet of eastern and New England cottontails
consists of bark and twigs, shrubs and vines, berries, and willow (Dalke and Sime, 1941).
In agricultural areas, corn, soybeans, wheat, and other crops may comprise a large portion
of their diet (Chapman et al., 1982). Younger rabbits prefer the more succulent weedy
forbs that contain more digestible energy and protein (Chapman et al., 1982).  Coprophagy
(ingestion of feces) has been reported in S. floridanus (Kirkpatrick, 1956).

       Temperature regulation and molt. Eastern cottontails do not undergo hibernation  or
torpor; they are active all year, showing peaks of daily activity at dawn and dusk
(Chapman et al., 1980). Adults molt gradually over about 9 mo of the year, with two
peak molting periods (Spinner, 1940).  In Connecticut, the spring peak occurs in May and
                                       2-351
Eastern Cottontail
-------
June and the fall peak occurs in September and October (Spinner, 1940).  In Texas, spring
and fall molts peak in April and October, respectively (Bothnia and Teer, 1982).

       Breeding activities and social organization.  Breeding activity  begins later at higher
elevations and at higher latitudes (Conaway et al., 1974), by January in Alabama and by
late March in southern Wisconsin (Chapman et al., 1980).  Several studies have shown
that continued harsh winter weather may delay the onset of the breeding season
(Hamilton, 1940; Conaway and Wight, 1962; Wight and Conaway,  1961).  Breeding
seasons are longer in the southern states (Lord, 1960). The onset of breeding varies
between different populations and within the same population from  year to year (Chapman
et al., 1980). Males may fight to establish dominance hierarchies for access to females
(Chapman and Ceballos, 1990; Nowak and Paradise, 1983).  Lagomorphs in general are
induced ovulators, and cottontails in particular demonstrate a synchronized breeding
season, with conception immediately after the birth of a litter (Chapman et al., 1982).

       Home range and resources.  Cottontails are found in a variety of habitats that
contain weedy forbs and perennial grasses; they prefer thick, short, woody perennials that
provide escape  sites (Chapman and Ceballos, 1990).  Cottontails usually do not defend
territories; the home ranges of different age and sex groups tend to  overlap, especially in
fall and winter when they look for areas offering a combination of food and cover
(Chapman et al., 1980, 1982). Home ranges are smaller when thick vegetation provides
abundant food and larger in habitats with less food (Chapman et al., 1982).  Home ranges
also are smaller during severe winter weather than at other times (Chapman et al., 1982).
During the breeding season, females build elaborate nests within slanting holes in the
ground where they give birth to their altricial (helpless) young.  These burrows are
vulnerable to flooding (Chapman et al., 1982). The size of male home ranges during the
breeding season can be more than double that in winter (Nowak and Paradise, 1983; Trent
and Rongstad, 1974).

      Population density.  Population density depends on the availability of resources
(e.g., food, cover) in an area, and tends to cycle over a period of several years (Chapman
and Ceballos, 1990). Usual densities range from 1 to 5 animals per hectare, although
values as high as 14 per hectare have been reported  (Chapman and  Ceballos,  1990;
Chapman et al., 1982).

      Population dynamics.  The eastern cottontail exhibits the highest fecundity of the
genus; they  often produce 25 to 35 young per year (Chapman and Ceballos,  1990).
Gestation lasts approximately 1 mo (Chapman et al., 1982). Females may produce five to
seven litters per year, and juvenile breeding has been reported (Chapman et al., 1982).
The first and last litters of the year are usually the smallest (Chapman et al., 1977).
Cottontails have more litters with fewer young each in the southern  states (Lord, 1960).
Young leave the nest when about age 14 to 16 d, although they may not be fully weaned
until a few weeks later (Ecke, 1955).  Female cottontails are capable of breeding by age 5
mo, and males as early as 3 mo (Bothma and Teer, 1977).  Adult mortality is high, from
approximately 65 to 75 percent per year in some places (Eberhardt et al., 1963).  Juvenile
mortality is even higher,  between 85 and 90 percent in the same areas {Eberhardt et al.,
1963).
                                      2-352
Eastern Cottontail
-------
Similar species (from general references)

      •      The mountain cottontail (Sy/vflagus nuttallii) (Nuttall's cottontail) is smaller
             (30 to 36 cm in length  and 0.7 to 1.3 kg) than the eastern cottontail. The
             only cottontail through  most of its range - the western United States -  it
             lives in thickets and sagebrush, around loose rocks, cliffs, and mountains. In
             the southwest, it lives in forests.

      «      The New England cottontail (Sylvilagus transitiona/is) is similar in size to the
             eastern cottontail and inhabits brushy areas, open forests, and mountain
             terrain  in New England, extending down the Appalachians into the southern
             United  States. In recent years, it has disappeared throughout much of the
             northeastern United States, apparently because of competition with S.
             floridanus.

      •      The desert cottontail (Sylvilagus audubonii) (Audubon's cottontail) (30 to  38
             cm in length and 0.6 to 1.2 kg) is common in valleys in the arid southwest,
             although its range extends south to Mexico and north into the Rocky
             Mountains.  It inhabits open plains, foothills, and low valleys and also areas
             of  grass, sagebrush, pinyons and junipers.  It is most active from late
             afternoon throughout the night.

      •      The brush rabbit (Sylvilagus bachmani) (28 to 33  cm; 0.6 to 0.8 kg) is
             usually seen around thick cover and rarely uses a  burrow. It feeds on green
             vegetation,  including lawns when in suburban areas. The species is found
             along the Pacific coast from the Columbia River in the north to the tip of
             Baja California in the south.

      «      The marsh rabbit (Sylvilagus palustris) is similar in size  to the eastern
             cottontail and ranges from  southeastern North Carolina to Florida. As the
             name implies, it inhabits swamps and hummocks, as well as wet
             bottomlands.  Mostly nocturnal, it feeds on marsh vegetation, rhizomes, and
             bulbs.

      •      The swamp rabbit (Sylvilagus aquaticus] is similar in size to the eastern
             cottontail and is a good swimmer found in swamps, marshes, and wet
             bottomlands.  It ranges primarily in the south, from Texas eastward.  It nests
             beneath logs or in the bases of stumps, rarely using a burrow and may harm
             crops near swamps.

      •      The pygmy rabbit (Sylvilagus idahoensis) is markedly smaller (22 to 28 cm;
             0.2 to 0.5 kg) than the  eastern cottontail, lacks a conspicuous tail, and is
             considered by some to be a distinct genus (Brachylagus). Its range is limited
             to  several western states, where it inhabits clumps of tall sagebrush. It is
             mostly  nocturnal.

      •      The white-tailed jackrabbit  (Lepus townsendii), larger (46 to 56 cm; 2.2 to
             4.5 kg) than the eastern cottontail, is limited to the northern United States
                                       2-353
Eastern Cottontail
-------
             west of the Great Lakes, into southern Canada.  It inhabits open, grassy, or
             sagebrush plains and may damage hay crops and small trees.

      *      The black-tailed jackrabbit (Lepus californicus) (43 to 53 cm; 1.3 to 3.1  kg)
             is the most common jackrabbit in the grasslands and open areas of the
             western United States, where it inhabits open  prairies and deserts with little
             vegetation. It is mostly nocturnal.

      •      The snowshoe hare (Lepus americanus) (33 to 46 cm; 0.9 to 1.8 kg)
             inhabits swamps, forests, and thickets in the northern United States and
             Canada. During summer, it feeds on succulent vegetation and during winter
             on twigs, buds, and bark. Its home range is about 4 ha, but populations
             fluctuate widely.

General references

      Allen (1984); Burt and Grossenheider (1980); Chapman et al. (1980, 1982); Lord
(1963); Nowak and Paradise (1983); and  Palmer and Fowler (1975).
                                      2-354
Eastern Cottontail
-------
                                      Eastern Cottontail (Sylvilagus floridanus}

Factors
Body Weight
M \











'




Growth Rate
fg/d)



Metabolic Rate \
flccai/kg-d) ;

Food tngestion :
ftate fg/g-d)
Age/Sex/
Cond./Seas.
AM
AF
A B winter
A B spring
A B summer
AB fall

A B not breed.
A B not breed.
A B not breed.
AB
neonate
age:
10d
30 d
50 d
101 d
149 d
day 0 - 30
day 11 -30
day 31 - 50
day 51 - 100
day 101 - 150
A B basal

A B free-living



Mean
1,134 ± 122 SD
1 ,244 ± 1 65 SD
1,176
1,286
1,197
1,255

1,229 ± 113SD
1,313 ± 141 SD
1,132 ± 136 SD
1,231 ± 164
42.2

58
159
401
822
1,106
3.2
3.7
8.8
11.3
6.4
71

203


Range or
(95% a of mean}
801 - 1,411
842-1,533
793- 1,671
898-1,630
910-1,608
886- 1,669

1,093- 1,461
986- 1,671
793- 1,579
700- 1,800
36.0 - 49.0













(77 - 535}



Location (subspecies)
w Maryland, West Virginia

Georgia
all areas combined


Georgia
mountain
coastal
Piedmont
Illinois
Alabama

Illinois




Illinois










Reference
Chapman & Morgan, 1973

Pelton & Jenkins, 1 970




Pelton & Jenkins, 1 970


Lord, 1963
Hill, 1972b

Lord, 1963




Lord, 1963




estimated

estimated


Note
No.























1

2
3

ro

w
01
01
rn
Q)
CD
^


o
o
Q)
-------
                                        Eastern Cottontail (Sylvilagus floridanus}

Factors
Water
Ingestion
Rate [g/g-dj
Inhalation
Rate (ma/d)
Surface Area
fern2)
Age/Sex/
Cond./Seas.
AB


AB

AB

Dietary
Composition
trees
shrubs & vines
herbs
grasses, sedges,
rushes
crops
woody plants
forbs
grasses
•- ,
Bluegrass
orchard grass
timothy grass
Nodding wild rye
Canada goldenrod
red clover
unidentified


Mean
0.097


0.63

1,254


Spring
13
4
44

26
13
17
19
64

34
4
5
5
-
-
52


Summer
2
2
23

56
17
23
30
47

34
1
12
11
-
-
42

Range or
(95% CI of mean)








Fall
7
27
34

30
2
20
46
34

25
-
7
8
3
6
51


Winter
39
40
5

6
10
100



32
1
1
4
-
-
62


Location (subspecies)







Location (subspecies)/
Habitat(measure)
Connecticut (mat/arus)/
various

(% frequence of occurrence;
observations of feeding on
plants)
Maryland/forest

(% frequency of occurrence;
stomach contents)
Ohio (mearnsi)/NS

(% frequency of occurrence;
scats)

(in winter, woody tissues
predominated in the
unidentified category)

Reference
estimated


estimated

estimated


Reference
Dalke & Sime, 1 941
(85% for mallarus
subspecies,
remainder for similar
species S. transitiona/is)

Spencer & Chapman, 1986



Dusi, 1952







Note
No.
4


5

6

Note
No.


















CO

Ol

05
m
CD
CO
rt-
CD
-t



O

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r+
i-t-
O

r-f
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-------
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 to
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cn o>
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CD CD
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k>
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xt
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CM
00
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CD
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£
a.
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a
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                                       2-357
Eastern Cottontail
-------
                                                Eastern Cottontail (Sylvitagus floridanus)
Population
Dynamics
Age at
Weaning
Age at
Sexual
Maturity
Annual
Mortality.
• Rates (%)
Longevity
Seasonal
Activity
Mating
Parturition
Molt fall
spring
Age/Sex/
Cond./Seas.

F
M
BB
BB
B
Begin
mid-March
year-round
April
August
September
February
March
Mean
20 - 25 days

80
65 ± 7 SD
1.25
Peak
January - April
May - July
October
Sept. - Oct.
April
May - June
Range

3-6 months
3-6 months


End
mid-September
August
December
November
July
August
Location (subspecfesJ/Habitat
lllinois/NS
s Texas/grassland
Missouri/NS
sw Wisconsin/farm
Illinois/sanctuary
Kentucky/NS
Location
Connecticut
s Texas
we New York
s Texas
Connecticut
s Texas
Connecticut
Reference
Ecke, 1955
Lord, 1961, Negus, 1959b
Conaway & Wight, 1963
Trent & Rongstad, 1 974
Lord, 1963
Bruna, 1952
Reference
Dalke, 1942
Bothma & Teer, 1977
Hamilton, 1940
Bothma & Teer, 1982
Spinner, 1940
Bothma & Teer, 1 982
"Spinner, 1940
Note
No.

8

9
Note
No,
9


N)
to
CJ1
00
m
0)
ft
CD
-*

O
o
0>
 1   Estimated using equation 3-43 (Boddington, 1978) and body weights from Lord (1963).
 2   Estimated using equation 3-46 (Nagy, 1987) and body weights from Lord (1963).
 3   See Chapters 3 and 4 for approaches to estimating food ingestion rates.
 4   Estimated using equation 3-17 (Calder and Braun, 1983) and body weights from Lord (1963).
 5   Estimated using equation 3-20 (Stahl, 1967) and body weights from Lord (1963).
 6   Estimated using equation 3-22 (Stahl, 1967) and body weights from Lord (1963).
 7   Summary of several studies.
 8   Cited in Conaway and Wight (1963).
 9   Cited in Chapman et al. (1980).
10   Cited in Chapman et al. (1982).
-------
References (including Appendix)
                                                         •
Allen, D. L. (1938) Breeding of the cottontail rabbit in southern Michigan. Am. Midi. Nat.
       20: 464-469.

Allen, D. L. (1939) Michigan cottontails in winter. J. Wildl. Manage. 3: 307-322.

Allen, A. W. (1984) Habitat suitability index models: Eastern cottontail. U.S. Fish Wildl.
       Serv. Biol. Rep. 82(10.66); 23 pp.

Althoff, D. P.; Storm, G. L. (1989) Daytime spatial characteristics of cottontail rabbits in
       central Pennsylvania. J. Mammal. 70: 820-824.

Bailey, J. A.; Siglin, R. J. (1966) Some food preferences of young cottontails. J. Mammal.
       47: 129-130.

Barkalow, F. S., Jr. (1962) Latitude related to reproduction in the cottontail rabbit. J.
       Wildl. Manage.  26: 32-37.

Beule,  J. D. (1940) Cottontail  nesting-study in Pennsylvania. Trans. North Am. Wildl. Nat.
       Resour. Conf. 5: 320-328.

Bittner, S. L.; Chapman, J. A.  (1981) Reproductive and physiological cycles in an island
       population of Sylvilagus floridanus.  In: Myers,  K. and Maclnnes, C. D., eds.
       Proceedings world lagomorph conference; August 1979; Guelph, Ontario. Guelph,
       Ontario, Canada:  University of Guelph; pp. 182-203.

Boddington,  M. J. (1978) An absolute metabolic scope for activity.  J. Theor. Biol. 75:
       443-449.

Bothma, J. P.; Teer, J. G. (1977) Reproduction and productivity in south Texas cottontail
       rabbits. Mammalia 41:  253-281.

Bothma, J. P.; Teer, J. G. (1982) Moulting in the cottontail rabbit in south Texas.
       Mammalia 46: 241-245.

Bruna,  J. F. (1952) Kentucky rabbit investigations. Fed. Aid Proj. 26-R. Kentucky; 83 pp.

Burt, W. H.;  Grossenheider, R. P. (1980) A field guide to the mammals of North America
       north of Mexico. Boston, MA: Houghton Mifflin Co.

Calder, W. A.; Braun, E.  J. (1983) Scaling of osmotic regulation in mammals and birds.
       Am. J. Physiol.  244: R601-R606.
                                      2-359
Eastern Cottontail
-------
Chapman, J. A.; Ceballos, G. (1990) Chapter 5: the cottontails. In: Chapman, J. A.; Flux,
       J. E., eds. Rabbits, hares and pikas; status survey and conservation action plan.
       International Union for Conservation of Nature and  Natural Resources in
       collaboration with World Wide Fund for Nature. Oxford, UK: Information Press.

Chapman, J. A.; Morgan, R. P., II. (1973) Systematic status of the cottontail complex in
       western Maryland and nearby West Virginia. Wildl.  Monogr. 36: 1-54.

Chapman, J. A.; Harman, A. L; Samuel,  D. E. (1977) Reproductive and physiological
       cycles in the cottontail complex in western Maryland and  nearby West Virginia.
       Wildl. Monogr.  56: 1-73.

Chapman, J. A.; Hockman, J. G.; Edwards, W. R. (1982) Cottontails. In: Chapman, J. A.;
       Feldhammer, G. A., eds. Wild mammals of North America. Baltimore, MD: Johns
       Hopkins University Press; pp. 83-123.

Chapman, J. A.; Hockman, J. G.; Ojeda,  M.  M. (1980) Sylvilagus floridanus. American
       Society of Mammalogists;  Mammalian Species No.  136; 8 pp.

Conaway, C. H.; Wight,  H. M. (1962) Onset of reproductive season and first pregnancy of
       the season in cottontails.  J. Wildl. Manage. 26: 278-290.

Conaway, C. H.; Wight,  H. M. (1963) Age at sexual maturity of young male cottontails. J.
       Mammal. 44: 426-427.

Conaway, C. H.; Wight,  H. M.; Sadler, K. C.  (1963) Annual production by a cottontail
       population. J. Wildl. Manage. 27:  171-175.

Conaway, K.; Sadler, C.; Hazelwood, D. H. (1974) Geographic variation in litter size and
       onset of breeding  in cottontails. J. Wildl. Manage. 38:  473-481.

Crunden, C. W.; Hendrickson, G.  0. (1955) Evaluations of techniques estimating a Mearns
       cottontail population. Proc. Iowa Acad. Sci. 62: 498-501.

Dalke, P. D. (1942) The  cottontail rabbits in Connecticut. Bull. Connecticut Geol. Nat. Hist.
       Surv. 65: 1-97.

Dalke, P. D.; Sime, P. R.  (1941) Food habits  of the eastern and new England cottontails. J.
       Wildl. Manage.  5: 216-228.

de Poorter, M.; van der Loo, W. (1981) Report on the breeding and behavior of the
       volcano rabbit at the Antwerp Zoo. In: Myers, K.; Maclnnes, C. D., eds.
       Proceedings of the world lagomorph conference;  August 1979; Guelph, Ontario.
       Guelph, Ontario, Canada: University of Guelph; pp.  956-972.
                                      2-360
Eastern Cottontail
-------
Dixon, K. R.; Chapman, J. A.; Rongstad, O. J.; et al. (1981) A comparison of home range
       size in Sylvilagus floridanus and S. bachmani. In: Myers, K.; Maclnnes, C. D., eds.
       Proceedings of the world lagomorph conference; August 1979; Guelph, Ontario.
       Guelph, Ontario, Canada: University of Guelph; pp. 541-548.

Dusi, J. L. (1952) The food  habits of several populations of cottontail rabbits in Ohio. J.
       Wildl. Manage. 16: 180-186.

Eberhardt, L.; Peterle, T. J.; Schofield, R. (1963) Problems in a rabbit population study.
       Wildlife Society Wildlife Monographs No. 10, Michigan  Department of Conservation
       and Ohio State University; 51 pp.

Ecke, D. H. (1955) The reproductive cycle of the Mearns cottontail in Illinois. Am. Midi.
       Nat. 54: 294-311.

Edwards, W. R.; Havera, S.  P.; Labisky, R. F.; et al. (1981) The abundance of cottontails
       in relation to agricultural land use in Illinois (U.S.A.) 1956-1978, with comments on
       mechanism of regulation. In: Myers, K.; Maclnnes, C. D.,  eds. Proceedings of the
       world lagomorph conference; August  1979; Guelph, Ontario. Canada, Guelph,
       Ontario: University of Guelph; pp. 761-789.

Eisenberg, J. F. (1981) The  mammalian radiations; an analysis of trends in evolution,
       adaptation, and behavior. Chicago, IL: University of Chicago Press.

Evans, R. D.; et al. (1965) Regional comparisons of cottontail  reproduction in Missouri.
       Amer. Midland Nat. 74: 176-184.

Gerstell, R. (1937) Management of the cottontail rabbit in Pennsylvania. Pa.  Game News;
       May.

Hamilton, W. J., Jr. (1940)  Breeding habits of the cottontail rabbit in New York state. J.
       Mammal. 21: 8-11.

Haugen, A. O.  (1942) Life history studies of  the cottontail rabbit in southwestern
       Michigan. Am. Midi.  Nat. 28: 204-244.

Heard, L. P. (1963) Notes on cottontail rabbit studies in Mississippi. Proc. Annu. Conf.
       Southeast.  Assoc.  Game and Fish Comm. 17: 85-92.

Hendrickson, G. O. (1943) Gestation period in Mearns cottontail. J. Mammal. 24: 273.

Hill, E.  P.,  HI. (1972a) The cottontail rabbit in Alabama. Auburn Univ., Agric Exp. Stn. Bull.
       440; 103 pp.

Hill, E.  P.,  III. (1972b) An  evaluation of several body measurements for determining age in
       live juvenile cottontails. Proc. Annu. Conf. Southeast. Assoc. Game and Fish
       Comm. 25: 269-281.
                                      2-361
Eastern Cottontail
-------
Hill, E. P., III. (1972c) Litter size in Alabama cottontails as influenced by soil fertility. J.
       Wildl. Manage. 36: 1199-1209.

Hinds, D. S. (1973) Acclimation of thermoregulatton in the desert cottontail, Sylvilagus
       audubonii. J. Mammal. 54: 708-728.

Janes, D. W. (1959) Home range and movements of the eastern cottontail in Kansas.
       Univ. Kansas Publ., Mus. Nat. Hist. 10: 553-572.

Jurewicz, R. L.; Gary, J. R.; Rongstad, O. J. (1981) Spatial relationships of breeding
       female cottontail rabbits in southwestern Wisconsin. In: Myers,  K.; Maclnnes, C.
       D., eds. Proceedings of the world lagomorph conference; August ^979; Guelph,
       Ontario. Guelph, Ontario, Canada: University of Guelph; pp. 295-309.

Kirkpatrick, C. M. (1956) Coprophagy in the cottontail. J. Mammal. 37: 300.

Leite, E. A. (1965) Relation of habitat structure to cottontail rabbit production, survival and
       harvest rates. Job Prog. Rep., Ohio J.A.P.R. Proj. W-103-R-8, Job 12; 12 pp.

Lord,  R. D., Jr. (1960) Litter size and latitude in North American mammals. Am. Midi. Nat.
       64: 488-499.

Lord,  R. D., Jr. (1961) Magnitudes of reproduction in cottontail rabbits. J. Wildl.  Manage.
       25: 28-33.

Lord,  R. D., Jr. (1963) The cottontail rabbit in Illinois. Tech. Bull. Illinois Dept. Conserv. 3:
       1-94.

Lord,  R. D., Jr.; Casteel, D. A. (1960) Importance of food to cottontail  winter mortality.
       Trans. North Am. Wildl. Conf. 25: 267-274.

Marsden, H. M.;  Conaway, C. H. (1963) Behavior and the reproductive cycle in the
       cottontail. J. Wildl. Manage. 27:  161-170.

Martin, A. C.; Zim, H. S.; Nelson, A. L. (1951) American wildlife and plants. New York,
       NY: McGraw-Hill Book  Company, Inc.

Nagy, K. A. (1987) Field metabolic rate and food requirement scaling in mammals and
       birds. Ecol. Monogr. 57: 111-128.

Negus, N. C. (1959a)  Pelage stages  in the cottontail rabbit. J. Mammal. 39:  246-252.

Negus, N. C. (1959b)  Breeding of subadult cottontail rabbits in Ohio. J. Wildl. Manage. 23:
       451-452.

Nowak, R. M.; Paradiso, J. L.  (1983) Walker's mammals of the world, v. 3, 4th ed.
       Baltimore, MD: Johns Hopkins University Press.
                                      2-362
Eastern Cottontail
-------
Palmer, E. L.; Fowler, H. S. (1975) Fieldbook of natural history. New York, NY:
       McGraw-Hill Book Co,

Pelton, M: R.; Jenkins, J. H. (1970) Weights and measurements of Georgia cottontails and
       an ecological principle.  Proc. Annu. Conf. Southeast. Assoc.  Game and Fish Comm.
       24: 268-277.

Pelton, M. R.; Jenkins, J. H. (1971) Productivity of Georgia cottontails. Proc. Annu. Conf.
       Southeast. Assoc. Game and Fish Comm. 25: 261-268.

Pelton, M. R.; Provost, E. E. (1972) Onset of breeding  and  breeding  synchrony by Georgia
       cottontails. J. Wild!. Manage. 36: 544-549.

Peterson, R. L. (1966) The mammals of eastern Canada. Toronto, Canada: Oxford
       University Press.

Pils, C. M.; Martin, M. A. (1978) Population dynamics, predator-prey relationships and
       management of the red foxes in Wisconsin. Wise. Dept. Nat. Resour.; Tech. Bull.
       105; 56 pp.

Prouty, J.  (1937) Cottontails of Massachusetts  [master's thesis]. MA: Massachusetts
       State College.

Rongstad, O. J. (1966) Biology of penned cottontail rabbits. J. Wildl. Manage. 30:
       312-319.

Sandt, J. !_.; McKee, R. M. (1978) Upland wildlife  investigations. Unpublished Federal Aid
       Performance Report (Maryland); W-47-7; 4 pp.

Schierbaum, D. (1967) Job completion report, evaluation of cottontail rabbit productivity.
       Albany, NY: Pittman-Robertson Proj. W-84-R-12; 21 pp.

Seton, E. T. (1929) Lives of game animals. Garden City, NY: Doubleday, Doran and Co.,
      ' Inc.

Sheffer, D. E. (1957) Cottontail rabbit propagation in small breeding pens. J.  Wildl.
       Manage. 21:  90.

Spencer, R. K.; Chapman, J. A. (1986) Seasonal feeding habits of New England and
       eastern cottontails. Proc. Penn. Acad. Sci. 60: 157-160.

Spinner, G. P. (1940) Molting characteristics in the eastern cottontail rabbits. J. Mammal.
       21:429-434.

Stahl, W. R.  (1967) Scaling of respiratory variables in mammals. J. Appl.  Physiol. 22:
       453-460.
                                      2-363
Eastern Cottontail
-------
Trent, T. T.; Rongstad, O. S. (1974) Home range and survival of cottontail rabbits in
      southwestern Wisconsin. J. Wildl. Manage. 38: 459-472.

Trethewey, D. E.; Verts, B. J. (1971) Reproduction in eastern cottontail rabbits in western
      Oregon. Am. Midi. Nat. 86: 463-476.

Wainright, L. C. (1969) A literature review on cottontail reproduction. Colo. Div.  Game,
      Fish Parks, Spec. Rep. No. 19; 24 pp.

Wight, H. M.; Conaway, C. H. (1961) Weather influences on the onset of breeding in
      Missouri cottontails. J. Wildl.  Manage. 25: 87-89.
                                      2-364
Eastern Cottontail
-------
2.3.   REPTILES AND AMPHIBIANS

      Table 2-3 summarizes the species of reptiles and amphibians included in this
section.  For range maps, refer to the general references identified in the individual species
profiles.  The remainder of this section is organized by species in the order presented in
Table 2-3.  The availability of information  in the published literature varies substantially
among species, which is reflected in the profiles.  The measures used to describe body
length are included in each species profile. Body weight is reported as fresh wet weight
(including the shell for turtles), unless otherwise noted.

      Unlike birds and mammals for which a single common name usually covers all
subspecies, many reptile and amphibian subspecies are recognized by different common
names.  For example, there are two subspecies of Rana clamitans: the green frog  and the
bronze frog (Section  2.3.7).  There are four subspecies of Terrapene Carolina: eastern box
turtle, three-toed box turtle,  Florida box turtle, and Gulf Coast box turtle (Section 2.3.3).
In this case, other species exist that are also known as box turtles: the ornate and desert
box turtles belong to the species T. ornata.  For species that could be confused with other
species unless a subspecies common name is used, we selected the common name of the
most  widespread subspecies to use in the tables and titles of the species profile.  As with
the other species in the Handbook, however, the profile covers all subspecies for the
selected species that were represented in  the literature reviewed.
       In these profiles, we use the word hibernation for the period of dormancy that
reptiles and amphibians undergo during winter, when they change their metabolism to
accommodate the low (often near freezing) temperatures and lack of food (and oxygen).
Use of the word for this group is controversial, however, because the word was developed
initially to describe mammalian winter dormancy.  Some investigators argue that a
different word, brumation, should be established to describe the overwintering dormancy
and associated metabolic changes for reptiles and amphibians (Hutchison, 1979).  Others
disagree, because significant physiological changes also occur in reptiles and amphibians
during  winter dormancy.  They argue that, although the physiological changes are different
from those in mammals, the Word hibernation is a general term that does not specify what
                                       2-365
-------
Table 2-3. Reptiles and Amphibians Included in the Handbook
  Order
Common name
Scientific name
Section
  Chelydridae

  Emydidae


  Colubridae


  Salamandridae

  Ranidae
snapping turtle

painted turtle
eastern box turtle3

racer
northern water snake6

eastern newt

green frog8
bullfrog •
Chelydra serpentina
2.3.1
Chrysemys picta           2.3.2
Terrapene Carolina Carolina 2.3.3

Coluber constrictor        2.3.4
Nerodia sipedon sipedon    2.3.5

Notophthalmus viridescens 2.3.6

Rana clamitans clamitans   2.3.7
Rana catesbeiana          2.3.8
"Additional subspecies also are included in the profile.


metabolic changes occur to allow overwintering in a dormant state (Gatten, 1987). We
have chosen this latter interpretation for the Handbook.


References


Gatten, R. E., Jr. (1987) Cardiovascular and other physiological correlates of hibernation in

       aquatic and terrestrial turtles. Am. Zool. 27: 59-68.


Hutchison, V. H. (1979) Thermoregulation. In: Harless, M.; Morlock, H., eds. Turtles:

       perspectives and research. Toronto, Canada: John Wiley and Sons; pp. 207-227.
                                       2-366
-------
2.3.1.  Snapping Turtle (snapping turtles)

       Order Testudines, Family Chelvdridae. Snapping turtles are among the largest of
the freshwater turtles.  They are characterized by large heads with powerful hooked jaws.
There are only two species of this family in North America (the snapping turtle, including
both the common and Florida snapping turtles, and the alligator snapping turtle).

Selected species

       The snapping turtle (Chelydra serpentine) is primarily aquatic, inhabiting freshwater
and brackish environments, although they will travel overland (DeGraaf and Rudis,  1983;
Ernst and Barbour, 1972; Smith, 1961).  There are two subspecies recognized in North
America that are primarily distinguished by range: C. s. serpentina (the  common snapping
turtle, which is the largest subspecies, primarily occupies the United  States east of the
Rockies, except for the southern portions of Texas and Florida), and  C. s. osceo/a (the
Florida snapping turtle, found in the Florida peninsula)  (Conant and Collins, 1991).  In this
profile, studies refer to the serpentina subspecies unless otherwise noted.

       Body size.  Adult snapping turtles are large, 20 to 37  cm in carapace  length, and
males attain larger sizes than females (Congdon et al., 1986; Ernst and Barbour, 1972;
Galbraith et al., 1988). In  a large oligotrophic lake in Ontario Canada, adult males
averaged over  10 kg, whereas the females averaged 5.2 kg (Galbraith et al., 1988). In
other populations, the difference in size between males and females  often is less (Congdon
et al., 1986; Galbraith et al., 1988; Hammer, 1969). They reach sexual maturity at
approximately 200 mm in carapace length (Mosimann  and Bider, 1960).  The cool, short
activity season in more northern areas results in slower growth rates and longer times to
reach sexual maturity (Bury,  1979).

      Habitat.  In the east, snapping turtles are found in and near permanent ponds,
lakes, and marshes. However, in the arid west, the species is primarily found in larger
rivers,  because these are the only permanent water bodies (Toner, 1960, cited in Graves
and Anderson, 1987).  They are most often found in turbid waters with a slow current
(Graves and Anderson, 1987).  They spend most of their time lying on the bottom of deep
pools or buried in the mud  in shallow water with only their eyes and  nostrils  exposed.
Froese  (1978) observed that young snapping turtles show a preference for areas with
some obstructions that may provide cover or food.

      Food habits.  Snapping turtles are omnivorous.  In early spring, when  limited
aquatic vegetation exists in lakes and  ponds, they may eat primarily animal matter;
however, when aquatic vegetation becomes  abundant, they become  more herbivorous
(Pell, 1941, cited in Graves and Anderson, 1987). Young snapping turtles are primarily
carnivorous and prefer smaller streams where aquatic vegetation is less abundant (Lagler,
1943; Pell, 1941, cited in Graves and Anderson, 1987).  Snapping turtles consume a wide
variety of animal material including insects, crustaceans, clams, snails, earthworms,
leeches, tubificid worms, freshwater sponges, fish (adults, fry, and eggs), frogs and toads,
salamanders, snakes, small turtles, birds, small mammals, and carrion and plant material
including various algae (Alexander, 1943; Graves and Anderson, 1987; Hammer, 1969;
                                      2-367
Snapping Turtle
-------
 Punzo, 1975).  Budhabatti and Moll (1988) observed no difference between the diets of
 males and females who fed at the surface, midpelagic, and benthic levels.  Bramble (1973)
 suggested that the pharyngeal mechanism of feeding (i.e., drawing water with food
 objects into the mouth) prevents snapping turtles from ingesting food above the air-water
 interface.

       Temperature regulation and daily activities.  Snappers are most active at night.
 During the day, they occasionally leave the water to bask on shore, but basking is
 probably restricted by intolerance to high temperatures and by rapid loss of moisture (Ernst
 and Barbour, 1972). In a study in Ontario, Canada, Obbard and Brooks (1981) found that
 the turtles were active in the early morning and early evening and basked in the afternoon
 but were rarely active at night.  Active turtles were found in  deeper waters than inactive
 snappers (Obbard and Brooks, 1981).  Cloacal temperatures  of 18.7 to 32.6°C were
 reported for snapping turtles captured in the water in Sarasota County, Florida, between
 May and October (Punzo, 1975).

       Hibernation.  Snapping turtles usually enter hibernation by late October and emerge
 sometime between March and May, depending on latitude and temperature. To hibernate,
 they burrow into the debris or mud bottom of ponds or lakes, settle beneath logs, or
 retreat into muskrat burrows or lodges.  Snapping turtles have been seen moving on or
 below the ice in midwinter. Large congregations sometimes  hibernate together (Budhabatti
 and Moll, 1988; Ernst and  Barbour, 1972).

       Breeding activities and social organization.  Mating occurs any time turtles are
 active from spring through fall, depending on latitude (Ernst and Barbour, 1972).  Some
 investigators believe that male snapping turtles are  territorial  (Kiviat, 1980; Pell, 1941,
 cited  in Galbraith et al., 1987), but Galbraith et al.  (1987) doubts that males defend their
 home ranges against other males.  Sperm may remain viable  in the female for several years
 (Smith, 1956).  Nesting occurs from late spring to early fall, peaking in June (Ernst  and
 Barbour,  1972). Hammer (1969) observed that larger, older females nested earlier  in the
 season than did smaller, younger ones.  Females often move  up small streams  to lay eggs
 (Ewert, 1976, cited in Graves and  Anderson, 1987). The nest site may be in the soil of
 banks or in muskrat houses but more commonly is  in the open on south-facing  slopes and
 may be several  hundred meters from water (DeGraaf and Rudis, 1983).  The turtle digs a
 4- to 7-in cavity on dry land, preferably in sand, loam, or vegetable debris.  The duration of
 incubation is inversely related to soil temperature (Ernst and Barbour,  1972; Yntema,
 1978, cited  in Graves and Anderson, 1987).  In more northerly populations,  hatchlings
 may overwinter in the nest {DeGraaf and Rudis, 1983).

      Home range and resources. Most turtles stay primarily within the same  marsh or in
 one general area from year to year ((Hammer, 1969; Obbard and Brooks, 1981).  The
summer home range includes a turtle's aquatic foraging areas, but females may need to
travel some distance outside of the foraging home range to find a suitable  nest site
 {DeGraaf and Rudis, 1983). Obbard and  Brooks (1980) found that females tagged at their
nesting site moved an average of 5.5 km (± 1.8 SD) from the nest site afterwards.  Lonke
and Obbard  (1977) observed that 91.9 percent of the turtles  in one population  returned to
the same nesting site a year after having  been tagged there.  Home ranges overlap both
between and within sexes (Obbard and Brooks, 1981). Young snapping turtles use

                                      2-368                         Snapping Turtle
-------
different habitats than adults; they tend to remain in small streams until shortly before
maturity, when they migrate to habitats preferred by adults (e.g., ponds, marshes, lakes)
(Hammer, 1971; Minton, 1972, cited in Graves and Anderson, 1987).

      Population density. The density of snapping turtles appears to be positively
correlated with the productivity of the surface water body (e.g.,  density in a eutrophic
surface  water body is higher than in an oligotrophic lake) (Galbralth et al.,  1988).  Specific
habitat characteristics and intraspecific interactions contribute to the variability of
observed population densities in snapping turtles (Froese and Burghardt, 1975).

      Population dynamics. Females do not begin laying eggs until age 6 to 19 yr
depending on latitude and when they reach an appropriate size (approximately 200 mm
carapace) (Galbraith et  al. 1989; Mosimann and Bider, 1960). Males mature a few years
earlier than females (see table). Females may lay one or two clutches per  season  (Minton,
1972, cited in Graves and Anderson, 1987).  Clutch size increases with female body size;
Congdon et al. (1987) calculated the relationship between clutch size (CS) and plastron
length (PL in mm) for a population in southeastern Michigan:

             CS = -21.227 + 0.242 PL,  (r2 = 0.409, n = 65).

Clutch size has also been positively correlated with latitude (Petokas and Alexander,
1980).  Hammer (1969) found that mammalian predators destroyed over 50 percent of the
turtle nests in  a South Dakota marsh, and in undisturbed nests, hatchling success was less
than 20 percent. Petokas and Alexander (1980) observed a 94 percent predation  rate of
nests under study in northern New  York. Adult mortality is low,  corresponding with the
long lives exhibited by these turtles (see table).

Similar species (from general references)

      •      The alligator snapping turtle (Macroclemys temmincki) is much larger (16 to
             68 kg; 38 to 66 cm carapace) than the common snapping turtle and is one
             of the largest turtles in the world.  Its range is from northern Florida  to east-
             central Texas and north in the Mississippi Valley.
                                 »
General references

      Conant and  Collins (1991); DeGraaf and Rudis (1983); Ernst and Barbour (1972);
Graves and Anderson (1987).
                                       2-369
Snapping Turtle
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                                                   Snapping Turtle (Chelydra serpentina]
Population \
Dynamics
Length at
Sexual
-Maturity
Annual
Mortality
Rates (%)
Longevity (yrj
Seasonal
Activity
Mating
Nesting
Hatching
Hibernation
Age/Sex/
Cond./Seas.
AB
AB
AB

Begin
April
early June
mid-June
May
late May
early June
August
late August
October
late September
mid-October
Mean
200 mm carapace
145 mm plastron


Peak
June
mid-June
June
early to mid-June
mid-June
September

Range Or
(95% Cl of mean)

3-7
at least 24
at least 1 9
End
November
end of June
September
late June
end of June
October
early October
March-May
mid-March
early May
Location/Habitat
Quebec, Canada/NS
Tennessee/NS
NS/NS
Michigan/marsh
South Carolina/river
Location
depends on latitude
New York
Florida
depends on latitude
northern New York
South Dakota
depends on latitude
se Michigan
depends on latitude
Iowa
Ontario, Canada
Reference
Mosimann & Bider, 1 960
White & Murphy, 1 973
Galbraith & Brooks, 1987
Gibbons, 1987
Gibbons, 1987
Reference ,
Ernst & Barbour, 1 972
Kiviat,. 1980
Punzo, 1975
Ernst & Barbour, 1972
Petokas & Alexander, 1 980
Hammer, 1969
Ernst & Barbour, 1972
Congdon et al., 1987
Ernst & Barbour, 1972
Christiansen & Burken, 1 979
Obbard & Brooks, 1981
Note
No*
9
10

Note
No.




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1   Cited in Sievert et al. (1988).
2   Estimated assuming temperature of 20°C, using equation 3-50 (Robinson et al., 1983) and body weights from Congdon et al. (1986), after
    subtracting 30 percent of body weight to eliminate the weight of the shell (Hall, 1924).  More information on estimating energy budgets for
    reptiles is provided in Congdon et al. (1982).
3   Method of estimating percent  diet not specified.
4   Summary of six field studies,  including the author's.
5   Summary of data from various authors for eleven eutrophip ponds.
6   Cited in Petokas and Alexander (1980).
7   Cited in Graves and Anderson  (1987).
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                                        2-374
Snapping Turtle
-------
References (including Appendix)

Alexander, M. M. (1943) Food habits of the snapping turtle in Connecticut. J. Wildl.
       Manage. 7: 278-282.

Barbour, R. W. (1950) The reptiles of Big Black Mountain, Harlan County, Kentucky.
       Copeia 1950: 100-107.

Bramble, D. M. (1973) Media dependent feeding in turtles. Am. Zool. 13: 1342.

Breckenridge, W. J.  (1944) Reptiles and amphibians  of Minnesota.  Minneapolis, MN:
       University of Minnesota Press.

Budhabhatti, J.;  Moll, E. O. (1988) Diet and activity  patterns of the common snapping
       turtle,  Chelydra serpentina (Linnaeus) at Chain O'Lakes State Park, Lake County,
       Illinois (abstract only). Bull. Ecol. Soc. Am.  Suppl. 69: 86.

Bury, R. B. (1979) Population ecology of freshwater  turtles.  In: Harless, M.; Morlock, H.,
       eds. Turtles:  perspectives and research. Toronto, Canada: John Wiley and Sons,
       Inc.; pp. 571-602.

Bush, F. M. (1959) Foods of some Kentucky herptiles. Herpetologica  15: 73-77.

Cahn, A. R. (1937) The turtles of Illinois. Illinois Biol. Monogr. 35: 1-218.

Carr, A. F. (1952) Handbook of turtles. Ithaca, NY: Comstock.

Christiansen,  J. L.; Burken, R. R. (1979) Growth and maturity of the snapping turtle
       (Chelydra serpentina) in Iowa. Herpetologica 35: 261-266.

Conant, R.; Collins, J. T. (1991) A field guide  to reptiles and amphibians - eastern and
       central  North America. Boston, MA: Houghton Mifflin Co.

Congdon, J.  D.; Gibbons, J. W. (1985) Egg components and  reproductive characteristics
       of turtles: relationships to body size. Herpetologica 41: 194-205.

Congdon, J.  D.; Dunham, A. E.; Tinkle, D. W. (1982) Energy budgets and life histories  of
       reptiles. In: Cans, C., ed. Biology of the reptilia. v. 13. New  York, NY: Academic
       Press;  pp. 233-271.

Congdon, J. D.; Greene, J. L.; Gibbons, J. W. (1986) Biomass of freshwater  turtles: A
       geographic comparison. Am. Midi. Nat. 115:  165-173.

Congdon, J. D.; Tinkle, D. W.; Rosen, P. C. (1983) Egg components and utilization during
       development  in aquatic turtles. Copeia  1983:  264-268.
                                      2-375
Snapping Turtle
-------
Congdon, J. D.; Breitenbach, G. L.; van Loben Sels, R. C.; et al. (1987) Reproduction and
      nesting ecology of snapping turtles (Chelydra serpentine) in southeastern Michigan.
      Herpetologica 43: 39-54.

DeGraaf, R. M.; Rudis, D. D. (1983) Amphibians and reptiles of New England. Amherst,
      MA: University of Massachusetts Press; p. 42.

Ernst, C. H. (1968) A turtle's territory. Int. Turtle Tortoise Soc. J. 2: 9-34.

Ernst, C. H. (1971) Population dynamics and activity cycles of Chrysemys picta in
      southeastern Pennsylvania. J. Herpetol.  140: 191-200.

Ernst, C. H.; Barbour, R. W.  (1972) Turtles of the United States.  Lexington, KY: University
      Press of Kentucky.

Ewert, M. A.  (1976)  Nests, nesting and aerial basking of Macroclemys under natural
      conditions, and comparisons with Chelydra (Testudines: Chelydridae). Herpetologica
      32: 150-156.

Ewert, M. A.  (1979)  The embryo and its egg: development and natural history. In: Harless,
      M.; Morlock, H., eds. Turtles: perspectives and research. Toronto,  Canada: John
      Wiley and Sons, Inc.; pp. 333-413.

Frazer, N. B.; Gibbons, J. W.; Greene, J. L. (1991) Growth, survivorship and longevity of
      painted turtles Chrysemys picta in a southwestern Michigan marsh. Am. Midi. Nat.
      125:245-258.

Froese, A. D. (1978) Habitat preferences of the common snapping turtle,  Chelydra s.
      serpentina (Reptilia, Testudines, Chelydridae). J. Herpetol. 12: 53-58.

Froese, A. D.; Burghardt, G.  M. (1975) A dense natural population of the common
      snapping turtle (Chelydra s. serpentina).  Herpetologica 31: 204-208.

Galbraith, D. A.; Brooks, R. J. (1987) Survivorship of adult females in a northern
      population of common snapping turtles, Chelydra serpentina. Can.  J. Zool. 65:
      1581-1586.

Galbraith, D. A.; Chandler, M. W.; Brooks, R. J. (1987) The fine structure of home ranges
      of male Chelydra serpentina: are snapping turtles territorial? Can. J. Zool. 65:
      2623-2629.

Galbraith, D. A.; Bishop, C. A.; Brooks, R. J.; et al. (1988) Factors affecting the density of
      populations of common snapping turtles (Chelydra serpentina serpentina). Can. J.
      Zool. 66: 1233-1240.

Galbraith, D. A.; Brooks, R. J.; Obbard, M. E. (1989) The influence of growth rate on age
      and body size at maturity in female snapping turtles (Chelydra serpentina). Copeia
      1989:  896-904.
                                       2-376
Snapping Turtle
-------
Gerholdt, J. E.; Oldfield, B. (1987) Chelydra serpentina serpentina (common snapping
      turtle), size. Herpetol. Rev. 18: 73.

Gibbons, J. W. (1968) Growth rates of the common snapping turtle, Chelydra serpentina,
      in a polluted river. Herpetologica  24: 266-267.

Gibbons, J. W. (1987) Why do turtles live so long? BioSci. 37: 262-269. '

Graham, T. E.; Perkins, R. W. (1976) Growth of the common snapping turtle, Chelydra s.
      serpentina, in a polluted marsh. Bull. Md. Herpetol. Soc. 12: 123-125.

Graves, B. M.; Anderson, S. H. (1987) Habitat suitability index models: snapping turtle.
      U.S. Fish Wildl. Serv. Biol. Rep. 82(10.141); 18 pp.

Hall, F. G. (1924) The respiratory exchange in turtles. J. Metab. Res. 6: 393-401.

Hammer, D. A. (1969) Parameters of a marsh snapping turtle population. La-creek Refuge,
      South Dakota. J. Wildl. Manage..  33: 995-1005.

Hammer, D. A. (1971) The durable snapping turtle. Nat. Hist.  80:  59-65.

Hotaling, E. C.; Wilhoft, D. C.; McDowell, S. B. (1985) Egg position and weight of
      hatchling snapping turtles, Chelydra serpentina, in natural nests. J. Herp. 19:
      534-536.

Hutchison, V. H. (1979) Thermoregulation. In: Harless, M.; Morlock, H., eds. Turtles:
      perspectives and research. Toronto, Canada: John Wiley and Sons, Inc.; pp.
      207-227.

Iverson, J.  B. (1977) Reproduction in freshwater and terrestrial turtles  of north Florida.
      Herpetologica 33: 205-212.

Kiviat, E. (1980) A Hudson River tide-marsh snapping turtle population. In: Trans.
      Northeast. Sec. Wildl. Soc. 37th  Northeast, Fish and Wildl. Conf.; April 27-30,
      1980; Ellenville, NY; pp. 158-168.

Lagler, K. F. (1943) Food habits and economic relations of the turtles of Michigan with
      special reference to game management. Am. Midi. Nat. 29: 257-312.

Lagler, K. F.; Applegate, V. C. (1943) Relationship between the length and the weight in
      the snapping turtle Chelydra serpentina Linnaeus. Am. Nat. 77:  476-478.

Lonke, D. J.; Obbard, M. E. (1977) Tag  success, dimensions, clutch size and nesting site
      fidelity for the snapping turtle, Chelydra serpentina (Reptilia, Testudines,
      Chelydridae), in Algonquin Park, Ontario, Canada. J. Herpetol. 11: 243-244.

Lynn, W. G.; von Brand, T. (1945) Studies on the oxygen consumption and water
      metabolism of turtle embryos. Biol. Bull. 88: 112-125.
                                       2-377
Snapping Turtle
-------
             Macnamara, C. (1919) Notes on turtles. Ottawa Natural. 32: 135.

             Major, P. D. (1975) Density of snapping turtles, Chelydra serpentine in western West
                    Virginia. Herpetologica 31: 332-335.

             Meyers-Schone, L.; Walton, B. T. (1990) Comparison of two freshwater turtle species as
                    monitors of environmental contamination. Oak Ridge, TN: Oak Ridge National Lab.;
                    Environmental Sciences Division Publication No. 3454. ORNL/TM-11460.

             Minton, S. A., Jr. (1972) Amphibians and reptiles of Indiana. Indianapolis, IN: Indiana
                    Academy of Science.

             Moll, E. O. (1979) Reproductive cycles and adaptations. In: Harless, M.; Morlock, H., eds.
                    Turtles: perspectives and research. Toronto, Canada: John Wiley and Sons, Inc.;
                    pp. 305-331.

             Mosimann, J. E.;  Bider, J. R. (1960) Variation, sexual dimorphism, and maturity in a
                    Quebec population of the snapping turtle, Chelydra serpentina. Can. J. Zool. 38:
                    19-38.

             Obbard, M. E.  (1983) Population ecology of the common snapping turtle, Chelydra
                    serpentina, in north-central Ontario [Ph.D. dissertation]. Guelph, Ontario Canada:
                    University  of Guelph.

             Obbard, M. E.; Brooks, R. J. (1980) Nesting migrations of the snapping turtle (Chelydra
                    serpentina). Herpetologica 36: 158-162.

             Obbard, M. E.; Brooks, R. J. (1981) A radio-telemetry and mark-recapture study of activity
                    in the common snapping turtle, Chelydra serpentina. Copeia  1981: 630-637.
                                                                             «•

             Pearse, A. S. (1923) The abundance and migration of turtles. Ecology 4: 24-28.

             Pell, S. M. (1940) Notes on the food habits of the common snapping turtle. Copeia 2: 131.

             Pell, S. M. (1941) Notes on the habits of the common snapping turtle, Chelydra serpentina
                    (Linn.) in central New York [master's thesis]. Ithaca, NY:  Cornell University.

             Petokas, P. J.; Alexander, M. M. (1980) The nesting of Chelydra serpentina in northern
                 '  New York. J. Herpetol. 14: 239-244.

             Punzo, F. (1975) Studies on the feeding, behavior, diet,  nesting habits and temperature
                    relationships of Chelydra serpentina osceola (Chelonia: Chelydridae). J. Herp. 9:
                    207-210.

             Robinson, R. W.; Peters, R. H.; Zimmermann, J. (1983) The effects of body size and
                   temperature on metabolic rate  of organisms. Can. J. Zool. 61: 281-288.
                                                   2-378
Snapping Turtle
L
-------
Sievert, L. M.; Sievert, G. A.; Cupp, P. V., Jr. (1988) Metabolic rate of feeding and fasting
      juvenile midland painted turtles, Chrysemys picta marginata. Comp. Biochem.
      Physiol. A Comp.  Physiol. 90: 157-159.

Smith, H. M.  (1956) Handbook of amphibians and reptiles of Kansas. Univ. Kansas Mus.
      Nat. Hist. Misc. Publ. 9; pp. 134-136.

Smith, P. W.  (1961) The amphibians and reptiles of Illinois. III. Nat. Hist. Surv. Bull. 28:
       118-120.

Toner, G. C. (1960) The  snapping turtle. Can. Audubon 22:97-99.

White, J. B.; Murphy, G. G. (1973) The reproductive cycles and sexual dimorphism of the
      common snapping turtle, Chelydra serpentina serpentina. Herpetologica 29:
      240-246.

Wilhoft, D.  C.; del Baglivo, M. G.; del Baglivo, M. D. (1979) Observations of mammalian
      predation of snapping turtle nests (Reptilia, Testudines, Chelydridae). J, Herpetol.
       13:435-438.

Yntema, C. L. (1968) A series of stages in the embryonic development of Chelydra
      serpentina. J. Morphol. 125: 219-252.

Yntema, C. L. (1970) Observations on females and eggs of the common snapping turtle,
      Chelydra serpentina. Am. Midi. Nat. 84: 69-76.

Yntema, C. L. (1978) Incubation times  for eggs of the turtle Chelydra serpentina
      (Testudines: Chelydridae) at various temperatures. Herpetologica 34: 274-277.
                                      2-379
Snapping Turtle
-------
-------
2.3.2.  Painted Turtle (pond and marsh turtles)

       Order Testudines. Family Emvdidae.  Pond and marsh turtles (i.e., sliders, cooters,
red-bellied turtles, and painted turtles) are small to medium-sized semiaquatic turtles well
known for basking in the sun.  Painted turtles are the most widespread of these in North
America, ranging across the continent.

Selected species

       The painted turtle (Chrysemys picta) is largely aquatic, living in shallow-water
habitats, and is among the most conspicuous of the  basking turtles.  There are four
subspecies in the United States (only one reaching slightly into Canada), distinguished by
color variations, body size, and range: C. p. picta (eastern painted turtle; 11.5 to 15.2
cm; range Nova Scotia to Alabama), C. p. marginata (midland painted turtle; 11.5 to 14
cm; range southern Quebec and southern Ontario to Tennessee), C. p. dorsalis (southern
painted turtle; 10 to 12.5 cm; range southern Illinois to the Gulf), and C. p.  belli! (western
painted turtle; the largest of the subspecies, 9 to  18 cm; range southwest Ontario and
Missouri to the Pacific Northwest) (Conant and Collins, 1991). C. p.  dorsalis is the
smallest subspecies and also one of the smallest emydid turtles in North America (Moll,
1973). Hybridization occurs between subspecies in areas where their ranges overlap (e.g.,
be/Hi x marginata hybrids may occur in areas of Michigan) (Snow, 1980).

      Body size.  Painted turtles are'medium-sized turtles (10 to 18 cm). Males are
smaller than females; adult males average from 170  to 190 g, whereas adult females
average from 260 to 330 g in some populations (Congdon et al., 1986; Ernst 1971b). In
general, the shell comprises approximately  30 percent of the total wet weight of turtles of
this size (Hall, 1924). Frazer et al.  (1991) estimated a relationship between plastron
length (PL in mm) and age (t in years) for a population in Michigan in  the 1980's using yon
Bertalanffy growth equations:
       PL = 111.8(1 -0.792e-°'184t)

       PL = 152.2(1 -0.852e-°'128t)
for males, and
for females.
Congdon et al. (1982) reported a relationship between plastron length (PL in mm) and
body weight (Wt in grams) for painted turtles:

      loge(Wt) = -6978 + 2.645 loge(PL).

Eggs weigh 4 to 6 g, and neonates retain a large yolk mass that they draw on for the first
few months of life (Cagle, 1954).

      Habitat.  Painted turtle habitat requirements include soft and muddy bottoms,
basking  sites/and aquatic vegetation (Sexton, 1959). Painted turtles prefer slow-moving
shallow  water such as ponds, marshes, ditches, prairie sloughs, spring runs, canals, .and
occasionally brackish tidal marshes (Conant and Collins,  1991).   They frequent areas with
floating  surface vegetation for feeding and for cover (Sexton, 1959).  These areas tend  to
                                       2-381
                          Painted Turtle
-------
be warmer than more open water, which is important in the early fall as temperatures
begin to drop (Sexton, 1959).  For winter hibernation or dormancy, painted turtles seek
deeper water (Sexton, 1959).  If outlying marsh areas are dry during the summer, the
turtles may return to the more permanent bodies of water sooner (McAuliffe,  1978).
Painted turtles sometimes inhabit stagnant and polluted water (Smith, 1956).

       Food habits.  Painted turtles are omnivorous. Depending on habitat and on age,
painted turtles may consume predominantly vegetation  or predominantly animal matter.
Marchand (1942, cited in Mahmoud and Klicka, 1979) found in one population that
juveniles consumed approximately 85 percent animal matter and 15 percent plant matter,
whereas the adults were primarily herbivorous, consuming 88 percent plant matter and 12
percent insects and amphipods. Knight and Gibbons (1968) found  oligochaets, cladocera,
dragonfly nymphs, lepidopteran larvae, and tendipedid larvae and pupae to dominate the
animal component of the diet and filamentous algae to dominate the plant component of
the diet in a population living in a polluted river in Michigan. Adult  painted turtles in a
Pennsylvania  population were found to consume only 40 percent plant matter (Ernst and
Barbour, 1972), whereas in a Michigan marsh and elsewhere, painted turtles of all ages
apparently  consumed 95 to 100 percent plant matter (Cahn,  1937, cited in Smith,  1961;
Gibbons, 1967). Some carrion also may be consumed (Mount, 1975).

       Temperature regulation and daily activities. Painted turtles are diurnal and usually
spend their nights sleeping submerged (Ernst, 1971c).  During the day, they forage in the
late morning and late afternoon  and bask during the rest of the day (Ernst, 1971c). Active
feeding does not occur until water temperatures approach 20 °C, and these turtles are
most active around 20.7 to 22.4°C (Ernst, 1972; Ernst and Barbour, 1972; Hutchinson,
1979).  Basking is.most frequent in the spring, summer, and fall, but occasionally painted
turtles bask during warm spells in the winter (Ernst and Barbour, 1972). Sexton (1959)
divided the annual activity cycle of painted turtles into five parts: (1) the prevernal, which
begins with the final melting  of winter ice and lasts until late March, or when  the turtles
begin to move in mass out of the hibernation  ponds; (2) the vernal, from late March to late
May, when the submerged aquatic plants important to the turtles grow to the surface of
the water (the initiation of feeding and mating activities and the emergence of the
hatchling turtles from the nests  of the previous year also occur during this season); (3) the
aestival, extending from June through August, when the turtles forage, grow, nest, and
return to their winter hibernation ponds; (4) the autumnal, including September through
November or when a permanent ice cover forms; and (5) the winter season, which lasts
while the water is permanently covered with ice.

      Hibernation., Most painted turtles become dormant during the colder months but
will become active during warm periods in the winter (Ernst and Barbour, 1972). C. picta
usually hibernates in muddy bottoms of ponds (DeGraaf and Rudis,  1983). Taylor and Nol
(1989) found  painted turtles overwintering in  an Ontario pond in areas with a  mean water
depth of 0.32 m (range 0.2 to 0.48 m), mean sediment depth of 0.79 m (0.5  to 0.95 m),
and mean sediment temperature of 4.1 °C (3 to 6°C).  During hibernation, painted turtles
shift toward more anaerobic metabolism, supported by glycolysis of liver and skeletal
muscle glycogen (Seymour, 1982).  After emerging from hibernation, the turtles convert
the accumulated lactate to glucose in  the liver (using aerobic metabolism) (Seymour,
1982).
                                      2-382
Painted Turtle
-------
       Breeding activities and social organization. Mating usually occurs in spring and
summer but may continue into the fall (Ernst, 1971c; Gibbons, 1968a; Gist et al., 1990).
Nesting occurs somewhat later (Cagle, 1954; Ernst and Barbour, 1972; Moll 1973). Eggs
are often laid in high banks (DeGraaf and Rudis, 1983).  The species does not appear to be
territorial and can be found in large aggregations, particularly at favorite basking sites
(Ernst, 1971c).

       Home range and resources.  In spring, as the winter ice melts, many painted turtles
move away from the ponds in which they hibernated to more shallow  ponds and marshes
with surface vegetation (Sexton, 1959).  Movements averaging 60 to  140 meters
characterized one population in Michigan (Sexton, 1959). The summer home range
includes the painted turtle's foraging areas and  basking sites. Females find nesting sites
on dry land outside of the foraging range; Congdon  and  Gatten (1989) found nests to
average 60 meters from the edge of a foraging  marsh.  Females initiate nesting migrations
during daylight hours, and most finish their nests before dark on the same day (Congdon
and Gatten, 1989).  In winter, painted turtles generally move back to the deeper ponds for
hibernation (DeGraaf and Rudis, 1983).

       Population density. Reported densities range from-11.1/ha in Saskatchewan
(MacCulloch and Secoy, 1983) to 830/ha in Michigan marshes (Frazer et al., 1991).
Accurate censuses are difficult, however (Bayless, 1975), and the distribution of painted
turtles in summer is highly clumped, corresponding to the patches of floating aquatic
vegetation (Sexton, 1959).

       Population dynamics. Sexual maturity is attained in about 2 to  7 years, depending
on the sex and size of the turtle and growing season (Christiansen and Moll, 1973; Ernst
and Barbour, 1972).  Males reach sexual maturity 1 to a few years  earlier than females
(Moll, 1973).  Once sexual maturity is reached, growth of painted turtles slows or
essentially ceases (Ernst and Barbour, 1972). Older, larger females tend to produce larger
clutch sizes and larger eggs than younger, smaller females (Mitchell, 1985). In more
southerly populations, painted turtles  produce more clutches annually with fewer eggs
each than in more northerly populations (Moll, 1973; Snow,  1980;  Schwarzkopf and
Brooks, 1986). Predation causes most nest losses, usually within the first 2 days after
laying (Tinkle et al., 1981). The duration of the incubation period depends on soil
temperature, and hatchlirigs may overwinter in the nest in more northerly populations
(Gibbons and Nelson, 1978).

Similar species (from general references)

       Many species of pond and marsh turtles  can  be found in similar habitats;  however,
there are important dietary differences among species that can affect exposure to
environmental  contaminants, as described below. Size is listed according to carapace
length, which is longer than plastron length.
      cooters
             The Florida cooter (Pseudemys floridana) is larger (23 to 33 cm) than the
             painted turtle.  The floridana subspecies ranges from the coastal plain of
                                       2-383
Painted Turtle
-------
       Virginia to eastern Texas and north in the Mississippi Valley to southern
       Illinois, while the peninsularis subspecies is restricted to the Florida
       peninsula. The Florida cooter resides in permanent bodies of water. In their
       first year, young cooters feed on both aquatic plant and animal life; later
       they become totally herbivorous.

       The river cooter (Pseudemys concinna), composed of five subspecies, also is
       larger (23 to 33 cm) than the painted turtle. It inhabits coastal plains
       ranging from southeastern Virginia to Georgia, southeast into  Florida, west
       into Texas and  New Mexico, and north in the Mississippi Valley to southern
       Illinois. It is chiefly a resident of streams and relatively large lakes. In their
       first year, young river cooters are  omnivorous; the adults are almost entirely
       herbivorous.

       The Texas river cooter (Pseudemys texana) (18 to 25.5 cm) prefers rivers
       but can be found in smaller creeks and ditches.  Its range is restricted to
       most of central and southeastern Texas.
red-bellied turtles
       The Florida red-bellied turtle (Pseudemys nelsoni) is larger (20 to 31 cm)
       than the painted turtle and has a range in the Florida peninsula  and
       panhandle. It can be found basking on logs over fresh to moderately
       brackish water, and it prefers abundant submerged aquatic vegetation, its
       principal food.

       The Alabama red-bellied turtle (Pseudemys alabamensis) is larger (23 to 33
       cm) than the painted turtle and is found only in the lower portion of the
       Mobile Bay drainage in Alabama. It prefers fresh to moderately brackish  •
       water with abundant aquatic vegetation, its principal food.

       The red-bellied turtle (Pseudemys rubriventris) is much larger (25 to 32 cm)
       than the painted turtle and is found in the mid-Atlantic states and eastern
       Massachusetts.
sliders
      The pond slider (Trachemys scripta) is similar in size or a little larger (12 to
      20 cm) than the painted turtle and has three subspecies ranging from
      southeastern Virginia to northern Florida and west to New Mexico.  During
      the first year, pond sliders are principally carnivorous, consuming aquatic
      insects, crustaceans, molluscs, and tadpoles.  As they mature, sliders
      become herbivorous, consuming a wide variety of aquatic plants.

      The big bend slider (Trachemys gaigeae) (12 to 20 cm) is similar to the pond
      slider in size and habits. It is abundant locally in its limited range along the
      upper Rio Grande and some of its tributaries.
                                 2-384
Painted Turtle
-------
General references

      Behler and King (1979); Conant and Collins (1991); Congdon et al. (1986); Ernst
and Barbour (1972); Moll (1973); Sexton (1959).
                                     2-385
Painted Turtle
-------
                                         Painted Turtle (Chrysemys plcta]
Factors
Body Weight
fa)



' i
Body Length
fmm plastron]
(mm plastron)

(mm carapace)] :
i ;
Egg Weight  12 yr
Mean
266.5 ± 60.1 SO
189.1 ± 52.3 SD
326.7 ± 4.95 SE
176.9 ± 1.92SE
64.2 ± 1.59 SE
3.7 ± 0.2 SD
4.1 ± 0.61 SD
157 ± 2.6 SE
132 ± 2.9 SE
125.1 ± 0.64 SE
99.9 ± 0.48 SE
65.0 ± 0.65 SE
134.2 ± 0.81 SE
109.7 ± 0.54 SE
71.5 ± 0.69 SE
6.17
6.65 ± 0.67 SD
8.62 ± 1.06 SD
35 mm/yr
1 9 - 20 mm/yr
1 2 mm/yr
8-10 mm/yr
3-6 mm/yr
< 3 mm/yr
Range or
(95% CI of mean)
83.5 - 450.3
102.0-274.5


3.5 - 3.9

136- 185
96- 155







Location (subspecies)
Pennsylvania (picta x
marginata}
Michigan

central Virginia (picta)
Iowa
Wisconsin (belli/}
Michigan

Michigan
Georgia (dorsalis)
Iowa

Quebec, Canada [marginata)
(measured using plastron)
Reference
Ernst, 1971b
Congdon et al., 1986

Mitchell, 1985
Ratterman & Ackerman,
1989
Moll, 1973
Congdon et a!., 1 986

Congdon et al., 1 986
Congdon & Gibbons,
1985
Ratterman & Ackerman,
1989
Christens & Bider, 1986
Note
No.













ro

t!o
oo
CD
Q.
S

CD
-------
                                         Painted Turtle (Chrysemys p/cta]
'
Factors
Metabolic Rate
i!02/kg-d}






Metabolic Rate
(kcal/d,
averaged over
1 year}



Food Ingestion
Rate (g/g-d)
Water
Ingestion
Rate (g/g-d)
Inhalation
Rate
Age/Sex/
Cond./Seas.
adults; 25 °C
land, rest
water,
juv.; 25
swim
°C
feeding
1-day
fast
1 0-day fast
1 9-day fast
J F-yr
J F-yr
J F-yr
JF-yr
A F-yr
A F-yr
A F - yr
1
3
5
7
9
11
13

AB



A B summer
A B resting


Dietary Composition
att ages:
plants






Mean



0.73 ± 0.44 SD
0.22 ± 0.32 SD
0.39 ± 0.68 SD
5.06 ± 0.42 SE
3.44 ± 0.29 SE
1.98 ± 0.13 SE
1.57 ± 0.19 SE
0.06
0.30
0.53
0.77
1.12
1.23
1.28







0.02
0.0025 ±0.0005 SE


Spring






Summer

> 95



Range or
(95% Cl of mean}



up to 0.025



0.016-0.022


Fall





Winter




"
Location (subspecies!
North Carolina




NS (marginata)


Michigan (marginata)








Wisconsin (bellii) (lab)

Pennsylvania (lab)
NS (lab)


Reference
Stockard & Gatten,
1983




Sievert et al., 1988

Congdon et al., 1982
•







Trobec & Stanley, 1971

Ernst, 1972
Milsom & Chan, 1 986

location/Habitat
(measure) Reference
Michigan/marsh Gibbons, 1967

(% wet weight; stomach
contents)
Note
No.
1




2


3






4

5

6


Note
No.




NJ

CO
CO
t)
Q>
CD
Q.

H
CD
-------
                                       Painted Turtle (Chrysemys p/cta)

Dietary Composition
all ages:
plants
animals
Oligochaeta
Cladocera
Qdonata nymphs
tepidoptera larvae
Tendipedidae larva
Tendipedidae pupae
'detritus
adults;
snails
amphipods I
crayfish
insects
fish
other artimais
algae
vascular plants
other plants
Population
Dynamics
Movements
(rel

Population
Density
(N/ha)

-


Spring

31.6
77.3
-
1.5
60.0
1.0
30.8
36.7
7.8










Age/Sex
Cond./Seas.
A B spring
A B summer
A B fall
B B summer

BB

BB
BB

Summer

38.7
72.3
30.0
48.5
38.3
50.0
,7.7
10.0
1.9

12.1
3.0
7.5
11.5
13.0
14.1
14.7
24.1
0.8

Fall





















Mean
63- 144
86-91
88-130
11.1



590
828

Winter












t







Range or
<95% Cl of mean)
up to 301
up to 300
up to 336


98-410

240 - 941

Location/Habitat
(measure)
Michigan/polluted river

(% wet weight; stomach
contents)







Pennsylvania (p/cte)/NS

(% wet volume; stomach
contents)

season not specif ied




Location/Habitat
Michigan [margfnata)fNS


Saskatchewan, Canada
(6e////)/river
Michigan (marginata] /ponds,
marsh
Pennsylvania/pond, marsh
Michigan/lake, marsh

Reference
Knight & Gibbons, 1968










Ernst & Barbour, 1 972





«


j ^ ^
Reference
Sexton, 1959


MacCulloch & Secoy, 1 983

Sexton, 1959

Ernst, 1971c
Frazeretal., 1991
Note
No.




















Note
No. '
7








Ni
CO
CO
CO
CD
Q.

H
CD
-------
                                         Painted Turtle (Chrysemys picta]
Population
Dynamics
Clutch Size


,


Clutches/Year








Pays
Incubation

Age at Sexual
Maturity (yr)




••

Age/Sex
CondJSeas*


















F
M
F
M
F
M
F
M

Mean
19.8

10.7
7.6
4.8

1 -2

1 -2

> 2

> 3





5-6
3
8
4
6
5
4-5
2-3
Range or
{95% Cl of mean}
17-23

4-16
2-11
2-9

2

2

3

5


65-80
60-65
72-99








,
Location/Habitat
Saskatchewan, Canada
(belli/) /creek
Wisconsin (6e////)/NS
Michigan (marginata) INS
Tennessee (dorsalis x
marginata)/NS
Ontario, Canada/NS

Michigan (bellii x marginata)
/NS
Illinois (bellii x marginata)
/kettle ponds
Tennessee, Louisiana
(dorsalis and d. x
marginata}!^
se Pennsylvania/NS
se Wisconsin/NS (natural)
nw Minnesota/NS (natural)
New Mexico (6e////)/NS

Wisconsin (6e///7)/NS

Pennsylvania (p/cte)/NS

Tennessee (dorsalis x
marginata)lNS

Reference
MacCulloch & Secoy, 1 983

Moll, 1973
Congdon & Tinkle, 1 982
Moll, 1973

Schwarzkopf & Brooks,
1986
Snow, 1980

Moll, 1973

Moll, 1973


Ernst, 1971 c
Ewert, 1979
Ewert, 1979
Christiansen & Moll, 1973

Christiansen & Moll, 1 973

Ernst & Barbour, 1972

Moll, 1973

Note
No,


























to
c!o
CO
CO
TJ
Q>
CD
Q.
CD
-------
                                         Painted Turtle (Chrysemys p/cta]
Population
Dynamics
Length at
Sexual
Maturity
(mm plastron)
Annual
Mortality Rates
(%1
Longevity
Seasonal
Activity
Mating
Nesting
Hatching
Hibernation
Age/Sex
Cond./Seas.
M
F
M
F
M
F
AF
AM
AB
JB
M
F
Begin
late April
March
June
June
late May
September
August
late October
late October
Mean
90
120-130
70
120-125
123
150
54

Peak
April - early May
October
June
late summer

Range or
(95% CI of mean)
88- 170
132-205
0- 14
2-46
4-6
up to 31 yrs
up to 34 yrs
End
mid-June
May
July
July
late June
spring
September
late March
April
Location/Habitat
northern Michigan
(marginata, dorsalis)INS
southern Illinois [marginata,
oforsa//s)/NS
New Mexico (6e////)/NS
Saskatchewan, Canada, Ml,
NY, NE/NS
Virginia/NS
Michigan/marsh
Location [subspecies)
se Pennsylvania
Michigan
Ohio
se Pennsylvania
Illinois, Kansas
se Michigan (marginata)
se Michigan (marginata)
Illinois (marginata)
Kansas (be/Hi)
se Michigan (marginata)
Kansas (bellii]
Reference
Cagle, 1954
Cagle, 1954
Christiansen & Moll, 1973
Zweifel, 1989
Mitchell, 1988
Frazer et al., 1991
Reference :.
Ernst, 1971c
Gibbons, 1968a
Gistetal., 1990
Ernst, 1971c
Smith, 1956, 1961
Tinkle etal., 1981
Tinkle et al., 1981
Cahn, 1937
Smith, 1956
Congdon et al., 1 982
Smith, 1956
Note
No.

8
8

Note
No.


9
•
to

to
CO
o
CD
Q.
c
•^
r-f

CD
-------
NJ
CO
CD
                                                      Painted Turtle (Chrysemys picta)

      1   Average mass of test animals resting on land and in water = 215 g (79 to 395 g) and of test animals swimming and measured for existence
         metabolism = 143 g (79 to 297 g).
      2   Average weight of juvenile turtles = 7.7 g.
      3   Based on an annual energy budget estimated by the authors assuming that females lay one clutch of eggs per year after their seventh year.
      4   See Chapters 3  and 4 for approaches to estimating food ingestion rates from metabolic rate and diet.
      5   Uptake of water by turtles  held in tap water.
      6   Measured as evaporative water loss.
      7   Spring:  from hibernation to other ponds; summer: back to hibernation ponds; fall:  to deep-water areas for hibernation.
      8   Cited in Frazer et al., 1991.
      9   Cited in Smith, 1961.
TJ
0)
CD
Q.
H
c
3
CD
-------
References (including Appendix)

Bayless, L. E. (1975) Population parameters for Chrysemys picta in a New York pond. Am.
       Midi. Nat. 93: 168-176.

Behler, J.  L.; King, F. W. (1979) The Audubon Society field guide to North American
       reptiles and amphibians. New York, NY: Alfred A. Knopf, Inc.

Blanchard, F. N. (1923) The amphibians and reptiles of Dickinson County, Iowa. Univ.
       Iowa Stud. Nat. Hist. 10: 19-26.

Breckenridge, W. J. (1944) Reptiles and amphibians of Minnesota. Minneapolis, MN:
       University of Minnesota Press.

Breitenbach, G. L.; Congdon, J. D.; van Loben Sels, R. C. (1984) Winter temperatures of
       Chrysemys picta nests in Michigan: effects on hatchling survival. Herpetologica 40:
       76-81.

Bury, R. B. (1979) Population ecology of freshwater turtles. In: Harless, M.; Morlock, H.,
       eds. Turtles:  perspectives and research. Toronto, Canada: John Wiley and Sons,
       Inc.; pp. 571-602.

Cagle, F. R. (1954)  Observations on the life cycles of painted turtles (Genus Chrysemys).
       Am. Midi. Nat. 52: 225-235.

Cahn, A. R. (1937) The turtles of Illinois. Illinois Biol. Monogr. 1-218.

Christens, E.; Bider, J. R. (1986) Reproductive ecology of the painted turtle (Chrysemys
       picta marginata) in southwestern Quebec. Can. J. Zool. 64: 914-920.

Christiansen, J. L.; Moll, E.  O. (1973) Latitudinal reproductive variation within a single
       subspecies of painted turtle, Chrysemys picta bellii. Herpetologica 29: 152-163.

Conant, R.; Collins,  J. T. (1991) A field guide to reptiles and amphibians - eastern and
       central North America. Boston, MA: Houghton Mifflin Co.

Congdon,  J. D.; Gatten, R. E., Jr. (1989) Movements and energetics of nesting Chrysemys
       picta. Herpetologica 45: 94-100.

Congdon,  J. D.; Gibbons, J. W. (1985) Egg components and reproductive characteristics
       of turtles: relationships to body size. Herpetologica 41: 194-205.

Congdon,  J. D.; Tinkle, D. W. (1982) Reproductive energetics of painted turtle (Chrysemys
       picta). Herpetologica 38: 228-237.
                                      2-392
Painted Turtle
-------
Congdon, J. D.; Dunham, A. E.; Tinkle, D. W. (1982) Energy budgets and life histories of
      reptiles. In: Cans, C., ed. Biology of the reptilia: v. 13. New York, NY: Academic
      Press; pp. 233-271.

Congdon, J. D.; Greene, J. L.; Gibbons, J. W. (1986) Biomass of freshwater turtles: a
      geographic comparison.  Am. Midi. Nat. 115: 165-173.

DeGraaf, R. M.; Rudis, D. D. (1983) Amphibians and reptiles of New England. Amherst,
      MA: University of Massachusetts Press.

Ernst, C. H. (1971 a) Sexual cycles and maturity of the turtle, Chrysemys p/'cta. Biol. Bull.
      140: 191-200.

Ernst, C. H. (1971b) Growth of the painted turtle, Chrysemys picta, in southeastern
      Pennsylvania. Herpetologica  27: 135-141.

Ernst, C. J. (1971c) Population dynamics and activity cycles of Chrysemys picta in
      southeastern Pennsylvania. J. Herpetol. 5: 151-160.

Ernst, C. H. (1972) Temperature-activity relationship in the painted turtle, Chrysemys
      picta. Copeia 1972: 217-222.

Ernst, C. H.; Barbour, R. W. (1972) Turtles of the United States. Lexington, KY: University
      Press of Kentucky.

Ewert, M. A. (1979) The embryo and its egg: development and natural history. In: Harless,
      M.; Morlock, H., eds. Turtles: perspectives and  research. Toronto, Canada: John
      Wiley and Sons, Inc.; pp. 333-413.

Frazer, N. B.; Gibbons, J. W.; Greene, J. L. (1991) Growth, survivorship and longevity of
      painted turtles Chrysemys picta in a southwestern Michigan marsh. Am. Midi. Nat.
      125: 245-258.

Gemmell, D. J. (1970) Some observations on the nesting of the western painted turtle,
      Chrysemys picta belli, in northern Minnesota. Can. Field-Nat. 84: 308-309.

Gibbons, J. W. (1967) Variation in growth rates in three  populations of the painted turtle,
      Chrysemys picta. Herpetologica 23: 296-303,

Gibbons, J. W. (1968a) Reproductive potential,  activity and cycles in Chrysemys picta.
      Ecology 49: 399-409.

Gibbons, J. W. (1968b) Population structure and survivorship in the painted turtle,
      Chrysemys picta. Copeia 2: 260-268.

Gibbons, J. W. (1987) Why do  turtles live so long? BioSci. 37: 262-269.
                                      2-393
Painted Turtle
-------
Gibbons, J. W.; Nelson, D. H. (1978) The evolutionary significance of delayed emergence
       from the nest by hatchling turtles. Evolution 32: 297-303.

Gist, D. H.; Michaelson, J. A.; Jones, J. M. (1990) Autumn mating in the painted turtle,
       Chrysemys picta. Herpetologica 46: 331-336.

Hall, F. G. (1924) The respiratory exchange in turtles. J. Metab. Res. 6: 393-401.

Hutchinson, V. H. (1979) Thermoregulation. In: Harless, M.; Morlock, H., eds. Turtles:
       perspectives and research. Toronto, Canada: John Wiley and Sons, Inc.; pp.
       207-227.

Iverson, J. B. (1982) Biomass in turtle populations: a neglected subject. Oecologia (Berl.)
       55: 69-76.

Knight, A. W.; Gibbons, J. W. (1968) Food of the  painted turtle, Chrysemys picta in a
       polluted river. Am.  Midi.  Nat. 80: 558-562.

Lagler, K. F. (1943) Food habits and economic relations of the turtles of Michigan with
       special reference to game management. Am. Midi. Nat. 29: 257-312.

Legler, J. M. (1954) Nesting habits of the western painted turtle, Chrysemys picta belli
       Gray. Herpetologica 10:  137-144.

Lynn, W. G.; von Brand, T. (1945) Studies on  the oxygen consumption and water
       metabolism of turtle embryos. Biol. Bull. 88: 112-125.

MacCulIoch, R. D.; Secoy, D. M. (1983) Demography, growth, and food of western
       painted turtles, Chrysemys picta belli! (Gray), from southern Saskatchewan. Can. J.
       Zool. 61: 1499-1509.

Mahmoud, I. Y.; Klicka, J. (1979) Feeding, drinking, and excretion. In: Harless, M.;
       Morlock, H.,  eds. Turtles: perspectives  and  research. Toronto, Canada: John Wiley
       and Sons, Inc.; pp.  229-243.

Marchand,  L.  J. (1942) A contribution to a knowledge of the natural history of certain
       freshwater turtles [master's thesis]. Gainesville, FL: University of Florida.

McAuliffe, J. R. (1978) Seasonal migrational movements of a population  of the western
       painted turtle (Chrysemys picta be/Hi} (reptilia, testudines, testudinidae). J. Herpetol.
       12: 143-149.

Milsom, W. K.; Chan, P. (1986)  The relationship between lung volume, respiratory drive
      and breathing pattern in the turtle, Chrysemys picta. J. Exp. Biol. 120: 233-247.

Mitchell, J. C.  (1985) Female reproductive cycle and life history attributes in a Virginia
      population of painted turtles, Chrysemys picta. J. Herpetol. 19: 218-226.
                                       2-394
Painted Turtle
-------
Mitchell, J. C. (1988) Population ecology and life histories of the freshwater turtles
       Chrysemys picta and Sternotherus odoratus in an urban lake. Herpetol. Monogr. 2:
       40-61.

Moll, E. 0. (1973) Latitudinal and intersubspecific variation in reproduction of the painted
       turtle, Chrysemys picta. Herpetologica 29: 307-318.

Morlock, H.; Herrington, S.; Oldham, M. (1972) Weight loss during food deprivation in the
       eastern painted turtle, Chrysemys picta picta. Copeia 1972: 392-394.

Mount, R. H. (1975) The reptiles and amphibians of Alabama. Auburn, AL: Auburn
       University Agricultural Experiment Station.

Packard, G. C.; Packard, M. J.; Boardman, T. J.; et al. (1983) Influence of water
       exchanges by  flexible-shelled eggs of painted turtles Chrysemys picta  on
       metabolism and growth of embryos. Physiol. Zool. 56:  217-230.

Pearse, A. S. (1923) The abundance and migration of turtles.  Ecology 4: 24-28.

Pope, C. H. (1939) Turtles of the United States and Canada. New  York, NY: Alfred A.
       Knopf.

Powell, C. B. (1967) Female sexual cycles of Chrysemys picta and Clemmys insculpta in
       Nova Scotia. Can. Field-Nat. 81: 134-140.

Ratterman, R. J.; Ackerman, R. A. (1989) The water exchange and hydric microclimate of
       painted turtle (Chrysemys pica)  eggs incubating in field nests. Physiol. Zool. 62:
       1059-1079.

Ream,  C. H. (1967) Some aspects of the ecology of painted turtles, Lake Mendota,
       Wisconsin [Ph.D. dissertation]. Madison, Wl: University of Wisconsin.

Schwarzkopf, L.; Brooks, R. J. (1986)  Annual variations in reproductive characteristics of
       painted turtles (Chrysemys picta). Can.  J. Zool. 64: 1148-1151.

Sexton, O. J. (1959)  Spatial and temporal movements of a population of the  painted
       turtle, Chrysemys picta marginata (Agassiz). Ecol.  Monogr.  29: 113-140.

Seymour, R. S. (1982) Physiological adaptations to aquatic life. In: Cans, C.;  Pough, F. H.,
       eds. Biology of the reptilia, physiology D;  physiological  ecology: v.  13. New York,
       NY: Academic Press; pp.  1-51.

Sievert, L. M.; Sievert, G. A.; Cupp, P. V., Jr. (1988) Metabolic rate of feeding and fasting
       juvenile midland painted turtles, Chrysemys picta marginata. Comp. Biochem.
       Physiol. A Comp. Physiol. 90: 157-159.

Smith,  H. M.  (1956) Handbook of amphibians and reptiles of Kansas. Univ. Kansas Mus.
       Nat. Hist. Misc. Publ. 9; 365 pp.
                                      2-395
Painted Turtle
-------
Smith, P. W. (1961) The amphibians and reptiles of Illinois. III. Nat. Hist. Surv. Bull. 28.

Snow, J. E. (1980) Second clutch laying by painted turtles. Copeia 1980: 534-536.

Snow, J. E. (1982) Predation on painted turtle nests: nest survival as a function of nest
       age. Can. J. Zool. 60: 3290-3292.

Stockard, M. E.; Gatten, R. E. (1983) Activity metabolism of painted turtles (Chrysemys
       picta). Copeia 1983: 214-221.

Taylor, G. M.; Nol, E. (1989) Movements and hibernation sites of overwintering painted
       turtles in southern Ontario. Can. J. Zool. 67: 1877-1881.

Tinkle, D. W.; Congdon, J. D.; Rosen, P. C. (1981) Nesting frequency and success:
       Implications for the  demography of painted turtles. Ecology 62: 1426-1432.

Trobec, T. N.; Stanley, J. G. (1971) Uptake of ions and water by the painted turtle,
       Chrysemys picta. Copeia  1971: 537-542.

Wade, S. E.; Gifford, C. E.  (1965) A preliminary study of the turtle population of a
       northern Indiana lake. Proc. Indiana Acad. Sci. 74: 371-374.

Wilbur, H. M. (1975a) The  evolutionary and mathematical demography of the turtle
       Chrysemys picta. Ecology  56: 64-77.

Wilbur, H. M. (1975b) A growth model for the turtle Chrysemys picta. Copeia 1975:
       337-343.

Zweifel, R.  G. (1989) Long-term ecological studies on a population of painted turtles,
       Chrysemys picta, on Long Island, New York,, Am. Mus. Novit. 2952: 1-55.
                                      2-396
Painted Turtle
-------
2.3.3.  Eastern Box Turtle (box turtles)

       Order Testudines. Family Emvdidae.  Box turtles are the most terrestrial of the
Emydid turtles, having close-fitting shells that have allowed them to adapt well to
terrestrial life.  They are found throughout the eastern and  central United States and into
the southwest. They are omnivorous.

Selected species

       The eastern box turtle (Terrapene Carolina Carolina) ranges from northeastern
Massachusetts to Georgia, west to Michigan, Illinois, and Tennessee (Conant and Collins,
1991). There  are four subspecies of T. Carolina, all found within the eastern United
States: T.  c. Carolina (above), T. c. major (Gulf Coast box turtle; the largest subspecies,
restricted to the Gulf Coast), T. c. triunguis (three-toed box turtle; Missouri to south-
central Alabama and  Texas), and T. c. bauri (Florida box turtle; restricted to the Florida
peninsula and  keys) (Conant and  Collins, 1991).

       Body size.  The eastern box turtle is small, with adults ranging  from 11.5 to 15.2
cm in length (plastron) and approximately 300 to over 400 g.  Hatchlings weigh
approximately  8 to 10 g. Turtles continue to grow throughout their lives; however, their
growth rate slows after reaching  sexual maturity (Ernst and Barbour, 1972), land growth
rings are no longer discernable after 18 to 20 years (Stickel, 1978). Body fat reserves in a
Georgia population averaged 0.058 to 0.060 g of fat per gram of lean  dry weight from
spring through fall (Brisbin,  1972).

       Habitat. Typical box turtle habitats include  open  woodlands, thickets, and well-
drained but moist forested areas (Stickel, 1950), but occasionally pastures and marshy
meadows are utilized (Ernst and Barbour, 1972).  In areas with mixed  woodlands and
grasslands, box turtles use grassland areas in times of moderate temperatures and peak
moisture conditions; otherwise, they tend to use the more moist  forested habitats
(Reagan, 1974). Many turtles are killed attempting to cross roads, and fragmentation of
habitat by roads can severely reduce populations (DeGraaf  and Rudis,  1983; Stickel,
1978).

       Food habits.  Adult T. Carolina are omnivorous CErnst and Barbour, 1972). When
young, they are primarily carnivorous, but they become more herbivorous as they age and
as growth slows (Ernst and Barbour, 1972).  They consume a wide variety of animal
material, including earthworms, slugs, snails, insects and their larvae (particularly
grasshoppers,  moths, and beetles), crayfish, frogs, toads,  snakes, and carrion; they also
consume vegetable matter, including leaves, grass, berries, fruits, and fungi (DeGraaf and
Rudis,  1983).  A high proportion of snails and slugs may comprise the animal matter in the
diet (Barbour, 1950), and seeds can become an important component  of the plant
materials in the late summer and fall (Klimstra and  Newsome, 1960).

       Temperature regulation and daily activities.  The species is diurnal and spends the
night resting in a scooped depression or form that  the turtle digs  in the soil with its front
feet (Ernst  and  Barbour,  1972; Stickel, 1950). T. Carolina are most active in temperate.
                                       2-397
Eastern Box Turtle
-------
humid weather (Stickel, 1950). In the summer, they avoid high temperatures during
midday by resting under logs or leaf litter, in mammal burrows, or by congregating in
mudholes (Smith, 1961; Stickel, 1950).  In the hottest weather, they may enter shaded
shallow pools for hours or days (Ernst and Barbour, 1972). In the cooler temperatures,
they may restrict their foraging activities to  midday (Stickel, 1950). In the laboratory,
locomotion is maximal  between 24 and 32°C (Adams et al., 1989).  In the field, their
mean active body temperature is approximately 2S°C (Brattstrom, 1965, cited in
Hutchinson, 1979).

       Hibernation.  In the northern parts of its range (northeastern Massachusetts,
Michigan, Illinois), the eastern  box turtle enters hibernation in late October or November
and emerges in April.  In Louisiana, Penn and Pottharst (1940, cited in Ernst and Barbour,
1972} found  that T. c.  major hibernated when temperatures fell below 65°F.  To
hibernate, the box turtle burrows into loose  soil and debris or mud of ponds or stream
bottoms.  Congdon et al. (1989) found a South Carolina population of box turtles to
occupy relatively shallow burrows (less than 4 cm) compared with those occupied by box
turtles in colder regions (up to  46 cm). Dolbeer (1971) found hibernacula of box turtles in
Tennessee to be under 15.5 cm of leaf litter and 5.8 cm of soil on average. In southern
states, during rainy and warm  periods, box turtles may become active again (Dolbeer,
1971). In Florida, the box turtle may be active all year (Ernst and  Barbour, 1972).
            *
       Breeding activities and social organization.  Box turtles are solitary except briefly
during the mating season. Individuals restrict their activities to a foraging home range, but
home ranges of different individuals  can overlap substantially (Stickel, 1950).  Mating
usually occurs in the spring but may continue into, fall, and eggs are laid in late spring and
summer (Ernst and Barbour,  1972).  The female digs a 3- to 4-inch cavity in sandy or
loamy soil in  which she deposits her eggs and then covers the nest with soil.  Nests tend
to be constructed several hundred meters from the female's foraging home range in the
warmer and drier uplands (Stickel, 1989). The duration of incubation depends on soil
temperatures, and sometimes hatchlings overwinter in the nest. The young are
semiaquatic but seldom seen (Smith, 1956).

       Home range and resources.  Measures of the foraging home range for box turtles
range from .5 ha to just over 5 ha (Dolbeer,  1969; Schwartz et al., 1984). A female may
need to search for suitable nest site (e.g., slightly elevated sandy soils) (Ernst and Barbour,
1972) outside of her foraging home range (Stickel, 1950). Winter hibernacula tend to be
within the foraging home range (Stickel, 1989).

       Population density.  Population density varies with habitat quality, but studies
linking density to particular habitat characteristics are lacking. In some areas, population
densities have declined steadily over the past several decades (Schwartz and Schwartz,
1974; Stickel, 1978).  Some investigators attribute the decline to increasing habitat
fragmentation and obstacles (e.g., highways) that prevent females from reaching or
returning from appropriate nesting areas (Stickel,  1978;  DeGraaf and Rudis, 1983).

       Population dynamics.  Sexual maturity is attained at about 4 or 5 years (Ernst and
Barbour, 1972) to 5 to  10 years of age (Minton, 1972, cited in DeGraaf and Rudis, 1983).
One to four clutches may be laid per year, depending on latitude (Oliver, 1955, cited in

                                      2-398                      Eastern Box Turtle
-------
Moll, 1979; Smith, 1961). Clutch size ranges from three to eight eggs, averaging three to
four in some areas (Congdon and Gibbons, 1985; Ernst and Barbour, 1972; Smith, 1956).
Juveniles generally comprise a small proportion of box turtle populations, for example> 18
to 25 percent in one population in Missouri (Schwartz and Schwartz, 1974) and 10
percent in a study in Maryland (Stickel, 1950).  Some individual box turtles may live over
100 years (Graham and Hutchinson, 1969, cited in DeGraaf and Rudis, 1983; Oliver,
1955, cited in Auffenberg and Iverson, 1979).

Similar species (from general references)

      •      The ornate box turtle (Terrapene ornata ornata) and the desert box turtle
             (Terrapene ornata luteola) are similar in size and habits to the eastern box
             turtle, they occur in the western, midwestern, and southern midwestern
             states.  Preferred habitats include open prairies, pastureland, open
             woodlands, and waterways in arid, sandy-soil terrains. The ornate box turtle
             and desert box turtle forage primarily on insects but also on berries and
             carrion.

General references

      Behler and King (1979); Conant and Collins (1991); DeGraaf and Rudis (1983);
Ernst and Barbour (1972); Stickel (1950).
                                      2-399
Eastern Box Turtle
-------
                                       Eastern Box Turtle (Terrapene Carolina]
Factors
Body Weight
(g)


•
; -
Body Fat
(g/g lean dry
weight)
Length
Egg Weight ig)
Metabolic Hate
(kcaJ/ks-d)
Food ingestion
Rate (g/g-d{
Age/Sex/
Cond./Seas.
A F fall
A M fall
A F spring
A M spring
AF
at hatching
2 months
1 .3 years
3.3 years
Bfall
B spring
B summer
AF
A
at hatching

A F basal

Mean
381 ± 29 SE
398 ± 47 SE
388 ± 29 SE
369 ± 47 SE
372
8.8
8.4
21
40
54
0.058 ± 0.01 4 SE
0.060 ± 0.01 6 SE
0.059 ± 0.006 SE
1 29 mm plastron
28 mm carapace
9.02 ± 0.17 SE
5.4

Range or
(95% Cl of mean)






up to 1 98 mm
carapace
6- 11


Location (subspecies)
Georgia (Carolina), captive
Georgia (Carolina)
South Carolina
Florida (major)
Indiana (Carolina)
Tennessee
Georgia (Carolina), captive
South Carolina
NS/NS
NS/NS
South Carolina
NS/NS


Reference
Brisbin, 1972
Brisbin, 1972
Congdon & Gibbons, 1985
Ewert, 1979
Ewert, 1979
Allard, 1948
Brisbin, 1972
Congdon & Gibbons, 1985
Oliver, 1955
Oliver, 1955
Congdon & Gibbons, 1985
Ernst & Barbour, 1972
estimated

Note
NO,




1

2
2

3
4
to
-k
o
o
m
CD
"^
3

03
O
X

H
CD
-------
                                       Eastern Box Turtle (Terrapene Carolina]

Dietary Composition
snails
Crayfish
plants
crickets -
unidentified seeds
plant matter
insects (adults)
insects (larvae)
seeds'
Gastropoda
(sopoda
Diplopoda
Decapoda
Annelida
mammals
reptiles
.birds
Population
Dynamics
Home Range
Size (ha)




Population
Density
IN/ha)

Spring





35
18
4
8
18
<1
3
2
1
2
1
3
Age/Sex/
Cond./Seas.
summer

B M
B F
B M
B F




Summer
60
15
12.5
7.5
5
39
12
5
16
6
5
2
2
1
<1
3
1

Fall





20
12
9
33
8
3
5
0
4
2
1
<1

Mean
0.46

1.2
1.1
5.2
5.1
2.8-3.6

17-35
s
Winter

















Range or
(95%,CI of mean)









Location {subspecies}/
Habitat (measure)
Kentucky (Carolina}!
Cumberland Mountains

(% volume; stomach
contents)
Illinois (caro///?3)/forest,
prairie

(% wet volume; digestive
tract)







Location •
(subspecies I/Habitat
Tennessee (Carolina}!
woodland
Maryland (Carolina}!
bottomland forest
Missouri (triunguis} /mixed
woods, fields
Tennessee/woodland

Maryland (triunguis)ftorest
••
Reference
Barbour, 1950




Klimstra & Newsome, 1960











-
Reference
Dolbeer, 1969

Stickel, 1 989

Schwartz et al., 1 984

Dolbeer, 1969

Schwartz et al., 1984
Note
No*

















Note
No,
5

5

5




fO
^
o
m
o>
CD
-t


CO
o
X

H
c
r+
CD
-------
1
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ca
I
LU
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zz







CD
o
Referen




^*
Location
(subspectes)/Habltf
1
CO
E
***
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fe HH
o
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IS




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§
s
1
en o
< 0

Population
|| Dynamics



in
CO
en
*~
0?
o
JD

!aS
CD 4-»
0 1
O CO




CO
South Carolina/NS
Washington, DC/N






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CM
LU
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CO
d
•H
"*
co -"fr



N
CO
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o.v-;.1..'


CO







in T-
m co
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O CO





Rorida/NS
tllinois/NS





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o
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Q.
3






*"



piC(iitches/ye


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en en
yw «—
•ff CD
ii

2
3

s
northwest
Minnesota/(natural!
Washington, DC/(r




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O CD
*~ *~"
oo en
r-» CD





O5
en


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n-
o
,1
£3


00


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en
*~
, ^
3
O CM
•Q p*s
co en
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o3 £*
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v. ^~
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CO CO












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in *-
i t
•* in

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l--
ll


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m
in
en
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0





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z
z



o
CO
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1
O
o
T—








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o
IS 1
iifi
,

00 CM






co
en
co in
en in
«- en
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2 v
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Z O





z>
is



00
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o o
•4-* 4-*
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3 3





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'5
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i
1
,



2
73
co
Q.
i
-------
to
-k
o
CO
rn
03
CD
—t

00
                                                Eastern Box Turtle (Terrapene Carolina]
     4   See Chapters 3 and 4 for methods of estimating ingestion rates from metabolic rate and diet.
     5   Foraging home range; nest sites can be several hundred meters away from the foraging home range.
     6   Cited in Moll (1979).
     7   Cited in Ewert (1979).
     8   Cited in DeGraaf and Rudis (1983).
c
rt
CD
-------
References (including Appendix)

Adams, N. A.; Claussen, D. L.; Skillings, J. (1989) Effects of temperature on voluntary
       locomotion of the eastern box turtle, Terrapene Carolina Carolina. Copeia 4:
       905-915.

Allard, H. A. (1935) The natural history of the box turtle. Sci. Monthly 41: 325-338.

Allard, H. A. (1948) The eastern box-turtle and its behavior, part 1. J. Tenn. Acad. Sci.
       23:307-321.

Auffenberg, W.; Iverson, J. G. (1979) Demography of terrestrial turtles. In: Harless, M.;
       Morlock, H., eds. Turtles: perspectives and research. Toronto, Canada: John Wiley
       and Sons; pp. 541-569.

Barbour, R. W. (1950) The reptiles of Big Black Mountain, Harlan County, Kentucky.
       Copeia 1950: 100-107.

Behler, J. L; King, F. W. (1979) The Audubon Society field guide to North American
       reptiles and amphibians. New York,  NY:  Alfred A. Knopf, Inc.

Brattstrom, B. H. (1965) Body temperatures of  reptiles. Am. Midi.  Nat. 73: 376-422.

Breder, R. B. (1927) Turtle trailing: a new technique for studying the life habits of certain
       testudinata. Zoologica  9: 231-243.

Brisbin, I. L., Jr.  (1972) Seasonal variations in the live weights and major body
       components of captive box turtles. Herpetologica 28: 70-75.

Bush, F. M. (1959) Foods of some Kentucky herptiles. Herpetologica 15: 73-77.

Cahn, A. R. (1937) The turtles of Illinois. Illinois Biol. Monogr. 1-218.

Carr, A. F. (1952) Handbook of turtles. Ithaca,  NY: Comstock.

Conant, R.; Collins, J. T. (1991) A neld guide to reptiles and amphibians: eastern/central
       North America. Boston, MA: Houghton Mifflin Co.

Congdon, J. D.; Gibbons,  J. W.  (1985) Egg components and reproductive characteristics
       of turtles: relationships to body size. Herpetologica 41: 194-205.

Congdon, J. D.; Gatten, R. E., Jr.; Morreale, S.  J. (1989) Overwintering activity of box
      turtles (Terrapene Carolina) in South  Carolina. J. Herpetol. 23: 179-181.

DeGraaf, R. M.; Rudis, D. D. (1983) Box turtle.  Amphibians and reptiles of New England.
      Amherst,  MA: University  of Massachusetts Press.
                                       2-404
Eastern Box Turtle
-------
Dickson, J. D., Ill (1953) The private life of the box turtle. Everglades Nat. Hist. 1: 58-62.

Dodge, C. H.; Dimond, M. T.; Wunder, C. C. (1979) The influence of temperature on the
       incubation of box turtle eggs (abstract only). Am. Zool. 19: 981.

Dolbeer,  R. A. (1969) Population density and home range size of the eastern box turtle
       (Terrapene c. Carolina) in eastern Tennessee. A.S.B. Bull. 16: 49.

Dolbeer,  R. A. (1971) Winter behavior of the eastern box turtle,  Terrapene c. Carolina L., in
       eastern Tennessee. Copeia 1971: 758-760.

Ernst, C. H.; Barbour, R. W.  (1972) Turtles of the United States. Lexington, KY: University
       Press of Kentucky.

Ewert, M. A. (1979) The embryo and its egg: development and natural history. In: Harless,
       M.; Morlock, H., eds. Turtles: perspectives and research.  Toronto, Canada: John
       Wiley and Sons, Inc.; pp. 333-413.

Ewing, H. E. (1933) Reproduction in the eastern box-turtle Terrapene Carolina Carolina.
       Copeia 1933: 95-96.

Graham,  T. E.; Hutchinson, V. H. (1969) Centenarian box turtles. Int. Turtle Tortoise Soc.
       J. 3:  24-29.

Hall, F. G. (1924) The respiratory exchange in turtles. J. Metab.  Res. 6: 393-401.

Hutchinson,  V. H. (1979) Thermoregulation. In: Harless, M.; Morlock, H., eds. Turtles:
       perspectives and research. Toronto, Canada: John Wiley and  Sons, Inc.; pp.
       207-227.

Klimstra, W. D.; Newsome, F. (1960) Some observations on the food coactions of the
       common box turtle, Terrapene c. Carolina. Ecology 41: 639-647.

Lynn, W. G.; von Brand, T. (1945) Studies on the oxygen consumption and water
       metabolism of turtle embryos. Biol. Bull. 88: 112-125.

Minton, S. A., Jr. (1972) Amphibians and reptiles of Indiana. Indianapolis, IN: Indiana
      Academy of Science.

Moll, E. O. (1979) Reproductive cycles and adaptations. In: Harless,  M.; Morlock, H., eds.
      Turtles: perspectives and research. Toronto, Canada: John Wiley and Sons, Inc.;
       pp. 305-331.

Nichols, J. T. (1939a) Data on size, growth and age in the box turtle, Terrapene Carolina.
      Copeia  1939: 14-20.

Nichols, J. T. (1939b) Range and homing of individual box turtles. Copeia 1939: 125-127.
                                      2-405
Eastern Box Turtle
-------
Oliver, J. A. (1955) The natural history of North American amphibians and reptiles.
       Princeton, NJ: Van Nostrand Co.

Penn, G. H.; Pottharst, K. E. (1940) The reproduction and dormancy of  Terrapene major'in
       New Orleans. Herpetologica 2: 25-29.

Reagan, D. P. (1974) Habitat selection in the three-toed box turtle Terrapene Carolina
       triunguis. Copeia 2: 512-527.

Robinson, R. W.; Peters, R. H.; Zimmermann, J. (1983) The effects of body size and
       temperature on metabolic rate of organisms. Can.  J. Zool. 61: 281-288.

Rosenberger, R. C. (1972) Interesting facts about turtles. Int. Turtle.Tortoise Soc. J. 6:
       4-7.

Schwartz, C. W.; Schwartz, E. R.  (1974) The three-toed box turtle in central Missouri: its
       population, home range, and movements. Missouri Dept. Conserv.  Terr. Ser. No.  5;
       28pp.

Schwartz, E. R.; Schwartz,  C. W.; Kiester, A. R. (1984) The three-toed  box  turtle in
       centra! Missouri,  part II: a nineteen-year study of home range,  movements and
       population. Missouri  Dept. Conserv. Terr. Ser. No. 12; 29 pp.

Smith, H. M. (1956) Handbook of amphibians and  reptiles of Kansas. Univ. Kansas Mus.
       Nat. Hist. Misc. Publ. 9.

Smith, P. W. (1961) The amphibians and reptiles of Illinois.  III. Nat. Hist. Surv. Bull. 28:
       118-120..

Stickel, L. F. (1950) Population and home range relationships of the box turtle, Terrapene
       c. Carolina (Linnaeus). Ecol. Monogr. 20: 351-378.

Stickel, L. F. (1978) Changes in a  box turtle population during three decades. Copeia
       1978: 221-225.

Stickel, L. F. (1989) Home range behavior among box turtles (Terrapene c. Carolina) of a
       bottomland forest in  Maryland. J. Herpetol.  23: 40-44.

Stickel, L. F.; Bunck, C.  M.  (1989) Growth and  morphometrics  of the box  turtle,  Terrapene
       c. Carolina. J. Herpetol. 23: 216-223.

Strang, C. A. (1983) Spatial and temporal activity patterns in two terrestrial  turtles. J.
       Herpetol. 17:43-47.
                                       2-406
Eastern Box Turtle
-------
 2.3 A.   Racer (and whipsnakes)

       Order Sauamata. Family Colubridae.  All racer snakes (Coluber constrictor) and
 whipsnakes (Masticophis) belong to the family Colubridae, along with 84 percent of the
 snake species in North America. Colubrids vary widely in form and size and can be found
 in numerous terrestrial and aquatic habitats.  The more terrestrial members of this family
 also include some brown and garter snakes; lined snakes; earth snakes; hognose snakes;
 small woodland snakes; green snakes; speckled racer and indigo snakes; rat snakes; glossy
 snakes; pine, bull, and gopher snakes; kingsnakes and milk snakes; scarlet, long-nosed,
 and short-tailed snakes; ground snakes; rear-fanged  snakes; and crowned and black-
 headed snakes (Conant and Collins, 1991).

 Selected species

       Racer snakes (Coluber constrictor) are slender and fast moving and are found in a
 wide variety of terrestrial habitats.  They are one of the most common  large snakes in
 North America (Smith, 1961). There are 11 subspecies in North America, limited to the
 United States and Mexico:  C. c. constrictor (northern  black racer; southern Maine to
 northeastern Alabama), C. c.  flaviventris (eastern yellowbelly racer; Montana, western
 North Dakota, and Iowa south to Texas), C. c. foxii (blue racer; northwest Ohio to eastern
 Iowa and  southeast Minnesota), C. c. anthicus (buttermilk racer; south  Arkansas,
 Louisiana, and east Texas), C. c. etheridgei (tan racer; west-central Louisiana and adjacent
 Texas), C. c. helvigularis (brownchin racer; lower Chipola and Apalachicola River Valleys in
 Florida panhandle and adjacent Georgia), C. c, latrunculus (blackmask racer; southeast
 Louisiana  along east side of Mississippi River to northern Mississippi), C. c. mormon
 (western yellow-bellied racer; south British Colombia to Baja California,  east to southwest
 Montana, western Wyoming,  and western Colorado), C. c. oaxaca (Mexican racer; south
 Texas and Mexico), C. c. paludicola (Everglades racer; southern Florida  Everglades region
 and Cape Canaveral area), and C. c. priapus (southern  black racer; southeastern states and
 north and west in Mississippi  Valley).

       Body size. Adult racer snakes are usually 76  to 152 cm in total  length (Conant and
 Collins, 1991). Brown and Parker (1984) developed an empirical relationship between
 snout-to-vent length  (SVL)1 and body weight for male and female racers of the mormon
 subspecies in northern Utah:
       weight (g) = -100.80  + 2.93 SVL (cm)

       weight (g) =  -82.65 + 2.57 SVL (cm)
females,1 and

males.
The equations apply only over a limited range of body sizes (40 to 70 cm) where the
relationship is approximately linear instead of exponential. Kaufman and Gibbons (1975)
'Measures of SVL exclude the tail.  Fitch (1963) estimated that the tail measures 28 percent of the
SVL of young females and 31 percent of the SVL of young males.
'Females collected when nonreproductive.
                                       2-407
                           Racer
-------
determined a relationship between length and weight for both sexes of a South Carolina
population:

       weight (g) = 0.0003 SVL (cm)2-97 (± °-15 2SE)    both sexes.k

Racers from populations in the northeastern United States tend to be the largest, while
those from the far west and south Texas are the smallest (Fitch, 1963).  Just prior to egg-
laying, the eggs  can account for over 40 percent of a gravid female's body weight (Brown
and Parker, 1984). At hatching, racers weigh about 8 or 9 g. Weight gain during the first
year is rapid, with both sexes increasing their weight after hatching by approximately 3.2
times in the first year (Brown and  Parker, 1984).  One-year-old females nearly double their
weight during their second year (Brown and Parker, 1984). By the time females are  3
years old (when  most reach sexual maturity), they are 1.3 times heavier than the males
(Brown and Parker, 1984).

       Habitat. Racers can be found in moist or dry areas, abandoned fields, open
woodlands, mountain meadows, rocky wooded hillsides, grassy-bordered streams, pine
flatwoods, roadsides, and marshes from sea level to 2,150 m in elevation (Behler and
King, 1979). Racers are partially arboreal (Behler and King, 1979; DeGraaf and Rudis,
1983).  C. c. constrictor seems to prefer forest edges and open grassy, shrubby areas
(Fitch, 1963, 1982).  In autumn, most C. constrictor move into  woodlands to find rock
crevices in which to overwinter (Fitch, 1982).

      Food habits. Racers are foraging generalists that actively seek their prey.  Their
varied diet includes small mammals (e.g., mice, voles), insects, amphibians (especially
frogs), small birds, birds' eggs, snakes, and lizards (Brown and Parker, 1982; Fitch, 1963;
Klimstra, 1959).  In early spring, C.c. flaviventris feeds primarily on mammals and from
May to October feeds primarily on insects (Klimstra, 1959).  They often capture new prey
before fully digesting previously captured prey (Fitch, 1982).  Females, which are larger
than males, tend to consume a higher proportion of vertebrate prey than do the males
(Fitch, 1982). Males tend to spend more time climbing among foliage in low  shrubs  and
trees and consuming insects (Fitch, 1982).

       Temperature regulation and daily activities.  C. constrictor is diurnal and spends a
good portion of the daylight hours foraging (Verrnersch and Kuntz, 1986). The species is
fast moving and  may be encountered in almost any terrestrial situation (Fitch, 1982).
Hammerson (1987) observed California racers to bask in the sun after emerging from their
night burrows or crevices until their internal body temperature reached almost 34°C, after
which they would begin actively foraging.  When temperatures are moderate, racers  will
spend much of their time during the day in the open above ground; at high temperatures,
racers may retreat underground  (Brown and Parker, 1982).  Although racers are good
climbers, they spend  most of their time on the ground (Behler and King, 1979). When
searching for food or being pursued, the racer snake will not hesitate  to climb or swim
(Smith, 1961).
k95 percent confidence interval for constant (intercept in log-transform regression) = 0.00015 to
 0.00058.
                                       2-408
Racer
-------
      Hibernation.  In fall, racers move to their hibernacula fairly directly and begin
hibernation soon thereafter (Brown and Parker,  1982; Fitch, 1963). Racers hibernate in
congregations of tens to hundreds of snakes (Brown and Parker, 1984), sometimes with
copperheads and rattlesnakes, often using deep rock crevices or abandoned woodchuck
holes (Parker and Brown, 1973).  They are among the earliest snakes to emerge from
hibernation (DeGraaf and Rudis, 1983).

. ••  .  Breeding activities and social organization.  The species breeds in the spring or early
summer. Racers defend home territories (DeGraaf and Rudis,  1983; Smith, 1956).  Eggs
are laid in the summer in rotting wood, stumps, decaying vegetable matter, or loose soil
and hatch about 2 months later (Behler and King, 1979; DeGraaf and Rudis, 1983). More
than one male may mate with one female in a breeding  season.  Eggs may double in size
before hatching by absorbing water from the surrounding soil (Fitch, 1963).

      Home range and resources. C. c. constrictor appears to have a definite home range
(Smith, 1956) and requires large tracts of mixed old fields and woodlands (M.  Klemens,
pers. comm., cited in DeGraaf and Rudis, 1983). Fitch  (1963) described four types of
movement depending on the season and activity:  (1) those in areas where hibernation
occurs (e.g., rocky ledges), (2) seasonal migration between hibernation and summer
ranges during spring and fall, (3) daily activities within a home range during the active
season, and (4) wandering movements during which the racer shifts its activities.

      Population density. Population densities of between 0.3 and 7 active snakes per
hectare have been recorded in different habitats and areas  (Fitch, 1963; Turner, 1977).
Data on population densities are limited due to the difficulty in accurately censusing
snakes.

      Population dynamics.  Male racers can reach sexual  maturity by 13 to 14 months,
whereas females tend not to mature until 2 or 3 years of age (Behler and King, 1979;
Brown and  Parker, 1984). Adult females produce at most a single clutch each year (some
may reproduce only in alternate years)  (Fitch, 1963). In general, the number of eggs in a
clutch is proportional to the size of the female and ranges from 4 to 30 eggs (Fitch, 1963).
Incubation lasts approximately 40  days to 2 months, depending on temperature (Behler
and King, 1979; Smith, 1956). Juvenile snakes suffer higher mortality rates (e.g., 80
percent) than adult snakes (e.g., 20 percent) (Brown and Parker, 1984).

Similar species (from general references)

      •      The eastern coachwhip (Masticophis flagellum flagellum) (black phase) is
             similar in size and ranges from North Carolina and south Florida to Texas,
             Oklahoma, and Kansas.

      •      The western coachwhip (Masticophis flagellum testaceus)  is similar in size to
             the racer.  It ranges from western Nebraska south to Mexico.

      •      The central Texas whlpsnake (Masticophis taeniatus girardi), Schott's
             whipsnake (Masticophis taeniatus schotti), and Ruthven's whipsnake
                                      2-409
Racer
-------
             (Masticophis taeniatus ruthveni) are all similar in size to the racer and are
             restricted to southern Texas and northern Mexico.

      •      The Sonora whipsnake (Masticophis bi/ineatus) can be slightly larger (76 to
             170 cm) than the racer and is found from Arizona southwest to New Mexico
             and Mexico.

      •      The striped racer (Masticophis lateralis) is also similar in size to the racer
             snake. It ranges from south-central Washington southeast in Great Basin to
             southern New Mexico and western and central Texas, south to west-central
             Mexico.

      •      The desert striped whipsnake (Masticophis taeniatus taeniatus) is similar to
             the central Texas whipsnake.  It ranges from northern  Texas and northern
             California to Washington state.

General references

      Behler and King (1979); Brown and Parker (1984); Conant and Collins (1991);
DeGraaf and Rudis (1983); Fitch (1963).
                                      2-410
Racer
-------
                                               Racer Snake (Coluber constrictor]
     Factors
ro
                    Age/Sex/
                    ContL/Seas*
                       5  620
                       6  632

                       males:
                     yrs/mm SVL
                       2  615
                       3  706
                       4  757
                       5  806
                       6  827
                       7  845
                       8  868
Mean
— 	
Body Weight males:
fa) j yrs/mm SVL
<1 266
..

"
- 1 420
2 486
3 520
4 541


*.•



5 564
6 573
females:
yrs/mm SVL
<1 272
1 430
I 2 524
I 3 575
8.3
27.0
41.0
49.1
53.4
60.4
61.2


8.8
28.4
51.6
66.2
J 4 599 I 71.4
  79.4
  84.0
  68.2
  102.1
  139.0
  152.4
  175.9
  181.2
  217.5
Range or        ,
{95% CI of mean) | Location (subspecfesl
                 Utah (mormon]
Reference
^»^^——
Brown & Parker, 1984
                                                                                                                       Note
                                                                                                                       No*
                                                                    Utah (mormon]
                                                                                              Brown & Parker, 1984
                                   Kansas (flaviventris]
                                            Fitch, 1963
 30
 Q>
 O
 CD
-------
                                       Racer Snake (Coluber constrictor]

Factors
Body Weight
<9>
(continued)



•
v f
,
•
Egg Weight (g]


••
Juvenile
Growth Rate
(g/d)
Body
Temperature
ra
Metabolic Bate
(kcat/kg-d)
Food Ingestion
Rate fg/g-d)
Age/Sex/
Cond./Seas.
females:
yrs/mm SVL
2 644
3 810
4 866
5 914
6 965
7 974
neonate
215mm SVL
female size:
892 mm SVL
773 mm SVL
size MS
both sexes;
0 to 1 0 wks

A B summer

A B summer
M basal
F basal
B B: spring
through fall

Mean


83.5
149.4
212.3
209.6
245.9
251.3
4.16


5.5
4.9
7.8 ± 0.17 SE
0.116


31.8 ± 0.20 SE

26 - 27 (mode)
6.78
6.19
0.02

Range or
(95% Cl of mean!








2.4 - 5.8


4.4 - 6.0
4.4 - 5.2
5.9 - 10.8



18.6-37.7

15.5-32.4





Location (subspecies)
Kansas (flaviventris)







Kansas (flaviventris}

Kansas (flaviventris)


Utah (mormon}
Kansas , (flaviventris}
'

Utah (mormon}

Kansas (flaviventris)


Kansas (flaviventris)


Reference
Fitch, 1963







Fitch, 1963

Fitch, 1963


Brown & Parker, 1 984
Fitch, 1963


Brown, 1973

Fitch, 1963
estimated

Fitch, 1982

Note
No.




**









1


2


3

4

•33
03
O
CD
-------
                                                  Racer Snake (Coluber constrictor]
                                                                        Ucatfon/Habrtat
                                                                        (measure)
     insects
     small mammals
     amphibians
     reptiles
     birds
     other
                                                                         Illinois/pastures,

                                                                        (% volume; digestive tracts)
    small mammals
    Qthopterans
    lizards
    snakes
         insects
   birds
   frogs
                                                                       Kansas (f/aviventris)/          Rt h
                                                                         locat,ons throughout state
                                                                          wet weight; scats and
                                                                         stomach contents)
   mice
   orthopteraos
   lizards
  'frogs
  snakes
  crickets
                                                                      Kansas (flaviventris}!
                                                                        woodland, grassland
                                                                      (% wet weight; stomach
                                                                        contents)
Population
 3ynarntc$

Home Range
                 Age/Sexjf
                 CondJSeas.
                                                                     Ucatfon (subspecies)/
                                                                     Habitat
                 A F summer
                   M summer
                                                                    Kansas (flaviventris)!
                                                                               , grassland
Population
Density
                                                                    Kansas (flaviventrls)!
                                                                      upland prairie, weeds,
                                                                      grasses
-------
                                        Racer Snake (Coluber constrictor]
Population
Dynamics
Clutch Size
Clutches/Year
Days
Incubation
Age at Sexual i
Maturity
Annual
Mortality Rates
'<%i
' Longevity
iyr}
Seasonal
Activity
Mating
Nesting
f :
Hatching
Age/Sex/
Cond./Seas.
average
average
average

summer
summer
F
M
B 2 yrs
B 3 - 6 yrs
B 7 yrs
AB
Begin
April
May
April
June
June
late August
Mean
16.8
12.6
5.28 ± 0.24 SE
0.5
51
45-50
2 - 3 years
13- 14 months
58
25-30
38

Peak
May

mid-late August
Range or
[95% CI of mean)
7-31
7-21
4-8
up to 1
43-63


up to 20
End
June
early June
May
July
early August
early September
Location (subspecies)/
Habitat
NS (constrictoriMS
NS (pr/a>pws)/NS
Utah {mor/770/7)/desert shrub
Kansas (flaviventris}!
woodland, grassland
Kansas (flaviventris)l\ab
Utah {/normo/7)/desert
Kansas (flaviventris)/
woodland, grassland
Kansas (flaviventris)!
woodland, grassland
Utah (mom?0/7)/cold desert
shrub
Location (subspecies)
Kansas (flaviventris)
NS (constrictor]
Texas (flaviventris)
Virginia, Carolinas
Texas (flaviventris)
Kansas (flaviventris)
Utah (mormon)
Reference
Fitch, 1963
Fitch, 1963
Brown & Parker, 1984
Fitch, 1963
Fitch, 1963"
Brown & Parker, 1 984
Fitch, 1963
Fitch, 1963
Brown & Parker, 1 982
Reference
Fitch, 1963
DeGraaf & Rudis, 1 983
Vermersch and Kuntz, 1986
Martof et al., 1 980
Vermersch and Kuntz, 1 986
Fitch, 1963
Brown & Parker, 1 982
Note
No.
6
6





Note
No.



-^
—k
•&•
3J
0)
o
CD
-------
                                                     Racer Snake (Coluber constrictor]
Seasonal
Activity
Hibernation
Begin
late November
early October
Peak

End
early April
early May
Location (subspecies)
Kansas (flaviventris)
Utah (mormon)
Reference
Fitch, 1963
Brown & Parker, 1 982
Note
No.

NJ
CJI
      1   Ten-week period from hatching to hibernation.
      2   Active snakes under natural conditions; cited in Brown and Parker (1982).
      3   Estimated assuming temperature of 20°C using Equation 3-50 (Robinson et al., 1983) and body weights of 3-year-old snakes from Fitch (1963).
      4   Author estimated that" the snakes eat approximately four times their body weight over the 213-day active season from spring through fall.
      5   Size of snakes not specified; captured within the range of C. c. flaviventris and C. c. priapus.
      6   Author summarizing own work and unspecified other studies.
01
o
CD
-------
References (including Appendix)

Behler, J. L.; King, F. W. (1979) The Audubon Society field guide to North American
      reptiles and amphibians. New York, NY: Alfred A. Knopf, Inc.

Brown, W. S. (1973) Ecology of the racer. Coluber constrictor mormon (Serprentes,
      Colubridae), in a cold temperate desert in northern Utah [Ph.D. dissertation]. Salt
      Lake City, UT: University of Utah.

Brown, W. S.; Parker, W. S. (1982) Niche dimensions and resource partitioning in a great
      basin desert snake community. U.S. Fish Wildl. Serv. Wildl. Res. Rep. 13: 59-81.

Brown, W. S.; Parker, W. S. (1984) Growth,  reproduction and demography of the racer,
      Coluber constrictor mormon, in northern Utah. In: Seigel, R. A.; Hunt, L. E.; Knight,
      J. L.; et al., eds. Vertebrate ecology and systematics. Lawrence, KS: Museum of
      Natural History, The University of Kansas;  pp. 13-40.

Conant, R.; Collins, J. T. (1991) A field guide to reptiles and amphibians: eastern/central
      North America. Boston, MA: Houghton Mifflin Co.

Corn, P. S.; Bury, R. B. (1986) Morphological variation and zoogeography of racers
      (Coluber constrictor) in the central Rocky mountains. Herpetologica  42: 258-264.

DeGraaf, R. M.; Rudis, D. D. (1983) Racer snake. Amphibians and reptiles  of New
      England. Amherst, MA: University of Massachusetts Press; pp. 68.

Fitch, H.  S. (1963) Natural history of the racer Coluber constrictor: v. 15. Lawrence, KS:
      University of Kansas Publications, Museum of Natural History; pp. 351-468.

Fitch, H.  S. (1982) Resources of a snake community in prairie woodland habitat of
      northeastern Kansas. In: Scott, N. J., Jr., ed.  Herpetological communities. U.S. Fish
      Wildl. Serv. Wildl. Res. Rep. 13; pp. 83-98.

Gibbons, J. W.; Semlitsch, R. D. (1991) Guide to the reptiles and amphibians of the
      Savannah River site. Athens, GA: The  University of Georgia Press.

Hammerson, G. A. (1987) Thermal behaviour of the snake Coluber constrictor in
      west-central California. J. Therm. Biol. 12: 195-197.

Kaufman, G. A.; Gibbons, J. W.  (1975) Weight-length relationship in thirteen species of
      snakes in the southeastern  United States. Herpetologica 31: 31-37.

Klimstra, W. D. (1959) Foods  of the racer. Coluber constrictor, in southern Illinois.  Copeia
      1959: 210-214,

Martof, B. S.; Palmer, W. M.;  Bailey, J. R.; et al. (1980) Amphibians  and reptiles of the
      Carolinas and Virginia.  Chapel Hill, NC: University of North Carolina  Press.
                                       2-416
Racer
-------
Parker, W. S.; Brown, W. S. (1973) Species composition and population changes in two
      complexes of snake hibernacula in northern Utah. Herpetologica 29: 319-326.

Pope, C. H. (1944) Amphibians and reptiles of the Chicago area. Chicago, IL: Chicago
      Natural History Museum Press.

Robinson, R. W.; Peters, R. H.; Zimmermann, J. (1983) The  effects of body size and
      temperature on metabolic rate of organisms. Can. J. Zool. 61: 281-288.

Ruben, J. A. (1976) Aerobic and anaerobic metabolism during activity in snakes. J. Comp.
      Physiol. B: Metab. Transp. Funct. 109: 147-157.            -    -    -

Smith, H. M. (1956) Handbook of amphibians and reptiles of Kansas. Univ. Kansas Mus.
      Nat. Hist. Misc. Publ. 9; 356 pp.

Smith, P. W. (1961) The amphibians and  reptiles of Illinois. III. Nat. Hist. Surv. Bull. 28.

Turner, F. B. (1977) The dynamics of populations of squamates, crocodilians and
      rhynchocephalians. In: Gans, C.; Tinkle,  D. W,, eds. Biology of the reptilia: v. 7.
      New York, NY: Academic Press; pp. 157-264.

Uhler, F. M.; Cottom, C.; Clarke, T. E. (1939) Food of snakes of the  George Washington
      National Forest, Virginia. Trans. North Am. Nat. Resour. Wildl. Conf. No. 4; pp.
      605-622.

Vermersch, T. G.; Kuntz, R. E. (1986) Snakes of south central Texas. Austin, TX: Eakin
      Press; pp. 18-19.

Wright, A. H.; Wright, A. A. (1957) Handbook of snakes: v. 2.  Ithaca, NY: Comstock.
                                      2-417
Racer
-------
-------
2.3.5.  Northern Water Snake (water snakes and salt marsh snakes)

       Order Sauamata, Family Colubridae. Water snakes and salt marsh snakes (genus
Nerodia) belong to the family Colubridae, along with 84 percent of the snake species in
North America. Colubrids vary widely in form and size and  can be found in numerous
habitats, including terrestrial, arboreal, aquatic, and burrowing. The more aquatic types of
snakes in this family include water snakes, salt marsh snakes, swamp snakes, brown
snakes, and garter and ribbon snakes (Conant and Collins, 1991).

Selected species

       The northern water snake (Nerodia sipedon sipedon)  is largely aquatic and riparian.
It ranges from  Maine and southern Quebec to North Carolina. It also inhabits the uplands
of western North  Carolina and adjacent portions of Tennessee and Virginia, and its range
extends west to eastern Colorado (Conant and Collins, 1991).  Three additional subspecies
are recognized, distinguished by range and habitat: N. s.  pleuralis (midland water snake;
ranges from Indiana to Oklahoma and the Gulf of Mexico  and south of the mountains to
the Carolinas, preferring fast-moving streams), N.  s. insularum (Lake Erie water snake;
inhabits islands of Put-in-Bay, Lake Erie), and  N. s. williamengelsi (Carolina salt marsh
water snake; inhabits the Outer Bank islands  and mainland coast of Pamlico and Core
sounds, North  Carolina) (Behler and King, 1979; Conant and Collins, 1991).

       Body size.  The northern water snake is typically 61 to 107 cm in total  length
(Conant and Collins, 1991).  Island populations of the species tend to be larger than
mainland ones (King, 1986). King (1986) estimated the relationship between snout-to-
vent length (SVL)' and body weight for Lake Erie water snakes (N. s. insularum):
      weight (g)  = 0.0005 SVL (cm)3-07

      weight (g)  = 0.0009 SVL (cm)2-88
      weight (g)  = 0.0008 SVL (cm)
                                   2.98
 all snakes;

 females; and

 males.
Kaufman and Gibbons (1975) determined a relationship between length and weight for
both sexes of a South Carolina  population:
      weight (g)  = 0.0004 SVL (cm)3-15 (± °-12 SE)
 all snakes
(95% Cl for intercept = 0.00015 to 0.0011).  Immediately after emergence from
hibernation, females begin to gain weight and continue gaining weight until giving birth in
late summer.  Weight loss associated with parturition in one population ranged from 28.2
to 45.5 percent of the female's weight just prior to parturition (King, 1986).
Measures of SVL exclude the tail. Kaufman and Gibbons (1975) estimated that the tail represents
21.8 percent (± 0.010 SE) of the total length of a female and 25.7 percent (±0.006 SE) of the
total length of a male.
                                       2-419
Northern Water Snake
-------
       Habitat. The northern water snake prefers streams but can be found in lakes and
 ponds and nearby riparian areas (King, 1986; Smith, 1961). In the Carolinas and Virginia,
 they can be found from mountain lakes and streams to large coastal estuaries (Martof et
 at., 1980). They are absent from water bodies with soft muddy  bottoms which may
 interfere with foraging (Lagler and Salyer, 1945).  In Lake Erie, N. s. insularum occurs in
 shoreline habitats where rocks or vegetation provide refugia (King, 1986).

       Food habits.  Northern water snakes consume primarily fish and amphibians and, to
 a lesser extent, insects and small mammals (Raney and Roecker, 1947; Smith,  1961).
 Diet varies according to the age (and size) of the snake and food availability (DeGraaf and
 Rudis, 1983).  Young snakes forage in shallow riffles and cobble bars, primarily waiting for
 prey to move within range (letter from K.B. Jones, U.S. Environmental Protection Agency
 Environmental Monitoring Systems Laboratory, to  Susan  B. Norton, January 6, 1992).
 Tadpoles comprise a large proportion of the diet of young snakes"1 in some areas (Raney
 and Roecker, 19'47).  Adults are strong swimmers and can swim and dive for fish
 midstream, often capturing large specimens (e.g.,  20 to 23 cm brown trout; 19 cm
 bullhead; 20-f cm lamprey) (Lagler and Salyer, 1945). They also tend to consume
 bottom-dwelling fish species (e.g., suckers) (Raney and Roecker, 1947).   In New York,
 Brown (1958) found that N. s. sipedon consumed  the most food  between June and,
 August; they consumed little during the remaining months prior to hibernation.

       Temperature regulation and daily activities.  The northern water snake is active
 both day and night but is most active  between 21  and 27°C (Brown, 1958; Smith,  1961).
 During the day, they are found in areas that provide basking sites and are not found in
 heavily shaded areas (DeGraaf and Rudis, 1983; Lagler and Salyer, 1945). They may
 become inactive and seek shelter, however, if temperatures exceed 27°C (Brown, 1958;
 Lagler and Salyer, 1945). They become torpid at temperatures less than  10°C (Brown,
 1958).

       Hibernation. In autumn, the N. sipedon leaves the aquatic habitats to overwinter in
 rock crevices or in banks nearby (DeGraaf and Rudis, 1983; Fitch, 1982).

       Breeding activities and social organization.  The northern water snake breeds
 primarily in early spring, and the young are born from late summer to fall  (i.e., viviparous)
 (DeGraaf and Rudis, 1983). The rate of development before hatching is temperature
 dependent (Bauman and Metter, 1977).

       Home range and resources. The northern water snake usually stays in the same
area of a stream, in the same pond, or in an adjacent pond for several years (Fraker,
 1970).  Snakes along streams have larger home ranges than snakes in ponds and lakes
 (Fraker, 1970). Fraker (1970) found that for large ponds (e.g., 1,500 to  2,000 m2), the
home range  of an individual snake is essentially the entire pond.  In fish hatcheries with
smaller ponds, individual snakes frequent  more than one pond (Fraker, 1970).
mSnakes less than 36 cm in length for this example.

                                      2-420
Northern Water Snake
-------
      Population density. Population density estimates for water snakes usually are
expressed relative to a length of shoreline. Values from 34 to 380 snakes per km of
shoreline have been reported for streams and Lake Erie islands (see table).

      Population dynamics. Northern water snakes reach sexual maturity at 2 or 3 years
of age, with males generally maturing earlier and at a smaller size than females (Feaver,
1977, cited in King, 1986; King, 1986). Clutch sizes vary from 5 or 10 to 50 or 60
depending on location and on female size (see table). The proportion of females breeding
in a given year increases with increasing female size, as does clutch size and offspring
weight (King, 1986).  King determined the relationship of  litter size to female SVL for Lake
Erie water snakes (N. s. insularum):

      litter size = -12.45 + 0.41 SVL (cm).

Feaver (1977, cited in King, 1986) determined the relationship for a Michigan population:

      litter size = -23.55 + 0.55 SVL (cm).

Females produce only one clutch per year (Beatson,  1976). Information on annual
survivorship of juveniles or adults was not identified  in the literature reviewed.

Similar species (from genera/ references)

      •      The Mississippi green water snake (Nerodia  cyclopion) can  be slightly larger
             (76 to 114 cm) than the northern water snake and is found in quiet waters
             of the Mississippi Valley.

      •      The blotched water snake (Nerodia erythrogaster transversa) is larger than
             the northern water snake (76 to 122 cm) and is found in western Missouri
             and Kansas to northeastern Mexico.

      •      The northern copperbelly (Nerodia erythrogaster neglecta) is larger than the
             northern water snake (76 to  122 cm) and ranges from western Kentucky to
             southeastern Illinois and to Michigan.

      •      The redbelly water snake (Nerodia erythrogaster erythrogaster) of the
             midwestern United States is  close in size to the water snake.  It is best
             suited to swampy areas and  sluggish streams.

      •      The yellowbelly water snake (Nerodia erythrogaster flavigaster) is found in
             the lower Mississippi Valley and adjacent areas.  Like the redbelly, it is
             similar in size to the water snake and likely to be found in swampy areas and
             sluggish streams.

      •      The banded water snake (Nerodia fasciata fasciata) is similar in size, and its
             range includes the coastal plain, North  Carolina to  Mississippi..
                                       2-421
Northern Water Snake
-------
       •     The broad banded water snake (Nerodia fasciata conf/uens) (56 to 90 cm)
             occurs in the Mississippi River delta region in marshes, swamps, and shallow
             waters, including brackish waters along the Gulf Coast.

       •     The Florida water snake (Nerodia fasciata pictiventris) is similar in size to the
             northern water snake and ranges from the extreme southeast of Georgia to
             the southern tip of Florida.  It lives primarily in shallow freshwater habitats.

       •     Harter's water snake (Nerodia harteri) is relatively small (51 to 76 cm) and is
             found in central Texas.

       •     The diamondback water snake (Nerodi rhombifer rhombifer) can be slightly
             longer (76 to 122 cm) than the northern water snake and is more thick-
             bodied than most Nerodia.  Its range extends south from the Mississippi
             Valley into  Mexico.

       •     The Gulf salt marsh snake (Nerodia clarkii clarkii) inhabits the Gulf  Coast
             from west-central Florida to southern  Texas.  It is abundant in coastal salt
             meadows, swamps, and marshes.

       •     The Atlantic salt marsh snake (Nerodia clarkii taeniata) is restricted to
             Volusia  County along the Atlantic Coast of north Florida.

       •     The mangrove salt marsh snake (Nerodia clarkii compressicauda) is small (38
             to 76 cm) and inhabits the mangrove  swamps of Florida's lower coasts.

       Dietary differences are evident among these  species. Mushinsky et al. (1982)
found in Louisiana forested wetlands that N. erythrogaster and N. fasciata change from a
diet of fish to one dominated by frogs when they exceed an SVL of  50 cm.  N. rhombifer
and N. cyclopion, on the  other hand, consume primarily fish throughout their lives,
although the species and  size composition of their diet changes as they grow larger
(Mushinsky et al., 1982).  As N. rhombifer exceeds 80 cm SVL, it begins to prey upon
larger fish that occupy deeper open-water habitats.  N. cyclopion eats a larger proportion
of centrarchid fish as its body size increases.   In a study of  the diet of N. rhombifer,
Plummer and Goy (1984) found a  relationship  between the  SVL of the snakes and the
standard length (SL) of the fish prey (defined as 80  percent of total length):

       SLfIsh (cm) = -5.9 + 0.23  SVLsnake (cm) for males,  and

       SLfish (cm) = -3.6 +0.17  SVLsnake (cm) for females.

The regression lines are not significantly different, however.

General references
(1986).
      Behler and King (1979); Conant and Collins (1991); DeGraaf and Rudis (1983); King
                                       2-422
Northern Water Snake
-------
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                                     2-423
Northern Water Snake
-------
                                          Water Snake (Nerodia sipedon)


Dietary Composition
Esocidae
Catostomidae
Percidae
Proteidae
Cyprintdae
Centrarchldae
crawfish
trout
non-trout fish
unidentified fish
Crustacea
Amphibia











.•' -
birds & mammals
' unidentified
minnows
darters
Amphibia
' 1 *



sculpin (.Cottidae}
trout percfi (Percopsrs)
• game fishes (Percaj
burbot (lota)

catfish (IctaTuridae)^
Population
Dynamics
Population
Density
(N/km shore)
Spring



Age/Sex/
Cond./Seas.
AB

B B summer

Summer
7.0
22.5
15.7
51.9
1.5
0.3
1.5
64
7
1
1
14
12
1










Fall


9.1
1
.4
52.8
2.2
2.8
14.1
17.4
0.3

Mean
138

34-41

Winter























Range
22-381


Location (subspecies)/
Habitat (measure)
Georgia/aquatic (NS)

(% wet volume;
stomach contents)

season not specified

n lower Michigan/streams

(% wet weight-
stomach contents)



n lower Michigan/lakes

{% volume; stomach
contents)




Location (subspecies)/
Habitat
Ohio, Ontario (insularum)/
Lake Erie islands
Kansas (s/pecfo/7)/stream

Reference
Camp etal., 1980






Alexander, 1977






Brown, 1958








Reference
King, 1986

Beatson, 1976
Note
No.







4






5







Note
No,



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-------
                                                          Water Snake (Nerodia sipedon)
 NJ
 NJ
 Ul
 CD
 -*



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 i-t-
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 -*
 CO

CD
7\
CD
         Population
         Dynamics
                   Age/Sex/
                   Cond./Seas
                                      Location (subspecies!/
                                      Habitat
                                                                                                     Reference
                                                                                                             ..

                                                                                                     Feaver, 1977

                                                                                                     Camin & Ehrlich, 1958

                                                                                                     King, 1986

                                                                                                     Smith, 1961
                                                                                                    •

                                                                                                     Bauman & Metter, 1977

                                                                                                    Beatson,  1976
                                                                                                    	    !....•

                                                                                                    Bauman & Metter, 1977
                                                                               Michigan (s/pecfo/7)/ponds,
                                                                                 marshes
                                                                               Ohio, Ontario (insularum)!
                                                                                 Lake Erie islands
                                                                               Ohio, Ontario (insularum)!
                                                                                 Lake Erie islands
                                                                               Illinois (pleuralis)/NS
20.8 ±  8.2 SD
                                                                              central Missouri
                                                                                (s/pecfo/7)/fish hatchery
                                                                              Kansas (s/peofo/7)/stream
        Days Gestation
                                                                              central Missouri
                                                                                (s/pecfo/?)/fish hatchery
        Age at Sexual
        Maturity id)
                                 34 mo
                                 23 - 2.4 mo
                                     Michigan (s/pecfo/?)/ponds,
                                       marshes
 Feaver, 1977


 King, 1986

 1 •        	

 Feaver, 1977


 King, 1986
                                                                              Ohio, Ontario (insularum)!
                                                                                Lake Erie islands
        Length at
        Sexual
        Maturity
        [mm SVL)
                                                    476 - 649
                                                    375 - 425
                                     Michigan (s/peoto/7)/ponds,
                                      marshes
                                                                             Ohio, Ontario (insularum)!
                                                                               Lake Erie islands
Seasonal
Activity
                                                                      Location (subspecies]
                                April - May
                                May
                                    Kansas (sipedon)
                                    Michigan (sipedon)
                                    central Missouri (sipedon}
Smith, 1956
Feaver, 1977
Bauman & Metter, 1977
-------
                                                      Water Snake (Nerodia sipedon}
Seasonal
Activity
Parturition
Hibernation
Begin
late August
mid-August
mid-October
November
Peak
late summer

End
September
late September
mid-April
late March
Location (subspecies)
Illinois {sipedon}
Ohio, Ontario dnsularum)
Virginia, Carolinas (sipedon)
Ohio, Ontario (insularum)
Michigan (sipedon)
Reference
Smith, 1961
King, 1986
Martof etal., 1980
King, 1986
Feaver, 1977
Note
No.

6
ro
NJ
o
r+

CD
QJ
i-»
CD
      1   SVL = snout-to-vent length, which excludes the tail beyond the vent.
      2   Total = total length, from nose to tip of tail.
      3   Snakes in captivity; mean temperatures  = 23°C. Snakes fed fish (one fed frogs).
      4   Collected whenever they were found; thought to be active in area from May to September.
      5   Months of collection and size of snakes not specified.
      6   Cited in King (1986).
Q)
7T
CD
-------
References  (including Appendix)

Aldridge, R. D. (1982) The ovarian cycle of the water snake, Nerodia sipedon, and effects
      of hypophysectomy and gonadotropin administration. Herpetologica 38: 71-79.

Alexander, G. (1977) Food of vertebrate predators on trout waters in north central lower
      Michigan. Michigan Academician 10: 181-195.

Baeyens, D. A.; Rountree, R. L. (1983) A comparative study of evaporative water loss and
      epidermal permeability in an arboreal snake, Opheodrys aestivus, and a semi-aquatic
      snake, Nerodia rhombifera. Comp. Biochem. Physiol.  76A: 301-304.

Barbour, R. W. (1950) The reptiles of Big Black Mountain, Harlan County, Kentucky.
      Copeia 1950:  100-107.

Bauman, M. A.; Metter, D. E. (1977) Reproductive cycle of the northern watersnake Natrix
      s. sipedon (Reptilia. Serpentes, Colubridae). J. Herpetol. 11: 51-59.

Beatson, R. R. (1976) Environmental and genetical correlates of disruptive coloration in the
      water snake, Natrix s. sipedon. Evolution 30: 241-252.

Behler, J.  L.; King,  F. W. (1979) The Audubon Society field guide to North American
      reptiles and  amphibians. New York: Alfred A. Knopf,  Inc.

Brown, E.  E. (1958) Feeding  habits of the northern water snake, Natrix sipedon sipedon
      Linnaeus. Zoologica (N.Y.) 43: 55-71.

Bush, F. M. (1959) Foods of  some Kentucky herptiles. Herpetologica 15:  73-77.

Camin, J.  H.;  Ehrlich, P. R. (1958) Natural selection in water snakes (Natrix sipedon L.) on
      islands in Lake Erie. Evolution 12: 504-511.

Camp, C.  D.; Sprewell, W. D.; Powders, V. N. (1980) Feeding habits of Nerodia taxispilota
      with comparative notes on the foods of sympatric congeners in Georgia. J.
      Herpetol. 14: 301-304.

Conant, R.; Collins, J. T. (1991) A field guide to reptiles and amphibians:  eastern/central
      North America. Boston, MA: Houghton Mifflin Co.

DeGraaf, R. M.; Rudis, D.  D.  (1983) Water snake. Amphibians and reptiles of New
      England. Amherst,  MA: University of Massachusetts Press.

Feaver, P.  E. (1977) The demography of a Michigan population of Natrix sipedon with
      discussions  of ophidian growth and reproduction [Ph.D. dissertation]. Ann Arbor,
      Ml: University  of Michigan.
                                      2-427
Northern Water Snake
-------
Fitch, H. S. (1982) Resources of a snake community in prairie woodland habitat of
       northeastern Kansas. In:  Scott, N. J., Jr., ed. Herpetological communities. U.S. Fish
       Wildl.  Serv. Wildl. Res. Rep. 13; pp 83-98.

Fraker, M.  A. (1970) Home range and homing in the watersnake, Natrix s. sipedon. Copeia
       1970: 665-673.

Gratz, R. K.; Hutchinson, V. H. (1977) Energetics for activity in the diamondback water
       snake, Natrix Rhombifera. Physiol. Zool.  50: 99-114.

Justy, G. M.; Mallory, F. F. (1985) Thermoregulatory behaviour in the northern water
       snake, Nerodia s. sipedon, and the eastern garter snake, Thamnophis s. sirtalis.
       Can. Field-Nat. 99: 246-249.

Kaufman, G. A.; Gibbons, J. W. (1975) Weight-length relationship in thirteen species of
       snakes in the southeastern United States. Herpetologica 31: 31-37.

King, R. B. (1986) Population ecology of the Lake Erie water snake, Nerodia sipedon
       insularum. Copeia 1986:  757-772.

King, R. B. (1989) Body.size variation among island and mainland snake populations.
       Herpetologica 45: 84-88.

Lagler, K. F.;  Salyer, J. C., II. (1945) Food and habits of the common water snake, Natrix
       sipedon, in Michigan. Pap. Michigan Acad. Sci., Arts and Letters 31: 169-180.

Martof, B. S.; Palmer, W. M.; Bailey, J. R.; et al. (1980) Water snake. Amphibians and
       reptiles of the Carolinas and Virginia. Chapel Hill, NC: University of North Carolina
       Press.

Mushinsky, H. R.; Hebrard, J. J.; Vodopich, D. S. (1982) Ontogeny of water snake
       foraging ecology. Ecology 63: 1624-1629.

Plummer, M. V.; Goy, J. M. (1984) Ontogenetic dietary shift of water snakes (Nerodia
       rhombifera) in a fish hatchery. Copeia 1984: 550-552.

Raney, E. C.; Roecker, R. M. (1947) Food and growth  of two species of watersnakes from
       western New York. Copeia 1947:  171-174.

Smith, H. M. (1956) Watersnake. Handbook of amphibians and reptiles of Kansas. Univ.
       Kansas Mus. Nat. Hist. Misc. Publ. 9; 356 pp.

Smith, P. W. (1961) The amphibians and  reptiles of Illinois. III. Nat.  Hist. Surv. Bull. 28.

Uhler, F. M.; Cottom, C.; Clarke, T. E. (1939) Food of  snakes of the George Washington
       National Forest, Virginia. Trans. North Am. Wildl. Nat. Resour. Conf. 4: 605-622.

Wright, A. H.; Wright, A. A. (1957) Handbook of snakes: v. 2. Ithaca, NY: Comstock.

                                      2-428                  Northern Water Snake
-------
2.3.6.  Eastern Newt (salamanders)

       Order Caudata, Family Salamandridae.  Notophthalmus, the genus comprising the
eastern newts, inhabits eastern North America.  A different genus, Taricha, comprises the
western newts along the Pacific coast of North America. Unlike other salamanders, the
skin of newts is rough textured, not slimy.  Eastern newts are primarily aquatic; western
newts are terrestrial. The life cycle of eastern newts is complex.  Females deposit their
eggs into shallow surface waters. After hatching, the larvae remain aquatic for 2 to
several months before transforming into brightly colored terrestrial forms, called efts
(Healy,  1974). Postlarval migration of efts from ponds to land may take place from July
through November, but timing varies between populations {Hurlbert, 1970).  Efts live on
land (forest floor) for 3 to 7 years (Healy, 1974). They then return to the water and
assume adult characteristics. In changing from an eft to an adult, the newt develops fins
and the skin changes to  permit aquatic respiration (Smith, 1961). Occasionally newts omit
the terrestrial eft stage, especially in the species located in the southeast coastal plain
(Conant and Collins, 1991) and along the Massachusetts coast (Healy,  1974). These
aquatic juveniles have the same adaptations (i.e., smooth skin and flattened tail) as the
aquatic adults but are not sexually mature (Healy, 1973).  Under favorable conditions,
adults are permanently aquatic; however, adults may migrate to land after breeding due to
dry ponds, high water temperatures, and low oxygen tension (Hurlbert, 1969). The life
cycle  of western newts does not include the eft stage (Conant and Collins,  1991).

Selected species

      The eastern newt  (Notophthalmus viridescens} has both  aquatic  and terrestrial
forms. The aquatic adult is usually yellowish-brown or olive-green to dark brown above,
yellow below. The land-dwelling eft is orange-red to reddish-brown, and its skin contains
tetrodotoxin,  a neurotoxin and powerful emetic. There are four subspecies of eastern
newts: N,  v. viridescens (red-spotted newt; ranges from Nova Scotia west to  Great Lakes
and south to the Gulf states), N. v. dorsalis (broken-striped newt; ranges along the coastal
plain of the Carolinas), N. v.  louisianensis (central newt; ranges from western Michigan to
the Gulf), and N. v. piaropicola (peninsula newt; restricted to peninsular Florida) (Conant
and Collins, 1991).  Neoteny" occurs commonly in the peninsula and broken-striped
newts.  In the central newt,  neoteny is frequent in the southeastern coastal plain. In the
red-spotted newt, neoteny is rare  (Conant and Collins, 1991).

      Body size.  Adult  eastern newts usually are 6.5 to 10.0 cm in total length (Conant
and Collins, 1991).  In North Carolina, N. v. dorsalis efts ranged from 2.1 to 3.8 cm snout-
to-vent length (SVL), which excludes the tail, and adults ranged from 2.0 to 4.4 cm SVL
(Harris,  1989; Harris et al., 1988). Healy (1973) found aquatic juveniles 1 year of age to
range from 2.0 to 3.2 cm SVL.  Adult eastern newts weigh approximately 2 to 3 g (Gill,
1979; Gillis and Breuer, 1984), whereas the efts generally weigh 1 to 1.5 g (Burton,
1977; Giliis and Breu'er, 1984).
"Neotenic newts are mature and capable of reproduction but retain the larval form, appearance,
 and habits (Conant and Collins, 1991).

                                       2-429                           Eastern Newt
-------
       Habitat. Larval and adult eastern newts are found in ponds, especially those with
abundant submerged vegetation, and in weedy areas of lakes, marshes, ditches,
backwaters, and pools of shallow slow-moving streams or other unpolluted shallow or
semipermanent water.  Terrestrial efts inhabit mixed and deciduous forests (Bishop, 1941,
cited in Sousa, 1985) and are found in moist areas, typically under damp leaves, brush
piles, logs, and stumps, usually in wooded habitats (DeGraaf and Rudis, 1983). Adequate
surface litter is important, especially during dry periods, because efts seldom burrow
(Healy, 1981, cited in Sousa, 1985).

       Food habits. Adult eastern newts are opportunistic predators that prey underwater
on worms, insects and their larvae (e.g., mayfly, caddisfly, midge, and mosquito  larvae),
small crustaceans and molluscs, spiders, amphibian eggs, and occasionally small  fish.
Newts capture prey at the surface of the water and on the bottom of the pond, as well as
in the water column (Ries and Bellis, 1966). The shed skin (exuvia) is eaten and  may
comprise greater than 5 percent of the total weight of food items of both the adult and eft
diets (MacNamara, 1977). Snails are an important food source for the terrestrial  eft
(Burton, 1976).  Efts feed only during rainy summer periods (Behler and King, 1979;
Healy, 1973). Healy (1975) noted that in late  August and September,  efts often were
found clustered around  decaying  mushrooms feeding  on adult and larval dipterans.  In a
northern hardwood hemlock forest in New York,  MacNamara (1977) found that most prey
of adult migrants and immature efts  were from the upper  litter layer, soil surface, or low
vegetation.

       Temperature regulation and daily activities. Adult newts are often seen foraging in
shallow water, and efts are often found in large numbers  on the forest floor after it rains
(Behler and King, 1979).  Efts may be found on the open forest floor even during  daylight
hours (Conant and  Collins, 1991), but they rarely emerge if the air temperature is below
10°C (Healy, 1975).

       Hibernation.  Most adults remain active  all winter underwater on pond bottoms or in
streams (DeGraaf and Rudis, 1983).  Some adults overwinter on land (Hurlbert, 1970)  and
migrate to ponds during the spring to breed (Hurlbert, 1969).  If the water body freezes to
the bottom, adults  may be forced to  hibernate  on land or to migrate to  another pool
(Smith, 1956). Efts hibernate on land, burrowing under logs and debris.  Hurlbert (1969)
observed that efts migrated to ponds for the first time in the spring and fall.

       Breeding activities and social organization.  In south-central New York, breeding
takes place in late winter or early spring, usually  in lakes,  ponds, and swamps (Hurlbert,
1970).  Ovulation and egg deposition occur over  an extended period (McLaughlin and
Humphries, 1978).  Females overwintering on land can store sperm for at least 10 months
(Massey, 1990). Spawning underwater, the female deposits eggs singly on leaves of
submerged plants, hiding and wrapping each in vegetation (Gibbons and Semlitsch, 1991;
Smith 1956).  The time to hatching depends on temperature (DeGraaf  and Rudis, 1983).
Smith (1961) found typical incubation periods to  be 14 to 21  days in Illinois, whereas the
incubation period observed by Behler and King  (1979) was 21  to 56 days.

       Growth and metamorphosis.  In late summer or early fall, the larvae transform into
either aquatic juveniles or  terrestrial efts (Behler and King, 1979). Harris (1987) showed
                                      2-430
Eastern Newt
-------
that, low larval density stimulated neoteny in larvae under experimental conditions. Larval
growth  rates were higher in ponds with low larval densities (Harris, 1987; Morin et al.,
1983).  Growth rates for aquatic juveniles are highest in the spring; however, maximum
seasonal growth for the terrestrial efts occurs between June and September when the
temperature is optimal for active foraging (Healy, 1973).

      Home range and resources.  For adult newts, Bellis (1968) found the mean distance
between capture and recapture sites to be about 7 m, indicating small home ranges.
Harris (1981, cited in DeGraaf and Rudis, 1983) did not find any defined home  range or
any territoriality for males. Most efts around a pond in Pennsylvania remained within  1.5
m of the shore XBellis, 1968). Healy (1975) estimated the home range for terrestrial efts
in a Massachusetts woodland to be 270 m2 and located approximately 800  m from the
ponds where the adults and larvae were located.

      Population density. Populations of aquatic adults may reach high local densities,
whereas terrestrial efts exhibit lower population densities. Recorded population densities
for terrestrial efts range from 34 per hectare (ranging from 20 to 50 efts per hectare) in a
North Carolina mixed deciduous forest (Shure et al., 1989) to 300 per hectare in a
Massachusetts woodland (Healy, 1975). Harris et al. (1988) observed a density of 1.4
adult newts per m2 (14,000 adult newts per hectare) in a shallow pond in North Carolina in
the winter, whereas the summer population density was only 0.2 adults per m2 (2,000
adults per hectare).

      Population dynamics.  Many populations of the eastern newt reach sexual maturity
when the eft stage returns to the water and changes to the adult form (Healy, 1974).
However, under certain conditions such as low larval density, most of the larvae present
have been shown to metamorphose directly into adults or even into sexually mature larvae
(Harris,  1987).  In experimental ponds, densities of 22 larvae per m2 resulted in
metamorphosis to eft by the majority, while a density of 5.5 larvae per m2 resulted in
metamorphosis directly to the adult form or sexual maturation without metamorphosis
(Harris,  1987).  Adult density also influences reproduction.  Morin et al. (1983)  found  that
doubling adult density resulted in a reduction of offspring  produced to one-quarter that
produced by adults at the lower density (i.e., from 36 offspring per female in tanks
containing 1.1 females per m2 to 9.7 offspring per female in tanks containing 2.2 females
per m2). The adult life expectancy noted by Gill (1978b) was 2.1 breeding seasons for
males and 1.7 breeding seasons for females.  Amphibian blood  leeches (ectoparasites) are
likely to be a primary source of mortality for adults; they also prey directly on larvae (Gill,
1978a).

Similar species (from general references)

      •     The black-spotted newt (Notophthalmus meridionalis) is similar in  size (7.5
            to 11.0 cm) to the eastern newt. It has large  black spots and  is found in
             south Texas in ponds, lagoons, and swamps.  There is no eft stage.

      •     The striped newt (Notophthalmus perstriatus)  is smaller (5.2 to 7.9 cm) than
            the eastern newt and ranges from southern Georgia to central  Florida. It is
            found in almost any body of shallow, standing water.
                                       2-431
Eastern Newt
-------
      •      The western newts (Taricha) are found along the Pacific coast. They do not
             undergo the eft stage but rather transform into land-dwelling adults that
             return to the water at breeding time.

      •      Other small salamanders are similar but vary by having slimy skin and
             conspicuous  costal grooves. They differ in life history, however; in the
             family Plethudontidae, all are lungless and breathe through thin, moist skin.
             Many are completely terrestrial.

General references

      Behlerand King (1979); Conant and Collins (1991); DeGraaf and Rudis (1983);
Hurlbert (1969);  Smith (1961).
                                      2-432
Eastern Newt
-------
                                  Eastern Newt (Notophthalmus viridescens]
Factors
Body Weight
(gl



•

!_
Age/Sex/
Cond./Seas.
adult:
B
F prebreed
F postbreed
M prebreed
M postbreed
B spring
B summer
B winter
Bfall
larvae:
12.8 mm SVL
21.9 mm SVL
eft:
B
B
B summer

Mean
2.24 ± 0.71 SD
3.05 ± 0.06 SE
2.49 ± 0.06 SE
2.49 ± 0.03 SE
2.76 ± 0.03 SE
1.71 ± 0.43 SD
2.13 ± 0.44 SD
1.94 ± 0.33 SD
1.63 ± 0.28 SD
0.04 + 0.025
SD
0.54 + 0.167
SD
1.10 ± 0.40 SD
1.45
1.23
Range or
(95% Cl of
mean)
1.12-3.52


0.42- 1.82

0.63-2.17

Location (subspecies)
New York
Virginia
Massachusetts
South Carolina
New York
New Hampshire (viridescens)
New York

Reference
Gillis-& Breuer, 1984
Gill, 1979
Pitkin, 1983
Taylor et al., 1988
Gillis & Breuer, 1 984
Burton, 1977
Stefanski et al., 1 989

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                                    2-435
Eastern Newt
-------
                                   Eastern Newt (Notophthalmus viridescens}

Dietary Composition
efts:
Basommatophora
Stylommatopnora
Acaii
Collembola
Thysanoptera
Homoptera
Coleoptera adult
Coleoptera farvae
Lepidoptera tarvae
Diptera adult
Diptera larvae
Hymenoptera aduft
larvae:
Zygoptera (Odonata)
Chironomidae
(Diptera}
Cfadocera
Ostfacoda
Hyallela azteca
(Amphlpodal
Sphaerium sp,
(Pelycepoda)
PJanorbidae
(Gastropoda)
Rhizopoda (Protozoa)

Spring



























Summer

5.5
18.3
13.8
10.4
3.4
4.7
2.3
3.5
7.9
9.7
10.6
5.8

0.8
16.2

12.7
5.3
55.1

9.4

0.5

0.01

Fall



























Winter


























Location (subspecies)/
Habitat (measure}
New York/leaf litter
surface in forest

(% dry weight; stomach
contents)








New Hampshire
(viridescens) /small
oligotrophic lake

(% wet weight; stomach
and gut contents)








; Reference :
MacNamara, 1977












Burton, 1977












Note
No.


























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                                      2-438
Eastern Newt
-------
                                               Eastern Newt (Notophthalmus viridescens)
Seasonal
Activity
Metamorphosis
to eft
-

Fall Migration
(of adults to
hibernaculae)
Spring Migration
(of adults to
breeding ponds)
Begin
June
mid-August
mid-July
August - Sept.
late March
Peak
-

August - Sept.


End
September
late November
early November
November
late April
Location
South Carolina
Virginia
New York
Virginia
Virginia
Reference
Gibbons & Semlitsch,
1991
Gill, 1978a
Hurlbert, 1970
Gill, 1978a
Massey, 1990
Note
No,





S3
i.
to
CO
      1   "Neonates" refers to newts that become sexually mature in the larval form (i.e., neoteny).
      2   Estimated assuming temperature of 20°C using Equation 3-50 (Robinson et al., 1983) and postbreeding body weights from (a) Gill (1979); (b)
         Taylor et al. (1988); and (c) Gillis and Breuer (1984).  The values for the larvae should be used with caution because these animals are smaller
         than any used to develop the allometric equations.
      3   See Chapters 3 and 4 for methods of estimating food ingestion rates from metabolic rate and diet.
      4   Estimated using  Equation 3-26 (Whitford and Hutchinson, 1967) and postbreeding body weights from Gill, 1979.
      5   Mean distance between capture and recapture sites, suggesting small home range size.
rn
0)
co
i-t
CD
-*
CD
-------
References (including Appendix)

Behler, J. L.; King, F. W. (1979) The Audubon Society field guide to North American
      reptiles and amphibians. New York, NY: Alfred A. Knopf, Inc.

Bellis, E. D. (1968) Summer movement of red-spotted newts in a small pond. J. Herpetol.
      1: 86-91.

Bennett, S. M. (1970) Homing, density and population dynamics in the adult newt,
      Notophthalmus viridescens Rafinesque [Ph.D. dissertation]. Hanover, NH:
      Dartmouth College.

Bishop,  S. C.  (1941) The salamanders of New York. N. Y.  State Mus. Bull. 324; 365 pp.

Brophy,  T. E.  (1980) Food habits of sympatric larval Ambystoma tigrinum and
      Notopthalmus viridescens. J. Herpetol. 14: 1-6.

Burton,  T. M. (1976) An analysis of the feeding ecology of the salamanders (Amphibia,
      Urodela) of the Hubbard Brook Experimental Forest, New Hampshire. J. Herpetol.
      10: 187-204.

Burton,  T. M. (1977) Population estimates, feeding habits and  nutrient and energy
      relationships of Notophthalmus v. viridescens, in Mirror  Lake, New Hampshire.
      Copeia  1977: 139-143.

Conant, R.; Collins, J. T. (1991) A field guide to reptiles and amphibians: eastern/central
      North America. Boston, MA: Houghton Mifflin Co.

DeGraaf, R. M.; Rudis, D.  D. (1983) Amphibians and reptiles of New England. Amherst,
      MA: University of Massachusetts Press.

Gage, S. H. (1891) The life history of the vermillion-spotted newt. Am. Nat. 25: 1084-
      1103.

Gibbons, J. W.; Semlitsch, R. D. (1991) Guide to the reptiles and amphibians of the
      Savannah River Site. Athens, GA: University of Georgia  Press.

Gill, D. E. (1978a) The metapopulation ecology of the red-spotted newt, Notophthalmus
      viridescens (Rafinesque).  Ecol. Monogr. 48: 145-166.

Gill, D. E. (1978b) Effective population size and interdemic migration rates in a
      metapopulation of the red-spotted  newt, Notophthalmus viridescens. Evolution 32:
      839-849.

Gill, D. E. (1979) Density dependence and homing behavior in adult red-spotted newts
      Notophthalmus viridescens (Rafinesque). Ecology 60: 800-813.
                                      2-440
Eastern Newt
-------
Gillis, J. E.; Breuer, W. J. (1984) A comparison of rates of evaporative water loss and
      tolerance to dehydration in the red-eft and newt of Notophthalmus viridescens. J.
      Herpetol. 18: 81-82.

Harris, R. N. (1981) Intrapond homing behavior in Notophthalmus viridescens. J. Herpetol.
       15:355-356.

Harris, R. N. (1987) Density-dependent paedomorphosis in the salamander Notophthalmus
      viridescens dorsalis. Ecology 68: 705-712.

Harris, R. N. (1989) Ontogenetic changes in size and shape of the facultatively
      paedomorphic salamander Notophthalmus viridescens  dorsalis. Copeia 1989:
      35-42.

Harris, R. N.; Alford, R. A.; Wilbur, H. M. (1988) Density and phenology of Notophthalmus
      viridescens dorsalis in a natural pond. Herpetologica 44: 234-242.

Healy, W. R. (1973) Life history variation and the growth of the juvenile Notophthalmus
      viridescens from Massachusetts. Copeia 1973: 641-647.

Healy, W. R. (1974) Population consequences of alternative life histories in Notophthalmus
      v. viridescens. Copeia 1974: 221-229.

Healy, W. R. (1975) Terrestrial activity and home range in efts of Notophthalmus
      viridescens. Am. Midi. Nat. 93: 131-138.

Healy, W. R. (1981) Field test of an HSI model for the red-spotted newt (Notophthalmus
      viridescens) for the Habitat Evaluation Procedures Group [unpublished material].
      Fort Collins, CO: U.S. Fish Wildl. Serv.; 21 pp.

Hurlbert, S. H. (1969) The breeding migrations and interhabitat wandering  of the
      vermilion-spotted  newt, Notophthalmus viridescens (Rafinesque). Ecol. Monogr. 39:
      465-488.

Hurlbert, S. H. (1970) The post-larval migration of the red-spotted newt, Notophthalmus
      viridescens (Rafinesque).  Copeia 1970: 515-528.

Logier, E. B. (1952)  The  frogs, toads and salamanders of eastern  Canada. Toronto,
      Canada: University of Toronto Press.

MacNamara, M. C. (1977) Food  habits of terrestrial adult migrants and immature red efts
      of the red-spotted newt, Notophthalmus  viridescens. Herpetologica 33: 127-132.

Massey, A. (1990) Notes on the reproductive ecology of red-spotted newts
      (Notophthalmus viridescens). J. Herpetol. 24: 106-107.

Mclaughlin, E. W.; Humphries, A. A., Jr. (1978) The jelly envelopes and fertilization of
      eggs of the newt, Notophthalmus viridescens. J. Morphol.  158: 73-90.
                                      2-441
Eastern Newt
-------
Morin, P. J. (1986) Interactions between intraspecific competition and predation in an
       amphibian predator-prey system. Ecology 67: 713-720.

Morin, P. J.; Wilbur, H. M.; Harris, R. N. (1983) Salamander predation and the structure of
       experimental communities: responses of Notophthalmus and Microcrustacea.
       Ecology 64: 1430-1436.

Pitkin, R. B. (1983) Annual cycle of body size and blood parameters of the aquatic adult
       red-spotted newt, Notophthalmus viridescens. J. Exp. Zool. 226: 372-377.

Ries, K. M.; Bellis, E. D. (1966) Spring  food habits of the red-spotted newt in
       Pennsylvania.  Herpetologica 22: 152-155.

Robinson, R. W.; Peters, R. H.; Zimmermann, J. (1983) The effects of body size and
       temperature on metabolic rate of organisms. Can. J. Zool. 61: 281-288.

Shure, D. J.; Wilson, L. A.; Hochwender, C.  (1989) Predation on aposomatic efts of
       Notophthalmus viridescens. J. Herpetol. 23: 437-439.

Smith, H. M. (1956) Handbook of amphibians and reptiles of Kansas. Univ. Kansas Mus.
       Nat. Hist. Misc. Publ. 9; 356 pp.

Smith, P. W. (1961) The amphibians and reptiles of Illinois. III. Nat. Hist. Surv. Bull. 28;
       pp. 118-120.

Sousa, P. J. (1985) Habitat suitability index models: Red-spotted newt. U.S. Fish Wildl.
       Serv. Biol. Rep. 82(10.111);  18  pp.

Stefanski, M.; Gatten, R. E.; Pough, F.  H. (1989) Activity metabolism of salamanders:
       tolerance to dehydration. J. Herpetol.  23: 45-50.

Taylor, B. E.; Estes, R. A.;  Pechmann, J. H.;  et al. (1988) Trophic relations in a temporary
       pond: larval salamanders and their microinvertebrate prey. Can. J. Zool. 66:
       2191-2198.

Whitford, W. G.; Hutchinson, V. H. (1967) Body size and metabolic rate in salamanders.
       Physiol. Zool. 40: 127-133.
                                      2-442
Eastern Newt
-------
2.3.7.  Green Frog (true frog family)

       Order Anura, Family Ranidae. These are typical frogs with adults being truly
amphibious, living at the edge of water bodies and entering the water to catch prey, flee
danger, and spawn (Behler and King, 1979).  This profile covers medium-sized ranids.  The
next profile (Section 2.3.8} covers large ranids.

Selected species

       The green frog (Rana clamitans) is usually found near shallow fresh water
throughout much of eastern North America. Two subspecies are recognized: R. c.
clamitans (the bronze frog; ranges from the Carolinas to northern Florida, west to eastern
Texas, and north along  the Mississippi Valley to the mouth of the Ohio River) and R. c.
melanota (the green frog; ranges from southeastern Canada to North Carolina, west to
Minnesota and Oklahoma but rare in much of Illinois and Indiana, introduced into British
Columbia, Washington, and Utah) (Conant and Collins,  1991).

       Body size.  The green frog is a medium-sized ranid usually between 5.7 and  8.9 cm
snout-to-vent length (SVL) (Conant and Collins, 1.991; Martof et a!.,  1980).  Its growing
period  is primarily confined to the period between mid May and mid September (Martof,
1956b). Females are usually larger than males (Smith,  1961).  Adults typically weigh
between 30 and 70 g (Wells, 1978). Hutchinson et al.  (1968) developed an allometric
equation relating green  frog surface area (SA  in cm) to body weight (Wt in grams):

       SA =  0.997 Wt0-712.

This equation also is presented in Chapter 3 as Equation 3-25.

       Habitat.  Adult green frogs live at the margins  of permanent or semipermanent
shallow water, springs, swamps, streams, ponds, and lakes (Wells, 1977).  Martof
(1953b) found green frogs primarily to inhabitat the banks of streams.  They also can be
found among  rotting debris of fallen trees (Behler and King, 1979; Conant and Collins,
1991).  Juveniles prefer shallower aquatic habitats with denser vegetation than those
preferred by adults {Martof, 1953b). McAlpine and Dilworth (1989) observed that green
frogs inhabited aquatic  habitats about two-thirds of the time and terrestrial habitats the
remaining time. Similarly, Martof (1953b) found that the green frog relies on terrestrial
habitats for feeding and aquatic habitats for refuge from desiccation, temperature
extremes, and enemies. Ponds used by green frogs are usually more permanent than
those used  by other anuran species (Rough and Kamel,  1984).

       Food habits.  Adult R. clamitans are terrestrial  feeders among  shoreline vegetation.
They consume insects,  worms, small fish, crayfish, other crustaceans, newts, spiders,
small frogs, and molluscs.  Stewart and Sandison (1973) found that terrestrial beetles
often are their most important food item but noted that any locally abundant insect along
the shoreline may be consumed in large numbers.  There is a pronounced reduction  in food
consumption during the breeding period for both males and females (Mele, 1980). During
the breeding season, males spend most of their energy defending breeding territories, and
                                      2-443
Green Frog
-------
females expend their energy producing eggs (Wells, 1977). Fat reserves acquired during
the prebreeding period compensate for reduced food intake during the breeding period
(Mele, 1980). Jenssen and Klimstra (1966) found that green frogs consume most of their
food in the spring and eat little during the winter. Food eaten in the spring,  summer, and
fall consists mostly of terrestrial prey, whereas winter food is composed mostly of aquatic
prey (Jenssen and Klimstra, 1966). Juveniles (sexually immature frogs) eat about half the
volume of food as do adults over the course of a year (Jenssen and Klimstra, 1966).
Tadpoles are herbivorous (DeGraaf and Rudis, 1983).  Green frogs eat their cast skins
following molting; the casting of skin is frequent during midsummer (Hamilton,  1948).

       Temperature regulation and dally activities.  Martof (1953b) found that the green
frog's activity period varies by frog size, with larger frogs being  primarily nocturnal, small
frogs being diurnal, and middle-sized frogs (5 to 7 cm  SVL) being equally active during day
and night.

       Hibernation. Adult green frogs overwinter by hibernating underground or
underwater from fall to spring (Ryan, 1953).  Martof (1956a) observed frogs hibernating in
mud and debris at the bottom of streams approximately 1 m deep.  Jenssen and Klimstra
(1966) noted that adults usually hibernate in restricted chambers within rock piles or
beneath plant debris, while juveniles are more often found in locations with access to
passing prey.  The frogs begin emerging when the mean daily temperature is about 4.4°C
and the maximum temperature is about 15.6°C for 3 to 4 days (Martof,  1953b).  Juvenile
frogs enter and exit hibernation after adult frogs (Martof,  1956a).

       Breeding activities and social organization. Green frogs breed from spring through
the summer, spawning at night (Smith, 1961; Wells, 1976). Female green frogs stay in
nonbreeding habitat until it is time to spawn (Martof, 1956a). In preparation for breeding/
males establish territories near shore that serve as areas for sexual display and as
defended oviposition  sites (Wells,  1977).  Males establish calling sites within their
territories where they attempt to attract females (Wells, 1977).  Females visit male
territories to mate and lay their egg masses. The masses are contained  in films of jelly and
are deposited in emergent, floating, or submerged vegetation; they hatch in about 3 to 6
days (Behler and King, 1979; Martof, 1956a; Ryan, 1953). Adults are solitary during non-
breeding periods (Smith, 1956).

       Tadpole and metamorphosis.  In the southern part of their range, green frog
tadpoles metamorphose into  frogs in the same season in which they hatched, while in the
northern part, 1 or 2  years pass before metamorphosis (Martof,  1956b).  Tadpoles that
hatch from egg masses laid in the spring usually metamorphose that fall, while those
hatching from summer-laid eggs typically overwinter as larvae and metamorphose the
following spring (Rough and Kamel, 1984). Ryan (1953) found that most tadpoles are 2.6
to 3.8 cm SVL at  the time of transformation.  Those that transform in late June or early
July grow rapidly, adding 1.4 to 2.0 cm SVL in the first 2 months and 0.4 to 0.7 cm SVL
more  before hibernation.  Tadpoles that transform at approximately 3.1 cm SVL may reach
between 5.0 and  5.8 cm SVL before hibernation (Ryan, 1953).  Newly transformed frogs
often  move from lakes and ponds where they were tadpoles to shallow stream banks,
usually during periods of rain (Martof, 1953b).
                                       2-444
Green Frog
-------
       Home range and resources,  the species' home range includes its foraging and
refuge areas in and around aquatic environments.  During the breeding period, the male's
home range also includes its breeding territory (Wells, 1976). Martof (1953b) found that
roughly 80 percent of adult frogs captured in the spring  and again in the fall occupied the
same home ranges.

       Population density. During the breeding season,  green frog densities at breeding
ponds can exceed several hundred  individuals per hectare (Wells, 1978).  Adult male frogs
space their breeding territories about 2 to 3 m apart (Martof, 1953a).

       Population dynamics. Sexual maturity is attained in  1 or 2 years after
metamorphosis; individuals  may reach maturity at the end of the first year but not attempt
to breed until the next year (Martof, 1956a,b).  Most females lay one clutch per year,
although some may lay two clutches, about 3 to 4 weeks apart (Wells, 1976). In natural
populations, green frogs can live to approximately 5 years of age (Martof,  1956b).

Similar species (from general references)

       •     The river frog (Rana heckscheri] is slightly larger than the green frog (8.0 to
             12.0 cm SVL) and is found in swamps from southeast North Carolina to
             central Florida and southern Mississippi.

       •     The leopard and pickerel frogs (Rana pip/ens and its relatives, and Rana
             palustris) are medium sized and strongly spotted.  There are  four leopard
             frogs whose ranges are mostly exclusive from each other, but overlap with
             the green frog.  The pickerel frog  has a similar range with gaps in the upper
             midwest and the southeast.

       «     The mink frog (Rana septentrionalis) is only slightly smaller (4.0 to 7.0 cm)
             and is found on the borders of ponds and lakes, especially near waterlilies.
             It ranges from Minnesota to New York, north  to Labrador.

       •     The carpenter frog (Rana virgatipes) is about the same size as the green frog
             (4.1 to 6.7 cm) and is closely associated with sphagnum bogs and
             grasslands. It has a coastal plain range from  New Jersey to  Georgia and
             Florida.

The bullfrog and pig frog are much  larger ranid species and  are covered in the next profile
(Section 2.3.8).

General references

       Behler and King (1979); Conant and Collins  (1991); DeGraaf and Rudis (1983);
Martof (1953a, b, 1956a, b); Smith (1956, 1961).
                                       2-445
Green Frog
-------
                                          Green Frog (Rana clamitans]

Factors
Body Weight


Length
(mm SVL)


Metabolic
Rate
(kcaf/kg-d)
Food Ingestion
Rate ig/g-d)
Surface Area
icm2)
Age/Sex/
Cond./Seas.
B B
A M breeding
at metamorphosis
A
A M
A F
J B
basal:
A
at metamorphosis


A
at metamorphosis


Dietary Composition
adults:
plant material
Araneae
Coleoptera
Hemiptera
Hymenoptera
Diptera
Ephemeroptera
Motlusca
Lepidoptera


Spring











Mean
49.1 ± 20.0 SD
44.0 ± 10.0SD
3
54- 102
79.8 ± 8.5 SD
80.3 ± 8.9 SD
32.6

8.08
15.8


17
2


Summer

10.8
12.1
32.8
12.9
14.4
6.8
5.6
5.4
2.5
Range or
(95% CI of mean)
25.5-103.5
27.0- 66.0


103 maximum
105 maximum
28.4-36.3









Fali











-
Winter











Location (subspecies)
New Brunswick, Canada
New York (melanota)
New York
NS
s Michigan

s Michigan







Location
(subspeciesl/Habitat
(measure)
New York/lake

(% total volume;
stomach contents)







Reference
McAlpine & Dilworth, 1 989
Wells, 1978
Rough & Kamel, 1 984
Behler and King, 1 979
Martof, 1956b

Martot 1956b

estimated
estimated


estimated
estimated


Reference
Stewart & Sandison, 1973









Note
No.


1





2
3
4

5
6

Note
No.
7









ro
O5
CD
CD
3

T1

O
CD
-------
                                         Green Frog (Rana clamitans]


Dietary Composition
adults:
mineral
plant
Pulmonata
Olifloehaeta
Amphipoda
Isopoda
Deeapoda
Julioforma
.Aranejda
Odonata
Orthoptera
Hemiptera
Coleoptera
Lepidoptera
Diptera
Hymenoptera
Salientia
Population
Dynamics
Home Range
Size







Population
Density
(N/ha)


Spring

-
5.7
15.7
2.1
1.2
5.6
-
7.5
2.8
1.6
0.9
1.0-
9.6
25.4
6.0
9.9
-
Age/Sex/
Cond./Seas. .
A B nonbreeding

A M breeding


A M breeding



AM
AF



Summer

-
8.3
18.3
0.8
0.1
1.4
-
0.3
3.4
12.4
3.0
7.0
19.6
7.0
5.2
6.0
-


Fait

-
4.2
6.4
2.3
-
-
4.1
1.7
6.6
5.9
1.5
6.1
15.9
25.1
4.5
13.5
3.9

Mean
0.0065 ± 0.0036
SD ha
meters shoreline:
4.0 - 6.0

meters shoreline:
1.0-1.5


476
567



Winter

2.6
0.5
11.0
6.4
4.6
4.6
-
-
7.4
-
-
2.2
9.1
-
10.3
-
-
Location
(subspeciesl/Habltat \
(measure)
s Illinois/swamp, stream

(% wet volume; stomach
contents)









,




Range or
[95% Cl of mean)
0.0020 - 0.020
ha










Location (subspecies)/
Habitat
s Michigan (me/anota)/
shallow water
New York (melanota)/
open nearshore areas
of ponds
New York (melanota)/
densely vegetated
nearshore areas of
ponds
New York (melanota)/
artificial pond

*

Reference:
Jenssen & Klimstra, 1966


















Reference
Martof, 1953b

Wells, 1977


Wells, 1977



Wells, 1978



Note
No,


















Note
No.
8








9


ro
CD
CD
O
CD
-------
                                          Green Frog (Rana c/amitans)
Population
Dynamics
Clutch Size.
Clutches/Year
Day$
Incubation (d)
Age at
Metamorphosis
Age at Sexual
Maturity lyr)
Age/Sex/
Cond./Seas.

•

early eggs
late eggs
early eggs
late eggs
AM
AF
B
Mean
4,100

3-6
3-5
3 mo
10- 12mo
2.5 - 3 mo
11-12mo
1 -2
1 -2
1
Range or
(95% Cl of mean}
3,800 - 4,300
1,000-7,000
3,500 - 4,000
1 -2

1 - 2 yrs

Location (subspecies}/
Habitat
s Michigan (melanota}!
pond
New York (melanota}!
shallow ponds
New York (melanota}!
shallow water •
New York (melanota}!
shallow ponds
Connecticut (melanota}!
shallow water
New York/ponds, pools
.New England
{melanota}!
shallow water
Virginia, Carolines/
shallow ponds
s Michigan (melanota}!
shallow ponds
s Michigan (melanota}!
shallow ponds
New York (melanota}!
pond
Reference
Martof, 1956a
Wells, 1976
Wright, 1914
Wells, 1976
Babbit, 1937
Ryan, 1953
DeGraaf & Rudis, 1 983
Martof et al., .1980
Martof, 1956a, b
Martof, 1 956a, b
Wells, 1977
Note
No.
10

10
11

to

•k
^
CO
CD
CD
3
O
CO
-------
                                                         Green Frog (Rana clamitans]
Seasonal
Activity
Mating/Laying
Meta-
morphosis
eggs laid early
eggs laid late
Hibernation
Begin
May
May
early June
early August
early June
Oct. - Nov.
Oct.
Peak
early June
August, September
next spring

End
mid-August
September
mid-August
late September
mid-July
March - April
late March
Location (subspecies)
s Michigan (melanota}
Illinois (melanota)
New York
s Michigan (melanota}
New York
s Michigan (melanota}
New York
s Michigan (melanota}
New York
Reference
Martof, 1956a
Smith, 1961
Wells, 1976
Martof, 1956b
Rough & Kamel, 1 984
Martof, 1956b
Rough & Kamel, 1984
Martof, 1956a
Ryan, 1953
Note
No.

12
12
13
13

N)
CD
      1   Weight at metamorphosis can vary by two to four times between the smallest and largest individuals.
      2   Estimated assuming temperature of 20°C using Equation 3-50 (Robinson et al., 1983) and body weights from McAlpine and Dilworth (1989).
      3   Estimated assuming temperature of 20°C using Equation 3-50 (Robinson et al., 1983) and body weights from Rough and Kamel (1984).
      4   See Chapters 3 and 4 for methods of estimating food ingestion rates from  metabolic rate and diet.
      5 '  Estimated using Equation 3-25 (Hutchinson et al., 1968) and body weights from McAlpine and Dilworth (1989).
      6   Estimated using Equation 3-25 (Hutchinson et al., 1968) and body weights from Rough and Kamel (1984).
      7   Season not specified.
      8   Daily activity range of rionbreeding frogs.
      9   Frogs were initially hand-captured and placed in pond; the numbers given are for those frogs that stayed.              .
     10   Cited in DeGraaf and Rudis (1983).
     11   Eggs laid before June.
     12   Metamorphosed in the same year eggs were laid.
     13   Metamorphosed the year following the season the eggs were laid.
CD
CD
D
O
CO
-------
References (including Appendix)

Babbitt, L. H. (1937) The amphibia of Connecticut.. Hartford, CT: State Geol. and Nat.
       Hist. Surv.; Bull. No. 57. 9-50

Behler, J. L.; King, F. W. (1979) The Audubon Society field guide to North American
       reptiles and amphibians. New York: Alfred .A. Knopf, Inc.

Bush, F.  M.  (1959) Foods of some Kentucky herptiles. Herpetologica 15: 73-77.

Conant, R.;  Collins, J. T. (1991) A field guide to reptiles and amphibians. Boston, MA:
       Houghton Mifflin Co.

DeGraaf, R.  M.; Rudis, D.D. (1983) Green frog. Amphibians and reptiles of New England.
       Amherst, MA: University of Massachusetts Press.

Hamilton, W. J., Jr. (1948) The food and feeding behavior of the green frog, Rana
       clamitans (Latreille), in New York state. Copeia 1948: 203-207.

Hutchinson, V. H.; Whitford, W. G.; Kohl, M.  (1968)  Relation of body size and surface
       area to gas exchange in anurans. Physipl. Zool. 41: 65-85.

Jenssen, T.  A.; Klimstra, W. D. (1966) Food habits of the green frog, Rana clamitans, in
       southern Illinois. Amer. Midi. Nat. 76: 169-182.

Martof, B. S. (1953a) Territoriality in the green frog, Rana clamitans. Ecology 34:
       165-174.

Martof, B. S. (1953b)  Home range and movements of the green frog, Rana clamitans.
       Ecology 34: 529-543.

Martof, B. S. (1956a) Factors influencing size and composition  of populations of Rana
       clamitans. Am. Midi. Nat. 56: 224-245.

Martof, B. S. (1956b) Growth and development of the green frog, Rana clamitans, under
       natural conditions. Am. Midi. Nat. 55: 101-117.

Martof, B. S.; Palmer, W. M.; Bailey, J. R.; et al. (1980). Amphibians and reptiles of the
       Carolinas and Virginia. Chapel Hill, NC: University of North Carolina Press.

McAlpine, D. F.; Dilworth, T. G. (1989) Microhabitat and prey size among three species of
      Rana  (Anura: Ranidae) sympatric in eastern Canada. Can. J. Zool. 67: 2241-2252.

Mele, J. A. (1980)  The role of lipids in storage and utilization of energy for reproduction
      and maintenance in the green frog, Rana clamitans [Ph.D. dissertation].  New
      Brunswick, NJ: Rutgers University.
                                      2-450
Green Frog
-------
Pope, C. H. (1947) Amphibians and reptiles of the Chicago area. Chicago, IL: Chicago Nat.
       Hist. Mus. Press.

Pough, F. H.; Kamel, S. (1984) Post-metamorphic physiological change in relation to
       anuran life histories. Oecologia 65: 138-144.

Robinson, F. W°; Peters, R. H.; Zimmermann, J. (1983) The effects of body size and
       temperature on metabolic rate of organisms. Can. J. Zool. 61: 281-288.

Ryan, R. A. (1953) Growth rates of some ranids under natural conditions. Copeia
       1953:73-80.

Smith, H. M. (1956) Handbook of amphibians and reptiles of Kansas. Univ. Kansas Mus.
       Nat. Hist. Misc. Publ. 9.

Smith, P. W. (1961) The amphibians and reptiles of Illinois. III. Nat.  Hist.  Surv.  Bull. 28.

Stewart, M. M.; Sandison, P. (1973) Comparative food habits of sympatric mink frogs,
       bullfrogs, and green frogs. J. Herpetol. 6: 241-244.

Wells, K. D. (1976) Multiple egg clutches in the green frog (Rana clamitans). Herpetologica
       32: 85-87.

Wells, K. D. (1977) Territoriality and male mating success in the green frog (Rana
       clamitans). Ecology 58: 750-762.

Wells, K. D. (1978) Territoriality in the green frog (Rana clamitans):  vocalizations and
       agonistic behaviour. Anim. Behav. 26: 1051-1063.

Wright, A. H. (1914) North American anura:  life histories of the anurans of Ithaca, New
      York. Washington, DC: Carnegie  Institute; Publ. No. 197.
                                      2-451
Green Frog
-------
-------
2.3.8.  Bullfrog (true frog family)

       Order Anura. Family Ranidae. These are typical frogs with adults being truly
amphibious. They tend to live at the edge of water bodies and enter the water to catch
prey, flee danger, and spawn (Behler and King, 1979). This profile covers large ranids.
Medium-sized ranids are covered in the previous profile (Section 2.3.7).

Selected species

       The bullfrog's (Rana catesbeiana) natural range includes the eastern and central
United States and southeastern Canada; however, it has been introduced in many areas in
the western United States and other parts of North America, It is continuing to expand its
range, apparently at the expense of several native species in many locations (Bury and
Whelan, 1984).  There are no subspecies for the bullfrog.

       Body size. The bullfrog is the largest North American ranid.  Adults usually range
between 9 and 15 cm in length from snout-to-vent length '(SVU and exceptional
individuals can reach one half kilogram or more in weight (Conant and Collins, 1991;
Durham and Bennett, 1963). Males are usually smaller than females (Smith, 1961). Frogs
exhibit indeterminate growth, and bullfrogs continue to increase in size for at least 6 years
after metamorphosis  (Durham and  Bennett, 1963; Howard, 1981 a).  Hutchinson et al.
(1968) developed an allometric equation relating bullfrog surface area (SA in cm) to body
weight (Wt in grams):

       SA = 0.953 Wt°'725.

This equation also is presented  in Chapter 3 as Equation  3-24.

       Habitat. Adult bullfrogs  live at the edges of ponds, lakes, and slow-moving streams
large enough to avoid crowding and with sufficient vegetation to provide easily accessible
cover (Behler and King,  1979).  Small streams are used when better habitat is lacking
(Conant and Collins, 1991). Bullfrogs require permanent bodies of water,  because the
tadpoles generally require 1  or more years to develop prior to metamorphosis (Howard,
1981 b). Small frogs favor areas of very shallow water where short grasses or other
vegetation or debris offer cover (Durham and Bennett, 1963).  Larger bullfrogs seem to
avoid  such areas (Durham and Bennett, 1963). Tadpoles tend to congregate around green
plants  (Jaeger and Hailman, 1976, cited in Bury and Whelan, 1984).

       Food habits.  Adult R. catesbeiana are indiscriminate and aggressive predators,
feeding at the edge of the water and among water weeds on any available small animals,
including insects, crayfish, other frogs and tadpoles, minnows, snails, young turtles, and
occasionally small birds, small mammals, and young snakes (Behler and King, 1979;
DeGraaf and Rudis, 1983; Korschgen and Baskett, 1963).  Bullfrogs often focus on locally
abundant foods (e.g., cicadas, meadow voles) (Korschgen and Baskett, 1963).
Crustaceans and  insects probably make up the bulk of the diet in most areas (Carpenter
and Morrison, 1973;  Fulk and Whitaker, 1968; Smith, 1961; Tyler and Hoestenbach,
1979). Bullfrog tadpoles consume primarily aquatic plant material and some invertebrates.
                                      2-453
Bullfrog
-------
but also scavenge dead .fish and eat live or dead tadpoles and eggs (Bury and Whelan,
1984; Ehrlich, 1979).

       Temperature regulation and daily activities. Bullfrogs forage by day (Behler and
King, 1979). They thermoregulate behaviorally by positioning themselves relative to the
sun and by entering or leaving the water (Lillywhite, 1970). In one study, body
temperatures measured in bullfrogs during their normal daily activities averaged 30°C and
ranged from 26 to 33°C (Lillywhite, 1970).  At night, their body temperatures were found
to range between 14.4 and  24.9°C (Lillywhite, 1970).  Tadpoles also select relatively
warm areas, 24 to 30°C (Bury and Whelan,  1984).  Despite this narrow range of
temperatures in which bullfrogs normally maintain themselves, they are not immobilized by
moderately lower temperatures (Lillywhite, 1970). The metabolic rate of bullfrogs
increases with increasing body temperature.  Between 15 and 25°C, the Q10 for oxygen
consumption is 1.87; between 25 and 33°C, the Q10 is 2.41 (Burggren  et al., 1983).

       Hibernation.  Most bullfrogs hibernate in mud and leaves under water beginning  in
the fall, but some bullfrogs in the southern states may be active  year round  (Bury and
Whelan, 1984).  They emerge sometime in the spring, usually when air temperatures are
about 19 to 24°C and water temperatures are at least 13 to 14°C (Wright, 1914; Willis et
al., 1956). Bullfrogs emerge from hibernation later than other ranid species (Ryan, 1953).

       Breeding activities and social organization. Bullfrogs spawn at night close to
shorelines in areas sheltered by shrubs (Raney, 1940, cited in DeGraaf and Rudis,  1983).
The timing and duration of the breeding season varies depending on the  location.  In the
southern states, the breeding season extends from spring to fall, whereas in the northern
states, it is restricted to late spring and summer (Behler and King, 1979). Males tend to
be territorial during the breeding season, defending their calling posts and oviposition sites
(i.e., submerged  vegetation near shore) (Howard, 1978b; Ryan, 1980).   Female visits to
the pond tend to be brief and sporadic (Emlen,  1976).  Some males mate with several
females whereas others, usually younger and smaller males, may not breed at all in a given
year (DeGraaf and Rudis, 1983).  Females attach their eggs, contained in floating films  of
jelly, to submerged vegetation (Behler and  King, 1979). Adults are otherwise rather
solitary occupying their own part  of a stream or pond (Smith, 1961).

       Tadpole and metamorphosis. Eggs  hatch in 3 to 5 days (Clarkson and DeVos,
1986; Smith, 1956). Temperatures above 32°C have been shown to cause abnormalities
in tadpoles and above 35.9°C to  kill embryos (Howard, 1978a).  Tadpole growth rates
increase with increasing oxygen levels, food availability, and water temperature (Bury and
Whelan, 1984).  Tadpole gill ventilation at 20°C can generate a branchial water flow of
almost 0.3 ml/g-min (Burggren and West, 1982). Metamorphosis from a tadpole to a frog
can occur  as early as 4 to 6 months in the southern parts of its range; however, most
tadpoles metamorphose from 1 to 3 years  after hatching, depending on latitude and
temperature (DeGraaf and Rudis,  1983; Martof et al., 1980).

      Home range and resources. The species' home range includes its  foraging areas
and refuges in and around aquatic environments.  Home range size decreases with
increasing  bullfrog density, and males tend to use larger home ranges than females (Currie
and Bellis, 1969). Bullfrogs  tend  to stay in the same pools throughout the summer months
                                      2-454
Bullfrog
-------
if'the water level is stable (Raney, 1940, cited in DeGraaf and Rudis, 1983). During the
breeding season, adult males establish territories that they defend against conspecific
males (Emlen,  1968).  During the non-breeding season, Currie and Bellis (1969) found no
evidence of territorial defense.  Males often do not return to the same pond the following
spring (Durham and Bennett, 1963).

      Population density.  During the breeding season, each breeding male may defend a
few meters of shoreline (Currie and Bellis, 1969; Emlen, 1968).  The densities  of females
and non-breeding males vary with time of day and season and are difficult to estimate.
Tadpoles can be present locally in extremely high densities (Cecil and Just, 1979).

      Population dynamics.  Sexual maturity is attained in about 1 to 3 years after
metamorphosis, depending on latitude (Howard, 1978a; Raney and Ingram, 1941, cited in
Bury and Whelan, 1984). Only females that are at least 2 years past metamorphosis mate
during the early breeding season; males and females 1 year past metamorphosis may
breed during the later breeding periods (Howard,  1978a, 1981b). Also, some older
females have been observed to mate and to lay a second clutch during  the later breeding
period (Howard, 1978a).  Willis et al. (1956) estimated the minimum breeding length for
females in Missouri to be 123 to 125 mm SVL.  Mortality of tadpoles is high (Cecil and
Just,  1979), and adult frogs are unlikely to live beyond 5 to 8 years postmetamorphosis
(Howard, 1978b).  In some areas, snapping turtles may be responsible  for a large    •
component of adult bullfrog mortality (Howard, 1981 a).
Similar species (from general references)

      •      The pig frog (Rana grylio) is smaller than the bullfrog (8 to 14 cm) and is
             found in south South Carolina to south Florida and south Texas.

The remaining ranid species are more similar in size to the green (or bronze) frog. See
Section 2.3.7 for a description of these frogs.

General references

      Behler and  King (1979); Bury and Whelan (1984); Conant and Collins (1991);
DeGraaf and Rudis (1983); Smith (1961).
                                      2-455
Bullfrog
-------
                                            Bullfrog (Rana catesbeiana]

Factors
Body Weight
M










~.

j


\

Metabolic Rate
()O2/kg-d)


Metabolic Bate
(kcal/kg-d)



Age/Sex/
Cond./Seas.
BB

AB
young tadpole
1 -yr tadpole
post-
emergence:
1 month
2 months
3 months
4 months

at metamorph.
1 yrB
2yrB
3 yrB
4 yr B
5 yrB
6 yr B
tadpole, 25°C

adult resting,
5°C
basal:
2 mo (30 g)
1 yr (91 g)
BB(143g)
A B (249 g)

Mean
142.8 ± 77.4 SD

249
2.0 ± 1.1 SD
35.7 ± 5.2 SD


18
30
42
56

9
91
210
240
260
290
360
2.6 ± 0.2 SE


1.0

9.1
7.0
6.3
5.5
Range or
{95% Cl of mean)
9.5 - 274.0






13-42
19-52
27 -77
41 - 101
total length:
(84 mm)
(240 mm)
(307 mm)
(320 mm)
(335 mm)
(348 mm)
(356 mm)



0.31 -2.3






Location
New Brunswick, Canada

central Arkansas
Kentucky



Louisiana/lab




east central Illinois






NS/lab


NS/NS






Reference
McAlpine & Dilworth, 1 989
-
McKamie & Heidt, 1974
Viparina & Just, 1975



Modzelewski & Culley, 1 974




Durham & Bennett, 1963






Burggren et al., 1983


Hutchinson et al., 1968
estimated




Note
No.
1






2











3


4
5




NJ

-k
Ol
CO
c
o
CQ
-------
                                            Bullfrog (Rana catesbeiana]

Factors
Food Ingestion ;
Rate (g/g-d) •


% Surf ace Area
(cm2)


Age/Sex/
Cond./Seas.
(13-42g)
(18-52g)
(28 - 77 g)
(40- 100g)
2 mo (30 g)
1 yr(91 g)
BB(143g)
A B (249 g)
Dietary
Composition
adults:
Decapoda-Astacidae
Lepidoptera ^
Coleoptera
, (Lampryidae)
(Chrysomeltdae)
(Carabjdae]
Pulmonata-Zonitidaa
Chtlipoda
sand, rock/ gravel
adults:
t plant
animal
{Qdonata)
(Coleoptera)
(Hemiptera)
{HymenopteraJ
{Amphibia)
unaccounted

Mean
0.071
0.059
0.040
0.033
11
25
. 35
52

Spring




















Summer

47.7
19.0
16.0
(5.8)
(5.8)
(4.1)
8.3
7.7
1.2

19.7
65.2
(8.8)
(15.8)
(0.5)
(2.2)
(26.4)
15.1
Range or
(95% Cl of mean}









Fall




















Winter




















Location
Louisiana (24 - 27 °C)







Location/Habitat
(measure)
Kentucky /NS

(% wet volume; stomach
contents)






New York/mountain lake

(% volume; stomach
contents)






Reference
Modzelewski & Culley, 1 974



estimated




Reference
Bush, 1959









Stewart & Sandison, 1973








Mote
No. \




6



Note
No.



















to

i-
01
CD
c
o
(O
-------
                                            Bullfrog (Rana catesbeiana]
Dietary
Composition
adults:
frogs
tadpoles
shiners
other fish'
Gastropoda
crayfish
other crustaeea
Arachnida
Coteoptera (adult)
Diptera (larvae)
Hemiptera
Population
Dynamics
Home Range
Size (m radius)

Population
Density
(N/hal




Clutch Size


Clutches/Year

Days to
Hatching

Spring

35
8
305
7
55
22
71
3
31
2
41
Age/Sex/
Cond./Seas.
A M nonbreed
A F nonbreed
A M territory
BB (1960)
BB(1961)

tadpoles:
November
March
May



93% of F
7% of F



Summer

33
11
157
2
70
162
42
23
33
7
43

FaU

39
0
25
5
26
18
47
3
15
0
16

Mean
2.9
2.4
2.7
1,376
• 892


130,000
69,000
16,000

7,360 + 741.7
SE
1
2
2-4
4-5

Winter












Range or
(95% Cl of mean)
0.76- 11.3
0.61 - 10.2








10,000-20,000






Location/Habitat
(measure)
Missouri/bait minnow pond

(number of items found;
stomach contents)









Location/Habitat
Ontario, Canada/pond

Michigan/pond
Ontario, Canada/pond


Kentucky /pond



Kansas/NS
New Jersey/pond

Michigan/pond

Arizona, California/river
Kansas/NS

Reference; : . .-:...•'..
Corse &Metter, 1980



"








Reference
Currie & Bellis, 1969

Emlen, 1968
Currie & Bellis, 1969


Cecil & Just, 1 979



Smith, 1956
Ryan, 1980

Emlen, 1977

Clarkson & DeVos, 1 986
Smith, 1956
Note
No.












Note
No.


7














to

i.
01
00
o
(Q
-------
                                           Bullfrog (Rana catesbeiana]
Population
Dynamics
Age at
Metamor-
phosis
Age at Sexual
Maturity



Annual
Mortality Rates
(%)
Mortality Rates
(%)
Longevity
fyr}
Seasonal
Activity .
Mating/Laying
Metamor-
phosis

Age/Sex/
Cond./Seas.
B
B
B
B
M
F

B

A M 1 - 2 yr
A M 2 - 3 yr
AM3-4yr
A M 4 - 5 yr
tadpoles {to
metamorph.)
AB

Begin
February
April
May
late May
August
March
June
July
Mean
1yr
1 -2yr
2-3 yr
Syr
1 yr after metam.
1 - 2 yr after
metam.
1 - 2 yr after
metam.
58
58
48
77
85.5

,
Peak
May
late June
July
(1st clutch)
(2nd clutch)
late June-Aug.
Range or
{95% Cl of mean]






82.4-88.2
up to 5 - 8

End
October
late June
August
July
October
April
early October
Sept., October
Location/Habitat !
Carolinas, Virginia/NS
Michigan/pond
New York/NS
Nova Scotia, Canada/NS
Michigan/pond

New York/NS

Michigan/pond
Kentucky/shallow ponds
Michigan/ponds

Location
southern range in N America
California, Arizona
Missouri
northern range in N America
California, Arizona
California, Arizona
Missouri
New York
Reference
Martof et al., 1 980
Collins, 1979
Ryan, 1953
Bleakney, 1952
Howard, 1978a

Ryan, 1953

Howard, 1984
Cecil & Just, 1 979
Howard, 1978b

Reference
Behler & King, 1979
Clarkson & DeVos, 1 986
Willis etal., 1956
DeGraaf & Rudis, 1983;
Behler & King, 1 979
Clarkson & DeVos, 1986
Clarkson & DeVos, 1 986
Willis etal., 1956
Ryan, 1953
Note
No.
8







Note
No.



01

CD
CO

C
o
to
-------
                                                         Bullfrog  (Rana catesbeiana]
Seasonal
Activity
Hibernation
Begin
late October
mid-October
Peak

End
late March
March
Location
east central Illinois
Missouri
Reference.
Durham & Bennett, 1963
Willis etal., 1956
Note
No.

to
.£»
0>
o
1   Mean snout-to-vent length (SVL) of frogs was 98 mm SVL and the range was 45 to 128 mm SVL.
2   Age postmetamorphosis; maintained at a temperature of 24 to 27 °C and fed mosquitofish, crickets, and earthworms.
3   Restrained, cannulated; weight 5.7 g.
4   Mean weight of frogs was 74.8 g.
5   Estimated assuming temperature of 20°C using Equation 3-50 (Robinson et al., 1983). Body weights (1) for 2-month postmetamorphosis frog
    from Modzelewski and Culley (1974);  (2) for a 1-year postmetamorphosis frog from Durham and Bennett (1963), Farrar and Dupre (1983); (3) for
    both juveniles and adults of both sexes, McAlpine and Dilworth (1989); and (4) for adults of both sexes, McKamie and Heidt (1974).
6   Estimated using Equation  3-24 (Hutchinson et al., 1968) and body  weights as described in note 5.
7.   Based on average distance between frogs.
8   Cited in Bury and Whelan (1984).
CO
c
o
CO
-------
References  (including Appendix)

Behler, J. L.; King, F. W. (1979) The Audubon Society field guide to North American
      reptiles and amphibians. New York, NY: Alfred A. Knopf, Inc.

Bleakney, J. S. (1952) The amphibians and reptiles of Nova Scotia. Can. Field-Nat. 66:
      125-129.

Brooks,  G. R., Jr.  (1964) An analysis of the food habits of the bullfrog by body size, sex,
      month, and habitat. Va. J. Sci. 15: 173-186.

Bruneau, M.; Magnin, E. (1980) Croissance, nutrition, et reproduction des ouaouarons
      Rana catesbeiana Shaw (Amphibia Anura) des Laurentides au nord de Montreal.
      Can J. Zool. 58: 175-183.

Burggren, W. W.;  West, N. H. (1982) Changing respiratory importance of gills, lungs and
      skin during metamorphosis in the bullfrog Rana catesbeiana. Physiol. Zool. 56:
      263-273.

Burggren, W. W.;  Feder, M. E.; Finder, A. W.  (1983) Temperature and the balance
      between aerial and aquatic respiration in larvae of Rana berlandieri and Rana
      catesbeiana. Physiol. Zool. 56: 263-273.

Bury, R. B.; Whelan, J.  A. (1984) Ecology and management of the bullfrog. U.S. Fish
      Wildl. Serv. Resour. Publ. No. 155; 23 pp.

Bush, F. M. (1959) Foods of some Kentucky herptiles.  Herpetologica 15: 73-77.

Carpenter, H. L.; Morrison, E. O. (1973) Feeding behavior of the bullfrog, Rana
      catesbeiana, in north central Texas. Bios 44: 188-193.

Cecil, S. G.; Just, J. J.  (1979) Survival rate, population density and development of a
      naturally occurring anuran larvae (Rana catesbeiana). Copeia 1979: 447-453.

Clarkson, R. W.; DeVos, J. C., Jr. (1986) The bullfrog, Rana catesbeiana Shaw, in the
      lower Colorado River, Arizona-California. J. Herpetol. 20: 42-49.

Cohen, N.  W.; Howard, W. E. (1958) Bullfrog food and growth at the San Joaquin
      Experimental Range, California. Copeia 1958: 223-225.

Collins, J.  P. (1975) A comparative study of life history strategies in a community of frogs
      [Ph.D.  dissertation]. Ann Arbor, Ml: University of Michigan.

Collins, J.  P. (1979) Intrapopulation variation in the body size at metamorphosis and timing
      of metamorphosis in the bullfrog. Ecology 60: 738-749.
                                      2-461
Bullfrog
-------
Conant, R.; Collins, J. T. (1991) A field guide to reptiles and amphibians - eastern and
       central North America. Boston,  MA: Houghton Mifflin Co.

Corse, W. A.; Metter, D. A. (1980) Economics, adult feeding and larval growth of Rana
       catesbeiana on a fish hatchery.  J. Herpetol. 14: 231-238.

Currie, W.; Bellis, E. D. (1969) Home range and movements of the bullfrog, Rana
       catesbeiana (Shaw), in an Ontario pond. Copeia 1969: 688-692.

DeGraaf, R. M.; Rudis, D. D. (1983) Amphibians and reptiles of New England. Amherst,
       MA: University of Massachusetts Press.

Dowe, B. J. (1979) The effect of time  of oviposition and microenvironment on growth of
       larval bullfrogs (Rana catesbeiana) in Arizona [master's thesis]. Tempe, AZ: Arizona
       State University.

Durham, L.; Bennett, G. W. (1963) Age, growth, and homing in the bullfrog. J. Wildl.
       Manage. 27: 107-123.

Ehrlich, D. (1979) Predation by bullfrog tadpoles (Rana catesbeiana) on eggs and newly
       hatched larvae of the plains leopard frog (Rana blairi). Bull. Md. Herpetol. Soc. 15:
       25-26.

Emien, S. T. (1968) Territoriality in the bullfrog, Rana catesbeiana. Copeia 1968: 240-243.

Emien, S. T. (1976) Lek organization and mating strategies of the bullfrog. Behav. Ecol.
       Sociobiol. 1: 283-313.

Emien, S. T. (1977) "Double clutching" and its possible significance in the bullfrog. Copeia
       1977:749-751.

Farrar, E. S.; Dupre, R. K. (1983) The role of diet in glycogen storage by juvenile bullfrogs
       prior to overwintering. Comp. Biochem. Physiol. A: Comp. Physiol. 75: 255-260.

Frost, S. W. (1935) The food of Rana catesbeiana Shaw. Copeia 1935:  15-18.

Fulk, F. D.; Whitaker, J. O., Jr. (1968)  The food of Rana catesbeiana in three habitats in
       Owen County, Indiana. Indiana Acad. Sci. 78: 491-496.

George, I.  D. (1940) A study of the bullfrog, Rana catesbeiana Shaw, at Baton Rouge,
       Louisiana [Ph.D. dissertation]. Ann Arbor, Ml: University of Michigan.

Gibbons, J. W.; Semlitsch, R.  D. (1991) Guide to the reptiles and amphibians of the
       Savannah River Site. Athens,  GA: The University of Georgia Press.

Glass, M. L.; Burggren, W. W,; Johansen, K. (1981) Pulmonary diffusing capacity of the
       bullfrog (Rana catesbeiana). Acta Physiol.  Scand. 113: 485-490.
                                      2-462
Bullfrog
-------
Hammer, D. A.; Under, R. L. (1971) Bullfrog food habits on a waterfowl production area in
       South Dakota. Proc. SD Acad. Sci. 50: 216-219.

Howard, R. D. (1978a) The influence of male-defended opposition sites on early embryo
       mortality in bullfrogs. Ecology 59: 789-798.

Howard, R. D. (1978b) The evolution of mating strategies in bullfrogs, Rana catesbeiana.
       Evolution 32: 850-871.

Howard, R. D. (1981a) Sexual dimorphism in bullfrogs. Ecology 62: 303-310.

Howard, R. D. (1981b) Male age-size distribution and male mating success in bullfrogs. In:
       Alexander, R. D.; Tinkle, D. W., ed. Natural selection and social behavior: recent
       research and new theory; pp. 61-77.

Howard, R. D. (1984) Alternative mating behaviors of young male bullfrogs. Am. Zool. 24:
       397-406.

Hutchinson, V. H.; Whitford, W. G.; Kohl, M. (1968) Relation of body size and surface
       area to gas exchange in anurans. Physiol. Zool.  41: 65-85.

Jaeger, R. G.; Hailman, J. P. (1976) Ontogenetic shift  of spectral phototactic preferences
       in anuran tadpoles. J. Comp. Physiol. Psychol. 90: 930-945.

Korschgen, L. J.;  Baskett, T. S. (1963) Foods of impoundment and stream dwelling
       bullfrogs in Missouri. Herpetologica 19: 89-97.

Korschgen, L. J.;  Moyle, D. L. (1955) Food habits of the bullfrog in central Missouri farm
       ponds. Amer. Midi. Nat.  54: 332-341.

Lillywhite, H. B. (1970) Behavioral temperature regulation in the bullfrog, Rana
       catesbeiana. Copeia 1970:  158-168.

Martof, B. S.; Palmer, W. M.; Bailey, J. R.; et al. (1980) Amphibians and reptiles of the
       Carolines and Virginia. Chapel Hill, NC: University of North Carolina Press.

McAlpine, D. F.; Dilworth, T. G. (1989) Microhabitat and prey size among three species of
       Rana (Anura: Ranidae) sympatric in eastern Canada. Can.  J. Zool. 67: 2241-2252.

McAuliffe, J. R. (1978) Biological survey and management of sport-hunted bullfrog
       populations in Nebraska. Lincoln, NE: Nebraska Game and Parks Commission; 78
       pp.

McKamie,  J. A.; Heidt, G. A. (1974) A comparison of spring food habits of the bullfrog,
       Rana catesbeiana, in three habitats of central Arkansas. Southwest. Nat. 19:
  :  ;   107-111.
                                      2-463
' Bullfrog
-------
Modzelewski, E. H., Jr.; Culley, D. D., Jr. (1974) Growth responses of the bullfrog, Rana
       catesbeiana fed various live foods. Herpetologica 30: 396-405.

Oliver, J. A. (1955) The natural history of North American amphibians and reptiles.
       Princeton, NJ: Van Nostrand Co.

Raney, E. C. (1940) Summer movements of the bullfrog, Rana catesbeiana (Shaw), as
       determined by the jaw-tag method. Am. Midi. Nat. 23: 733-745.

Raney, E. C.; Ingram, W. M. (1941) Growth of tagged frogs (Rana catesbeiana Shaw and
       Rana clamitans Daudin) under natural conditions. Am. Midi. Nat. 26: 201-206.

Robinson, R. W.; Peters, R. H.; Zimmermann, J. (1983) The effects of body size and
       temperature on metabolic rate of organisms. Can. J. Zool.  61: 281-288.

Ryan, M. J. (1980) The  reproductive behavior of the bullfrog (Rana catesbeiana). Copeia
       1980: 108-114.

Ryan, R. A. (1953) Growth rates of some ranids under natural conditions. Copeia 1953:
       73-80.

Smith, H. M. (1956) Handbook of amphibians and reptiles of Kansas. Univ. Kansas Mus.
       Nat. Hist. Misc. Publ. 9.

Smith, P. W. (1961) The amphibians and reptiles of Illinois. III.  Nat. Hist. Surv. Bull. 28.

Stewart, M. M.; Sandison, P.  (1973) Comparative food habits of sympatric mink frogs,
       bullfrogs, and green frogs. J. Herpetol. 6: 241-244.

Storer, T. I. (1922) The eastern bullfrog in California. Calif. Fish and Game 8: 219-224.

Treanor, R. R.; Nichola, S. J. (1972) A  preliminary study of the commercial and sporting
       utilization of the bullfrog, R. catesbeiana Shaw in California. Calif. Dept. Fish and
       Game, Inland Fish. Admin. Rep.  72-4; 23 pp.

Turner, F. B. (1960) Postmetamorphic growth in anurans. Am.  Midi. Nat. 64: 327-338.

Tyler, J. D.; Hoestenbach,  R. D., Jr. (1979) Differences in food of bullfrogs (Rana
       catesbeiana)  from pond and stream habitats in southwestern  Oklahoma. Southwest.
       Nat. 24: 33-38.

Viparina, S.; Just, J. J. (1975) The life  period, growth and differentiation of Rana
       catesbeiana larvae occurring in nature.  Copeia 1975: 103-109.

Weathers, W. W. (1976) Influence of temperature acclimation on oxygen consumption,
       haemodynamics and oxygen transport in bullfrogs. Aust. J. Zool. 24: 321-330.
                                      2-464
Bullfrog
-------
Willis, Y. L.; Moyle, D. L.; Baskett, T. S. (1956) Emergence, breeding, hibernation,
      movements and transformation of the bullfrog, Rana catesbeiana, in Missouri.
      Copeia 1956: 30-41.

Wright, A. H. (1914) North American Anura: life histories of the Anurans of Ithaca, New
      York. Washington, DC: Carnegie Institute; Publ. No. 197.

Wright, A. H.; Wright, A. A. (1949) Handbook of frogs and toads of the United States and
      Canada. Ithaca, New York: Comstock Publishing  Co.
                                      2^465
Bullfrog
-------
-------
                         3.  ALLOMETRIC EQUATIONS

      Values for key contact rate factors such as food and water ingestion rates have
been measured for few wildlife species.  In this section, we describe allometric equations
that can be used to estimate several exposure factors on the basis of animal body weight
using models derived from taxonomically similar species.  We emphasize, however, that
measured values'from well-conducted studies on the species of concern are likely to be
more accurate and to have narrower confidence limits.
      Allometry is defined as the study of the relationships between the growth and size
of one body part to the growth and size of the whole organism; however, allometric
relationships also exist between body size and other biological  parameters (e.g., metabolic
rate). The relationship between the physiological and physical  parameters and body
weight frequently can be expressed as:
      Y = a Wtb ± SE of Y, or
[3-1]
      log Y = log a + b log Wt ± SE of log Y
[3-2]
where Y is the biological characteristic to be predicted, Wt is the animal's body weight
(mass),  a and b are empirically derived constants, and SE is the standard error of the mean
value of the  parameter.

      Equation 3-2 is the log transformation of Equation 3-1.  Equation 3-2 represents a
straight line, with b equal to the slope of the line and log a equal  to the Y-intercept of the
line. Values for a and b usually are determined empirically from measured values using
linear regression analysis. Once values are determined for a and  b, Equation 3-1 can be
used to predict a value of Y from the body weight of the animal.  The SE of Y is the
standard error of the mean Y estimated for the mean of the Wt values; the SE of log Y is
the standard error of the mean log Y estimated for the mean of the log Wt values.
                                        3-1
-------
       Allometric equations can be used to estimate parameter values for species for
which measured values are not available.  The equations presented in this chapter,
however, should not be used for taxonomic categories other than the category for which
each was developed.  For example, equations developed for iguanid lizards cannot be used
for amphibians and should not be used for other groups  of reptiles without careful
evaluation of likely differences between the groups. It also is important to remember that
the allometric equations presented in this chapter have been developed using mean values
for a number of species within a taxonomic category.  Individual species usually exhibit
values somewhat different from those predicted by an allometric model based on several
species. Furthermore, different-sized individuals within a species and individuals at varying
stages of maturation are likely to exhibit a different allometric relationship between body
weight and the dependent variable. For further discussion of within-species allometric
equations related to growth and reproduction, see Reiss (1989).

       In the next five sections, we describe empirically  derived allometric equations that
relate food ingestion rates (Section 3.1), water  intake  rates (Section 3.2), inhalation rates
(Section 3.3), surface area (Section 3.4), and metabolic  rate (Section 3.5) to body weight.
As discussed above, most of the allometric models differ for birds, mammals, reptiles, and
amphibians, and many also vary within these taxonomic groups. In Section 3.6, we
provide a  summary of operations involving logarithms and powers and unit conversion
factors for those persons who may want to modify allometric equations found in the
literature. Finally, in Section  3.7 we describe how to estimate 95-percent confidence
intervals for food ingestion rates and free-living  metabolic rates  predicted  on the basis of
allometric equations presented in this chapter.  We present most equations in the
untransformed form only.  For equations for which an investigator reported standard errors
for the log transformation of the relationship, we present the equation both ways. For
those persons interested in estimating confidence intervals for other allometric equations.
Peters (1983) provides a simple review of how to estimate regression statistics for
equations of the form of Equation 3-2.  Section  3.8 contains the references for this
chapter.
                                        3-2
-------
3.1.  FOOD INGESTION RATES

       Food ingestion rates vary with many factors, including metabolic rate, the energy
devoted to growth and reproduction, and composition of the diet. The metabolic rate of
free-ranging animals is a function of several factors, including ambient temperature,
activity levels, and body weight. In birds and mammals, thermoregulation can
considerably increase an animal's metabolic requirements during the winter, whereas
reproductive efforts can replace thermoregulation as the predominant extra metabolic
expenditure in the spring and summer.  Many reptiles and amphibians, on the other hand,
drop their activity levels and metabolic rates in the winter.

       For homeotherms (i.e., animals that maintain a relatively constant body temperature
such as most birds and mammals), metabolic rate generally decreases with increasing body
mass (see Section 3.5).  The smallest birds and mammals must consume quantities of
food equal to their body weight or more daily; in contrast, the larger homeotherms may
consume only a small fraction of their body weight in food daily.  Herbivores tend to
consume larger quantities of food than carnivores because of the lower energy content of
their food.  Ingestion rates, expressed in units of food energy normalized to body size
(e.g., kcal/kg-day), are not significantly  different for herbivores and carnivores (Peters,
1983). Four-legged poikilotherms (those animals whose usual  body temperatures are the
same as that of their environment, such as reptiles and amphibians) exhibit the same slope
of decreasing ingestion rates per unit body weight with increasing body size but show a
lower intercept (i.e., lower ingestion rate for a given body weight) than homeotherms
(Nagy, 1987).
      The rate of food consumption that an animal must achieve to meet its metabolic
needs can be calculated by dividing its free-living (or field) metabolic rate (FMR) (see
Section  3.5) by the metabolizable energy in its food (Nagy, 1987).  Metabolizable energy
(ME) is the gross energy (GE) in a unit of food consumed  minus the energy lost in feces
and urine. Assimilation efficiency (AE) equals the ratio ME/GE, or the fraction of GE that is
metabolizable. AE is relatively constant among different groups of consumer species of
mammals and birds that are all  either carnivorous, insectivorous, herbivorous, or

                                        3-3
-------
granivorous (Hume, 1982; Peters, 1983; Nagy, 1987; Bobbins, 1983). Nagy (1987)
calculated the mean ME (i.e.', kilojoules of ME per gram of dry matter) of various diets for
birds and mammals from average values of AE for birds and mammals and typical GE
contents of those diets as reported by Golley (1961) and Robbins (1983). These values
are presented in Table 3-1. (For more information on ME and AE, see Section 4.1.2.)
Using the values presented in Table 3-1, Nagy (1987) developed allometric equations for
food ingestion (Fl) rates as a function of body weight (Wt) for birds, mammals, and lizards
using estimated FMRs and general dietary composition.  In the remainder of this section,
we present these equations for birds (Section 3.1.1) and  mammals (Section 3.1.2).
Section 3.1.3 summarizes Nagy's food ingestion allometric equations for iguanid lizards.
We report this information even though no iguanid lizards were among our selected
species because it is the only information of this type we identified for any amphibian or
reptile.

       Nagy's (1987) estimates of FMR are based on doubly labeled water measurements
of CO2 production in free-living animals.  When performed correctly, this method is more
accurate for estimating the metabolic rate of free-living animals than other methods
commonly used (King, 1974). Other allometric equations for food ingestion rates that we
identified in the open literature are based largely on  captive animals without corrections for
the additional energy requirements of free-living animals.  For more accurate estimates of
food ingestion rates by type of diet, we recommend following the procedures outlined in
Section 4.1.2 instead of using these generic equations.

3.1.1. Birds
      For birds, Nagy (1987) calculated Fl rates (in grams dry matter per day) from ME
and FMR and developed the following equations:  ,
      Fl (g/day) =  0.648 Wt0-651 (g), or
      Fl (kg/day) = 0.0582 Wt0-651 (kg)

      Fl (g/day) = 0.398 Wt0-850 (g)
all birds
passerines
[3-3]
[3-4]
                                        3-4
-------
Table 3-1.  Metabolizable Energy (ME) of Various Diets for Birds and Mammals
Diet
insects

fish

vegetation
seeds
nectar
omnivory
Metabolizable Energy
(kJ/g}a (kcal/g)a
18.7
18.0
18.7
16.2
10.3
18.4
20.6
14
= 4.47
= 4.30
= 4.47
= 3.87
= 2.46
= 4.92
= 4.92
= 3.35
Animal Group
mammals
birds
mammals
birds
mammals
mammals
hummingbirds
mammals and birds
ag = grams dry weight.
Source: Nagy, 1987.
                           0.751
       Fl (g/day) = 0.301 Wtu-/ai  (g)
       Fl (g/day) = 0.495 Wt°-704 (g)
non-passerines
seabirds
[3-5]
[3-6]
where Wt equals the body weight (wet) of the animal in grams (g) or kilograms (kg) as
indicated. We provide the regression statistics for these equations (including sample size
and regression coefficient) and information required to estimate a 95-percent confidence
interval for an Fl rate predicted for a specified body weight in Section 3.7.  More accurate
estimates of food requirements can be made from estimates of FMR (Section 3.5), dietary
composition,  and AE for the species of interest, as outlined in Section 4.1.2.

3.1.2.   Mammals

      For placental mammals, Nagy (1987) calculated Fl rates (in grams dry matter per
day) from ME and FMR values and developed the following equations:
                                        3-5
-------
       Fl (g/day)  = 0.235 Wt°-822 (g), or
       Fl (kg/day) = 0.0687 Wt°-822 (kg)
all mammals    [3-7]
                            .0.564
       Fl (g/day) =0.621 Wtu-0b* (g)
       Fl (g/day) = 0.577 Wt°-727 (g)
rodents
 [3-8]
herbivores      [3-9]
We provide the regression statistics for these equations (including sample size and
regression coefficient) and information required to estimate a 95-percent confidence
interval for an Fl rate predicted for a specified body weight in Section 3.7. More accurate
estimates of food requirements can be made from estimates of FMR (Section 3.5), dietary
composition, and AE for the species of interest, as outlined in Section 4.1.2.
       Herbivores tend to consume more food than carnivores or omnivores on a dry-
weight basis because of the lower energy content of the herbivores' diets. On an energy
basis (e.g., kilocalories), the ingestion rates of carnivores and herbivores are not
significantly different (Farlow, 1976):
       Fl (kjoule/day)  = 971 Wt°-73 (kg) (r2  = 0.942), or
       Fl (kcal/day) = 1.518 Wt°-73 (g)

       Fl (kjoule/day)  = 975 Wt°-70 (kg)  (r2 = 0.968), or
       Fl (kcal/day) = 1.894 Wt°-70 (g)
herbivores
[3-10]
carnivores     [3-11]
3.1.3.  Reptiles and Amphibians

       This section summarizes food ingestion allometric equations for iguanid lizards,
which  is the only information of this type we identified for any amphibian or reptile.  Nagy
(1987) calculated Fl rates  (in grams dry matter per day) from ME and  FMR values on
spring  and summer days and developed the following equations:
                                        3-6
-------
       Fl (g/day) = 0.019 Wt°-841 (g)
                           0.773
       Fl (g/day) = 0.013 Wtu-//cs (g)
herbivores
insectivores
[3-12]
[3-13]
Again, on an energy basis, carnivores and herbivores are not significantly different and can
be represented by a single relationship:
       Fl (kjoule/day) = 0.224 Wt°-799 (g), or
       Fl (kcal/day)  = 0.054 Wt°-799 (g)
all iguanids
[3-14]
We provide the regression statistics for these equations (including sample size and
regression coefficient) and information required to estimate a 95-percent confidence
interval for an Fl rate predicted for a specified body weight in Section 3.7. More accurate
estimates of food requirements for these and other groups of reptiles and amphibians can
be made from estimates of FMR (Section 3.5), dietary composition, and AE for the species
of interest, as outlined in Section 4.1.2.                           .

       Allometric equations for Fl rates for other groups of reptiles and amphibians were
not found.  For other groups, we recommend estimating Fl rates from FMR and diet, as
described in Section 4.1.2.

3.2.   WATER INTAKE RATES.

       Daily water requirements depend on the