3-EPA
United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
PO. Box 15027
Las Vegas NV 89114-5027
EPA 600/4-85-030
DOE/DP/00539-054
April 1985
Research and Development
Characteristics and
Migration Patterns of
Mule Deer on the
Nevada Test Site
prepared for the
U.S. Department of tnergy
under Interagency Agreement
Number DE-A108-76DP00539
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EPA 600/4-85-030
DOE/DP/00539-054
April 1985
CHARACTERISTICS AND MIGRATION PATTERNS OF MULE DEER ON THE
NEVADA TEST SITE
o .
_g by
Kenneth R. Giles
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
and
Jack Cooper
Nevada Department of Wildlife
Las Vegas, Nevada 89108
this study was conducted by the
U.S. Environmental Protection Agency
under interagency agreement
DE-4108-76DP00539
with the
U.S. Department of Energy
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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NOTICE
This report has been reviewed in accordance with the U.S. Environmental
Protection Agency's peer and administrative review policies and approved for
publication. Mention of trade names or commercial products does not consti-
tute endorsement or recommendation for use.
n
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CONTENTS
Page
F1 gures Ill
Introduction and Acknowledgements 1
Study Area 2
Methods 4
Results and Discussion 7
Mi grati on 8
Winter Range 10
Herd Composition and Population Estimates 11
Predati on 13
Summa ry 16
Literature Cited 16
m
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FIGURES
Number Page
1 Migration pattern and hunter kill in relation to
NTS and Nellis Bombing and Gunnery Range 3
2 Map of NTS summer and winter deer ranges 6
3 Ratio compositions of mule deer herd per 100 does.
Echo Peak and Rainier Mesa, July through October 12
4 Mule deer population estimates for Echo Peak and
Rainier Mesa, 1977 through 1981 14
5 Predator kills of mule deer during migration study 15
IV
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June 1984
Kenneth R. Giles
EMSL
P.O. Box 15027
Las Vegas, NV 89114
RH: MULE DEER MIGRATION. Giles and Cooper
CHARACTERISTICS AND MIGRATION PATTERNS OF MULE DEER ON THE NEVADA
TEST SITE1
Kenneth R. Giles, EMSL, P.O. Box 15017, Las Vegas, NV 89114
Jack Cooper, Nevada Department of Wildlife, 4747 Vegas Drive,
Las Vegas, NV 89108
Key words: mule deer, Nevada Test Site, migration, Clover Traps,
Cap-chur gun, triangulation.
INTRODUCTION AND ACKNOWLEDGEMENTS
Two major mule deer herds (Odocoileus heminous) reside on the
Nevada Test Site (NTS), apparently unaffected by nuclear testing
activities. Although radionuclide analyses of animals periodically
sacrificed or killed by auto traffic have shown no significant burden
of radioactivity, studies of the deer's migratory patterns were prompted
by their potential as carriers of radioactivity to areas accessible
This study was conducted by the U.S. Environmental Protection Agency
under interagency agreement DE-AI08-76DP00539 with the U.S. Department
of Energy.
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611 es
to the public (Smith, et al., 1980). The west portion of the NTS was
withdrawn from public use in October 1940 for use by the U.S. Air Force
(USAF) as an aerial bombing and gunnery range, and returned to Atomic
Energy Commission jurisdiction in December 1961. The east portion of
the site was withdrawn in April 1943 for use as a weapons testing site.
This report covers the last 6 of the 7 years (1977-1982) during
which mule deer were closely observed. The study was funded by the
U.S. Department of Energy and undertaken by the U.S. Environmental
Protection Agency with the cooperation and support of the Nevada
Department of Wildlife.
STUDY AREA
The NTS occupies 2,217 square kilometers (1,378 square miles) of
Nye County, Nevada, about 104 km (65 mi.) northwest of Las Vegas. It
is bordered on the east, north, and west by the USAF Nellis Bombing
and Gunnery Range (Figure 1).
The topography, typically southwest desert, ranges from dry lake
beds at 850 meters (2,800 feet) above sea level to the pinon-juniper
forests as high as 2,200 m (7,300 ft.). Intermediate areas, deeply
cut in washes and ravines, are generally alluvial fans that slope
sharply from several hundred meters per kilometer to about 3 meters
per kilometer in the valleys. Vegetation in the area consists mainly of
desert bitterbrush (Purshia glandulosa), Gambel oak (Quercus gambeli),
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Miles
Olometers
0 10 20 30 40 50
— Summer Range
— Winter Range
• Hunter Kill
•••• Reported Sightings
Figure 1. Migration pattern and hunter kill in relation to NTS
and Nell is Bombing and Gunnery Range.
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Gi 1 es
big sage (Artemisia tridentata), cliffrose (Cowania Mexicana), basin
wild rye (Elymus cinereus), longflower snowberry (Symphoricarpos
longiflorus), service berry (Amelanchier alnifolia), and a variety
of other forbs and grasses.
Strong south-southwesterly winds predominate in the summer and
north-northwesterlies in the winter. Precipitation is irregular and
ranges from slightly over 28.0 cm (12 in.) annually at the higher
elevation to 9.5 cm (3.8 in.) on the dry valley floors (Quiring, 1983).
Average temperature varies from summer maximum highs of 46° centigrade
(115° Fahrenheit) in the flats to 34° C (94° F) at the highest
measurement point on the NTS, and winter lows at the same stations
of -11° C (13° F) and -20° C (-2° F).
METHODS
Initially, deer were captured using the immobilizing drugs Sernylan
(Bio-Ceutic Lab, Inc.) and M-99/Etorphine (American Cycnomid) injected
from a Cap-chur gun (Palmer Chemical and Equipment Co., Douglasville,
GA; Silberman and McWilliams, 1972). Although successful, this method
required many man-hours to locate, approach, and immobilize the animals.
A highly successful alternate trapping method (Giles, 1979) was
developed by modifying Clover traps (Clover, 1954-56), and using water
trucked in as bait since there are no other natural water sources in
the area of the trap sites. Deer were also captured in other areas
using a spotlight and Cap-chur gun.
All captured deer were marked with cattle ear tags (both ears).
Large bucks over 90 kilograms and deer less than 2 years old were
4
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Gi les
tagged with visual markers, while all other mule deer were fitted with
collars containing a miniature radio transmitter equipped with a
mortality sensor (Telonics, Mesa, AZ). These transmitters operated
from 1 to 3 years and could be tracked from high ground line of sight
more than 40 km (25 mi.) distance. Even at such range, with two or
more good radio plots, the animal could be located by triangulation
with reasonable accuracy. On three occasions, animals were killed or
died on the winter ranges and the radios were recovered.
Observations of deer movements were made weekly from the ground.
When weather conditions limited access to the area or when deer could
not be located by ground tracking, observations were made by helicopter
over the area or by triangulation from fixed locations on the NTS that
overlook a great portion of the winter range. The most reliable means
of observation were by spotlighting at night and radio tracking during
the daylight hours. Capture and tracking activity during the summer
trapping period averaged 3 days and 2 nights weekly (Figure 2).
Several deer were tracked over long periods before recapture
permitted replacement of inactive radios. In the Echo Peak area,
25 deer were tracked from 2 years to 4.6 years, and, on Rainier Mesa,
five deer were tracked from 2 to 4.2 years.
Weekly location plots were made of each radio-tagged deer until
significant movement was noticed. The most accurate radio triangulation(s)
for the week was used in plotting the movement of these deer (Heezen
and Tester, 1967). When significant movement of individual deer was
noted, plots of the daily movement were made on a daily basis.
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Summer Range
Winter Range
• Trap Sites
1 - Echo Peak
2 - Rainier Mesa
0 5 10 15 20
1/80 Scale in Kilometers
(65 miles from Mercury)
Figure 2. Map of NTS summer and winter deer ranges.
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Giles
RESULTS AND DISCUSSION
The Echo Peak herd summers on Pahute Mesa in an area of about
102 km2 (39.4 mi.2) at about 2,100 m (7,000 ft.) elevation. The
area is lightly forested with pinon-juniper. This is the largest
concentration of deer on the NTS.
Between June 1975 and November 1982, 41 bucks and 30 does were
fitted with radio telemetry devices; additionally, 21 bucks, 15 does
and 10 fawns in this same herd were marked with ear and neck tags.
No attempt was made to establish a daily life style for the animals
since the intended purpose of the deer study was to determine their
migration patterns and to locate their wintering range.
2 2
The Rainier Mesa herd summers in an approximate 150 km (58 mi. )
area of pinon-juniper in the north central portion of the NTS. Natural
water sources include two springs and one natural reservoir that
supplies water year-round on the north slope of the Mesa (Giles, 1976).
There are also several construction reservoirs in the area that support
tunneling operations at the base of the mesa. The Rainier study area
presented other factors that had to be considered. The available
water supply is located at approximately 1,760 to 1,950 m (5,800 to
6,400 ft.) elevation around the perimeter of the mesa. The study area
located at the 2,160 m (7,100 ft.) elevation has natural water available
only during the winter months, and, in order to hold deer in the study
area during the summer trapping period, water was hauled into an
established livestock tank when the deer became accustomed to using
this alternate water source. The trap was constructed around the
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Giles
livestock tank. A periodic trapping schedule was established so as
not to disrupt deer dependency on this water source. The deer appear
to have become conditioned to the vehicular traffic and equipment
which are present at all hours within 1 kilometer of the trap site.
Initial capture attempts were much the same as on Echo Peak.
Periodic trapping on Rainier Mesa, however, was not started until the
last two years of the study when the Echo Peak trap site was closed
and the equipment moved to Rainier Mesa. Trapping efforts at this
location were less successful, possibly because water was more
readily available around the perimeter. Also, trap time was lost due
to the repeated capture of previously marked deer. As an example, a
particular doe whose home range centered around the trap site was
captured on numerous occasions, thus preventing other animals from
entering the trap and being marked.
During the study period, 10 bucks and 11 does were fitted with
radio devices by which they were tracked and their location plotted.
An additional 12 bucks and two does marked with ear and neck tags were
plotted through visual observations only.
MIGRATION
Maintaining contact with individual deer was not difficult during
the summer and fall months because of their limited home range. The
majority could be found within 2 km (1.25 mi.) of their capture area
or water source and, since escape cover and feed were abundant in
these areas, they seldom traveled far.
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Giles
There were a few exceptions, i.e., individuals that moved about
8 km (5 mi.) for no apparent reason, sometimes staying in an area for a
few days before returning. Both herds followed the same general timetable
during migration: leaving their summer ranges by mid-November and nearly
all vacating the summer/fall range by mid-February. A few resident deer
(less than 40) remained on Echo Peak and Rainier Mesa year-round,
adjusting to climatic conditions by altitudinal movement.
A portion of the Rainier Mesa herd which does not winter with the
Echo Peak herd in the Timber Mountain area leaves the west side of the
NTS and moves onto the Nellis Bombing and Gunnery Range around Black
Mountain and in the deep canyon areas between Timber and Black Mountains.
At least one radio-equipped deer was tracked off the northern edge
of NTS and remained two winters in the foothills and canyons of the
Belted Range area. One doe migrated as far south as Skull Mountain,
45 km (28 mi.) from her capture site (this is the southernmost movement
recorded in the study).
The deer, including the majority of the Echo Peak herd and that
portion of the Rainier Mesa herd that wintered in the Timber Mountain
mixing area, gradually dispersed during the winter over a wide area
within the western foothills of Timber Mountain and the Beatty Wash
area and in the Yucca Mountain/Calico Hills area on the southern border
of Forty-Mile Canyon on the western edge of the NTS (Figure 2). The
most extreme movement recorded in the study involved two deer from Echo
Peak (Figure 1). One 5- to 6-year-old buck spent the winter of '77-'78
on Timber Mountain and moved the following spring northwest about 120 km
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Giles
(75 mi.) to Kawich Peak, where it was killed that fall by a hunter.
The other deer, a 2- to 3-year-old doe trapped in mid-December at
Echo Peak and tagged with ear tags and neck collar, was seen twice
the following summer in the Barley Creek area of central Nevada,
approximately 200 km (125 mi.) from her capture site.
It was determined from observations that the majority of deer in
both herds follow the same timetable, beginning their general migration
to their summer ranges in April and completing the move by mid-June.
Although some individuals remained year-round within the confines of
their winter range, the majority of the radio-equipped deer generally
returned to the area where they were tagged. In several instances, deer
were recaptured in the same clearing or within 1,500 to 2,000 m (456 to
608 ft.) of their capture site, which took place as long ago as two summers,
WINTER RANGE
About one-half of the Rainier Mesa deer herd wintered in the
Shoshone Mountain area and about 40 percent of the herd wintered with
the majority of the Echo Peak herd in the Timber Mountain area known
as Forty-Mile Canyon, which serves as a mixing area. Approximately
10 percent of the herd remained in the study area on a year-long basis.
Of much larger dimension than the summer ranges of either herd,
the Timber Mountain/Shoshone Mountain winter area ranges in vegetation
from pinon and juniper at the 1,830 m (6,000 ft.) elevations to
primarily dwarf sagebrush (Artemisia arbuscula) and big sagebrush
(Artemisia tridentata subspecies) in the lower reaches (Beatley, 1969).
10
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Giles
Very little water, except occasional snow, is available, with only one
small spring being accessible to deer.
HERD COMPOSITION AND POPULATION ESTIMATES
The two herds studied are identified as the Rainier Mesa herd and
the Echo Peak herd. All marked and unmarked deer sighted during both
day and night observations were recorded. The buck:doe:fawn ratios
were tabulated from data compiled from 1977 through 1981. The buck
per doe ratio consistently found throughout the study on Rainier Mesa
and Echo Peak was considerably higher than that reported in studies of
herds off the Test Site (Figure 3). This situation is attributable to
the fact that the Test Site deer are not hunted. The old aged segments
of the Rainier Mesa and Echo Peak herds occupies a larger percentage of
the total population than this same segment would in a herd that was
subjected to hunting. This has lead to a lower fawn production and
survival over a long period of time.
In contrast, the Nevada Department of Wildlife (Papez, 1976),
reports a lower buckrdoe ratio and a higher fawn ratio for other herds.
This variance in fawn ratio is probably related to the season in which
NTS observations were made (July-October), and the fact that EPA
objectives were not directed toward fawn production data or fawn sex
ratio data. Although at tagging time nearly all does of breeding age
had fawns, or showed signs of lactation, the fawns were less easily
observed in the dense vegetation and because the does tend to hide
their young, especially while feeding.
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250 —
200 —
Ratio Composition of Deer Herd Per 100 Doe
Echo Peak and Rainier Mesa, July Through October
Legend
D
- Buck
- Doe
- Fawn
Total Deer Observed
July - October
(234)
150 —
100 —
50 —
(116)
(166)
(55)
(31)
n
!
I
H:
•:•:
I
!
:•
106)
(54)
;
I
|
(166)
(130)
(44)
|
|
3
(115)
(114)
(69)
|
|
|
3
(84)
(28)
|
1
31
1977 78 79 80 81
ECHO PEAK
(30) _(46)
(30)
(24)
! (20)
|
i
(27)
1 (23)
';
1
|
3
|
|
1
:;
(75)
(22)
(8)
1
1
\
:•:
(35)
(30)
(27)
|
i
I
i
l
_(55)
(23)
I
1
1
i
77 78 79 80 81
RAINIER MESA
Figure 3. Ratio compositions of mule deer herd per 100 does. Echo Peak and Rainier Mesa,
July through October.
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Giles
It should be kept in mind that there are large areas of rugged
terrain with very limited access, especially in the Echo Peak area.
The observations made during the study were obtained from road surveys
around the peripheral areas and at the water sources where the animals
are concentrated. Figure 4 shows the total buckrdoe count as well as
the maximum-minimum range. These statistical values were obtained
using the Lincoln-Patterson Index (Overton, et al., 1969). on Rainier
Mesa in 1980, there were not sufficient observations of marked deer to
establish a range. Although an attempt was made to arrive at a reasonable
population figure for both deer herds on the NTS, THE EPA and other
trained observers conclude that the statistically generated (estimated)
figures are low. Based on the available sample data, it is estimated
that there are between 1,500 and 2,000 deer total for both herds on the NTS.
PREDATION
The EPA recorded seven deer kills by large predators: six by
mountain lions (Felis concolor), and one by two large coyotes (Cam's
latrans). In this latter incident, the deer was partially immobilized
during capture attempts and was attacked by coyotes before capture
could be effected. Figure 5 locates these kills; two at the Echo Peak
trap site while in the capture corral. The other four kills were
scattered at random throughout the summer range. On three occasions,
mountain lions were trapped in the Clover trap, but escaped by chewing
through the netting. No known kills can be attributed to bobcats
(Lynx rufus), although they were seen on numerous occasions while
spotlighting.
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Population Estimation for Buck and Doe
on the Nevada Test Site
_<0
CO
'c
H-
o
V
1
3
z
2000n
1000-
900-
800-
700-
600-
500-
400-
300-
200-
100
9-
8
7
6
5-
4-
3-
2-
I
I
Lincol
'Mean
i Index 9
'Range
5% Confidence Level
S
u-
»
I
1977 1978 1979 1980 1981
Echo Peak
1977 1978 1979 1980 1981
Ranier Mesa
Figure 4. Mule deer population estimates for Echo Peak and
Rainier Mesa, 1977 through 1981.
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•—••— Summer Range
1 -6 Lion Kill
7 Coyote Kill
• Trap Site
0 5 10 15 20
3/84 Scale in Kilometers
165 miles from Mefcurv)
Figure 5. Predator kills of mule deer during migration study.
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Giles
SUMMARY
When NTS deer migrate, the majority of the animals stay within
the confines of the NTS or the Nellis Bombing Range, and present
little potential for radiation transport off the NTS. Also, the few
deer that leave the NTS area do so during the winter when they cannot
legally be hunted in Nevada. The one exception from the apparent
migration pattern was a buck that was followed by telemetry until
the end of April, when the animal could no longer be located, and was
harvested the following fall in the Kawich Peak area about 120.9 km
(75 mi.) northwest of the study area (see Figure 1).
The makeup of the deer herds on the NTS is quite different from
that of deer in offsite areas. The large buck population indicates
that an aged pristine herd exists on the NTS. In general, it should
be noted that the deer populations are tied to the available water
sources, although a vast area of excellent deer range is present but
unavailable to the deer because of the lack of available water
sources. This range condition has been maintained because of the
periodic changes of available water due to construction activity,
therefore resulting in a browsing rest rotation system.
LITERATURE CITED
Beatley, Janice C. 1969. Vascular Plants of the Nevada Test Site,
Nellis Air Force Range, and Ash Meadows. University of California,
Los Angeles, 12-705.
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Giles
Clover, M. R. 1976. Single-Gate Deer Trap and Catch Net. California
Fish and Game, 40:367-373.
Giles, K. R. 1979. Springs of the Nevada Test Site and Their Use by
Wildlife. U.S. Environmental Protection Agency, NERC-LV-0539-26.
Giles, K. R. 1979. A Summer Trapping Method for Mule Deer. U.S.
Environmental Protection Agency, EMSL-LV-0539-27.
Heezen, Keith L. and J. R. Tester. 1967. Evaluation of Radio-Tracking
by Triangulation with Special Reference to Deer Movements.
J. Wildlife Management, 31:124:141.
Knox, K. L., J. G. Nagy, and R. D. Brown. 1969. Water Turnover in
Mule Deer. Journal of Wildlife Management, 33:389-393.
Overton, Scott W. and David E. Davis. 1969. Estimating the Number of
Animals in Wildlife Populations. Wildlife Management Techniques,
3rd Edition, pp. 433-437.
Papez, Nick J. 1976. The Ruby Butte Deer Herd. Biological Bulletin
No. 5, Nevada Department of Fish and Game.
Quiring, R. F. 1983. Precipitation Climatology of the Nevada Test
Site. U.S. Department of Commerce. W.S.N.S.O. 351-88, pp. 25-26.
Silberman, M. S., and L. J. McWilliams. 1972. Notes on Practical
Applications of Cap-chur Equipment in Large Animal Medicine.
The Georgia Veterinarian, Vol. 24, No. 3.
Smith, D. D., K. R. Giles and D. E. Bernhardt. 1980. Animal
Investigation Program, 1980 Annual Report: Nevada Test Site
and Vicinity. U.S. Environmental Protection Agency, EMSL-LV.
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