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Vk/ffa courtesy of Charlie Mwres, WOOObircU.c&m
The California clapper rail
is an endangered species.
Endangered species are
plants and animals that are
in immediate danger of
becoming extinct.
Threatened species are plants
and animals whose population
numbers are so low that they
may become endangered in the
future.
The U.S. Environmental
Protection Agency's (EPA)
Endangered Species Protection
Program (ESPP) will help
ensure that pesticide use does
not jeopardize the survival of
listed species.
Efuuutaered Species Facts
California Clapper Rail
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Description and Ecology
Status Endangered, listed October 13, 1970.
Critical Habitat Not designated.
Appearance The California clapper rail measures 13-19
inches from bill to tail. That males are slightly larger than
females is the only difference between them. The upper body
parts are olive brown; the breast is a solid cinnamon-buff.
The dark flanks are crossed with white bars, and white under-
tail coverts are often visible when the California clapper rail is
agitated. The bill is long, and curves downward slightly. Legs
appear strong, as do the long toes. Juveniles have a paler bill,
and a darker body; gray, with blackish flanks and sides. Their
white bars and undertail coverts are faint.
Range Populations of the California clapper rail now live
almost exclusively in the marshes of the San Francisco
estuary (San Mateo, Santa Clara, Alameda, Contra Costa,
Solano, Napa, Sonoma, and Marin Counties). Thousands of
California clapper rails were eliminated by market hunters
from the time of the Gold Rush until the passage of the
Weeks-McLean Law in 1913, which was a precursor to
the Migratory Bird Treaty Act and was designed to stop
commercial market hunting and illegal shipment of migratory
birds from one state to another. Since that time diking and
filling for conversion to agriculture, urban development,
and salt production have reduced the San Francisco Bay
tidal marshes by 84% or more. Originally the salt marshes
of South San Francisco Bay had the largest populations of
California clapper rails. Now, populations there are found
in remnant salt marshes such as those on Bair and Greco
Islands, along Coyote Creek, and throughout the marshes in
the Don Edwards San Francisco Bay National Wildlife Refuge.
Smaller populations have been and still are located in western
Contra Costa, eastern Marin, and northern Alameda Counties.
California clapper rails are also found in northern San
Pablo Bay, along the Petaluma River as far north as Schultz
Creek, along major creeks and marshes in both Sonoma
and Napa Counties and on Bull Island on the Napa River.
The extension of range further east in Suisun Marsh and
northern Contra Costa County may bear some relationship
to reductions in Sacramento-San Joaquin Delta freshwater
outflow and increases in salinity.
Habitat California clapper rails inhabit a range of salt and
brackish water marshes. Typically they utilize salt marshes
dominated by both pickleweed (Salicornia virginica) and
Pacific cordgrass (Spartina foliosa). Originally these marshes
had vegetation zones that included both high, middle, and
low marshland. High marsh zones functioned as refugium for
many salt marsh animals escaping high tides, particularly
winter flood tides, but these have largely been eliminated
by the dyking required for fill and land conversion. Some
lower marshes are being lost to erosion, and some middle
marshes lost to subsidence.
Clapper rails use a network of small tidal sloughs for
foraging and quick escape. They construct nests near
them (within 10 meters), canopied with either pickleweed
or cordgrass, sometimes gum-plant, salt grass, or drift
materials. Density of cover, floatability of materials, height
above tides, and annual climate changes are all variables
of successful nesting. California clapper rails also construct
"brood nests" on higher ground to protect their young from
storm tides. These are usually simple floatable, platforms of
twigs or stems, without a canopy.
Biology and Behavior California clapper rails nest
from mid-March into July. Nesting peaks occur in late
April-early May and late June-early July. The second peak
may include late nesters and pairs attempting to overcome
initial nesting failure. These failures most often result from
inundation by high tides and by Norway rat predation.
Norway rats also prey upon young rails. The increasing
presence of non-native red foxes is further impacting the
rail population. The predators of adult rails include northern
KaUam Umxjirc9trk oindetus
Office of Pesticide Programs (7507P)
http://www.epa.gov/espp/
February 2010

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orma.
harriers, red-tailed hawks, arid peregrine faicoris.
California clapper rails eat spiders, amphipods, yellow and
striped shore crabs, clams (Macoma balthica), and the
introduced horse mussel. The horse mussel may sometimes
trap the foot or bill of a rail attempting to pry it open,
California clapper rail juveniles can disperse a sufficient
distance to be found in both residential and agricultural areas
east of San Francisco Bay and along the open coast.
Recovery Plan The U.S. Fish and Wildlife Service (FWS)
developed a recovery plan for the California clapper rail in
1984. Recovery plans outline reasonable actions that FWS
believes are required to recover or protect listed species.
FWS prepares recovery plans, sometimes with the assistance
of recovery teams, contractors, state agencies, and others.
Recovery plans do not necessarily represent the views nor the
official positions or approvals of any individuals or agencies,
other than FWS, involved in the plan formulation. Approved
recovery plans are subject to modification as dictated by new
findings, changes in species' status, and the completion of
recovery tasks.
California Clapper Rail Information Sources
Primary Reference Beacham, Walton, Castronova,
Frank F., and Sessine, Suzanne (eds.), 2001, Beacham's
Guide to the Endangered Species of North America, Gale
Group, New York. Vol. 1, pp. 348-350.
Listing Notice U.S. Fish and Wildlife Service,
1970. Federal Register 35, No. 199, pp. 16047-16048.
http://ecos.fws.gov/docs/federal_register/fr27.pdf
Recovery Plan U.S. Fish and Wildlife Service,
1984. Salt Marsh Harvest Mouse and California
Clapper Rail Recovery Plan. U.S. Fish and Wildlife
Service, Pacific Region, Portland, Oregon. 141 pp.
http://ecos.fws.gov/docs/recovery__plan/841116.pdf
Species Account u.s. Fish and wildlife
Service, Sacramento Fish and Wildlife Office.
http://www.fws.gov/sacramento/es/animal_spp_acct/ca_
clapper_rail.pdf
Coiwui Marsh habitat/Steven. Sckwarzback, USQS WER.C
ie Moores, WOOOUrds.cmt
CaljvrnZa. clamper rail outfitted with, radio irattMtutter.
Toby RffkwAK/USQS Western. Ecoiojical Research Center
&EPA

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