| General
Information |
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Official Status: Threatened,
the Pacific Coast population of the western snowy plover is
federally listed under the Endangered Species Act of 1973
as threatened. The western snowy plover is a Bird Species
of Special Concern in California. Snowy plovers were listed
as endangered under Washington Department of Game Policy No.
402 in 1981, and as threatened by the Oregon Fish and Wildlife
Commission in 1975. The threatened status in Oregon was reaffirmed
in 1989 under the Oregon Endangered Species Act
Date Listed: The Pacific coast population
of the western snowy plover was listed as threatened on March
5, 1993. Federal
Register
58 FR 12864. (pdf, 4.0 MB)
Critical Habitat: On June 19, 2012,
we published a final rule of critical habitat
along the coasts of California, Oregon, and Washington. Federal
Register
77 FR 36728. (pdf
4.5 MB)
Recovery Plan: A recovery plan was published
in 2007. The plan identifies six recovery units for the listed
population. Del Norte, Humboldt, and Mendocino counties are
located in Recovery Unit 2.
Revised Final Critical Habitat: : USFWS
releases Final Rule for Revised Critical Habitat for the
Pacific Coast Population of the Western Snowy Plover:
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| Identifying
Characteristics: |
The western
snowy plover is a small shorebird, about 6 inches long, with a
thin dark bill, pale brown to gray upper parts, white or buff
colored belly, and darker patches on its shoulders and head, white
forehead and supercilium (eyebrow line). Snowy plovers also have
black patches above their white forehead and behind the eye. Juvenile
and basic (winter) plumages are similar to adult, but the black
patches are absent. Some breeding males, especially in the southern
portion of the species’ range, may exhibit a rusty or tawny
cap. Their dark gray to black legs are a useful characteristic
when comparing them to other plover species (Page et al. 1995).
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| Current
Geographic Range: |
The Pacific
coast population of the snowy plover is defined as those individuals
that nest adjacent to tidal waters of the Pacific Ocean, and includes
all nesting birds on the mainland coast, peninsulas, offshore
islands, adjacent bays, estuaries, and coastal rivers (USDI Fish
and Wildlife Service 2004). The current known breeding range of
this population extends from Damon Point, Washington, to Bahia
Magdelena, Baja California, Mexico (USDI Fish and Wildlife Service
2006). Snowy plovers that nest at inland sites are not considered
part of the Pacific coast population, although they may migrate
to coastal areas during winter months.
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Life History: |
Pacific
coast plovers typically forage for small invertebrates in wet
or dry beach-sand, among tide-cast kelp, and within low foredune
vegetation (USDI Fish and Wildlife Service 2004). Some plovers
use dry salt ponds and river gravel bars. The breeding season
in the United States extends from March 1 through September 30,
although courtship activities have been observed during February.
Clutches, which most commonly consist of three eggs, are laid
in shallow scrapes or depressions in the sand. Pacific coast snowy
plovers are polyandrous (i.e., a female may breed with more than
one male), and share incubation duties. Females typically desert
the brood shortly after hatching, leaving the chick rearing duties
to the male. Females may renest if another male is available and
if time remains in the season to do so. Snowy plover chicks are
precocial, leaving the nest within hours after hatching to search
for food. Males attend the young until they fledge, which takes
about a month. Females generally assist the male to care for the
last brood of the season. Adult plovers do not feed their chicks,
rather they lead them to suitable feeding areas. Adults will present
a broken-wing or tail-drag display when a predator approaches
a brood or nest.
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General Habitat Characteristics: |
The Pacific
coast population of the western snowy plover breeds primarily
on coastal beaches from southern Washington to southern Baja California,
Mexico. The population breeds above the high tide line on coastal
beaches, sand spits, dune-backed beaches, sparsely-vegetated dunes,
beaches at creek and river mouths, and salt pans at lagoons and
estuaries (U.S. Fish and Wildlife Service 2001). Less common nesting
habitat includes bluff-backed beaches, dredged material disposal
sites, salt pond levees, dry salt ponds, and river bars (U.S.
Fish and Wildlife Service 2001). Suitable nesting habitat is distributed
throughout the listed range, but may be widely separated by areas
of rocky shoreline.
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| Population
and Habitat Status: |
Historical
records indicate that nesting western snowy plovers were once
more widely distributed in coastal California, Oregon, and Washington.
In Washington, snowy plovers formerly nested at five coastal locations
(USDI Fish and Wildlife Service 2006). Only three sites currently
are known to be active, representing, a minimum 40 percent decline
in Washington breeding sites. In Oregon, snowy plovers historically
nested at 29 locations on the coast (USDI Fish and Wildlife Service
2006). Currently, there are only 10 nesting locations, representing
a 65 percent decline in active breeding areas. In California,
there has also been a significant decline in breeding locations,
especially in southern California.
From 2001
to 2005, the size of the breeding population of plovers in Recovery
Unit 2 has ranged from 60 to 74 adults; the non-breeding population
probably exceeds 100 birds (Colwell et al. 2005). Reproductive
success in Recovery Unit 2 during this time period has ranged
from 0.8 to 1.7 fledglings per adult male (Colwell et al. 2005).
In recent years, nesting has occurred at the following locations
in northern California: Gold Bluffs Beach, Big Lagoon, Clam Beach,
South Spit, Eel River Wildlife Area, Centerville Beach, Eel River
gravel bars, Brush Creek, Ten Mile River, and Virgin Creek.
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| Threats: |
Poor reproductive
success, resulting from human disturbance, predation, and inclement
weather, combined with permanent or long-term loss of nesting
habitat to encroachment of non-native European beachgrass (Ammophila
arenaria) and urban development has lead to a decline in
active nesting, as well as an overall decline in the breeding
and wintering population of the snowy plover along the Pacific
coast (USDI Fish and Wildlife Service 1993).
Human activities,
such as walking, jogging, running pets, horseback riding, and
vehicle use, are key factors in the ongoing decline in breeding
sites and populations. The nesting season of the western snowy
plover (March through September) coincides with the period of
greatest human use (Memorial Day through Labor Day) on beaches
of the west coast. Intensive beach use by humans may result in
abandonment of nest sites, reductions in nest density, and reductions
in nesting success.
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| Conservation
Needs: |
The western
snowy plover recovery plan provides a strategy for recovery of
the listed population. Recovery objectives in the recovery plan
include: (1) achieving well-distributed increases in numbers and
productivity of breeding adult birds, and (2) providing for long-term
protection of breeding and wintering plovers and their habitat.
The recovery
plan states that delisting will be considered when the following
criteria have been met: (1) maintain for 10 years an average of
3,000 breeding adults distributed among 6 recovery units as follows:
Washington and Oregon, 250 breeding adults; Del Norte to Mendocino
Counties, California, 150 breeding adults; San Francisco Bay,
California, 500 breeding adults; Sonoma to Monterey Counties,
400 breeding adults; San Luis Obispo to Ventura Counties, California,
1,200 breeding adults; and Los Angeles to San Diego Counties,
California, 500 breeding adults; (2) maintain a 5-year average
productivity of at least 1.0 fledged chick per male in each recovery
unit in the last 5 years prior to delisting; and (3) have in place
participation plans among cooperating agencies, landowners, and
conservation organizations to ensure protection and management
of breeding, wintering, and migration areas listed in Appendix
B of the plan to maintain the subpopulation sizes and average
productivity specified in criteria 1 and 2 above.
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| Related
Documents: |
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| Site
Reports: |
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Washington
Oregon
California
- Monterey Bay 2012
- 2012
Coastal Northern California, Recovery Unit 2
- 2012
Monterey Bay and Beaches of Northern Santa Cruz County, California (pdf, 4.0 MB)
- 2012 Monitoring WSP nests with remote surveillance systems in San Francisco Bay
- 2011
Bolsa Chica, Orange County, California (pdf, 1.63 MB)
- 2011
Coastal Northern California, Recovery Unit 2
- 2011
San Francisco Bay California, Recovery Unit 3
- 2011
Point Reyes
National Seashore, Marin County, California - 2011 Annual Report
- 2009-2010
CA State Park WSP Annual Report
- 2010
Bolsa Chica, Orange County, California
- 2010
Coastal Northern California, Recovery Unit 2
- 2010
Monterey Bay and Beaches of Northern Santa Cruz County, California
(pdf, 6.7MB)
- 2010
Point Reyes
National Seashore, Marin County, California - 2010 Annual Report
- 2010
San Francisco Bay California, Recovery Unit 3
- 2009
Bolsa Chica, Orange County, California
- 2009
CA State Park System-wide Summary Report
- 2009
CA State Park Annual Nest Success Chart
- 2009
Coastal Northern California, Recovery Unit 2 (pdf,
850 KB)
- 2009
Mendocino District of California State Parks, Annual Report
(compressed file, 3.3 MB )
- Winter
Distribution of Western Snowy Plovers in Humboldt County - 2007/2008,
2008/2009
- 2009
San Francisco Bay California, Recovery Unit 3
- 2008
Bolsa Chica, Orange County, California
- 2008
CA State Park System-wide Summary Report
- 2008
Coastal Northern California, Recovery Unit 2
- 2008
Monterey Bay and Beaches of Northern Santa Cruz County, California
(pdf, 11 MB)
- 2008
San Francisco Bay California, Recovery Unit 3
- 2007
Bolsa Chica, Orange County, California (pdf,
1.5 MB)
- 2007
CA State Park System-wide Summary Report
- 2007
Coastal Northern California, Recovery Unit 2 (pdf,
500 KB)
- 2006
Bolsa Chica, Orange County, California (pdf,
4.0 MB)
- 2006
CA State Park System-wide Summary Report
- 2006
California State Parks, North Coast Redwoods District Western
Snowy Plover Annual Report (pdf,
1.3 MB)
- 2006
Coastal Northern California, Recovery Unit 2 (pdf,
1.3 MB)
- 2005
CA State Park System-wide Annual Report Overview 1-27-06
- 2004
CA State Park System-wide Annual Report Overview 2-15-05
- 2003
CA State Park System-wide Annual Report Overview 1-23-04
- 2002
CA State Park System-wide Annual Report Overview 3-5-03
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| Other
Informational Weblinks: |
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