of the Snowy Plover:
Does It Live?:
Does It Eat (Feeding)?:
Eats It (Predation)?:
and Conservation Status:
western snowy plover is listed by the U.S. Fish and Wildlife Service as
a threatened species. This species has become threatened as a result
of increasing human and environmental impacts on its nesting habitat.
This impacts have forced the snowy plover to move or migrate to different
nesting sites in order to reduce these stresses on breeding behavior.
For instance, many snowy plovers have migrated to the Great Salt Lake during
their breeding season to avoid pressures caused by habitat degradation.
On U.S. coasts this habitat degradation is caused primarily by expanding
beach front development. Recreation has also been responsible for
a significant decline in the size of breeding populations. The use
of beach grass (Ammophila arenaria) to stabilize dunes along the
Pacific Coast has also greatly affected these birds. This stabilization
has reduced the extent of open nesting habitat. Other impacts include
frequent mechanical raking of beaches to remove garbage, seaweed, and other
debris which has made beaches in southern California unsuitable for nesting
and harms food resources for the snowy plover. These and other human
pressures have caused this species to migrate inland to available breeding
habitats such as the Great Salt Lake playa margins.
However, while this migration has allowed the snowy plover to avoid pressures
along the Pacific Coast, this movement has caused them to encounter other
impacts. The snowy plovers breeding habitat around the Great Salt
Lake has been reduced significantly due to long term oscillations and high
water years. In addition, breeding habitat along stream side and
lake shorelines has been invaded by the introduced salt cedar (Tamarix
gallica), significantly reducing remaining nesting habitat.
The access of off road vehicles in certain areas has also cause significant
disturbance to nesting areas on the Great Salt Lake shorelines. These
impacts around the Great Salt Lake causing the snowy plover to again move
to other more isolated breeding habitats.
of the Snowy Plover:
The snowy plover (Charadrius alexandrinus) is a small bird ranging
from about 15-17 cm long, and weighing between 34-58 g. This small
bird is identified by its breast band always restricted to lateral patches.
The snowy plover also has pale brown upper parts and dark gray to blackish
legs, very important in identification. The western snowy plover
is presently on the USFWS Threatened Species List and is cause for concern
to wildlife managers in the western United States.
Does It Live?:
In North America, there are two recognized subspecies the western snowy
plover (Charadrius alexandrius nivosus) and Cuban snowy plover (Charadrius
alexandrinus tenuirostris). The western snowy plover nests west
of the Rocky Mountains and the Cuban snowy plover resides on the Gulf Coast
from western Florida to Texas. We are obviously concerned with the
western snowy plover, which is found inhabiting coastal beaches and interior
alkaline lakes, like the Great Salt Lake. Both coastal and interior
populations winter on beaches along the Gulf of California, Gulf of Mexico,
and Pacific Ocean. The interior populations are migratory and use
areas, such as the Great Salt Lake to nest at during the summer, and then
winter in these southern coastal areas.
Does It Eat? (Feeding):
The western snowy plover mainly feeds on terrestrial and aquatic invertebrates,
for instance brine
flies, brine fly larvae and brine
shrimp. These birds use several different techniques to capture
and consume food items. In some instances, when dense prey items,
such as brine flies are present, they lower their head and charge through
prey aggregations snapping their bill and swallowing them quickly.
At other times they pause, look, and then seize prey from the surface of
the beach or tidal flats. They are also found probing for food in
sand and mud.
Eats It? (Predation):
These small aquatic birds have many different types of predators in the
different regions that they inhabit. Many different birds are predators
to this smaller land shore dwelling bird. For instance, many raptors
like the peregrine falcons and other falcons and the northern
harrier and other hawks may prey on plovers. Eggs or nestlings
are also fed on by the California gull, the cattle egret and other large
birds. And If this aerial attack were not enough, beach nesting plovers
may also be threatened by the red fox, kit fox, striped skunks, raccoons,
and other carnivorus mammals which may inhabit the playa ecosystem.
These birds create a nest on a scrape or natural depression, with pebbles,
shell fragments, fish bones, mud chips, vegetation fragments, or invertebrate
skeletons. Their nesting behavior has been found to be greatly impacted
by the use of off road vehicles near their nesting habitat.
However, the primary threat facing plovers today at the Great Salt Lake
is nest predation by the red fox (Vulpes vulpes). A management
plan may be needed to relieve this pressure on the western snowy plover.
and Conservation Status:
As mentioned before, the population breeding along the Pacific Coast of
the U.S. and Baja California is listed by U.S. Fish and Wildlife as a Threatened
species. In Washington and Alabama it has been designated an Endangered
species by those states. These designations have given rise to many
measures being taken to protect this animal's habitat. Some states
have posted informative signs and roped of areas to reduce disturbance
of nesting birds. In some states such as Oregon, beaches have been
closed. These and other techniques have lead to improved hatching
success. However, there is still research being done to improve snowy
plover nesting and hatching success. For instance, experiments with
solar powered electric fences, chick shelters, and artificially elevated
nesting substrates at the Great Salt Plain, Oklahoma, show promise for
increasing reproductive success. All measures to protect snowy plovers
have been too recent to determine their effect on population size.
G.W. Page, J.S. and J.C. Warriner, P.W.C. Paton.
1995. Snowy Plover. The Birds of North America. No. 154.
Paton, Peter W.C. Breeding Ecology of Snowy Plovers Utah
Coop. Fish and Wildlife Research Unit, Dept. of Fisheriesand Wildlife,
Utah State University, Logan, UT. (November 18, 1999).
America's National Wildlife Refugees Where Wildlife Comes
Naturally. (June 11, 1997) http://refuges.fws.gov/NWRSFiles/WildlifeMgmt/SpeciesAccounts/Birds/WestSnowyPlover
/WestSnowyPloverIndex.html (November 20, 1999).
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