The western snowy plover is listed as threatened in 1993. Critical habitat was designated in 2005 for 32 areas along the coasts of California, Oregon and Washington. A recovery plan was finalized in September 2007. On December 17, 2010, the U.S. Fish and Wildlife Service, along with other federal agencies and the State of Oregon signed off on a statewide Habitat Conservation Plan. On March 22, 2011, the U.S. Fish and Wildlife Service proposed a revision to the critical habitat designation. A final rule on the proposed revision is due on June 5, 2012.

Description

The western snowy plover is a small shorebird distinguished from other plovers (family Charadriidae) by its small size, pale brown upper parts, dark patches on either side of the upper breast, and dark gray to blackish legs. Snowy plovers weigh between 1.2 and 2 ounces. They are about 5.9 to 6.6 inches long.

Historical Status and Current Trends

The Pacific coast population of the western snowy plover is defined as those individuals that nest beside or near tidal waters, and includes all nesting colonies on the mainland coast, peninsulas, offshore islands, adjacent bays and estuaries from southern Washington to southern Baja California, Mexico. Historic records indicate that western snowy plovers nested in at least 29 locations on the Oregon coast. Currently, only eight locations in Oregon support nesting western snowy plovers, a 72 percent reduction in active breeding locations.

As early as the 1970s, observers suspected a decline in plover numbers. The primary cause of decline is loss and degradation of habitat. The introduced European beachgrass (Ammophila arenaria) contributes to habitat loss by reducing the amount of open, sandy habitat and contributing to steepened beaches and increased habitat for predators. Urban development has reduced the available habitat for western snowy plovers while increasing the intensity of human use, resulting in increased disturbance to nesting plovers.

Habitat

The Pacific coast population of western snowy plovers breeds on coastal beaches from southern Washington to southern Baja California, Mexico. Plovers lay their eggs in shallow depressions in sandy or salty areas that generally do not have much vegetation. Because the sites they choose are in loose sand or soil, nesting habitat is constantly changing under the influence of wind, waves, storms, and encroaching plants.

Life History

The nesting season extends from early March through late September. The breeding season generally begins earlier in more southerly latitudes, and may be two to four weeks earlier in southern California than in Oregon and Washington. Fledging (reaching flying age) of late-season broods may extend into the third week of September throughout the breeding range. Nests typically occur in flat, open areas with sandy or saline substrates. Vegetation and driftwood are usually sparse or absent. The typical clutch size is three eggs but can range from two, and in rare cases, up to six eggs.

Snowy plover chicks leave the nest within hours after hatching to search for food. They are not able to fly for approximately four weeks after hatching, during which time they are especially vulnerable to predation. Adult plovers do not feed their chicks, but lead them to suitable feeding areas. Adults use distraction displays to lure predators and people away from chicks. Adult plovers signal the chicks to crouch, with calls, as another way to protect them. They may also lead chicks, especially larger ones, away from predators. Most chick mortality occurs within six days after hatching.

Snowy plovers are primarily visual foragers. They forage on invertebrates in the wet sand and among surf-cast kelp within the intertidal zone, in dry, sandy areas above the high tide, on salt pans, and along the edges of salt marshes, salt ponds, and lagoons. They nest in open, flat, sparsely vegetated beaches and sand spits above the high tide. Plovers often return to the same breeding sites year after year.

Conservation Measures

In the eight areas of the Oregon coast that are currently used for nesting by the snowy plover, seasonal restrictions on beach use are implemented in an effort to reduce disturbance to breeding plovers. Activities that may adversely affect plovers include dune stabilization using vegetation or fencing, construction of breakwaters and jetties, sand deposition, and driving off-road vehicles near nesting areas. Recreational activities near nests, such as dog walking, horseback riding, kite-flying, and picnicking may result in abandonment of the nest by adult plovers. Trash or food left on the beach may attract predators.

The public can help in the increase the chance of plover survival and breeding success by:

• staying out of the signed nesting areas

• "sharing the beach" by recreating away from plovers and using the wet sand

• keeping dogs pets on leash or leaving them at home

• removing litter from beaches to discourage predators

• flying kites, which may be mistaken for avian predators by plovers, on non-nesting plover beaches

• volunteering to monitor plovers or to provide educational material to other beach users

• leaving the area immediately and contacting the U.S. Fish and Wildlife Service or the Oregon Department of Fish and Wildlife if a plover nest is found in an unprotected area

In addition to seasonal closures, there are other management tools used to help recover the western snowy plover. USDA Forest Service, Bureau of Land Management, and Oregon Department of Parks and Recreation Department, in partnership with U.S. Fish and Wildlife Service, Oregon Department of Fish and Wildlife and others, restore habitat in areas with a history of plover use. Habitat restoration includes removal of European beachgrass, leveling steep dunes that formed as a result of beachgrass introduction, or placement of shell material in areas which are selected to provide high quality nesting habitat with minimal beach use conflicts. Predator management in the form of nest exclosures (mesh fences that surround a nest and act to keep out predators) and trapping and removing predators such as ravens, crows, foxes, raccoons, and feral cats are also management tools. The Oregon Natural Heritage Information Center (and previously, The Nature Conservancy) has been monitoring plover reproduction and survival since 1990.

References and Links

Lauten, D. J., K. A. Castelein, R. Pruner, M. Friel, and E. Gaines. 2007. The Distribution and Reproductive Success of the Western Snowy Plover along the Oregon Coast - 2007. Unpublished report. Prepared for Coos Bay District Bureau of Land Management, Oregon Dunes National Recreational Area, U.S. Fish and Wildlife Service, Oregon Department of Fish and Wildlife, and Oregon Department of Parks and Recreation Department.

Page, G.W., L.E. Stenzel, W.D. Shuford, and C.R. Bruce. 1991. Distribution and abundance of the snowy plover on its western North American breeding grounds. J. Field Ornithology. 62(2):245-255.

Page, G.W., J. S. Warriner, J. C. Warriner and P. W. C. Paton. 1995. Snowy plover (Charadrius alexandrinus). In: The Birds of North America, No. 154 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists Union, Washington, DC.

U.S. Fish and Wildlife Service. 1993. Determination of Threatened Status for the Pacific Coast Population of the Western Snowy Plover. FR 58:12864-12874.

U.S. Fish and Wildlife Service. 2005. Designation of Critical Habitat for the Pacific Coast Population of the Western Snowy Plover; Final Rule. FR 70:56969-57119.

U.S.Fish and Wildlife Service. 2007. Recovery Plan for the Pacific Coast Population of  the Western Snowy Plover (Charadrius alexandrinus nivosus). In two volumes.  Sacramento, California. xiv + 751pp.