Snowy Plover

The snowy plover is a plump shorebird with a large head, a short and slender bill, and short neck and tail. It is a small plover, with adults ranging from 15 to 17 cm (5.9 to 6.7 in) in length, from 34 to 43.2 cm (13.4 to 17.0 in) in wingspan, and from 40 to 43 g (1.4 to 1.5 oz) in weight. Its body is typically held horizontally. Compared to other plovers, its legs are relatively long and its wings short. The bill is black, the iris dark brown, and the legs gray to black.

Snowy plovers are pale brown above and white below, with a white band on the hind neck and a smudgy eyestripe (absent in the South American subspecies). Breeding males have black patches behind the eye ("ear patch"), on the sides of the neck, and on the forehead. In males, the crown may be reddish at the start of the breeding season. The breeding female is slightly duller, and typically one or more of the patches are partly or completely brown. The neck patches on each side are well separated and rarely joined at the front, giving the appearance of a "broken" breast band in contrast to the continuous breast band in many other plovers. Outside the breeding season, the neck and ear patches are pale and the forehead patch is absent, and plumages of males and females cannot be distinguished. …

The snowy plover is distributed along the Pacific coast of North and South America, in areas inland of the US and Mexico, along the coast of the Gulf of Mexico, and on the Caribbean islands and Bermuda. On the Pacific coast, it breeds from south Washington down to Oaxaca in Mexico, and non-breeding individuals can be found as far south as Panama. In South America, it breeds from south Ecuador to Chiloé Island in Chile. In the Caribbean, breeding occurs eastwards as far as the Virgin Islands and Margarita Island. The coastal populations consist of both migratory and residential birds; migration occurs over relatively short distances north- or southward along the coast. Inland breeding populations exist in the US eastward to the Great Plains of Kansas and Oklahoma, as well as in Mexico north of Mexico City. These populations are mostly migratory, with western populations migrating to the Pacific coast, and the Great Plains populations to the Gulf of Mexico coast. Breeding has been recorded at elevations up to 3,000 m (9,800 ft). The species inhabits open areas in which vegetation is absent or sparse, in particular coastal sand beaches and shores of salt or soda lakes. It also breeds on river bars that are located close to the coast, and adopts human-made habitats such as wastewater and salt evaporation ponds, dammed lakes, and dredge spoils. …

The species feeds on invertebrates such as crustaceans, worms, beetles, and flies. An analysis of feces from a coastal population in California during breeding season found beetles in 72%, flies in 44%, and insect larvae in 25% of the feces. Prey is taken from above and below the sand surface, from plants, and from carcasses. In inland habitats, snowy plovers usually forage on wet substrates that may be under a shallow water cover. As is typical for plovers, prey is found visually by briefly standing to scan the area, followed by running and capturing. Snowy plovers also forage by probing the substrate with their bills, by charging or hopping into accumulations of flies, and by "foot trembling" on wet substrates or in shallow water, where one foot shakes to stir up prey. Brine fly larvae are often shaken before consumption, and captured flies are often bitten two or three times. Snowy plovers may forage during day and night, with one individual observed feeding in almost complete darkness. Snowy plovers drink when fresh water is available, but when it is not, they can sustain themselves on the water content of their prey.

Habitat degradation is a major cause for the declines in both coastal and inland populations in the US. Many coastal beaches have been developed for recreational use. Periodic raking of beaches to remove garbage and natural debris such as kelp causes plovers to abandon breeding areas, and reduces biodiversity and biomass of the invertebrates the plovers feed on. Dune habitat was lost to the invasive European beachgrass, which had originally been planted to stabilize dunes. This species, as well as the American beachgrass from the Atlantic coast, have replaced native foredune vegetation in most of the North American Pacific coast. In the Great Salt Plains in Oklahoma, controlled flooding, as well as an invasive shrub, the French tamarisk, have destroyed much plover habitat. In the Great Plains of Texas, sinking groundwater levels due to water extraction has been identified as the primary cause of decline. River habitats in Kansas and Oklahoma have been decimated by the extraction of water, the erection of water reservoirs, and vegetation growth. Habitat is lost to housing and urbanization adjacent to beaches. Less significant are habitat losses due to the trapping of sediments by dams and jetties that affect coastal erosion and sedimentation. Habitat degradation is also a major concern for populations of lower altitudes. …