snowy plover

n.
A small plover (Charadrius alexandrinus) of the western United States and Mexico, generally yellowish gray above and snowy white below and on the sides of the head.

Charadrius alexandrinus

SUBFAMILY

Charadriinae

TAXONOMY

Charadrius alexandrinus Linnaeus, 1758. At least six subspecies are recognized.

OTHER COMMON NAMES

English: Kentish plover, sandplover; French: Gravelot à Collier interrompu; German: Seeregenpfeifer; Spanish: Chorlitejo Patinegro.

PHYSICAL CHARACTERISTICS

6–6.75 in (15–17 cm); 1–2 oz (28–57 g). Upperparts pale brown, especially pale in North American population. Breast band restricted to the lateral edges of the breast; white ring around the neck. Crown may be rufous. In breeding males a distinct, dark frontal bar marks the end of a white forehead and a dark line extends from bill to ear. Bill is black, and legs and feet are dark gray to black.

DISTRIBUTION

Breeds along the western U.S. coast from Washington to lower California and intermittently along the Gulf Coast from Marco Island, Florida, to the north coast of the Yucatan Peninsula. Breeds inland in south central Oregon, Salton Sea and eastern California, western and central Nebraska, northwestern Utah, and southern Arizona. Also breeds in the West Indies and on islands off the coast of Venezuela. Winters in

the Gulf drainage south to Yucatan and northern South America and in the Pacific drainage from central California to western Mexico. A resident population (C. a. occidentalis) is found on the coast of Peru and Chile. C. a. alexandrinus breeds in Eurasia from southern Sweden to the northern Sahara to western India and the steppes of central Asia through western China. Winters from the Mediterranean Basin south to tropical Africa, Angola, and Sri Lanka. C. a. seebohmi is resident in Sri Lanka. C. a. dealbatus breeds in eastern China and Japan and winters from Japan to Taiwan and the Philippines and from southeastern China to Indochina and the Greater Sundas.

HABITAT

Prefers open coastal areas, including sand and shingle beaches, estuaries, lagoons, and mudflats as well as inland along saline lakes. May also be found along rivers and on sparsely vegetated steppes. In North America it favors beaches and both coastal and inland salt flats. Inland it is found along braided river channels. Nests primarily on sandy coastal beaches, dunes, spoil islands, and salt flats or inland near brackish or saline wetlands. Several hundred birds nest and winter at agricultural wastewater ponds in the San Joaquin Valley and at the Salton Sea formed in southern California as a result of accidental flooding in the early 1900s. Mostly coastal outside the breeding season. Rare in freshwater habitats.

BEHAVIOR

Species includes both resident and migrant populations. Most birds in flocks of up to 300 during winter, although some defend winter territories. Small groups of birds may take off in coordinated flights when disturbed. Both chicks and adults can swim, and adults may lead chicks across ponds and rivers.

While territories are important sites for nesting and feeding, some birds frequently forage communally at undefended feeding areas. Feeding areas as much as 3.7 mi (6 km) from the nest have been documented.

FEEDING ECOLOGY AND DIET

Runs, stops, looks, and pecks as is common in plovers, but also probes at the bases of plants and runs into dense masses of flies with bill open and snapping. May also charge after solitary insects. Occasionally pats substrate with foot. Mostly gathers food from sand surface both above and below mean high tide mark. Inland, often forages in 0.39–0.79 in (1–2 cm) deep water or on wet surfaces.

REPRODUCTIVE BIOLOGY

Frequently retain their mate for more than one year, and one pair remained mated for at least six years, apparently as a result of territorial fidelity. Rarely male may mate with two females and alternate incubation at the two resulting nests. Birds often show nest site fidelity. Nest is often located near an item such as piece of driftwood or small clump of vegetation that distinguishes an otherwise uniform landscape. Nests are formed by scraping and lined by both sexes randomly picking up bits of debris and tossing it over their shoulders and into the nest. Lining eventually includes such items as pebbles, fish bones, and arthropod skeletons. During copulation male grasps the female's neck and falls backward, pulling her with him. Clutch size is usually three, but varies from 2–6.

Both sexes incubate, but at least in some localities the female incubates more during the day and the male at night. Incubation requires from 23–32 days. Young are precocial and leave nest soon after hatching.

In western North America females desert broods soon after hatching, mate with a different male, and initiate another nest. This allows for the production of multiple broods. Males also take a new mate and re-nest, in some cases as early as 10 days before the current brood fledges. Birds may move several hundred kilometers to re-nest. Females may mate with original mate to produce a third brood. In some localities only one brood is produced. Parental care includes leading chicks to food, watching and warning of danger, and giving injury-feigning distractions.

Breeding territories may be small. In some localities average distance between nests was 120 ft (36 m). Breeding typically occurs during the first year.

CONSERVATION STATUS

North American Pacific and Gulf Coast populations are shrinking, with current populations estimated at 21,000 individuals in the United States. The Pacific Coast population is listed as Threatened by the U.S. Fish and Wildlife Service. Habitat loss and destruction is an important factor contributing to population decline. Chief problems are increased recreational use of beaches, regular raking to keep beaches attractive to humans, and use of beach grass (Ammophila arenaria) to stabilize beaches. Inland habitat has been lost as a result of human-mediated changes such as dam construction and growth of vegetation. Less important factors include pesticides, entanglement in monofilament line, being run over and stepped on, and shooting and trapping.

SIGNIFICANCE TO HUMANS

None known.

Charadrius alexandrinus 6½″ (16 cm). A pale plover of the beaches. Similar to the Piping Plover, which replaces it to the east and north (see map), but male Snowy has a slim black bill, dark (sometimes pale) legs, and a dark ear patch. Females and juveniles may lack the black in their plumage. Juvenile and winter Piping Plovers may also have dark bills, but they have white on the rump, visible in flight.

Voice: A musical whistle; pe-wee-ah or o-wee-ah.

Range: Southern U.S., cen. and S. America, s. Eurasia, Africa, Australia.

Habitat: Beaches, sandy flats.

---

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)