They are 27-30 cm (11-12 in) long with a wingspan of 71-83 cm (28-33 in) and a weight of 190-280 g. In spring and summer the adults are spotted black and white on the back and wings. The face and neck are black with a white border. They have a black breast and a white rump. The tail is white with black barring. The bill and legs are black. They moult to winter plumage, this being a fairly plain grey above, with a grey-speckled breast and white belly. The juvenile and first-winter plumages, are similar to the adult winter plumage but with the back feathers blacker with creamy white edging. In all plumages, the inner flanks and axillary feathers at the base of the underwing are black.
Habitat and Distribution
They breed in Arctic islands and coastal areas across the northern coasts of Alaska, Canada, and Russia. They migrate to winter in coastal areas throughout the world. They also winter from southwest British Columbia and Massachusetts south to Argentina and Chile. Also from Britain and southwestern Norway south throughout coastal Africa to South Africa, and from southern Japan and Australia, with a few reaching New Zealand.
They forage for food on beaches and tidal flats, usually by sight. The food consists of small molluscs, polychaete worms, crustaceans, and insects.
They nest on the ground in a dry open tundra with good visibility; the nest is a shallow gravel scrape. Four eggs (sometimes only three) are laid in early June, with an incubation period of 26-27 days. The chicks fledge when 35-45 days old.