The ruddy turnstone is a small wading bird, one of two species of turnstone in the genus Arenaria. It is now classified in the sandpiper family Scolopacidae but was formerly sometimes placed in the plover family Charadriidae. It is a highly migratory bird, breeding in northern parts of Eurasia and North America and flying south to winter on coastlines almost worldwide. It is the only species of turnstone in much of its range and is often known simply as turnstone. In all seasons, the plumage is dominated by a harlequin-like pattern of black and white. Breeding birds have reddish-brown upper parts with black markings. The head is mainly white with black streaks on the crown and a black pattern on the face. The breast is mainly black apart from a white patch on the sides. Non-breeding adults are duller than breeding birds and have dark grey-brown upperparts with black mottling and a dark head with little white.
The ruddy turnstone breeds in northern latitudes, usually no more than a few kilometres from the sea. The ruddy turnstone has a varied diet including carrion, eggs and plant material but it feeds mainly on invertebrates. Insects. It often flips over stones and other objects to get at prey items hiding underneath; this behaviour is the origin of the name “turnstone”. It usually forages in flocks. This species is classified as least concern by IUCN.