The ruddy turnstone (Arenaria interpres ) 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.
Ruddy turnstones are small highly migratory wading birds. In all seasons, their plumage is dominated by a harlequin-like pattern of black and white. Breeding birds have reddish-brown upperparts 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. The rest of the underparts are white. The females are slightly duller than the males and have a browner head with more streaking. Non-breeding adults are duller than breeding birds and have dark grey-brown upperparts with black mottling and a dark head with little white. Juvenile birds have a pale brown head and pale fringes to the upperpart feathers creating a scaly impression.