White-winged Coot

The white-winged coot is 35 to 43 cm (14 to 17 in) long and weighs about 400 to 600 g (14 to 21 oz). The sexes are alike. Adults have a yellow to greenish yellow bill and a small yellow to orange-yellow frontal shield, though these colors may further vary. Their legs and feet are pale sea green to yellow-green and have blackish toes and joints. Their plumage is slaty gray that is blacker on the head and neck. They have white undertail coverts, and wide white tips on the secondaries provide the English name. Immature birds have a dusky olive bill, greenish gray legs and feet, gray-brown upperparts, and paler underparts than adults. Juveniles are dark drab gray with dusky mottling on a white head and neck.

The white-winged coot is found in most of southern South America, in northern to central Chile and separately from eastern and southern Bolivia, Paraguay, and far southeastern Brazil south through Uruguay and Argentina into Tierra del Fuego. There is also a population in the Falkland Islands and the species occurs as a vagrant in Peru. It inhabits freshwater lagoons, ponds, marshes, and river backwaters, favoring those with grassy or bare shores and many submerged plants or floating duckweed. It is sometimes found on saltwater close to shore.

The white-winged coot feeds mostly on aquatic vegetation, though it also grazes on land away from water. In water it mostly feeds on the surface but occasionally dives. Except when breeding it is gregarious and usually seen in large flocks.