Some classifications place the white-winged duck in the family Anatidae, to which most ducks belong. Others unite it with the whistling ducks in the family Dendrocygnidae. Current literature ascribes two different scientific names to this species: Asarcornis scutulata and Cairina scutulata. The latter places it in the same genus as the Muscovy duck of South America and tropical North America.
Shorter flight feathers called tertiaries form a white patch on each wing. Short feathers at the base of the flight feathers also are white. The duck has a dark body, black on top and chestnut below. The neck and head have a speckled or mottled white appearance. It is exceptionally large for a duck, measuring 26 to 32 inches long.
The white-winged duck can be found in parts of southeastern Asia. It lives in Bangladesh, the extreme eastern provinces of India, Myanmar, Thailand, Cambodia, Laos, Vietnam and the island of Sumatra.
Cairina scutulata is a typical duck in that it feels at home in water. It also likes it when trees are nearby. Consequently, it lives near sluggish rivers that flow through forests or in wetlands adjacent to forested areas.
The white-winged duck does not practice a seasonal migration. Such non-migratory birds are called sedentary birds or resident birds.
The white-winged duck is nocturnal. It sleeps perched in a tree during the day and hunts food in shallow water at night. It eats the seeds and vegetation of aquatic plants and small fish, snails and arthropods.
White-winged ducks breed during the rainy season, which occurs during the summer throughout its range. Their rudimentary nest consists of a few twigs and leaves sprinkled in a hollow part of a tree.
The white-winged duck is a critically endangered species. Its numbers have dwindled throughout the past century, to about 1,000, chiefly due to a loss of wetlands and forest habitat.