a family of aquatic birds of the order Anseriformes. The body length varies from 29 to 150 cm. The edges of the bill are lined with thin transverse plates or serrations. The feet are webbed. The dense plumage, which is white, gray, brownish, black, or spotted, has a thick down covering. Some Anatidae have a dark-blue, green, or spotted speculum on the wings. The majority fly well. Many are good divers, obtaining food from the water itself or from the bottom.
Anatidae, which include swans, geese, brants, and ducks, are distributed throughout the world. The family comprises 43 genera, which encompass 147 species. There are 58 species in the USSR, including eight species that occasionally migrate into but are not indigenous to the USSR.
Anatidae nest on the ground, in rock crevices, in tree hollows, or in burrows. A clutch contains two to 16 solid white, greenish, or yellowish eggs. Depending on the species, the eggs are incubated and the young are reared by the female alone, by the male alone, or by both. The South American duck of the genus Heteronetta is parasitic, that is, it lays its eggs in the nests of other Anatidae. Anatidae feed on plants and animals. Many are hunted commercially or for sport.