North American duck (Aix sponsa, family Anatidae); a popular game bird. Wood ducks, 17–21 in. (43–52 cm) long, nest in a tree cavity up to 50 ft (15 m) off the ground; they have long-clawed toes for perching. Both sexes have a head crest in winter. The beautifully coloured male has a purple and green head, red-brown breast flecked with white, and bronze sides; the female has a white eye ring and duller colouring. Ducklings eat aquatic insects and other small organisms; adults prefer acorns or other nuts. Hunted nearly to extinction for its flesh and feathers, it has been restored to healthy populations by strong conservation efforts.