Medium-sized to large (30-180 cm long) water birds found in a wide variety of aquatic habitats in all regions of the globe except the Antarctic. Although ten species of ducks have been recorded in Java and Bali, few are breeding residents, and only 1 may be found in Baluran. Ducks are easily recognized with their broad flattened and round-tipped bill, plump body and short legs with fully-webbed toes. In flight the neck appears long, wings short and pointed and tail short. Eating aquatic plants or small aquatic invertebrate animals, they employ various methods of foraging, the most widely used being surface-feeding (or dabbling), diving and grazing. Serrated lamellae inside the bill are an adaptation for those that filter plankton. In many species the male is more brightly coloured than the female, especially when entering the breeding season. Duck as are very sociable, gathering in flocks sometimes composed of hundreds of birds.
Gaining or maintaining momentum in the air requires continuous, fast beating.