Duck

Duck, aquatic bird, any of the smaller members of the family Anatidae, which also contains the geese and swans. The word is properly used to describe the females of many members of the Anatidae, the term for the male being drake. Ducks are, broadly, of 3 types: surface-feeding (dabbling), diving, and fish-eating. The most familiar are the dabblers such as the mallard, which is found throughout the Northern Hemisphere and is the ancestor of the domestic duck. Many ducks are killed for sport and food. Their down (soft layer of feathers), particularly that of the eider duck, is of commercial importance.