scoter, (genus Melanitta), any of three species of sea duck of the family Anatidae. Within the divisions of true duck species, the scoter belongs in the diving duck group. Scoters are good swimmers and divers and are mainly marine except during the breeding season. The males are generally shiny black in colour. The surf scoter (Melanitta perspicillata) of North America breeds in the boreal forests and tundra of Canada and Alaska. It winters on coasts from Nova Scotia to Florida in the east and from the Aleutian Islands to southern California in the west. The white-winged, or velvet, scoter (M. deglandi, or fusca) is nearly circumpolar in distribution north of the Equator, as is the black, or common, scoter (M., or sometimes Oidemia, nigra). The black scoter is the least abundant in the New World. All three species of scoter feed mainly on marine animals such as clams; only about 10 percent of their diet is plant material. The three species may be seen feeding in mixed flocks.