The Greater Scaup (Aythya marila) breeds in Alaska and northwest Canada, and in winters is found along both coasts to north Mexico, and accidental farther south. Inhabits in humid places, especially in salt ponds. Its size is of 46 cm (18 inches) in height and 950 g in weight.
This bird is similar at Lesser Scaup. Dark head, with green gloss. It has black vermiculations on mantle. Black breast and tail. Blue bill, and legs gray. This bird eats insects.