This attractive diving duck often gathers by the thousands on lakes or bays in the winter. Dives to reach submerged aquatic vegetation. Nests on marshy freshwater ponds and lakes. Slightly smaller than a Mallard with rounded, puffy head. Males have reddish-brown head, straw-yellow eye, and gray body. Females are plain brown overall; a lighter blonde color than scaup and Ring-necked Duck. Best separated from Canvasback by rounded head and the male's darker gray body. About the size of Greater Scaup, but slightly larger than Lesser Scaup and Ring-necked Duck—this can be helpful when they are together in mixed flocks.