The chunky little Bufflehead is the smallest diving duck native to North America. Males seldom exceed 1 lb. in weight and the smaller females weigh on average less than 12 oz.
Buffleheads are sexually dimorphic in plumage as well as overall size.
Breeding males have black backs and white underparts. Their wings are black with a large white patch covering the secondary flight feathers and a large portion of the coverts. Their heads are predominantly black with iridescent green and purple highlights. A wide white patch extends from just behind the ears all the way to the back of the head. Their bills are blue-black in color.