A small, teal-sized duck (13-15 inches), the male Bufflehead may be most easily identified by the large white patch on the back of its head. Other distinguishing characteristics include its iridescent green head, white body, and patchy black-and-white wings visible in flight. The female Bufflehead is dull brown above with a white belly, light brown flanks, and a smaller white patch behind the eye. Duck hunters refer to this species as the “butterball” in reference to the male’s large white head patch. The Bufflehead breeds primarily in west-central Canada, in central Alaska, and at higher elevations in the Rocky Mountains. Small numbers of Buffleheads breed elsewhere in western North America, extending east to the Great Lakes. This species migrates south for the winter, when it may be found unevenly distributed across the southern half of North America. Buffleheads are found locally in the interior of their winter range, but are more common along the Atlantic and Pacific coasts north to Nova Scotia and Alaska, respectively. In summer, Buffleheads breed on ponds and lakes near forests. Buffleheads are particularly attracted to forests inhabited by the Northern Flicker (Colaptes auratus) because this species builds its nest in old Flicker nest cavities. In winter, Buffleheads may be found on sheltered saltwater bays and estuaries or, inland, on large lakes or rivers. This species primarily eats small animals, such as crustaceans, mollusks, and insects when available. One of several species of “diving ducks” in North America, Buffleheads may be observed submerging themselves to feed in the water or on the bottom. In winter, they may also be observed in small flocks on large, slow-moving bodies of water. This species is primarily active during the day.