Habitat

Lake/Pond

Bufflehead breed near ponds and lakes in boreal forest and aspen parkland of Canada and Alaska, with isolated populations in the western United States. The Bufflehead’s breeding range is limited by the distribution of Northern Flickers, which are their main source of nesting cavities. Bufflehead are North America’s smallest diving duck; they benefit by using old flicker nests that larger ducks such as goldeneyes and mergansers cannot fit into. In winter they occur mainly near the coast (although they can be found in smaller numbers inland). They use shallow, sheltered coves, harbors, estuaries, or beaches, avoiding open coastlines. Inland, they use ponds, lakes, impoundments, or bays along slow-moving rivers. During spring migration they spend time on major rivers or valley lakes, often in the first spots to become free of ice.

Food

Insects

Bufflehead dive for aquatic invertebrates, crustaceans, and mollusks. They typically swallow their food while still underwater. Dives last on average about 12 seconds and rarely more than 25 seconds, typically staying on the surface another 12 seconds or so before diving again. Bufflehead forage in open, shallow water over sparse submerged vegetation or over mudflats that would be exposed at low tide. On freshwater they mostly eat damselfly and dragonfly larvae, midge larvae, water boatmen, mayfly larvae, caddisfly larvae, large zooplankton such as amphipods, and snails and clams in winter. They eat some plant matter in fall and winter, mainly seeds of pondweeds and bulrushes. In saltwater, Bufflehead eat shrimp, crabs, amphipods, isopods, snails, mussels, herring eggs, sculpins, and ratfishes. Downy ducklings sometimes dabble at the surface rather than diving.

Nesting

Nest Placement

Cavity

Bufflehead nest only in cavities, using holes dug by Northern Flickers and sometimes Pileated Woodpeckers (as well as artificial nest boxes). In the summer, females that are too young to breed, or whose nests have failed, fly around in noisy groups and scope out the available nest holes for the following breeding season. Just before laying, females make more secretive flights to prospective holes, either alone or with their mates. They usually choose cavities in poplar or aspen trees, except in California where they often use pine trees.

Behavior

Surface Dive

Bufflehead swim buoyantly, dive easily, and take flight by running a short distance on the surface. They fly low over the water and higher over the land. To dive, Bufflehead compress their plumage to squeeze out air, then give a slight forward leap and plunge powerfully downward. They hold their wings tightly against their bodies underwater and use only their feet to propel themselves. At the end of a dive, they may bob to the surface like a cork. Throughout the day they alternate between bouts of feeding, swimming alertly, preening, and sleeping. Bufflehead are seldom seen on dry land: females walk only when they lead their broods from the nest to the water or when they’re forced to switch ponds with their ducklings. Males court females by flying over them, skiing to a stop on the water with their crests raised, and bobbing their heads. During the breeding season, territorial birds attack intruders by flying or swimming underwater at them and thrashing at them with their wings. When a pair intrudes into a territory, the territorial male often chases the intruding female while the intruding male chases after them both. Males leave their mates during incubation in order to molt, but return to the same mate multiple years in a row (one of the few duck species in which this is true).

Conservation

Least Concern

In the early twentieth century Bufflehead had become scarce from overshooting, but they recovered under the protection of the Migratory Birds Convention between the United States and Canada. Christmas Bird Counts show a steady increase in Bufflehead numbers between 1927 and 1992, with an overall population estimate of some 1.4 million Bufflehead in 1992. The Bufflehead’s tendency to winter near to shore along coastlines tends to put it within range of hunters. Duck hunting is carefully managed to maintain populations; nevertheless between 200,000 and 250,000 are shot per year in the U.S. and Canada combined. Bufflehead are also losing nest sites as loggers clear-cut boreal forest, and as agricultural fields replace aspen parklands in western North America. Putting up nest boxes with small (2.5-inch diameter) openings in appropriate habitat can help.

Credits

• Gauthier, Gilles. 1993. Bufflehead (Bucephala albeola). In The Birds of North America, No. 67 (A. Poole and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.
• Bellrose, F. C. 1976. Ducks, Geese, and Swans of North America. Stackpole Books, Harrisburg, PA.
• Raftovich, R.V., K.A. Wilkins, S.S. Williams, H.L. Spriggs, and K.D. Richkus. 2011. Migratory bird hunting activity and harvest during the 2009 and 2010 hunting seasons [PDF]. U.S. Fish and Wildlife Service, Laurel, MD.
• U.S. Fish and Wildlife Service. 2012. Harvest Information Program.
• USGS Patuxent Wildlife Research Center. 2011. Longevity Records of North American Birds.