Bufflehead (Bucephala albeola)
by Wanda Gorsuch

Common Names: Butterball, dipper

Buffleheads are the smallest diving duck in North America.  Their small size allows them to nest in tree holes made by northern flickers.  These holes are too small to accommodate other cavity nesting ducks.

Identification

A compact duck, with a short neck and narrow grey bill, the bufflehead looks almost like a miniature goldeneye.  But besides its smaller size, male buffleheads also have a distinctive white wedge-shaped cap that extends from below the eye across the top of the head, while the females sport a white dash on the side of their head.

Males are black, with a glossy green and purple sheen.  Underparts are white and there is a large white patch the covers most of the secondary and covert feathers. 

Females have a dark brown head, back and wings.  Their underparts are a pale grey and their white wing patch is smaller than the males.

Distribution

Main breeding area is the boreal forest and aspen parkland of Canada and Alaska.  Since they are cavity nesters, their range is limited by woodlands and the distribution of the northern flicker, which is the main source of their nesting cavities.  During winter months buffleheads can be found on the \ east and west coasts and across the southern USA.

Habitat

During breeding season, buffleheads like freshwater, permanent ponds with no outlet or only seasonal outflow, as well as small lakes.  Tree cavities are generally found in poplar or aspen trees.  In the winter months, buffleheads predominantly inhabit sheltered, shallow saltwater such as coves, harbors, estuaries, or beaches.  Inland, they are found on ponds, lakes, impoundments or bays on slow moving rivers.

Food

Buffleheads mostly eat aquatic insects, and occasionally some seeds.  In the winter months (on saltwater) they concentrate on crustaceans and mollusks, while in the summer (freshwater) they mostly eat insects such as dragon fly larvae, midge larvae and water boatmen.  Along the Pacific coast, buffleheads sometimes feed on herring eggs.

Reproduction

Currently it is unknown exactly when buffleheads form pair bonds, only that most bonds are formed by the time they reach the breeding grounds.  Unlike most other ducks, buffleheads may keep the same mate for several years.

Buffleheads nest in tree cavities created by northern flickers and sometimes pileated woodpeckers.  They also readily use nest boxes.  Cavity heights range from 0.6 to 14 m.  One nest was reported at an amazing 27 meters.  No nesting material is used.  Eggs are laid in the bare bottom of the cavity, or on top of old nesting material from past occupants.  Hens pluck down from their breast to cover the eggs as do other ducks.

Usually about 8 – 9 eggs are laid.  Probably due to their small size, bufflehead hens lay their eggs 1 – 3 days apart whereas most other ducks lay an egg a day.  Generally eggs are laid in the early afternoon.  Incubation starts when the last egg is laid.

Hens incubate eggs for 28 – 33 days.  Up to 2 days before hatching, ducklings will start making “peeping” noises in the egg.  Most hatchings occur overnight and are completed within 24 hours.  Ducklings are brooded for 24 – 36 hours before leaving the nest.  When it is time to leave, the hen will fly in and out of the nest several times and spend some time inspecting the surroundings from the cavity entrance.  The ducklings climb up to the cavity entrance and jump out.  After all the ducklings are on the ground, the hen leads them to water.  Ducklings will dabble for their food on the surface for the first few days, but quickly start diving to feed.

Conservation and Management

Early in the 20^th century, hunting had decreased bufflehead populations to a severely low level.  However, buffleheads recovered well under the Migratory Birds Convention between Canada and the USA.  Care needs to be taken as deforestation and hunting pressure can easily cause a decline in population again. 

Sources of Information

Bellrose, F.C.  1976.  Ducks, geese and swans of North America, 2^nd edition. Stackpole Books, Pennsylvania.

Gauthier, G.  1993.  Bufflehead (Bucephala albeola). In The Birds of North America, No. 67 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.

Johnsgard, P.A.  1978.  Ducks, geese, and swans of the world. University of Nebraska Press, Nebraska.