This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the bufflehead.
What does this diving duck that spends little time on land have in common with a familiar woodpecker? It might surprise you to find out that the answer is they both nest in tree cavities. This small duck is just the right size to nest in old woodpecker holes, and almost always in those drilled by northern flickers. They are so reliant on the cavities built by these woodpeckers that the bufflehead’s breeding range is limited by the distribution of flickers.
Buffleheads compete with green-winged teal for the distinction of being the smallest duck species on the continent. They have large, round heads and small bills. Males have a large, white patch on their otherwise iridescent purple-green head and a white body with a dark back. Brownish females are distinguished by a white patch on their cheeks.
Soon the buffleheads that are here now will be leaving for their breeding territories dominated by ponds and small lakes in boreal forests of Canada and Alaska. Flying under cover of night, many females will return with their mate to the same tree and same hole where they nested last summer.
Arriving at the breeding territory where they were born, nonbreeding females fly around in groups, checking out cavities that may be available for nesting the following summer and noting their locations. Larger cavity-nesting ducks like goldeneyes and mergansers are too big to squeeze through the hole made by a flicker, but mountain bluebirds, tree swallows, starlings and the flickers themselves compete for use of these cavities.
Bufflehead pairs are mostly faithful to each other for several years, a behavior unusual in ducks. Once incubation by the female begins, the male departs to molt, but the pair can reunite during winter. Within 36 hours of hatching, young must climb up the inside of the nest cavity and jump to the ground. Although the female doesn’t feed her young, she does watch over them and broods them at night. When the chicks are only 5 to 6 weeks old and still too young to fly, the female abandons them.
With more than 300 bird species regularly breeding in the boreal, this area is known as “North America’s Bird Nursery.”
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