October 2016

Vol. 44, No. 5

Front Cover: October 2016

American Wigeon by Barry Van Dusen

American Wigeon by Barry Van Dusen

An artist who has created many of our covers, Barry Van Dusen, lives in Princeton, Massachusetts, and is well known in the birding world. Barry has illustrated several nature books and pocket guides, and his articles and paintings have been featured in Birding, Bird Watcher’s Digest, and Yankee Magazine as well as Bird Observer. Barry’s interest in nature subjects began in 1982 with an association with the Massachusetts Audubon Society. He has been influenced by the work of European wildlife artists and has adopted their methodology of direct field sketching. Barry teaches workshops at various locations in Massachusetts. For more information, visit Barry’s website.

American Wigeon

The American Wigeon (Anas americana) is an “odd duck” among the dabblers (Anas spp.), because of its short bill that enables it to graze on vegetation in terrestrial habitats. Males in breeding plumage are easily recognized by their white crown and forehead that once gave them their colloquial name “baldpate.” Males have a dark green patch from the eye to the nape, a gray neck, and pinkish to brown body. In flight, both sexes have a white patch on the forewing, which is generally smaller in females. Females can be distinguished with difficulty from the similar Eurasian Wigeon by their gray rather than rusty brown heads. Males are readily distinguished from the Eurasian Wigeon by the latter’s rusty face and neck, and gray rather than brown body. The American Wigeon is monotypic and, not surprisingly, is closely related to the Eurasian Wigeon.

The breeding range of the American Wigeon extends from Alaska across much of western Canada and to the east along the southern flanks of James and Hudson bays, and sporadically across the Great Lakes to Newfoundland and Nova Scotia. In the United States, the American Wigeon breeds across the prairie states to eastern Washington, Oregon, and California. Most populations are migratory, wintering along the British Columbia coast south through Mexico to Panama and across much of the United States south of the Great Lakes and east to Massachusetts. They also winter in the Caribbean and a few even winter in Hawaii—wigeon really get around. They are year-round residents in about half of their western United States breeding range.

After breeding, American Wigeon males migrate to protected lakes and marshes to molt, where they are unable to fly for more than a month. Females usually remain on the breeding grounds to molt. As a result, males tend to make their post-molt migration earlier than the females and young. The American Wigeon is one of the earliest duck species to migrate. In Massachusetts, they are considered rare and local breeders, uncommon spring migrants, and locally common migrants in fall. They are also fairly common winter residents in a few localities. Spring migration occurs in April and fall migrants arrive in September with many remaining until their preferred ponds freeze over.

American Wigeons are seasonally monogamous and only produce a single brood each year. The male gives a three-syllable, high-pitched call often referred to as the slow whistle, which is used in courtship, serves to establish individual recognition, and is also used in threatening situations. What is described as a fast whistle is used in aggressive situations. Females have a variety of calls, including a brood call, which probably also functions in individual recognition, letting the chicks know that it’s mom calling. Courtship occurs on the wintering grounds and is highly competitive since there are often more males than females in the population. Males perform a number of courtship displays. In one, the male starts the display with tail-wagging, followed by raising his breast out of the water and shaking his head. He then tucks his head onto his breast and again wags his tail. In another display, the male stretches his head and neck upwards, fluffing his crown feathers and uttering the slow whistle. In yet another common display, the male arches his wings over his back, crosses the primary feathers, and wags his tail, tucking his head and whistling at the same time. These and other displays serve to emphasize the striking color pattern on the head and the white on wings and flanks. American Wigeon males defend a territory by rushing at intruders, biting and bill-grabbing. During courtship and territorial defense a male may swim at an intruder, head and neck extended, flush the opponent, and chase it nipping at its tail. Most aggression is intraspecific.

Nesting habitat consists of upland areas of brush or grass near lakes, ponds, or marshes. Short-grass prairies and parkland are favored in western Canada where wigeon populations are most dense, but they also nest in coastal tundra. Nests are usually on dry ground in tall grass or shrubbery. The nest typically is a depression lined with down and grass, leaves, or other vegetation. The female may lay up to a dozen cream-colored eggs. She alone develops a brood patch and she alone incubates the eggs for three weeks or more until they hatch. The chicks are precocial, covered with down and eyes open. They are mobile, leave the nest within a day of hatching, and feed themselves. The female broods the chicks and defends them against intruders, wildly beating her wings in distraction displays or even attacking interlopers while the chicks hide. The male usually deserts the family before hatching but occasionally one will stay on for the six-to-seven weeks until the chicks become independent.

American Wigeon feed in ponds, rivers, and marshes, but also feed extensively, often at night, by grazing in terrestrial habitats such as grasslands and agricultural fields. The combination of a short, wide, and deep bill at its base results in a strong bite that facilitates plucking leafy vegetation and seeds. Conversely, wigeon have less ability to strain food from the water than other dabbling ducks. On the water they forage mostly from the surface and tip up less than other dabblers. They are opportunistic and aggressive foragers, often feeding with diving ducks that stir algae and other plant food to the surface. They regularly kleptoparasitize American Coots, stealing plant material from them. During the winter and migration, they are almost entirely herbivorous. In the breeding season, however, they take insects including beetles and dragonflies, prey upon crustaceans, eat more seeds, and sometimes take fruit.

American Wigeons suffer nest predation from gulls, crows, and mammals, adult females being taken at the nest as well as chicks. Hunters take more than a half million wigeons each year, but fortunately during hunting season wigeons tend to feed at night in terrestrial habitats and spend their days in sheltered areas. Loss of wetlands and upland breeding areas is a continuing problem for them, but they are nonetheless expanding their breeding range to the east. With a breeding population of about three million, it appears that the American Wigeon is secure.

William E. Davis, Jr.

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