Game Birds of the World

The common eider is a widely ranging species whose various populations encircle the globe at high latitudes. These numerous populations vary somewhat in size and plumage. The Pacific race is the largest and most distinctive, the male having a black V-pattern on its throat, and occasionally is regarded as a separate species. Generally, adult birds weigh 3–5 pounds. The male has a black-and-white plumage pattern that includes black crown, white cheeks, greenish yellow sides of the head, and an all-white back and breast. The female is strongly vertically barred with tones of brownish buff and blackish brown, in an overall pattern slightly resembling that of female mallards. In both sexes and all races, the feathers on the sides of the cheeks extend forward, almost reaching the rear edge of the nostrils.

Like other larger eider species, males of this species have a variety of cooing calls that are used during social courtship and are accompanied by various head movements. Females lay rather small clutches of 4–5 eggs; early clutches are larger than later ones, and those of middle latitudes are larger than extreme northern or southern ones. Incubation lasts about 25–30 days, and fledging requires about eight weeks. Eiders often nest colonially, and the young of many females frequently merge to form large crèches, which are attended by several females.