The common eider (Somateria mollissima) is the largest of the sea ducks. The mature male presents a somewhat strange appearance, not likely to be confused with that of any other species. He is one of the few ducks with a black belly and white back. Likewise, his cheeks and flanks are white, while he sports a black cap and black tail. But he is by no means a study in newsprint—for variety he features a dull yellowish-orange bill and a pale green wash over the back of his neck. Even his white breast may sometimes display a little pink.
The immature male can be somewhat variable in appearance. He starts out more or less grayish-brown. Fairly soon, however, he develops white mottling on the back, and typically ends up with a white collar, as well.
The female is a very rich brown with striking barring. In flight, she displays two subtle white stripes on her secondary flight feathers.
Best Field Marks
- Sloping facial profile.
- White back and black belly of male.
- Barred plumage of female.
Both the male and the female make drawn out cooing calls. The female also quacks hoarsely. However, this species is silent in winter.
Distribution & Occurrence
The common eider breeds in Greenland, Canada, and the northeastern United States. In the winter, eastern populations migrate to Hudson Bay and further south along the Atlantic coast as far as South Carolina. Western populations travel to the Bering Sea and Alaska.
The only known common eider to have reached Kansas was discovered on the Kansas River near Lecompton in November 1891.
The common eider typically flies low. While its movements in the air look sluggish and ponderous, it can actually fly at speeds up to 70 mph.
This species does not dive as deeply as the king eider, reaching depths of only 60 feet maximum. The common eider then swims around under the water using its wings, seeking crustaceans, mollusks, and mussels.
Kansans are not likely to be able to attract common eiders for either birdwatching or hunting purposes.
While mature male eiders are not likely to pose an identification problem, females and immature males can be tricky. Female common eiders usually have some white mottling on their backs that king eiders lack. The most reliable way to tell the two species apart, however, is to take a look at the shape of the head and bill. The common eider has a straight, slanting forehead and bill, creating a distinctive sloping profile. The king eider, on the other hand, has a rounder head and a slightly concave bill.
Scoters are smaller than eiders, eiders being particularly large, chunky ducks. Also, scoters are more or less uniformly dark brown, while the female common eider is barred.
Photos, audio, and more information from Cornell’s All About Birds site.