Common Eider (Somateria mollissima)


Class: Aves
Order: Anseriformes
Family:    Anatidae
Size:    Length: 18 to 30 inches  (46 to 76 cm)  Wingspan: 30 to 42 inches (76 to 106 cm)
Weight: 4.5 to 5 pounds (2 to 2.2 kg)
Diet: Fish, especially mussels, herring roe, scallops, clams and crabs
Distribution: Northern coastal areas
Young:  3 to 5 chicks, once a year
Animal Predators:  Foxes and rats
IUCN Status: No special status
Terms: Young: Duckling   Male: Drake   Female:  Hen   Group:  Brace or Flock
Lifespan: Up to 20 years in the wild



·     Common eiders are the largest ducks in the northern hemisphere.

·     The down from 100 nests is required to fill one sleeping bag or quilt.

·     Eiders can crack open shellfish with their powerful bills.

·     In winter, eiders become inactive to save energy and gather in dense crowds to keep warm.



Adult males have a distinct look with their black cap and undersides, light green nape and white middle area. Females range in colour from rust to grey and are speckled with various shades of brown and white. Females can be distinguished from female king eiders by their larger size and sloping forehead.  Eider ducks are well known for the down that comes from their breast, especially from the females. It is used in pillows, duvets, sleeping bags and parkas and is a multi-million dollar industry in areas such as Iceland, where eiders are protected from being hunted. The down is obtained without killing the ducks or damaging their nests.



These sea ducks live on ocean coasts and islands throughout the Arctic, in the upper reaches of North America, along the Baltic and Scandinavian coasts of Europe and the northern tip of Russia. They prefer shallow bays and rocky shores, and are sometimes found as far south as the Great Lakes. 


Feeding Habits

Their diets consist entirely of fish, especially mussels, herring roe, scallops, clams and crabs. They obtain their food by diving to the bottom in waters that are 9 to 66 feet (3 to 20 m) deep. 



Common eiders usually breed in large colonies on offshore islands, where the eggs are safe from mammals such as foxes or rats. Eiders form long-lasting pairs and usually have a mate when they return to the breeding grounds in early summer. Unpaired eiders begin actively courting at this time. Males are three years of age before they begin breeding, but females may begin at age two. While in the water, the male circles the female and coos at her. After mating, they find a nesting site on shore, in the midst of thousands of other eider nests. During the courtship, the drake refrains from eating. Once the pale green eggs are laid, the male has little to do—he does not do any of the incubating, and it is unknown whether he has a role in raising the chicks. While the female is incubating the eggs, she does not eat. The nest is a shallow hollow in the ground that the female lines with down, plucked from her breast. The eggs hatch 25 to 30 days later, and the fuzzy, down-covered chicks are fully formed. The mother leads them to the shore where they begin to swim. Females with chicks often congregate together and their chicks form large groups in which they can socialize and play. Although they can swim from birth, the chicks will not begin to fly until they are approximately two months of age. Once an eider begins to fly, the chances of it living a long life are quite good. This is in contrast to other species of ducks that have a high level of adult mortality due to predators. Young eiders do not obtain full adult plumage until three years of age; during these three years, the eiders proceed through different stages of plumage. Therefore, in a single flock of eiders, one may observe many different plumages.



Common eiders can be found in large flocks of up to thousands of ducks.



Common eider ducks were heavily hunted at one time for their down and for food, and were in serious decline. They began to recover after the Migratory Birds Convention Act in 1916 between Canada and the United States was put into place.



Common Eider Wildlife Fact File, IM Pub, US

National Geographic Field Guide to the Birds of North America (1999)