The common eider is a species of sea duck found in northern coastal regions of North America, Europe and eastern Siberia. A common breeder in Maine, they nest as far south as Massachusetts. Common eiders are important members of Arctic breeding bird communities.

Common eiders withdraw from their more northerly breeding areas after nesting and winter in coastal flocks. Winter aggregations may number in the thousands. In Maine, this species is present year-round.

Common eiders are distinctive birds, often recognizable merely by their silhouette. The combination of a long, sloping bill (think ski jump), long neck and peaked head give them a distinctive look. At a length of 2 feet, common eiders are among our biggest ducks.

Adult drakes are subtly beautiful birds. The crown is black but the cheeks, neck and dorsal body are mostly white. A close look in favorable light reveals a light green wash on the posterior side of the face and nape. The mostly black wings contrast with the white sides when an eider is on the water. The bill is a dull yellow.

Like most ducks, the adult females are much less brightly marked. The body is barred with irregular dark and light brown stripes. The head is mostly brown.

First-year males are highly variable with brown heads like females but with splotches of white and brown on the dorsal surface. The breast is white.

Common eider females make a nest on rocky islands, not far above the high tide mark. A female plucks down from her breast to line the nest. The down used to create soft warm pillows, coats and sleeping bags often comes from eider down.

Harvesting eider down is typically done after the nesting season. A down collector simply gathers the down from the nest once the young eiders have hatched. But synthetic insulating materials have been developed with properties comparable insulating to eider down. These synthetic products are relatively cheap to produce, so a vest or coat filled with eider down will cost a pretty penny compared to a product made from synthetic material.

By the way, some down used for insulation comes from geese. That down has to be plucked directly from the geese. Goose down is inferior in insulating properties.

A hen eider can lay up to 14 eggs. When they hatch, they are covered with a down coat and leave the nest quickly.

Once the ducklings have hatched, they aggregate into creches of 100 birds or more, watched over by the moms as well as nonbreeding females.

The ducklings start to form their contour feathers in their second week and complete their feather growth by seven weeks. They take their first flight nine or 10 weeks after hatching.

Common eiders dive in search of invertebrate food from the sea bottom. Mussels are one of the most common prey items, although crabs and sea urchins are important for their diet as well.

The fondness of common eiders for mussels poses a challenge for mussel mariculture. Not surprisingly, the dense aggregation of mussels attracts eiders. Nets seem to be the only practical way to protect the mussels from the eiders and other sea ducks.

Common eiders are doing well now, with an estimated population of 2 million birds in North America and Europe.

Our New England population was nearly decimated by market hunters by the end of the 19th century. Fortunately, the eiders have recovered.

Herb Wilson teaches ornithology and other biology courses at Colby College. He welcomes reader questions and comments at

[email protected]

filed under: