The Common Eider (Somateria mollissima) is a large sea duck that breeds in the arctic and subarctic regions of the Northern Hemisphere. Adult males can reach a length of up to 25 inches and weigh between 3.3 and 5.5 pounds, while adult females can grow up to 23 inches in length and weigh between 2.2 and 4.4 pounds. This sexually dimorphic species is easily distinguished by its distinctive appearance and behavior.
Male Common Eiders have a distinctive black and white plumage, with a green nape and a large bill that curves downward. The female Common Eider, on the other hand, has a brown plumage, with pale underparts and a distinctive white patch on the throat. Both sexes have a prominent wedge-shaped head and a rounded body, which helps them to float effortlessly on the water. The Common Eider also has a unique vocalization, a deep crooning call that can be heard from a long distance.
The Common Eider is a migratory bird, spending the winter months in coastal areas and moving to its breeding grounds in the spring. During the breeding season, these ducks gather in large colonies along rocky coasts, islands, and cliffs. They nest on the ground, often in the shelter of rocks or vegetation, and lay between 3 and 6 olive-green eggs. The young hatch after about 25-30 days and are able to leave the nest within a few hours.
During migration, Common Eiders can be seen flying in large flocks, often in a V-formation, following the coastlines and crossing open water. They are also known to make use of tailwinds to reduce their energy expenditure during flight. The Common Eider is an important species for hunters and birdwatchers alike, and is widely distributed throughout the northern hemisphere, from Scandinavia to Canada and Alaska. In some areas, such as the Faroe Islands, they are also used for their down feathers, which are prized for their insulating properties.