The Common Eider (Somateria mollissima) is a large species of duck occurring along the coasts of northern Europe, northern America, and Siberia. The birds are characterized by strong sexual dimorphism: males have a black-and-white plumage with a green nape, while females are dull brown. They are excellent swimmers and able to dive to depths of many metres. Their diet consists mainly of mussels which are swallowed whole. The shells are only crashed in the stomach and lateron excreted. In addition, the birds prey on snails, crustaceans, and fish.
The Common Eider is a very social bird even breeding together in colonies. After hatching, mothers often team up and raise the young together. However, the ducks are truly famous only because of their renowned eiderdown which are plucked from the female’s breast. Originally these feathers are used to pad the nests, but humans began to commercially use them in the 10th century to fill pillows and quilts. Today these feathers are still harvested, but only from empty nests. This way the birds are not harmed and their population is indeed quite large. I have photographed these pretty ducks during a visit to the little island Helgoland in the North Sea of Germany (May 2014).