Eiders are sea ducks which belongs to family Anatidae, genus Somateria. The three existing species of Eiders are given below with their binomial name:
- King Eider (Somateria spectabilis)
- Spectacled (Eider Somateria fischeri)
- Common Eider (Somateria mollissima)
The duck named, Steller's Eider, despite its name, is belongs to another genus. There are two more species from fossils. One is from the Middle Oligocene rocks in Kazakhstan and the second one is from Early Pliocene or Late Miocene of Lee Creek Mine, USA.
All the existing eiders inhabit in the northern hemisphere. The three species king, spectacled and common are the largest ducks found in North America. However, the stellar's eider is relatively smaller one and is distinct in duck family. All these species breeds in Alaska.
Eider are the diving ducks. There is difference in the plumage of male and female eider. Male eiders have bold white and black plumage, while the female eiders have soft black, brown, grey plumage.
Eiders also have commercial importance. The underlayer of their feathers is an excellent insulator, which is used in sleeping bags and comforters. These feathers are called as down or eider down. The manufacturers collect these feathers from eider nests from the farms in Scandinavia and Iceland.
The two species of eiders stellar's and spectacled are threaten to extinction.