Eiders are large seaducks in the genus Somateria. Steller's Eider

Steller's Eider

The Steller's Eider is a medium-large sea duck that breeds along the Arctic coasts of eastern Siberia and Alaska. The lined nest is built on tundra close to the sea, and 6-10 eggs are laid....

, despite its name, is in a different genus.

The three extant species all breed in the cooler latitudes of the Northern hemisphere.

The down feather

Down feather

The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...

s of eider ducks, and some other ducks and geese, are used to fill pillows and quilts—they have given the name to the type of quilt known as an eiderdown.

Species

• Common Eider
  Common Eider
  The Common Eider, Somateria mollissima, is a large sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters somewhat farther south in temperate zones, when it can form large flocks on...
  
   Somateria mollissima
• King Eider
  King Eider
  The King Eider is a large sea duck that breeds along northern hemisphere Arctic coasts of northeast Europe, North America and Asia. The birds spend most of the year in coastal marine ecosystems at high latitudes, and migrate to Arctic tundra to breed in June and July...
  
   Somateria spectabilis
• Spectacled Eider
  Spectacled Eider
  The Spectacled Eider is a large sea duck that breeds on the coasts of Alaska and northeastern Siberia.The lined nest is built on tundra close to the sea, and 5–9 eggs are laid. This species dives for crustaceans and molluscs...
  
   Somateria fischeri
• Steller's Eider
  Steller's Eider
  The Steller's Eider is a medium-large sea duck that breeds along the Arctic coasts of eastern Siberia and Alaska. The lined nest is built on tundra close to the sea, and 6-10 eggs are laid....
  
   Polysticta stelleri

Two undescribed species are known from fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s, one from Middle Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

 rocks in Kazakhstan

Kazakhstan

Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

 and another from the Late Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 or Early Pliocene

Pliocene

The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

 of Lee Creek Mine, USA. The former may not actually belong into this genus.