» For the river see Eider River. For other uses see Eider (disambiguation). Eiders are large seaducks in the genus Somateria. Steller's Eider, despite its name, is in a different genus. The three extant species all breed in the cooler latitudes of the Northern hemisphere. Species Common Eider Somateria mollissima Spectacled Eider Somateria fischeri King Eider Somateria spectabilis Two undescribed species are known from fossils, one from Middle Oligocene rocks in Kazakhstan and another from… (More on Eider)