Stock Photo: COMMON EIDER. Common eider Couple of common eider Somateria mollissima, Shetland Islands, Scotland. On this image, we can see a female betwen two males. Among common eiders, there is an important sexual dimorphism between male and female. In fact, the female has a dull plumage, in the brown tones, whereas the male is usually white and black. Somateria mollissima Common eider Eider Duck Anatid Palmiped Bird