Somateria mollissima - Common Eider
Feather characters. Barbules are short (0.6-0.8 mm) and barbules contain lightly stippled pigment. Triangular nodes are located on distal end, covering less than 30% of the total barbule length. On proximal end, nodal structures are visible but undeveloped and hardly swollen, and thus too small to qualify as nodes (17-19 per mm). An abrupt increase in size of nodes is seen distally along the barbules. In a very few cases triangular nodes may not be present. Villi are absent and internodes are occasionally kinked. Prongs are mostly located on distal end of barbules, on both sides of the pennulum. Their length varies but the longest prongs may reach a length between half and the entire length of the adjacent internode.
Field characters. Size 50-71 cm. Weight: male 2218 g (1384-2800), female 1915 g (1192-2895) (Dunning, 1993). A large, long-headed, bulky sea-duck. Male is the only duck with black belly and white back; breast white, tinted pinkish; head white with black crown; green patches on the sides of the head and nape; white patch on sides of rump. Bulky in flight, with short, thick neck and entirely white forewing, contrasting with black quills. Bill with long triangular profile continued in almost straight line by that of flat forehead; olive-grey, with yellow or green tinge to base. Male in eclipse highly variable, essentially blackish brown except for white patch on sides and white on wing. Female is warm brown, streaked and barred with blackish; in flight with two buffish or white wing-bars. Juvenile resembles female, but brown duller. Young birds slowly attain adult plumage, and males therefore have irregular piebald appearance.
Voice. Male utters a low, crooning sound during courtship "ah-oo"; female utters hoarse, grating "k-r-r-r".
Distribution. Common in northern Europe and Iceland. Map: see MapIt.
Habitat. Breeds on low-lying coasts, islands, skerries and reefs with rocky or sandy shores. Mainly on sea outside the breeding season.
Food. Dives for bottom-living animals, mainly molluscs and, to a lesser extent, crustaceans and echinoderms. In small quantities it takes also fish, sea-anemones, cuttlefish, insects and polychaetes. On the breeding grounds, incubating females take also berries, green algae, leaves, and seeds. Prey is swallowed under water or brought to the surface and shaken in order to separate mussel clumps.