Scientific name: Clangula hyemalis (Linnaeus, 1758)
Bird group: Ducks
Field characters. 40-47 cm (excluding 13 cm of elongated tail-feathers in male). A small sea-duck with delicate head, short, high-based bill, and steep forehead. Male in summer predominantly brown with white face, flanks, and belly. In winter male is predominantly white, with dark brown cheek patch, broad brown pectoral band, middle of back dark brown; bill pink or yellow-orange with black base and tip. Female in summer with dark head with whitish area around eye, breast brownish, upperparts darker and duller than in winter. In winter female has mottled dark brown back, white head with brown crown, nape, and ear-coverts, white underparts, and brownish pectoral band; bill slate-grey. Juveniles with uniform dull grey backs, greyish flanks.
Voice. Male utters loud, yodelling notes, resembling those of geese and swans; female produces low quacking notes.
Distribution. Common breeding bird of Iceland and fairly common in northern Europe.
Habitat. In the breeding season, frequents both freshwaters and salt water; outside the breeding season mainly along rocky sea-shores.
Food. Catches crustaceans and molluscs after surface-dive up to 10 m. Also takes small fish, polychaetes, echinoderms, and plant material. In freshwater areas diet includes waterinsects, craneflies, crustaceans, molluscs, berries, tubers, roots, leaves.
Eggs. Unmarked or sometimes with faint pale clouding. Ground colour olive-buff/olive-green/green-grey/grey/blue-green/cream/pale brown. Texture very glossy when fresh, otherwise dull. Shape subelliptical/long subelliptical. Size 54 x 38 mm (47-58 X 35-41), weight 39 g (38-40).