Scientific name: Mergus serrator Linnaeus, 1758
Bird group: Ducks
Field characters. 52-58 cm. Somewhat smaller and more slender than Mallard, with thin, red bill and red legs. Differs from Goosander in more distinct, stiff, ragged crest divided into two. Male with greenish black head separated by broad white collar from chestnut-brown upper-breast, spotted with black; flanks vermiculated grey; black patch at shoulder with white blobs. In flight forewing is blackish and hindwing white with two black bands; female in flight has white speculum crossed with one black line; primaries blackish in both sexes. Female differs from female Goosander in brownish grey upperparts; indistinct white throat patch; more conspicuous crest and duller brown head, shading off at white of lower neck; bill brown-red. Juvenile as adult female but with darker grey plumage and shorter crest.
Voice. During courtship male utters loud, rough purr; female has harsh, grating note.
Distribution. Fairly common breeding bird in Fenno-Scandia; rare in other parts of Europe.
Habitat. During breeding season occurs on fresh and salt waters in wooded and treeless areas; nests on the ground, but requires substantial woody cover.
Food. Mainly fish, obtained by foraging from surface with head immersed, followed by dive. Prey may be brought to surface or swallowed under water. Prefers to feed in shallow waters up to 3.5 m.
Eggs. Unmarked, ground colour pale yellowish brown/buff-olive. Texture smooth, not glossy. Shape subelliptical/short subelliptical. Size 65 x 45 mm (57-70 x 41-8), weight 73 g (68-77).