Scientific name: Gavia arctica (Linnaeus, 1758)
Bird group: Divers
Field characters. 58-73 cm. In breeding plumage with grey head and hind neck, black throat, regular pattern of black-and-white stripes at sides of neck and breast; on either side two sharply defined white areas on scapulars and shoulders. Straight and slender bill grey with black culmen. In winter, forehead, mantle, and scapulars uniform blackish; crown and hindneck paler; underparts white, sharply contrasting with upperparts; white on rear flanks reaches further than on Red-throated Diver.
Voice. A low, guttural "kwuk-kwuk-kwuk".
Distribution. Breeding bird of northern Europe and Scotland.
Habitat. Prefers fairly large, deep lakes in tundra or taiga habitats; usually in somewhat sheltered areas with small islets, peninsulas, etc. Outside the breeding season in sheltered coastal, marine waters, rarely on inland waters.
Food. Mostly fish, captured with bill in underwater pursuit at depths of 3-6 m. Catches also crustaceans, molluscs, and aquatic insects.
Eggs. With spots and blotches, sometimes clustered at the large end of the egg. Ground colour greenish olive/dark umber/dark brown. Marking colour black/very dark brown/very dark grey. Texture slightly glossy, sometimes with few small notches at the large end of the egg. Shape subelliptical/long elliptical. Size 84 x 52 mm (76-95 x 46-56), weight 120 g (92-134).