Scientific name: Gavia adamsii (Gray, 1859)
Bird group: Divers
Field characters. 75-100 cm. Largest diver. In breeding plumage shows a characteristic yellowish-white bill, held upright on the water. Head and neck pattern similar to Great Northern Diver, but fewer stripes in collar. White spots on upper parts sparser and larger. In winter with brownish-grey neck-sides and head, paler than Great Northern Diver. Foreneck light brown. Bill grey at base changing to yellow-white towards tip; culmen never fully dark.
Voice. Like Great Northern Divers but louder and harsher.
Distribution. Sporadic in N Russia and Siberia but no precise data.
Habitat. Breeds along littoral of Arctic Ocean and on waters of tundra zone, mostly beyond tree-limit.
Food. Mainly fish.
Eggs. Not distinguishable from Great Northern Diver.