Scientific name: Cygnus columbianus (Ord, 1815)
Bird group: Swans
Field characters. 115-127 cm. Considerably smaller and with shorter neck than Whooper Swan and Mute Swan. Resembles Whooper Swan but differs in shorter bill with the yellow bill-base ending rounded, jagged, or truncated behind nostril, instead of tapering into a point below nostril; much variation in shape and extent of yellow. Leg and feet black. Plumage of juvenile as that of young Whooper but greyer and paler. Bill pattern of juveniles as in adult, but base dirty pink base instead of yellow.
Voice. During feeding flocks utter a musical, goose-like babble; flight-call a louder, goose-like note without trumpeting character of Whooper: "bong", "bung", or "ong".
Distribution. In breeding season restricted to Arctic, in winter mainly in countries bordering the North Sea.
Habitat. Breeds on the arctic tundra; in winter frequents inland localities such as lowland lakes, reservoirs, pools, and rivers in the vicinity of suitable grazing areas, preferably flooded grasslands.
Food. Almost entirely consists of leaves, roots, shoots and tubers, which are obtained by dipping (immersing head and neck) or by up-ending. Grazes and digs also for roots and stolons in floodlands.
Eggs. Unmarked, ground colour white or slightly yellow, becoming stained brown or yellow during incubation. Texture often slightly glossy, becoming scratched during incubation. Shape long subelliptical/long elliptical. Size 103 x 67 mm (96-112 x 65-73), weight 260-306 g.