Tundra Swan

The Tundra Swan is a large white swan, smaller and shorter-necked than the Whooper Swan. The Eurasian Bewick's form has a black bill with a variable yellow patch near the base, usually more rounded and less extensive than on a Whooper Swan. Juveniles are greyish with pink-toned bills. Individual yellow bill patterns can be distinctive enough for researchers to recognize particular birds (Wikipedia, general species account).

Tundra Swans breed beside shallow pools and lakes across Arctic tundra, building mound nests on low dry ground. They feed on aquatic plants, roots and tubers by dipping and upending, and use waste grain and grasses on migration and wintering grounds. Strongly migratory family groups travel to temperate wetlands; Bewick's Swans winter locally in Japan on lakes, estuaries and surrounding farmland (Wikipedia, general species account).