In different languages the Tundra Swan is known as Cygne de Bewick, Cisne Chico, Cisne-pequeno, Zwergschwan, Kis hattyú, Американский лебедь, 小天鹅, Fluitzwaan, Cigno minore, Tundrasvan, Dvergsvane, łabędź czarnodzioby, labuť malá, labuť malá, Pibesvane, pikkujoutsen, アメリカコハクチョウ.
The Tundra Swan is from the Anatidae family, order Anseriformes. It is similar to the Whooper Swan but it is smaller measuring between 4.5 kg and 8.2 kg in weight, 120-150 cm in length, and 190-225 cm in wingspan. There is no marked sexual dimorphism. Its plumage is pure white and at the base of its bill it has a yellow spot on each side, which is similar to the Whooper Swan, only that it is smaller. Its neck is also thicker and looks shorter.
Distribution and Habitat
The Tundra Swan is widely spread in Asia and Europe including Bulgaria where it is a rare wintering species. Since 1989 it has regularly wintered in small numbers mostly on the Black Sea coast. Its wintering population in the Burgas lakes region tends to increase. It nests in the tundra of North America, Northeast Europe and Siberia.
The Tundra Swan inhabits permanent inland and coastal water basins with different salinity, shallow coastal areas, bays, straits, tidal marshes, swamped low lands, arable lands, pastures, seasonally flooded lands, valleys.
The Tundra Swan is a migratory bird that winters in the coastal low lands of North Europe and East Asia to Taiwan. There is a small population which winters at the south coast of the Caspian Sea in Iran. During migration it is occasionally found in Mongolia and in the interior of northern China.
The Tundra Swan feeds mainly on the underwater parts of plants, occasionally on seeds and animal food that it swallows by chance with plants.
The Tundra Swan is a monogamous bird which reaches sexual maturity at its 2-3rd year. It builds its nest on the ground, close to water, and it lays from 1 to 7 white eggs. Both parents incubate the eggs for 30-32 days. The chicks hatch during the second half of July and are developed enough to walk and eat independently. Both parents take care of the chicks.
According to IUCN its status is Least Concern, but in Bulgaria according to the Red Data Book it is Critically Endangered. Durankulak lake, Shabla, Lake Pomorie, Lake Atanasovsko, Vaya lake and Poda area with Foros bay are declared Ramsar wetlands.