The common shelduck (Tadorna tadorna) is a waterfowl species of the shelduck genus, Tadorna. It is widespread and common in the Euro-Siberian region of the Palearctic, mainly breeding in temperate and wintering in subtropical regions; in winter, it can also be found in the Maghreb.
Fossil bones from Dorkovo (Bulgaria) described as Balcanas pliocaenica may actually belong to this species. More likely, they are an extinct species of Tadorna (if not a distinct genus) due to their Early Pliocene age; the present species is not unequivocally attested from the fossil record until some 2–3 million years later (Late Pliocene/Early Pleistocene).
The common shelduck resembles a small short-necked goose in size and shape. It is a striking bird, with a reddish-pink bill, pink feet, a white body with chestnut patches and a black belly, and a dark green head and neck. The wing coverts are white, the primary remiges black, and the secondaries green (only showing in flight) and chestnut. The underwings are almost entirely white. Sexes are similar, but the female is smaller, with some white facial markings, while the male is particularly crisply coloured in the breeding season, his bill bright red and bearing a prominent knob at the forehead.
