25-4-2016 RACO DE OLLA, VALENCIA - COMMON SHELDUCK (MALE) (Tadorna tadorna)

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.

Ducklings are white, with black cap, hindneck and wing and back patches. Juveniles are similarly coloured, greyish above and mostly white below, but already have the adult's wing pattern.

The call is a loud honk.

Habitat The species shows a preference for saline habitats and frequents mudflats and muddy or sandy estuaries in coastal regions, and occurs inland on saline and brackish lakes in steppe or semi-desert.  Asiatic populations also occupy freshwater rivers or marshes and other populations utilise freshwater habitats on migration. 

Diet Its diet consists predominantly of salt-water molluscs (e.g. Hydrobia spp.) as well as other aquatic invertebrates (e.g. insects, crustaceans and worms), small fish, fish spawn and plant material (e.g. algae, seeds and agricultural grain)

Breeding site The nest is commonly positioned in a tree-hollow up to 8 m above the ground or in a mammal burrow (e.g. of European rabbit Oryctolagus cuniculus).  Rarely nests may also be placed in the open or in dense vegetation up to 1 km from water. The species will also nest in artificial nest-boxes.