The Shelducks (genus Tadorna), fall between most ducks and geese in size, reaching 50-60cm in length. They are normally semi-terrestrial, spending some time on shore. The sexes are similar but not identical in most species. They all have green, black and white upper wings when seen in flight. The name Tadorna might have come from the Old French tadorne, possibly referring to a species of pied waterbird.
The English Shelduck comes from Middle English, and combines Sheld (pied, from Middle Dutch schillede or variegated) and dufan/ duken (diving bird). It originally appeared as Sheldrake, with Shelduck first emerging in the early eighteenth century.
Their diet consists of small shore animals, grasses and plants.
The Tadorna are very closely related to the Alopochen (containing only the Egyptian Goose), and may share a reasonably recent common ancestor.
The Common Shelduck is the only resident breeding member of the Genus found in Britain, and had a range that spreads across Europe and Asia. British and north-western European birds are resident all year round, while other populations migrate between breeding grounds in central Asia and wintering groups stretching from the Mediterranean to the southern Chinese coast.
The Ruddy Shelduck is normally found in south-eastern Europe and Asia, but some vagrants reach as far as Britain. There also some escapes from collections.
Classification
Order: Anseriformes (Geese, swans, ducks)
Family: Anatidae (Swans, Geese, Ducks)
Genus: Tadorna
Number of Species 7: (as of March 2015)
British Members of the Genus
Resident Breeders
Shelduck, Tadorna Tadorna
Vagrants
Ruddy Shelduck, Tadorna Ferruginea