The common shelduck (Tadorna tadorna) is a waterfowl species of the shelduck genus Tadorna. It is widespread and common in the Palearctic, in Europe and northwest Africa mainly breeding on temperate coasts, saline pools and estuaries, and in Asia on inland salt lakes; increasingly it is also using open freshwater habitats inland. Wintering is in temperate to subtropical regions.

Taxonomy

The common shelduck was formally named by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Anas tadorna. Linnaeus largely based his description on "The Sheldrake or Burrough-Duck" that had been described and illustrated in 1731 by the English naturalist Eleazar Albin. The specific epithet comes from the French word Tadorne for this species, a name that was used by the French naturalist Pierre Belon in 1555. It may originally derive from Celtic roots meaning "pied waterfowl", essentially the same as the English "shelduck". The species is monotypic, with no subspecies being recognised.

The ducklings are white, with blackish-brown 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.

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Brandgans - Steigflug (51956054436).jpg|Male in flight

Common shelduck (Tadorna tadorna) female in flight Sfax.jpg|Female in flight

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Distribution and habitat

This is a bird which breeds in the temperate Palearctic region. It has increased and spread markedly since the mid 20th century; at that time in Europe it was strongly restricted to coasts, estuaries and other saline habitats, but is now widespread inland in open freshwater wetlands. It has also spread northwards; in the mid 20th century, it only reached north to 66°N latitude in Norway, but by 2020 had spread along the entire Norwegian coast and into northwestern Russia, including since 2000 in the Murmansk area and the White Sea. and Newfoundland in Canada.

Fossil bones from Dorkovo in 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).

Captivity

Shelduck are attractive birds, and often kept as ornamental wildfowl. Escaped captive birds have been reported as occurring in the United States and Canada. In South America, a record of the species exists in Colombia but is excluded from the national list.

Behaviour

Moulting flocks can be very large (100,000 on the Wadden Sea), since most pairs leave their partially grown young in a crèche with just one or two adults.

This bird is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.

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File:Brandgans auf Schotterinsel.jpg|Male

File:Common shelduck, male, female (Tadorna tadorna).jpg|Common shelduck, male and female together on the island of Amrum, Germany

File:2014-04-18 Tadorna tadorna pair, Swallow Pond.jpg|Pair swimming; the difference in bill shape can be seen

File:Shelduck mating.jpg|Adults mating in Lancashire (UK) (male right), note size difference

File:Brandgans Küken, Borkum.JPG|Ducklings on Borkum (Germany)

File:Tadorna tadorna MWNH 1969.JPG|Egg, Collection Museum Wiesbaden

File:Gravand (tadorna tadorna) - Ystad-2020.jpg|Female and two half-grown ducklings.

File:Gravand (Tadorna tadorna) - Ystad-2022.jpg|Female with one week old ducklings.

File:Common Shelduck.ogv|Common Shelduck

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References

  • RSPB Birds by Name
  • Ageing and sexing (PDF; 1.2 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze