Common shelduck

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: no subspecies are recognised.

Description

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.

500px photo (31688843).jpeg|male Common shelduck (Tadorna tadorna) female in flight Sfax.jpg|female

Distribution and habitat

This is a bird which breeds in temperate Eurosiberia. Most populations migrate to subtropical areas in winter, but this species is largely resident in westernmost Europe, apart from movements to favoured moulting grounds, such as the Wadden Sea on the north German coast.

The common shelduck is common around the coastline of Great Britain and Ireland (where it is known simply as the shelduck), where it frequents salt marshes and estuaries. It frequently nests in rabbit burrows. Sightings of this bird are rare in North America and are reported as infrequent visitors to the U.S. and Canada. In South America, a record of the species exists in Colombia.

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 species is mainly associated with lakes and rivers in open country, breeding in rabbit burrows, tree holes, haystacks or similar. In winter it is common on suitable estuaries and tidal mudflats as well.

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

The young will dive under water to avoid predators and the adults will fly away from them to act as a decoy.

File:Tadorna tadorna (Linnaeus, 1758).jpg|A female ruffles up her feathers. File:Brandgans gründelnd.JPG|Adults upending, note underside and feet colors File:Common shelduck, male, female (Tadorna tadorna).jpg|Common shelduck, male and female together on the island of Amrum, Germany File:Shelduck mating.jpg|Adults mating in Lancashire (UK) (male right), note size difference File:Diorama Brandgänse.JPG|Nesting site diorama, Küstenmuseum Juist (Germany) 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

References

References

1. BirdLife International. (2019). "''Tadorna tadorna''".
2. Linnaeus, Carl. (1758). "Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis". Laurentii Salvii.
3. (1731). "A Natural History of Birds: Illustrated with a Hundred and One Copper Plates, Curiously Engraven from the Life". Printed for the author and sold by William Innys.
4. (1979). "Check-List of Birds of the World". Museum of Comparative Zoology.
5. Jobling, James A. (2010). "The Helm Dictionary of Scientific Bird Names". Christopher Helm.
6. Belon, Pierre. (1555). "L'histoire de la natvre des oyseavx: avec levrs descriptions, & naïfs portraicts retirez du natvrel, escrite en sept livres". Gilles Corrozet.
7. Linnaeus, Carl. (1761). "Fauna svecica: sistens animalia sveciae regni: mammalia, aves, amphibia, pisces, insecta, vermes, distributa per classes & ordines, genera & species, cum differentiis specierum, synonymis auctorum, nominibus incolarum, locis natalium, descriptionibus insectorum". Sumtu & Literis Direct. Laurentii Salvii.
8. Boie, Friedrich. (1822). "Tagebuch gehalten auf einer Reise durch Norwegen im Jahre 1817". Königl Taubstummen - Institut.
9. (January 2021). "Screamers, ducks, geese & swans". International Ornithologists' Union.
10. (2013-11-18). "ML69184861 - Common Shelduck - Macaulay Library".
11. de Schauensee, Rodolphe Meyer. (1959). "Additions to the "Birds of the Republic of Colombia"". Proceedings of the Academy of Natural Sciences of Philadelphia.
12. Kear, Janet. (2005). "Ducks, Geese, and Swans". [[Oxford University Press]].
13. "NARBA North American Rare Bird Alert".