{{Short description|Species of bird}} {{Speciesbox |name = Common shelduck |image = Common Shellduck (Tadorna tadorna) (26499348215).jpg |image_caption = Adult male |image2 = Shelducks (42458242862).jpg |image2_caption = Adult female with ducklings thumb|center| Female sounds recorded in England |status = LC |status_system = IUCN3.1 |status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=BirdLife International |date=2019 |title=''Tadorna tadorna'' |volume=2019 |article-number=e.T22680024A154560262 |doi=10.2305/IUCN.UK.2019-3.RLTS.T22680024A154560262.en |access-date=12 November 2021}}</ref> |genus = Tadorna |species = tadorna |authority = (Linnaeus, 1758) |range_map = TadornaTadornaIUCN.png |range_map_caption = Range of ''T. tadorna'' (Compiled by BirdLife International and Handbook of the Birds of the World (2019) 2019.){{leftlegend|#00FF00|Breeding|outline=grey}} {{leftlegend|#008000|Resident|outline=grey}} {{leftlegend|#007FFF|Non-breeding|outline=grey}} |synonyms = ''Anas tadorna'' {{small|Linnaeus, 1758}} }}
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''.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title= Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1 | edition=10th | page=122 | publisher=Laurentii Salvii | location=Holmiae (Stockholm) | language=Latin | url=https://www.biodiversitylibrary.org/page/727027 }}</ref> 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.<ref>{{ cite book | last1=Albin | first1=Eleazar | author1-link=Eleazar Albin | last2=Derham | first2=William | author2-link=William Derham | year=1731 | title=A Natural History of Birds: Illustrated with a Hundred and One Copper Plates, Curiously Engraven from the Life | volume=1 | page=90, Plate 94 | location=London | publisher=Printed for the author and sold by William Innys | url=https://www.biodiversitylibrary.org/page/41130512 }}</ref><ref name=mayr>{{ cite book | editor1-last=Mayr | editor1-first=Ernst | editor1-link=Ernst Mayr | editor2-last=Cottrell | editor2-first=G. William | year=1979 | title=Check-List of Birds of the World | volume=1 | edition=2nd | publisher=Museum of Comparative Zoology | place=Cambridge, Massachusetts | page=451 | url=https://www.biodiversitylibrary.org/page/16109091 }}</ref> The specific epithet comes from the French word ''Tadorne'' for this species,<ref name= job90>{{cite book | last= Jobling | first= James A | year= 2010| title= The Helm Dictionary of Scientific Bird Names | url= https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling | publisher = Christopher Helm | location = London | isbn = 978-1-4081-2501-4 |page = [https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling/page/n377 377]}}</ref> a name that was used by the French naturalist Pierre Belon in 1555.<ref>{{ cite book | last=Belon | first=Pierre | author-link=Pierre Belon | date=1555 | title=L'histoire de la natvre des oyseavx: avec levrs descriptions, & naïfs portraicts retirez du natvrel, escrite en sept livres | language=French | location=Paris | publisher=Gilles Corrozet | pages=172–173 | url=https://archive.org/details/gri_33125008413490/page/n203/mode/2up }}</ref> It may originally derive from Celtic roots meaning "pied waterfowl", essentially the same as the English "shelduck".<ref name=Kear2/> Linnaeus specified the locality as Europe but restricted this to Sweden in 1761.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1761 | title= 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 | edition=2nd | language=Latin | location=Stockholmiae | publisher=Sumtu & Literis Direct. Laurentii Salvii | page=40 | url=https://www.biodiversitylibrary.org/page/32170509 }}</ref><ref name=mayr/> The common shelduck is now placed in the genus ''Tadorna'' that was introduced in 1822 by the German zoologist Friedrich Boie.<ref>{{ cite book | last=Boie | first=Friedrich | author-link=Friedrich Boie | year=1822 | title=Tagebuch gehalten auf einer Reise durch Norwegen im Jahre 1817 | language=German | location=Schleswig | publisher=Königl Taubstummen - Institut | pages=140, 351 | url=https://archive.org/details/tagebuchgehalten00boie/page/140/mode/1up }}</ref><ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela Rasmussen | date=January 2021 | title=Screamers, ducks, geese & swans | work=IOC World Bird List Version 11.1 | url=http://www.worldbirdnames.org/bow/waterfowl/ | publisher=International Ornithologists' Union | access-date=11 June 2021 }}</ref> The species is monotypic, with no subspecies being recognised.<ref name=ioc/>
==Description== The common shelduck resembles a small short-necked goose in size and shape. It is 55–65 cm long and with a wingspan of 100–120 cm, 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 black with a strong green iridescent reflection in good light (only showing in flight). The outer tertial feather is orange-brown, with the inner tertials white. The underwings are white, except for the flight feathers, which are black. The sexes are similar, but the female is slightly smaller, usually with some white flecks on the green face, while the male is particularly crisply coloured in the breeding season, his bill bright red and bearing a prominent knob at the base of the bill.<ref name="BWP">{{cite book |last=Cramp |first=Stanley |title=Handbook of the birds of Europe, the Middle East, and north Africa: the birds of the western Paleartic |publisher=Oxford university press |publication-place=Oxford London New York |date=1986 |isbn=0-19-857358-8 |pages=455–464}}</ref><ref name="Svensson">{{cite book |last1=Svensson |first1=Lars |last2=Mullarney |first2=Killian |last3=Zetterstroem |first3=Dan |title=Collins Bird Guide |publisher=William Collins |date=2023-03-16 |isbn=978-0-00-854746-2 |pages=22–23}}</ref>
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.
<gallery mode = packed heights = 180px> Brandgans - Steigflug (51956054436).jpg|Male in flight Common shelduck (Tadorna tadorna) female in flight Sfax.jpg|Female in flight </gallery>
==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.<ref name="BWP"/><ref name="EBBA2">{{cite book |title=European Breeding Bird Atlas |publisher=Lynx Edicions |publication-place=Barcelona |date=2020 |isbn=978-84-16728-38-1 |pages=138–139}}</ref> 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.<ref name="BWP"/><ref name="EBBA2"/> Breeding has also expanded south, with extensive colonisation of the Iberian Peninsula, where it formerly only wintered.<ref name="BWP"/><ref name="EBBA2"/> Much of the increase is thought to be related to improved protection from hunting,<ref name="BWP"/><ref name="EBBA2"/> but also increased eutrophication of estuaries and wetlands increasing the availability of food.<ref name="EBBA2"/> In northwest Africa, breeding is restricted to Tunisia, but it is more widespread in winter west to Morocco.<ref name="BWP"/><ref name="Svensson"/>
Asian populations migrate to subtropical areas in winter, south to northern India and southern China, but this species is largely resident in Europe, apart Scandinavian and some eastern European populations which migrate southwest, and from movements to favoured late summer moulting grounds, such as the Wadden Sea on the north German coast.<ref name="Svensson"/>
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.
Vagrants have been recorded in Barbados,<ref>{{Cite web |date=2013-11-18 |title=ML69184861 - Common Shelduck - Macaulay Library |url=https://macaulaylibrary.org/asset/69184861 |access-date=2025-03-10 |website=macaulaylibrary.org}}</ref> and Newfoundland in Canada.<ref>{{cite journal |last1=Chesser |first1=R. Terry |last2=Burns |first2=Kevin J. |last3=Cicero |first3=Carla |last4=Dunn |first4=Jon L. |last5=Kratter |first5=Andrew W. |last6=Lovette |first6=Irby J. |last7=Rasmussen |first7=Pamela C. |last8=Remsen |first8=J. V. |last9=Stotz |first9=Douglas F. |last10=Winger |first10=Benjamin M. |last11=Winker |first11=Kevin |title=Fifty-ninth Supplement to the American Ornithological Society's Check-list of North American Birds |journal=The Auk |volume=135 |issue=3 |date=2018 |issn=0004-8038 |doi=10.1642/AUK-18-62.1 |page=801 |url=https://academic.oup.com/auk/article/135/3/798-813/5148958 |access-date=2026-05-09}}</ref>
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).{{citation needed|date=May 2026}}
===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.<ref>{{cite book |last=Sibley |first=David |title=The North American Bird Guide |publisher=Christopher Helm Publishers, Incorporated |date=2000 |isbn=1-873403-98-4 |page=89}}</ref> In South America, a record of the species exists in Colombia but is excluded from the national list.<ref>{{Cite journal |last=de Schauensee |first=Rodolphe Meyer |date=1959 |title=Additions to the "Birds of the Republic of Colombia" |url=https://www.jstor.org/stable/4064506 |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=111 |pages=53–75 |jstor=4064506 |issn=0097-3157}}</ref>
==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.<ref name="BWP"/>
This species is mainly associated with estuaries and tidal mudflats, but increasingly also in freshwater lakes and rivers in open country inland, breeding in rabbit burrows, tree holes, haystacks or similar. In winter it is more confined to estuaries and tidal mudflats.<ref name="BWP"/>
Like geese and swans but unlike most ducks, both parents protect the ducklings and lead them to good feeding areas, which can be up to 3 km from the nest site; only the female broods the young though.<ref name="BWP"/> The young will dive under water to avoid predators and the adults will fly away from them to act as a decoy.
Shelduck typically breed for the first time when 2 years old; the maximum recorded age is just short of 20 years.<ref name="BTO">{{cite web |title=Shelduck |website=BTO |url=https://www.bto.org/learn/about-birds/birdfacts/shelduck |access-date=2026-05-09}}</ref>
This bird is one of the species to which the ''Agreement on the Conservation of African-Eurasian Migratory Waterbirds'' (AEWA) applies.
<gallery> 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 </gallery>
==References== {{Reflist|refs= <ref name=Kear2>{{cite book|last=Kear|first=Janet|title=Ducks, Geese, and Swans|publisher=Oxford University Press|year=2005|page=420|url=https://books.google.com/books?id=MfrdBcKd79wC&q=crested+shelduck&pg=RA1-PA439|isbn=0-19-861008-4}}</ref> }}
==External links== {{Commons category|Tadorna tadorna}} {{Wikispecies|Tadorna tadorna}} *[http://www.rspb.org.uk/birds/guide/s/shelduck/index.asp RSPB Birds by Name] *[https://web.archive.org/web/20161108183510/http://aulaenred.ibercaja.es/wp-content/uploads/71_ShelduckTtadorna.pdf Ageing and sexing (PDF; 1.2 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze] *{{BirdLife|22680024|Tadorna tadorna}} *{{IUCN_Map|22680024/166197940|Tadorna tadorna}} *{{Xeno-canto species|Tadorna|tadorna|Common shelduck}}
{{Taxonbar|from=Q25761}} {{Authority control}}
Category:Tadorna Category:Birds of Asia Category:Birds of Europe Common shelduck Common shelduck