Common Shelduck
Encyclopedia
The Common Shelduck is a waterfowl
Waterfowl
Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....

 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 shelduck genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Tadorna
Shelduck
The shelducks, genus Tadorna, are a group of large birds in the Tadorninae subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans....

. It is widespread and common in Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

, mainly breeding in temperate and wintering in subtropical regions; in winter, it can also be found in the Maghreb
Maghreb
The Maghreb is the region of Northwest Africa, west of Egypt. It includes five countries: Morocco, Algeria, Tunisia, Libya, and Mauritania and the disputed territory of Western Sahara...

. Its scientific name comes from Celtic roots and means "pied waterfowl", essentially the same as the English
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

 "shelduck".

Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 bones from Dorkovo
Dorkovo
Dorkovo is a village in the Rakitovo municipality, Pazardzhik Province, western Bulgaria. The population of the village is 2,955.-Geography:Dorkovo is situated in the western Rhodope Mountains on the two banks of the river Matnitsa in the north-eastern parts of the Chepino Valley...

 (Bulgaria
Bulgaria
Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...

) 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
Early Pleistocene
Calabrian is a subdivision of the Pleistocene Epoch of the Geologic time scale. ~1.8 Ma.—781,000 years ago ± 5,000 years, a period of ~.The end of the stage is defined by the last magnetic pole reversal and plunge in to an ice age and global drying possibly colder and drier than the late Miocene ...

).

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 colored 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 colored, greyish above and mostly white below, but already have the adult's wing pattern.

The call is a loud honk.

Distribution and habitat

This is a bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 which breeds in temperate Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

. Most populations migrate
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...

 to subtropical areas in winter, but this species is largely resident in westernmost Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, apart from movements to favoured moulting grounds, such as the Wadden Sea
Wadden Sea
The Wadden Sea is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of Frisian Islands, forming a shallow body of water with tidal flats and wetlands. It is rich in biological diversity...

 on the north German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 coast.

The Common Shelduck is common around the coastline of Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 (where it is simply known as Shelduck), where it frequents salt marshes and estuaries. Sightings of this bird are rare in North America and are reported as infrequent visitors to the U.S. and Canada.

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
Breeding in the wild
Breeding in the wild is the natural process of animal reproduction occurring in the natural habitat of a given species. This terminology is distinct from animal husbandry or breeding of species in captivity...

 in rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...

 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
AEWA
The Agreement on the Conservation of African-Eurasian Migratory Waterbirds is the largest of its kind developed so far under the Bonn Convention. It was concluded on 16 June 1995 at The Hague, the Netherlands and entered into force on 1 November 1999 after the required number of at least fourteen...

) applies.

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

External links

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