The yellow-billed pintail (''Anas georgica'') is a

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

n dabbling duck of the genus ''Anas'' with three described subspecies.

Taxonomy

The yellow-billed pintail was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

's '' Systema Naturae''. He placed it with all the ducks, geese and swans in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Anas ''Anas'' is a genus of dabbling ducks. It includes the pintails, most teals, and the mallard and its close relatives. It formerly included additional species but following the publication of a molecular phylogenetic study in 2009 the genus was s ...

'' and coined the binomial name ''Anas georgica''. Gmelin based his description on the "Georgia duck" that had been described in 1785 by the English ornithologist John Latham in his ''A General Synopsis of Birds''. The naturalist Joseph Banks had provided Latham with a water-colour drawing of the duck by

Georg Forster Johann George Adam Forster, also known as Georg Forster (, 27 November 1754 – 10 January 1794), was a German naturalist, ethnologist, travel writer, journalist and revolutionary. At an early age, he accompanied his father, Johann Reinhold ...

who had accompanied James Cook on his second voyage to the Pacific Ocean. The watercolour was painted in 1775 on South Georgia. This picture is now the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

for the species and is held by the

Natural History Museum A natural history museum or museum of natural history is a scientific institution with natural history collections that include current and historical records of animals, plants, fungi, ecosystems, geology, paleontology, climatology, and more. ...

in London. The genus name ''Anas'' is the Latin word for a duck. Three subspecies are recognised: *† ''A. g. niceforoi'' Wetmore & Borrero, 1946 – east-central Colombia (extinct) * ''A. g. spinicauda''

Vieillot Louis Pierre Vieillot (10 May 1748, Yvetot – 24 August 1830, Sotteville-lès-Rouen) was a French ornithologist. Vieillot is the author of the first scientific descriptions and Linnaean names of a number of birds, including species he collect ...

, 1816 – south Colombia to south Argentina, south Chile and

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...

* ''A. g. georgica'' Gmelin, JF, 1789 – South Georgia

Description

The yellow-billed pintail has a brown head and neck. The bill is yellow with a black tip and a black stripe down the middle. The tail is brownish and pointed. The upper wing is grayish-brown, and the secondaries are blackish-green. The rest of the body is buffish brown with varying size black spots. The species is sometimes confused with

yellow-billed teal The yellow-billed teal (''Anas flavirostris'') is a South American species of duck. Like other teals, it belongs to the diverse genus ''Anas''; more precisely it is one of the "true" teals of subgenus ''Nettion''. It occurs in Argentina, the Fa ...

(''Anas flavirostris''), but can be differentiated by the yellow stripes on its bill, its larger size and its tendency not to form large groups. The nominate subspecies is smaller and darker than ''Anas g. spinicauda''. The yellow-billed pintail forms a superspecies with the northern pintail (''Anas acuta'').

Distribution and habitat

The range includes much of South America, the

and South Georgia. The nominate and smallest subspecies, the South Georgia pintail ''A. g. georgica'', is thought to number between 1000 and 1500 pairs, and is found only in South Georgia. The Chilean, or brown, pintail ''A. g. spinicauda'' is widespread on the South American mainland from extreme southern Colombia southwards, as well as in the

, and numbers well over 110,000. Niceforo's pintail ''A. g. niceforoi'', formerly found in central Colombia, is believed to be extinct, having been last recorded in 1952 (and described only in 1946). Their habitat ranges from high elevation lakes and marshes to low elevation lakes and rivers and coasts in open country.

Breeding

The nest is placed on the ground in vegetation close to water. It is lined with grass and down. The clutch is 4 to 10 eggs which hatch after incubation for around 26 days. The chicks have dark brown down above and yellow down below.

Physiology

In high altitude populations of yellow-billed pintail, hemoglobin has a higher affinity for oxygen than in lower altitude populations, which can be attributable to substitutions in their beta-globin gene. These substitutions are shared by speckled teal because of

introgressive hybridization Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Intr ...

between the two species. Gene flow between populations also suggests that yellow-billed pintails that are heterozygous for the βA

hemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyt ...

subunit may be able to acclimate to high altitudes more efficiently than those that are homozygous for the βA hemoglobin subunit.

Gallery

Anas georgica -Puerto Natales, Patagonia, Chile-8 (1).jpg Image:Yellow-billed Pintail RWD2.jpg

References

{{Taxonbar, from=Q598302

yellow-billed pintail The yellow-billed pintail (''Anas georgica'') is a South American dabbling duck of the genus ''Anas'' with three described subspecies. Taxonomy The yellow-billed pintail was formally described in 1789 by the German naturalist Johann Friedric ...

Birds of South America Birds of the Falkland Islands Birds of islands of the Atlantic Ocean Birds of subantarctic islands