The Andean gull (''Chroicocephalus serranus'') is a species of

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...

in the family

Laridae Laridae is a family of seabirds in the order Charadriiformes that includes the gulls, terns, skimmers and kittiwakes. It includes around 100 species arranged into 22 genera. They are an adaptable group of mostly aerial birds found worldwide. ...

. As is the case with many gulls, it has traditionally been placed 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 ...

Larus ''Larus'' is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls ...

''. It is found in the Andes in mountainous regions of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, Bolivia,

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, Colombia,

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ' ...

, and

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

. It is unusual for a gull in that it breeds inland in mountain areas. It may be variously found around

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of w ...

s, freshwater

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s, saline

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

es, and pastureland.

Description

At long, the Andean gull is large for a black-headed gull (it is the largest gull with that kind of plumage in the Americas). It is the largest species in the genus ''

Chroicocephalus ''Chroicocephalus'' is a genus of medium to relatively small gulls which were included in the genus '' Larus'' until recently. Some authorities also include the Saunders's gull in ''Chroicocephalus''. The genus name '' Chroicocephalus'' is from ...

'' and has a dark hood, a pale grey back and a pattern of black and white on its primaries.

Distribution and habitat

The Andean gull is known from Chile, Peru, Argentina, Bolivia, Ecuador and Colombia where it breeds in mountainous areas, usually at elevations of over . In areas with harsh winters it migrates to lower elevations in winter, sometimes as far as the coast. Flocks of these gulls are common on the coast in southern Peru and northern Chile, but It has yet to be established where these particular birds breed. In the wetlands of the

Altiplano The Altiplano (Spanish for "high plain"), Collao (Quechua and Aymara: Qullaw, meaning "place of the Qulla") or Andean Plateau, in west-central South America, is the most extensive high plateau on Earth outside Tibet. The plateau is located at the ...

it is resident and breeds at while in southern Argentina it may breed at as little as but this is in similar habitats to the birds further north. The Andean Gull nests in small scattered colonies, sometimes even as solitary pairs, in small, isolated ponds. Unusually for a gull of this size, it becomes sexually mature at the age of two years rather than three. It feeds on a variety of prey items, including

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s and

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wo ...

s taken on fields and grasslands; it also sometimes catches aerial insects and eats some garbage when available.

Gallery

Image:Andean Gull RWD4.jpg, Nonbreeding plumage, Peru Image:Andean Gull 01.jpg, Breeding plumage Image:Andean Gull.jpg, Gulls in Southern Bolivia

References

* "The Birds of Ecuador" by Robert S. Ridgely & Paul Greenfield. Cornell University Press (2001), . * {{Taxonbar, from=Q490439 Andean gull Birds of the Andes Andean gull Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN Taxa named by Johann Jakob von Tschudi