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