Anas sibilatrix , Photo: Duncan Wright (*)
Anas sibilatrix Poeppig, 1829
* Notizen[Froriep] 25 col.10
The Chilöe Wigeon (Anas sibilatrix) is one of three species of wigeon in the dabbling duck genus Anas. Unlike other wigeons, the sexes are similar (though the male is often slightly brighter) and pairs are monogamous. This bird has a metallic green head, and a gray bill with a black tip. Its breast is barred black and white and its sides are orange brown. It has white cheeks and a white forehead and also white on its wings. Its length is approximately 18 inches.
The female will lay between 6 and 10 eggs. This duck is unusual in the sense that the male will help raise the young.
This duck is found in southern South America, on freshwater lakes, marshes, lagoons and slow flowing rivers. It breeds on the Falkland Islands, Argentina, Uruguay, and Chile. It migrates to southeastern Brazil for the winters. It is an omnivore.
The conservation status of this wigeon is Least Concern.
Chilöe Widgeons reach a body length between 17 and 21 inches. Their wing length measures 9.25 to 9.75 inches and a weight of 1.75 to 2 pounds. Males are usually somewhat larger and heavier. Otherwise sexual dimorphism is relatively subtle.
Chilöe Widgeons have a black neck and back of the head. The forehead and the front face are white. The black sides of the head gleam greenish, somewhat more strongly pronounced with males. The flanks of males are rust red colored, and light-brown on females. The back plumage is gray with white pulled through. The chest is white with a black transverse waving. Due to the variability in width of the plumage coloring, however, no clear sexing can be made on the basis of the plumage.
The bill is bluish gray with a black bill point. The legs and feet are gray and the eyes are dark-brown. Young birds resemble adult birds, but the red-brown coloring on the flanks is either completely missing or is smaller than the adults.
Chilöe Widgeons are resident to South America. The norther border of the breeding range is in Argentina at 36° S and Chile at 40° S. They will also breed sparingly in the Falkland Islands. Stray members may also occasionally reach southern Georgia[disambiguation needed], Orkney and Shetland Islands.
Chilöe Widgeons display a variety of behaviors depending on their habitat. Prototypical ducks find themselves flying from the southernmost point of South America to as far north as Brazil during winter.
The IUCN estimates the present population to be around 500,000 adult individuals and determines their numbers are stable in the very large occupancy zone.
Chilöe Widgeons live in river valleys and small artificial lakes and in flat lagoons near lakes of Pampa. Chilöe Widgeons live predominantly on vegetables. In addition, they eat aquatic plants and grass. Occasionally they are seen eating algae on the coast.
Chilöe Widgeons breed between September and December when it's spring in the southern hemisphere. The pairs always inhabit very small breeding territories and put their nests in grasses and under bushes. The female will lay eight to ten white or light-creme eggs. After a gestation period of approximately 24 to 25 days the ducklings are born. The father helps raise the ducklings, however, he leaves the family once they molt and grow new feathers.
The first Chilöe Widgeons were domesticated in 1870 and 1871 and sent from South America to Europe and bred very soon in the zoos. Today Chilöe Widgeons are very wide-spread due to their attractive plumage coloring.
* Hartmut Kolbe; The Ducks of the World, Ulmer Verlag 1999, ISBN 3-8001-7442-1
* BirdLife International (2009). "Anas sibilatrix". IUCN Red List of Threatened Species. Version 2010.4. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/141500.
1. ^ a b IUCN (2009)
* Clements, James, (2007) The Clements Checklist of the Birds of the World, Cornell University Press, Ithaca
Source: Wikipedia, Wikispecies: All text is available under the terms of the GNU Free Documentation License