Wigeon

The wigeons or widgeons are dabbling ducks in the genus Mareca, which also includes the Gadwall and Falcated Duck.

The species now placed in this genus were formerly placed in the genus Anas. A molecular phylogentic study comparing mitochondrial DNA sequences published in 2009 found that the genus Anas, as then defined, was non-monophyletic. Based on the published phylogeny, the genus Anas was split into four monophyletic genera with five extant species moved into the resurrected genus Mareca.

The genus Mareca was introduced by the English naturalist James Francis Stephens in 1824. The type species is the Eurasian Wigeon. The name of the genus is from the Brazilian-Portuguese word Marréco for a small duck.

Biology
There are five extant species: the Eurasian Wigeon (Anas penelope), the American Wigeon (A. americana), the Chiloé Wigeon (A. sibilatrix), the Falcated Duck (A. falcata) and the Gadwall (A. strepera). A sixth species, the Amsterdam Wigeon (Anas marecula), became extinct in the 19th century. The wigeons are closely related to the Gadwall and the Falcated Duck.

All three wigeons are similarly shaped, with a steep forehead and bulbous rear to the head. Males have a distinctive breeding plumage, in their eclipse plumage they resemble females, which are similar in appearance year-round. The three species' closest relatives within the genus Anas are the gadwall and the falcated duck. All three wigeon species hybridise in captivity while American and Eurasian wigeons hybridise in the wild. An American Wigeon × Mallard hybrid has also been recorded.

The American Wigeon was formerly called the baldpate by ornithologists, and some people still use that name.

The diet of the wigeon consists mainly of grass leaves (~80%), other food types eaten are seeds (~10%) and roots and stems (~5%).

Phylogeny
Cladogram based on the analysis of Gonzalez and colleagues published in 2009.