ヒドリガモ
There are three extant species: the Eurasian wigeon ("Mareca penelope"), the American wigeon ("M. americana") and the Chiloé wigeon ("M. sibilatrix"). A fourth species, the Amsterdam wigeon ("Mareca marecula"), became extinct in the 19th century. The wigeons' closest relatives, forming with them the genus "Mareca", are the gadwall and the falcated duck.