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The pygmy geese are a group of very small "perching ducks" in the genus ''Nettapus'' which breed in the Old World tropics. They are the smallest of all wildfowl. As the "perching ducks" are a paraphyletic group,〔 〕 they need to be placed elsewhere. The initially assumed relationship with the dabbling duck subfamily Anatinae has been questioned, and it appears they form a lineage in an ancient Gondwanan radiation of waterfowl, within which they are of unclear affinities. An undescribed fossil species from the late Hemphillian (5.0–4.1 mya) of Jalisco, central Mexico, has also been identified from the distal end of a tarsometatarsus. It is only record of the genus in the New World. There are three extant species in the genus: * Green pygmy goose (''Nettapus pulchellus'') of northern Australia and southern New Guinea * Cotton pygmy goose (''Nettapus coromandelianus'') of Southeast Asia * African pygmy goose (''Nettapus auritus'') of Sub-Saharan Africa Their habitat is still freshwater lakes, where these neat ducks feed on seeds and other vegetation, especially water lilies. Pygmy geese have short bills, rounded heads and short legs. They nest in tree holes. ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「pygmy goose」の詳細全文を読む スポンサード リンク
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