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The steamer ducks are a genus (''Tachyeres'') of ducks in the family Anatidae. All of the four species occur at the southern cone of South America in Chile and Argentina, and all except the flying steamer duck are flightless; even this one species capable of flight rarely takes to the air. The genus name ''Tachyeres'', "having fast oars" or "fast rower", comes from Ancient Greek ταχυ- "fast" + ἐρέσσω "I row (as with oars)". The common name "steamer ducks" arose because, when swimming fast, they flap their wings into the water as well as using their feet, creating an effect like a paddle steamer. They can be aggressive and are capable of chasing off predators like petrels. They are usually placed in the shelduck subfamily Tadorninae. However, mtDNA sequence analyses of the cytochrome ''b'' and NADH dehydrogenase subunit 2 genes indicate that ''Tachyeres'' rather belongs in a distinct clade of aberrant South American dabbling ducks, which also includes the Brazilian, the crested, and the bronze-winged ducks. There are four species:〔 *Flying steamer duck (''Tachyeres patachonicus'') *Fuegian steamer duck (''Tachyeres pteneres'') *Chubut steamer duck (''Tachyeres leucocephalus'') *Falkland steamer duck (''Tachyeres brachypterus'') The Chubut steamer duck was only described in 1981.〔 == 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「steamer duck」の詳細全文を読む スポンサード リンク
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