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The pintail or northern pintail (''Anas acuta'') is a duck with wide geographic distribution that breeds in the northern areas of Europe, Asia and North America. It is migratory and winters south of its breeding range to the equator. Unusually for a bird with such a large range, it has no geographical subspecies if the possibly conspecific duck Eaton's pintail is considered to be a separate species. This is a large duck, and the male's long central tail feathers give rise to the species' English and scientific names. Both sexes have blue-grey bills and grey legs and feet. The drake is more striking, having a thin white stripe running from the back of its chocolate-coloured head down its neck to its mostly white undercarriage. The drake also has attractive grey, brown, and black patterning on its back and sides. The hen's plumage is more subtle and subdued, with drab brown feathers similar to those of other female dabbling ducks. Hens make a coarse quack and the drakes a flute-like whistle. The northern pintail is a bird of open wetlands which nests on the ground, often some distance from water. It feeds by dabbling for plant food and adds small invertebrates to its diet during the nesting season. It is highly gregarious when not breeding, forming large mixed flocks with other species of duck. This duck's population is affected by predators, parasites and avian diseases. Human activities, such as agriculture, hunting and fishing, have also had a significant impact on numbers. Nevertheless, owed to the huge range and large population of this species, it is not threatened globally. ==Taxonomy== This species was first described by Linnaeus in his ''Systema naturae'' in 1758 as ''Anas acuta''.〔 The scientific name comes from two Latin words: ''anas'', meaning "duck", and ''acuta'', which comes from the verb ''acuere'', which means "sharpen"; the species term, like the English name, refers to the pointed tail of the male in breeding plumage.〔 Within the large dabbling duck genus ''Anas'',〔 the northern pintail's closest relatives are other pintails, such as the yellow-billed pintail (''A. georgica'') and Eaton's pintail (''A. eatoni''). The pintails are sometimes separated in the genus ''Dafila'' (described by Stephens, 1824), an arrangement supported by morphological, molecular and behavioural data.〔〔〔 The famous British ornithologist Sir Peter Scott gave this name to his daughter, the artist Dafila Scott.〔 Eaton's pintail has two subspecies, ''A. e. eatoni'' (the Kerguelen pintail) of Kerguelen Islands, and ''A. e. drygalskyi'' (the Crozet pintail) of Crozet Islands, and was formerly considered conspecific with the northern hemisphere's northern pintail. Sexual dimorphism is much less marked in the southern pintails, with the male's breeding appearance being similar to the female plumage. Unusually for a species with such a large range, northern pintail has no geographical subspecies if Eaton's pintail is treated as a separate species.〔 A claimed extinct subspecies from Manra Island, Tristram's pintail, ''A. a. modesta'', appears to be indistinguishable from the nominate form.〔 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「northern pintail」の詳細全文を読む スポンサード リンク
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