Taxonomy

This species was first described by Linnaeus in his Systema naturae in 1758 as Anas acuta[3] 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.[4]
Within the large dabbling duck genus Anas,[3] 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.[5][6][7] The famous British ornithologist Sir Peter Scott gave this name to his daughter, the artist Dafila Scott.[8]
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.[9]