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}} Two species of chough constitute the genus ''Pyrrhocorax'' of the Corvidae (crow) family of birds. These are the red-billed chough (''Pyrrhocorax pyrrhocorax''), and the Alpine or yellow-billed chough (''P. graculus''). The white-winged chough of Australia, despite its name, is a member of the family Corcoracidae and only distantly related. The choughs have black plumage and brightly coloured legs, feet, and bills, and are resident in the mountains of southern Eurasia and North Africa. They have long broad wings and perform spectacular aerobatics. Both species pair for life and display fidelity to their breeding sites, which are usually caves or crevices in a cliff face. They build a lined stick nest and lay three to five eggs. They feed, usually in flocks, on short grazed grassland, taking mainly invertebrate prey, supplemented by vegetable material or food from human habitation, especially in winter. Changes in agricultural practices, which have led to local population declines and range fragmentation, are the main threats to this genus, although neither species is threatened globally. ==Taxonomy== The first member of the genus to be described was the red-billed chough, named as ''Upupa pyrrhocorax'' by Linnaeus in his ''Systema Naturae'' in 1758. His genus ''Upupa'' contained species that had a long curved bill and a short blunt tongue. These included the northern bald ibis and the hoopoe, birds now known to be completely unrelated to the choughs.〔 (‘Beak curved, convex, slight compressed. Tongue blunt, very full, triangular and very brief.’)〕 The Alpine chough was described as ''Corvus graculus'' by Linnaeus in the 1766 edition of the ''Systema Naturae''. Although ''Corvus'' is the crow genus to which the choughs' relatives belong, they were considered sufficiently distinctive to be moved to the new genus, ''Pyrrhocorax'', by English ornithologist Marmaduke Tunstall in his 1771 ''Ornithologia Britannica'', The genus name is derived from Ancient Greek ''purrhos'' (, ‘flame-coloured’) and ''korax'' (, ‘Raven, crow’). "Chough" was originally an alternative onomatopoeic name for the jackdaw, ''Corvus monedula'', based on its call. The similar red-billed chough, formerly particularly common in Cornwall, became known initially as "Cornish chough" and then just "chough", the name transferring from one species to the other.〔 406–8〕 The fossil record from the Pleistocene of Europe includes a form similar to the Alpine chough, and sometimes categorised as an extinct subspecies of that bird,〔(Hungarian with English abstract) Válóczi, Tibor (1999) "(Vaskapu-barlang (Bükk-hegység) felső pleisztocén faunájának vizsgálata (Investigation of the Upper-Pleistocene fauna of Vaskapu-Cave (Bükk-mountain)) ). ''Folia Historico Naturalia Musei Matraensis'' 23: 79–96 (PDF)〕〔Mlíkovský, Jirí (2002) (''Cenozoic Birds of the World )'' (Part 1: Europe) Ninox Press, Prague. (PDF)〕 and a prehistoric form of the red-billed chough, ''P. p. primigenius''. There are eight generally recognised extant subspecies of red-billed chough, and two of Alpine, although all differ only slightly from the nominate forms.〔 The greater subspecies diversity in the red-billed species arises from an early divergence of the Asian and geographically isolated Ethiopian races from the western forms. The closest relative of the choughs as indicated by a study of molecular phylogeny is the ratchet-tailed treepie (''Temnurus temnurus'') and they form a clade that is sister to the remaining living members of the corvidae. The genus ''Pyrrhocorax'' species differ from ''Corvus'' in that they have brightly coloured bills and feet, smooth, not scaled tarsi and very short, dense nasal feathers. Choughs have uniformly black plumage, lacking any paler areas as seen in some of their relatives.〔 The two ''Pyrrhocorax'' are the main hosts of two specialist chough fleas, ''Frontopsylla frontalis'' and ''F. laetus'', not normally found on other corvids. The Australian white-winged chough, ''Corcorax melanorhamphos'', despite its similar shape and habits, is only distantly related to the true choughs, and is an example of convergent evolution.〔(【引用サイトリンク】url= http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=557570 )〕 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「chough」の詳細全文を読む スポンサード リンク
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