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The New World vulture or condor family Cathartidae contains seven species in five genera, all but one of which are monotypic. It includes five vultures and two condors found in warm and temperate areas of the Americas. The "New World" vultures were widespread in both the Old World and North America during the Neogene. New World vultures do not form a monophyletic clade with the superficially similar family of Old World vultures, but similarities between the two groups are due to convergent evolution. Many now consider them to be in their own order Cathartiformes, closely related to, but distinct from, Old World vultures and allies (Accipitriformes). Vultures are scavenging birds, feeding mostly from carcasses of dead animals without apparent ill effects. Bacteria in the food source, pathogenic to other vertebrates, dominate the vulture’s gut flora, and vultures benefit from the bacterial breakdown of carrion tissue. New World vultures have a good sense of smell, whereas Old World vultures find carcasses exclusively by sight. A particular characteristic of many vultures is a bald head, devoid of feathers. ==Taxonomy and systematics== The New World vultures comprise seven species in five genera. The genera are ''Coragyps'', ''Cathartes'', ''Gymnogyps'', ''Sarcoramphus'', and ''Vultur''. Of these, only ''Cathartes'' is not monotypic.〔Myers (2008)〕 The family's scientific name, Cathartidae, comes from ''cathartes'', Greek for "purifier".〔Brookes (2006)〕 Although New World vultures have many resemblances to Old World vultures they are not very closely related. Rather, they resemble Old World vultures because of convergent evolution.〔Phillips (2000)〕 New World vultures were traditionally placed in a family of their own in the Falconiformes.〔Sibley and Ahlquist (1991)〕 However, in the late 20th century some ornithologists argued that they are more closely related to storks on the basis of karyotype,〔de Boer (1975)〕 morphological,〔Ligon (1967)〕 and behavioral〔König (1982)〕 data. Thus some authorities placed them in the Ciconiiformes with storks and herons; Sibley and Monroe (1990) even considered them a subfamily of the storks. This was criticized,〔Griffiths (1994)〕〔Fain & Houde (2004)〕 and an early DNA sequence study〔Avise (1994)〕 was based on erroneous data and subsequently retracted.〔Brown (2009)〕〔Cracraft ''et al.'' (2004)〕〔Gibb ''et al.'' (2007)〕 There was then an attempt to raise the New World vultures to the rank of an independent order, Cathartiformes not closely associated with either the birds of prey or the storks and herons.〔Ericson ''et al.'' (2006)〕 However, recent multi-locus DNA studies on the evolutionary relationships between bird groups〔〔Hackett ''et al.'' (2008)〕 indicate that New World vultures are related to the other birds of prey, excluding the Falconidae which are distantly related to other raptors, and are not close to storks. In this analysis, the New World vultures should be part of a new order Accipitriformes instead,〔 or perhaps as part of an order (Cathartiformes) closely related to, but distinct from, other birds of prey (besides falcons).〔 New World vultures are a sister group to Accipitriformes〔 when the latter is viewed as a group consisting of Accipitridae, the osprey and secretarybird. Both groups are basal members of the recently recognized clade Afroaves.〔 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「New World vulture」の詳細全文を読む スポンサード リンク
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