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''Nycticebus kayan'' is a strepsirrhine primate and a species of slow loris that is native to the northern and central highland region of the island of Borneo. The species was originally thought to be a part of the Bornean slow loris (''N. menagensis'') population until 2013, when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it. It is distinguished by the high contrast of its black and white facial features, as well as the shape and width of the stripes of its facial markings. The species is named after the Kayan River, which runs through its native habitat. As with other slow lorises, this arboreal and nocturnal species primarily eats insects, tree gum, nectar, and fruit and has a toxic bite, a unique feature among primates. Although not yet evaluated by the International Union for Conservation of Nature (IUCN), it is likely to be listed as "Vulnerable" or placed in a higher-risk category when its conservation status is assessed. It is primarily threatened by habitat loss and the illegal wildlife trade. ==Taxonomy and phylogeny== ''N. kayan'' is a strepsirrhine primate, and species of slow loris (genus ''Nycticebus'') within the family Lorisidae. Museum specimens of this animal had previously been identified as the Bornean slow loris (''Nycticebus menagensis''), first described by the English naturalist Richard Lydekker in 1893 as ''Lemur menagensis''. In 1953, all of the slow lorises were lumped together into a single species, the Sunda slow loris (''Nycticebus coucang''). In 1971, that view was refined by distinguishing the pygmy slow loris (''N. pygmaeus'') as a species, and by further identifying four subspecies, including ''N. coucang menagensis'', the Bornean slow loris. The Bornean slow loris was elevated to the species level (as ''N. menagensis'') in 2006, when molecular analysis showed it to be genetically distinct from ''N. coucang''. A 2013 review of museum specimens and photographs attributed to ''N. menagensis'' resulted in elevating two of its former subspecies to the species ''N. bancanus'' and ''N. borneanus''. Additionally, ''N. kayan'' was recognized as a new species, distinct from the nominate subspecies, ''N. menagensis''. All newly recognized or elevated species showed significant differences in their "facemask"—the coloration patterns on their face. Analysis of the facemask patterns suggests that ''N. kayan'' diverged from ''N. menagensis'' and ''N. borneanus'' through sympatric speciation (divergent evolution of organisms living in the same geographic region), while geographic barriers may account for its divergence with ''N. bancanus'' (allopatric speciation). ''N. kayan'' is named after the Kayan River, which runs through its native habitat and near Peleben, the type locality of the original specimen. The holotype, AMNH 106012, was originally collected on 8 October 1935 by Baron V. von Plessen near Peleben in the province of East Kalimantan in Borneo and is housed in the American Museum of Natural History in New York. It consists of a male skin and skull, with a head-body length of . 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「Nycticebus kayan」の詳細全文を読む スポンサード リンク
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