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The siamang (''Symphalangus syndactylus'') is an arboreal black-furred gibbon native to the forests of Malaysia, Thailand, and Sumatra. The largest of the gibbons, the siamang can be twice the size of other gibbons, reaching 1 m in height, and weighing up to 14 kg. The siamang is the only species in the genus ''Symphalangus''. The siamang is distinctive for two reasons. The first is that two digits on each foot are partially joined by a membrane—hence the name "syndactylus", from the Ancient Greek ''sun-'', "united" + ''daktulos'', "finger". The second is the large gular sac (found in both males and females of the species), which is a throat pouch that can be inflated to the size of the siamang's head, allowing the animal to make loud, resonating calls or songs. There may be two subspecies of the siamang. If so, they are the nominate Sumatran siamang (''S. s. syndactylus'') and the Malaysian siamang (''S. s. continentis'', in peninsular Malaysia). Otherwise, the Malaysian individuals are only a population. The siamang occurs sympatrically with other gibbons; its two ranges are entirely within the combined ranges of the agile gibbon and the lar gibbon. The siamang can live to around 40 years in captivity.〔Gron KJ. 2008 May 20. Primate Factsheets: Siamang (Symphalangus syndactylus) Taxonomy, Morphology, & Ecology . While the illegal pet trade takes a toll on wild populations, the principal threat to the siamang is habitat loss in both Malaysia and Sumatra. The palm oil production industry is clearing large swaths of forest, reducing the habitat of the siamang, along with that of other species, such as the Sumatran tiger. ==Ecology== The siamang inhabits the forest remnants of Sumatra Island and the Malay Peninsula, and is widely distributed from lowland forest to mountain forest—even rainforest—and can be found at altitudes of up to 3800 m.〔Rowe, Noel. (1996) "Pictorial Guide to the Living Primates" Charlestown, RI: Pagonia Press〕 The siamang lives in groups of up to six individuals (four individuals on average) with an average home range of 23 hectares.〔 Their day ranges are substantially smaller than those of sympatric ''Hylobates'' species, often less than 1 km.〔 The siamang's melodious singing breaks the forest's silence in the early morning after the agile gibbons' or lar gibbons' calls. The siamang in Sumatra and the Malay Peninsula are similar in appearance, but some behaviors differ between the two populations. 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「siamang」の詳細全文を読む スポンサード リンク
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