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The Asian black bear (''Ursus thibetanus'', previously known as ''Selenarctos thibetanus'') is also known as moon bear and white-chested bear. It is a medium-sized bear species and largely adapted to arboreal life.〔〔 It lives in the Himalayas, in the northern parts of the Indian subcontinent, Korea, northeastern China, the Russian Far East, the Honshū and Shikoku islands of Japan, and Taiwan. It is classified as vulnerable by the IUCN, mostly because of deforestation and hunting for its body parts. The species is morphologically very similar to some prehistoric bears, and is thought by some scientists to be the ancestor of other extant bear species (aside from pandas and spectacled bears).〔 Though largely herbivorous, Asian black bears can be very aggressive toward humans, who frequently trap or kill them for traditional medicine.〔 ==Characteristics== Asian black bears are black and have a light brown muzzle. They are white on the chin, and have a distinct white patch on the chest, which sometimes has the shape of a V. Their ears are bell shaped, proportionately longer than those of other bears, and stick out sideways from the head. The tail is long.〔Brown, G. (1993). ''Bear Anatomy and Physiology'' from ''The Great Bear Almanac'', Lyons & Burford, Publishers.〕 Adults measure at the shoulder, and in length. Adult males weigh with an average weight of about . Adult females weigh , and large ones up to .〔 Asian black bears are similar in general appearance to brown bears, but are more lightly built and are more slender limbed. The lips and nose are larger and more mobile than those of brown bears. The skulls of Asian black bears are relatively small, but massive, particularly in the lower jaw. Adult males have skulls measuring in length and in width, while female skulls are long and wide. Compared to other bears of the genus ''Ursus'', the projections of the skull are weakly developed; the sagittal crest is low and short, even in old specimens, and does not exceed more than 19–20% of the total length of the skull, unlike in brown bears, which have sagittal crests comprising up to 41% of the skull's length.〔Heptner, V. G. & Naumov, N. P. (1998). (White-chested, black bear ). Pages 713–733 in: ''Mammals of the Soviet Union'' Vol. II Part 1a, Sirenia and Carnivora (Sea cows; Wolves and Bears). Washington, D.C. : Smithsonian Institution Libraries and National Science Foundation.〕 Although mostly herbivorous, the jaw structure of Asian black bears is not as specialised for plant eating as that of pandas: Asian black bears have much narrower zygomatic arches, and the weight ratio of the two pterygoid muscles is also much smaller in Asian black bears. The lateral slips of the temporal muscles are thicker and stronger in black bears.〔Endo, H., Taru, H., Yamamoto, M., Arishima, K., & Sasaki, M. (2003). Comparative morphology of the muscles of mastication in the giant panda and the Asiatic black bear. Annals of Anatomy. Anatomischer Anzeiger 185 (3): 287–292.〕 A black bear with broken hind legs can still climb effectively. In contrast to polar bears, Asian black bears have powerful upper bodies for climbing trees, and relatively weak hind legs. which are shorter than those in brown bears and American black bears.〔〔 They are the most bipedal of all bears, and have been known to walk upright for over a quarter mile.〔(Asiatic Black Bear ''Ursus thibetanus'', Denver Zoo ). (PDF). Retrieved on 2011-09-26.〕 The heel pads on the forefeet are larger than those of most other bear species. Their claws, which are primarily used for climbing and digging, are slightly longer on the fore foot (30–45 mm) than the back (18–36 mm),〔 and are larger and more hooked than those of the American black bear.〔''The Dublin penny journal'' 1835〕 On average, adult Asian black bears are slightly smaller than American black bears, though large males can exceed the size of several other bear species.〔Knight, C. (2008). (The Moon Bear as a symbol of ''Yama'': Its significance in the folklore and upland hunting in Japan. ). Asian Ethnology 67 (1): 79–101.〕 The famed British sportsman known as the "Old Shekarry" wrote of how a black bear he shot in India probably weighed no less than based on how many people it took to lift its body. The largest Asian black bear on record allegedly weighed .〔 Zoo-kept specimens can weigh up to .〔(Bear Species @ Great Bear Foundation ). Greatbear.org. Retrieved on 2011-09-26.〕 Although their senses are more acute than those of brown bears,〔 their eyesight is poor, and their powers of hearing moderate, the upper limit being 30 kHz.〔 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「Asian black bear」の詳細全文を読む スポンサード リンク
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