Ursus thibetanus Asian Black Bear

The Asian black bear (Ursus thibetanus), also known as the Asiatic black bear, moon bear and white-chested bear, is a medium-sized bear species native to Asia that is largely adapted to an arboreal lifestyle. It lives in the Himalayas, southeastern Iran, the northern parts of the Indian subcontinent, the Korean Peninsula, China, the Russian Far East, the islands of Honshū and Shikoku in Japan, and Taiwan. It is listed as vulnerable on the IUCN Red List, and is threatened by deforestation and poaching for its body parts, which are used in traditional medicine.

The Asian black bear has black fur, a light brown muzzle, and a distinct white patch on the chest, which is sometimes V-shaped. Its ears are bell shaped, proportionately longer than those of other bears, and stick out sideways from the head. Its tail is short, around 11 cm (4.3 in) long. Adults measure 70–100 cm (28–39 in) at the shoulder, and 120–190 cm (47–75 in) in length. Adult males weigh 60–200 kg (130–440 lb) with an average weight of about 135 kg (298 lb). Adult females weigh 40–125 kg (88–276 lb), and large ones up to 140 kg (310 lb).

Asian black bears are similar in general build to brown bears (Ursus arctos), 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 311.7 to 328 mm (12.27 to 12.91 in) in length and 199.5–228 mm (7.85–8.98 in) in width, while female skulls are 291.6–315 mm (11.48–12.40 in) long and 163–173 mm (6.4–6.8 in) 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.

Although mostly herbivorous, the jaw structure of Asian black bears is not as specialized for plant eating as that of giant 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 Asian black bears.

An Asian 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 of a mile. 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.

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.

Biologically and morphologically, Asian black bears represent the beginning of the arboreal specializations attained by sloth bears and sun bears. Asian black bears have karyotypes nearly identical to those of the five other ursine bears, and, as is typical in the genus, they have 74 chromosomes. From an evolutionary perspective, Asian black bears are the least changed of the Old World bears, with certain scientists arguing that it is likely that all other lineages of ursine bear stem from this species. Scientists have proposed that Asian black bears are either a surviving, albeit modified, form of Ursus etruscus, specifically the early, small variety of the Middle Villafranchian (Upper Pliocene to Lower Pleistocene)[16] or a larger form of Ursus minimus, an extinct species that arose 4,000,000 years ago. With the exception of the age of the bones, it is often difficult to distinguish the remains of Ursus minimus with those of modern Asian black bears.

Asian black bears are close relatives to American black bears, with which they share a European common ancestor; the two species are thought to have diverged 3,000,000 years ago, though genetic evidence is inconclusive. Both the American and Asian black species are considered sister taxa and are more closely related to each other than to the other species of bear. The earliest known specimens of Asian black bears are known from the Early Pliocene of Moldova. The earliest American black bear fossils, which were located in Port Kennedy, Pennsylvania, greatly resemble the Asian black species. The first mtDNA study undertaken on Asian black bears suggested that the species arose after the American black bears, while a second study could not statistically resolve the branching order of sloth bears and the two black species, suggesting that these three species underwent a rapid radiation event. A third study suggested that American black bears and Asian black bears diverged as sister taxa after the sloth bear lineage and before the sun bear lineage. Further investigations on the entire mitochondrial cytochrome b sequence indicate that the divergence of continental Asian and Japanese black bear populations might have occurred when bears crossed the land bridge between the Korean peninsula and Japan 500,000 years ago, which is consistent with paleontological evidence.

Fossil record indicate that the Asian black bear once ranged as far west as Western Europe, though it now occurs very patchily throughout its former range, which is limited to Asia. Today, it occurs from southeastern Iran eastward through Afghanistan and Pakistan, across the foothills of the Himalayas in India and Myanmar to mainland Southeast Asia, except Malaysia. Its range in northeastern and southern China is patchy, and it is absent in much of east-central China. Other population clusters exist in the southern Russian Far East and in North Korea. A small remnant population survives in South Korea. It also occurs on the Japanese islands of Honshu and Shikoku, as well as on Taiwan and the Chinese island of Hainan.

It typically inhabits deciduous forests, mixed forests and thornbrush forests. In the summer, it usually inhabits altitudes of around 3,500 m (11,480 ft) in the Himalayas but rarely above 3,700 m (12,000 ft). In winter, it descends to altitudes below 1,500 m (4,920 ft). In Japan, it also occurs at sea level.

There is no definitive estimate as to the number of Asian black bears: Japan posed estimates of 8–14,000 bears living on Honshū, though the reliability of this is now doubted. Although their reliability is unclear, rangewide estimates of 5–6,000 bears have been presented by Russian biologists. In 2012, Japanese Ministry of the Environment estimated the population at 15–20,000. Rough density estimates without corroborating methodology or data have been made in India and Pakistan, resulting in the estimates of 7–9,000 in India and 1,000 in Pakistan. Unsubstantiated estimates from China give varying estimates between 15 and 46,000, with a government estimate of 28,000.

This gallery will show the very few and very poor images I have been able to take of the two wild Asian Black Bears I have seen - one in the Russian Far East and one in Viet Nam, both from many years back.

Vietnamese (Tibetan) Black Bear (Ursus thibetanus mupinensis) - Seen in Cat Tien National Park in the 90’s. Now it is evidently nearly impossible to see there.

Ussuri Black Bear (Ursus thibetanus ussuricus) - seen in Lazovsky in the Russian Far East. The hollow tree is an active den for an Asian Black Bear

Himalayan Black Bear (Ursus thibetanus thibetanus) - A captive individual seen in the hills outside of Chiang Rai in a hilltribe open market. My goal for 2022-23 is to finally capture a series of images of a wild individual here in Thailand!