The Sloth bear (Melursus ursinus) is a myrmecophagous bear species native to the Indian subcontinent. It is listed as vulnerable on the IUCN Red List, mainly because of habitat loss and degradation. When their territories are encroached upon by humans, Sloth bears sometimes attack them. Historically, humans have drastically reduced these bears' habitat and diminished their population by hunting them for food and products such as their bacula and claws. Sloth bears have been tamed and used as performing animals and as pets.
Sloth bears have been called "labiated bears" because of their long lower lip and palate used for sucking insects. Their long lower lips can be stretched over the outer edge of their noses, and they lack upper incisors, thus allowing the bears to suck up large numbers of insects. Sloth bears have long, shaggy fur, a mane around the face, and long, sickle-shaped claws. Their fur is completely black (rusty for some specimens) with a whitish Y- or V-shaped mark on the chest. The fur does not have an undercoat, thus keeping Sloth bears cool in the tropical climate and protecting them from insects. Females in this species are smaller than males and typically have more fur between their shoulders.
Sloth bears are found in India, the southern lowlands of Nepal, and Sri Lanka. They live in a wide range of habitats including wet and dry tropical forests, savannahs, scrublands, and grasslands.
Sloth bears are generally solitary animals, however, they are sometimes seen in pairs. They are nocturnal, though females become more active in the daytime when with cubs. Sloth bears do not hibernate. They make their day beds out of broken branches in trees and rest in caves during the wet season. Sloth bears walk in slow, shambling motion but are capable of galloping faster than running humans. Although they appear slow and clumsy, Sloth bears are excellent climbers. They may climb to feed and to rest, though not to escape enemies, as they prefer to stand their ground. Females carry their cubs up trees as the primary defense against attacks by predators instead of sending them up trees. To mark their territories, they scrape trees with their forepaws and rub against them with their flanks. Sloth bears are very vocal and communicate with the help of barks, screams, grunts, roars, snarls, whickers, and woofs. Yelps are made when bears are angered, threatening, or when fighting. When hurt or afraid, they shriek, yowl, or whimper. Sounds such as gurgling or humming are made by bears resting or sucking their paws. Females emit crooning sounds to their cubs.
Sloth bears are omnivorous, mainly myrmecophagous animals. They are expert hunters of termites and ants, which they locate by smell. They also supplement their diet with fruit, honey, and plant matter.
Little is known about the mating system of Sloth bears. The breeding season varies according to the location: in India, they mate in April, May, and June, and give birth in December and early January, while in Sri Lanka, it occurs all year. Females gestate for 210 days and typically give birth in caves or in shelters under boulders. Litters usually consist of 1 or 2 cubs, or rarely 3. Cubs are born blind and open their eyes after 4 weeks. Sloth bear cubs develop quickly compared to most other bear species: they start walking a month after birth, become independent at 24-36 months, and become reproductively mature at the age of 3 years. Young cubs ride on their mother's back when she walks, runs, or climbs trees until they reach a third of her size. Individual riding positions are maintained by cubs through fighting. Intervals between litters can last 2 to 3 years.
Historically, humans have drastically reduced the habitat of Sloth bears and diminished their population by hunting them for food and products such as their bacula and claws. Their habitat was lost due to destruction, fragmentation, over-grazing, extraction of minerals, human settlements, and expansion of agricultural areas, and roads. Sloth bears were also captured and used as performing pets.
According to the IUCN Red List, the total population size of Sloth bears is around 20,000 individuals. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List, and its numbers today are decreasing.
Sloth bears play an important part in ecosystems due to their effects on fruits and insects. They help spread the seeds of plants that they eat and they also eat big amounts of termites controlling their population growth.