The sloth bear (Melursusursinus) is a well-known myrmecophagous bear species endemic to the Indian subcontinent. Its diet is made up of ants, fruits, and termites.
It is listed on the IUCN Red List as Vulnerable, mainly because of degradation and habitat loss.
It is often called “labiated bear” because of its palate and long lower lip used for sucking up insects. It has a mane around the face, a long, shaggy fur, and long, sickle-shaped claws.
It is lankier than Asian black bears and brown bears. Due to its evolution during the Pleistocene from the ancestral brown bear through convergent evolution, it is said to have similar traits to insectivorous mammals.
Sloth bears breed during early summer & spring and give birth towards the beginning of winter. They attack humans who encroach on their territory.
Historically, humans have drastically diminished their population by hunting them for food and products, such as their claws and bacula, which has also reduced the habitat of these bears.
Sloth bears have been tamed as pets or as performing animals.
Scientific Classification
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Mammalia |
| Order | Carnivora |
| Family | Ursidae |
| Subfamily | Ursinae |
| Genus | Melursus |
| Species | M. ursinus |
Subspecies
| Name | Description | Distribution |
| Indian sloth bear (M. u. ursinus) | This is the nominate subspecies of the sloth bear and has a large skull with a condylobasal length of about 11 in (290 mm) in females and about 12 in (310 mm) in males. | Himalayas, Punjab, and Arunachal Pradesh. |
| Sri Lankan sloth bear (M. u. inornatus) | The Sri Lankan sloth bear is quite smaller than the nominate subspecies, has a smaller skull with a condylobasal length of about 9.8 in (250 mm) in females and about 10.4 in (264 mm) in males. | Sri Lanka |
Characteristics
An adult sloth bear is a medium-sized species, though weight ranges from 121 – 231 lb (55 – 105 kg) in typically-sized females and 176 – 320 lb (80 – 145 kg) in typically-sized males. Exceptionally large females can weigh up to 273 lb (124 kg), and males up to 423 lb (192 kg).
In Nepal, the average weight of sloth bears from the nominate subspecies was 209 lb (95 kg) in females and 251 lb (114 kg) in males. In India, nominate bears weighed an average of 205 lb (93.2 kg) in males and 184 lb (83.3 kg) in one study.
In Sri Lanka, specimens (M. u. inornatus) may weigh up to 150 lb (68.2 kg) in females and 230 lb (104.5 kg) in males. However, six Sri Lanka male sloth bear specimens averaged only 165 lb (74.8 kg), and 127 lb (57.5 kg) was the average for four females.
They are 2 ft 0 to 3 ft 0 in (60 to 92 cm) high at the shoulder height and have a body length of 4 ft 7 to 6 ft 3 in (1.4 to 1.9 m). Sloth bear muzzles are long and thick, with bulbous snouts & wide nostrils, and small jaws.
The teeth in adults are usually in poor condition because they suck up some soil and chew when feeding on insects. The back of the palate is broad and long, similar to other ant-eating mammals.
The paws are abnormally large and have highly developed blunt claws shaped like a sickle, which measure 4 in (10 cm) in length. They possess the longest tail in the bear family, growing to 6 to 7 inches (15 to 18 cm). The ears are floppy & very large, and it’s the only bear with long hair on its ears.
Sloth bear fur is sometimes completely black or rusty for some species, save for a whitish V- or Y-shaped mark on the chest. This trait may be absent, especially in Sri Lankan specimens. This trait, also present in sun and Asian black bears, is assumed to be a threat display.
The coat is long, unkempt, and shaggy despite the warm environment in which the species is native. The sloth bear coat is particularly heavy between the shoulders and behind the neck, forming a 12-inch (30 cm) long mane.
The underlegs and belly can be almost bare. Similar to the Asian bear, sloth bears are about the same size but are distinctive for their whitish claws, shaggier coats, and rangier build.
Distinct from sloth bears, black bears have narrower, longer skull shapes (especially the snout), paler muzzle color, and loose-looking, flappier lips.
Reproduction
Sloth bears’ breeding season varies on location; in Sri Lanka, it occurs throughout the year, while in India, they mate in April, May, and June and give birth in December or early January.
Female sloth bears gestate for 210 days and typically give birth in shelters under boulders or caves. A litter usually consists of 1 – 2 cubs, or rarely 3. Sloth bear cubs are born blind, although their eyes open after four weeks.
Compared to most bear species, sloth bear cubs develop quickly; they walk a month after birth and become independent at 24 to 36 months. They become sexually mature at the age of 3 years.
Until the cubs reach a third of the mother’s size, they ride on their mother’s back when she runs, walks, or climbs.
Diet
Sloth bears are expert hunters of ants and termites, which they locate by smell. After arriving at the mound, they scrape at the structure with their whitish claws until they reach the gallery’s bottom. After that, the termites will be sucked up through the muzzle, which produces a sucking sound that can be heard 180 m away.
Sloth bears possess a strong sense of smell that can detect grubs 3 ft below ground. Distinct from other bears, they converge in feeding groups. Sloth bears may complement their diet with plant matter, fruits, and carrion.
In March and April, they base their diet on fallen petals of mowha trees and are partial to sugar cane, mangoes, the pods of the golden shower tree, and jackfruits.
Habitat and Distribution
The sloth bear’s global range includes the southern lowlands of Nepal, India, and Sri Lanka. It is known to be extinct in Bangladesh.
It occurs in a wide range of habitats, including dry and wet tropical forests, scrublands, savannahs, and grasslands below 4,900 ft (1,500 m) on the Indian subcontinent and below 980 ft (300 m) in Sri Lanka’s dry forests.
