Sloth Bear

About the sloth bear

The sloth bear, also called the Indian bear, is the only species in the genus Melursus. It's native to the Indian subcontinent, where it ranges across India, Nepal's Terai lowlands, Bhutan, and Sri Lanka; the species has been wiped out in Bangladesh. In the wild it turns up in a surprising spread of habitats below 1,500 m in elevation on the subcontinent and below 300 m in Sri Lanka's dry forests, from moist and dry tropical forest to savanna, scrubland, and open grassland.

Everything about the sloth bear's face points to its specialty. The muzzle is thick and long, the jaws are small, and the snout is bulbous with wide nostrils. It has long lower lips that stretch over the outer edge of the nose, and it lacks upper incisors entirely — a combination that turns the mouth into a vacuum for insects. The premolars and molars are smaller than in other bears since the animal chews less vegetation than its relatives, and by adulthood the teeth are often in rough shape from the soil ingested while feeding. The paws are disproportionately large, tipped with sickle-shaped, blunt claws about 10 cm (4 in) long, and the toe pads are joined by a hairless web. The tail, at 15–18 cm (6–7 in), is the longest in the bear family, and the sloth bear is the only bear with long hair on its ears.

The coat is black — occasionally rusty — long, shaggy, and unkempt, thickening into a mane up to 30 cm (12 in) long behind the neck and shoulders, while the belly and underlegs can be nearly bare. Most individuals carry a whitish Y- or V-shaped mark on the chest, a feature shared with Asian black bears and sun bears that's thought to work as a threat display toward tigers, which share the sloth bear's range. Compared with an Asian black bear of similar size, a sloth bear is immediately distinctive for its shaggier coat, whitish claws, and rangier build, along with a longer, narrower skull and paler, flappier lips.

Behavior and diet

Sloth bears walk with a slow, shambling gait, feet slapping down noisily, yet they can gallop faster than a running human and are capable swimmers that enter water mainly to play. Despite their clumsy look, both cubs and adults climb well — though not to escape danger, since sloth bears generally prefer to stand their ground against threats rather than flee up a tree. Mothers instead carry cubs on their backs as their main defense, moving them out of harm's way rather than sending them up on their own.

The species is built to hunt termites, ants, and bees, tracking them by smell and detecting grubs as deep as 3 ft underground. At a mound, a sloth bear scrapes through the structure with its claws, blows away the loosened soil in violent puffs, and sucks up the exposed insects through its muzzle — a sound reportedly audible up to 180 m away. Diet shifts with the seasons in the Aravalli hills of Rajasthan, where fruit dominates winter diets and insects dominate summer diets, and sloth bears also eat mahua petals, mangoes, maize, sugar cane, jackfruit, honey, carrion, and occasionally other mammals. Nursing sows regurgitate a mixture of half-digested fruit and honeycomb that hardens into a bread-like mass fed to cubs, sometimes called "bear's bread" locally. Unlike other bears, sloth bears don't gather in feeding groups.

Breeding season varies by location: sloth bears in India mate from April through June and give birth in December or early January, while in Sri Lanka breeding can happen year-round. Gestation runs about 210 days, and sows typically give birth in caves or shelters under boulders to litters of one or two cubs, occasionally three. Cubs are born blind, open their eyes after about four weeks, start walking within a month, and ride on their mother's back until they reach roughly a third of her size. They become independent at 24–36 months and reach sexual maturity around age three, with two to three years typically passing between litters.

Range and habitat

The sloth bear's range covers India, Nepal's Terai lowlands, temperate zones of Bhutan, and Sri Lanka, and it is regionally extinct in Bangladesh. Within that range it occupies a wide mix of habitat types — moist and dry tropical forest, savanna, scrubland, and grassland — up to 1,500 m (4,900 ft) in elevation on the Indian subcontinent, dropping to below 300 m (980 ft) in Sri Lanka's dry forests. Sri Lankan sloth bears, classified as a separate subspecies, tend to run noticeably smaller and lighter than the nominate population on the mainland, with males averaging around 74.8 kg (165 lb) against a mainland average closer to 114 kg (251 lb) in Nepal.

Human encroachment on sloth bear territory has been the main driver of habitat loss across its range, and the species has also historically been hunted for food, bacula, and claws, and captured for use as a performing or tamed animal.

Conservation status

The sloth bear is listed as Vulnerable on the IUCN Red List, primarily because of habitat loss and degradation across its range. Where its territory overlaps with expanding human settlement, encounters can turn dangerous in both directions — sloth bears sometimes attack people when their space is encroached upon, and historically hunting for food, bacula, and claws, along with capture for use as performing animals or pets, has cut into wild populations. The species also faces natural pressure from tigers, which occasionally prey on sloth bears near termite mounds, and to a lesser extent from leopards, which can follow bears up trees.