Sloth bear

Name and taxonomy

George Shaw named the animal Bradypus ursinus in 1791, placing it in the sloth genus because of its long claws and odd gait. The English name stuck even after later authors moved it to its own genus, Melursus. It has also been called the labiated bear, for its long lower lip, and the Indian bear. Hindi speakers call it bhalu, Kannada and Tamil speakers call it karadi, and Sinhala speakers call it valasa.

It belongs to the bear family, Ursidae, within the order Carnivora, and it is the only species in Melursus. Two subspecies are recognised: Melursus ursinus ursinus on the mainland and the smaller, less shaggy Melursus ursinus inornatus of Sri Lanka.

Evolution and relatives

The sloth bear is one of eight living bear species and one of six in the subfamily Ursinae. A genetic study in 2017 put the origin of the ursine bears at about five million years ago, with much hybridisation between species. The sloth bear probably arose in the Middle Pliocene and evolved on the Indian subcontinent. Fossil skulls from the Siwalik Hills, once named Melursus theobaldi, may be a stage between ancestral brown bears and the modern species.

Its long palate, mobile lips and missing upper incisors match those of other ant-eating mammals. That is convergent evolution: the bear line arrived at the anteater's tools by its own route. Its neighbours in the wild are the Asian black bear and the sun bear. All three meet in the hills south of the Brahmaputra.

Appearance

Adults measure 140 to 190 centimetres from nose to rump and stand 60 to 92 cm at the shoulder. Typical females weigh 55 to 105 kilograms and males 80 to 145 kg. The largest recorded male reached 192 kg. Sri Lankan bears may be about 30 percent lighter than mainland bears. The tail reaches 15 to 18 cm, the longest of any bear.

The coat is long, shaggy and black, though a few animals are rusty brown. It is thickest behind the neck and between the shoulders, where it forms a mane up to 30 cm long. The belly and the lower legs can be almost bare. A pale V- or Y-shaped patch marks the chest, though some Sri Lankan bears lack it. The ears are large and floppy, and no other bear grows long hair on its ears.

The muzzle is long and pale, with a bulbous nose and wide nostrils that the bear can close at will. The lower lip stretches past the nose, and the upper incisors are missing, which leaves a gap for sucking. The paws are oversized and carry blunt, sickle-shaped, ivory-coloured claws about 10 cm long. The build is rangier than a black bear's, and the hind legs are weak but very flexible.

Habitat and range

The sloth bear lives across India, in the Terai lowlands of Nepal, in Bhutan and in Sri Lanka. It has never been recorded west of Gujarat, and it is regionally extinct in Bangladesh. GBIF holds records from 11 countries, but that count includes zoos.

It occupies moist and dry tropical forest, savanna, scrub and grassland, mostly below 1,500 metres. In the Western Ghats it climbs to 2,000 m, while in Sri Lanka's dry forests it stays below 300 m. Densities are highest on the alluvial grasslands of the Nepal lowlands and in deciduous forest. It prefers drier forest with rocky outcrops, where caves give shelter by day.

Home ranges are small for a bear. In Sri Lanka a female uses about 2 square kilometres and a male under 4. In Nepal the figures are about 9 and 14 square kilometres, and some Indian bears use more than 100.

Diet and feeding

Termites, ants and fruit make up most of the diet, in proportions that shift with season and place. In southern India fruit can reach 90 percent of the diet in the fruiting season, and in Sri Lanka 70 percent. In Nepal, with less fruit, insects matter more. In the Aravalli hills of Rajasthan fruit dominates in winter and termites and ants in summer.

The bear finds a termite mound by smell and tears it open with its claws. It blows the loose soil away in hard puffs, then sucks the insects up through the gap in its teeth. The noise carries about 180 metres. Its nose can find grubs about 3 feet underground. It closes its nostrils to keep the dust out.

It eats mangoes, jackfruit, wood apples, fallen mahua petals and golden shower tree pods. It raids maize and sugar cane near villages and takes honey freely, bee stings and all. It also takes carrion, and very rarely another mammal. Some bears become addicted to sweet hotel waste and visit rubbish bins inside towns all year. Unlike other bears it never feeds in groups.

Behaviour and social life

The sloth bear is more nocturnal than other bears, probably because of the heat and thin cover of its range. Activity varies from 40 to 70 percent of the day and night depending on conditions. By day it sleeps in caves, often on river banks. It does not hibernate, though it slows down during the rains.

Adults are solitary apart from mothers with cubs, though pairs sometimes travel together. Males are often gentle with cubs, but adults may fight over food. It marks its range by scraping trees with its forepaws and rubbing them with its flanks.

It walks with a slow, shambling gait and slaps its feet down noisily. Even so it can gallop faster than a running person. It climbs well to feed or rest but not to escape, because it prefers to stand its ground. A mother carries her cubs up a tree on her back rather than sending them up. It swims well and enters water mainly to play.

Communication and senses

Smell is the sloth bear's main sense, and its sight and hearing are poor. That is why a person can walk up on one unnoticed, with dangerous results. The bear has a very large tongue and a mobile snout that it uses to probe nests.

It is a noisy bear. Howls, squeals, screams, barks and trumpet-like calls accompany aggressive encounters. A huff is a warning, and a chuff means the bear is disturbed. A mother keeps in touch with her cubs by a grunt-whicker, and a lost cub yelps. Mating bears are loud too.

Reproduction and life cycle

In India mating runs from April to June, with a peak in June, and cubs arrive in December and early January. In Sri Lanka breeding happens all year. Males gather near a receptive female and fight for access. She mates with several males in the order of their dominance, which depends mostly on weight.

Pregnancy lasts about 6 to 7 months, or 210 days by one account. The mother gives birth in a cave or under a boulder to one or two cubs, rarely three. The cubs arrive blind, and their eyes open at about four weeks. They walk at a month old and soon ride on their mother's back, each holding its own place by squabbling. The rides stop once a cub grows to about a third of its mother's size.

The cubs stay with their mother for 24 to 36 months, so she breeds only every two to three years. Both sexes mature at about three years. A captive bear has lived up to 40 years.

Predators and threats

The tiger is the only regular predator of adult sloth bears. A tiger waits near a termite mound, creeps up behind the feeding bear and pins it by the neck. Most tigers give up if the bear notices them first, because the bear's claws can cause serious wounds. In 2011 a mother with cubs drove off two tigers in a row.

Leopards can follow a bear up a tree, and one killed a three-quarters grown female after a long fight. Dhole packs attack bears and try to cut off the retreat to a cave, but they seldom threaten a healthy adult. Elephants and Indian rhinos charge sloth bears on sight, for reasons nobody understands.

People are the real threat. Forest has given way to farms and towns, and Sri Lanka lost about 1.85 million hectares of high forest between 1956 and 1983. Poachers take bears in traps and by electrocution for their canines, claws, paws and gall bladders. Villagers kill bears that raid crops or attack people, which the law allows in defence of life or property.

Population and conservation

The IUCN lists the sloth bear as Vulnerable, and the trend is downward. Fewer than 20,000 are thought to survive across the subcontinent and Sri Lanka. The bear specialists' association puts the total above 10,000. It counts about 7,500 to 8,000 in India, 800 to 1,000 in Sri Lanka and more than 300 in Nepal.

India lists the species in Schedule I of its Wildlife Protection Act of 1972, its highest level of protection. CITES lists it in Appendix I, which bans international trade in bears or their parts. All five range countries protect it to some degree. Numbers grow inside the big tiger and elephant reserves, so those reserves protect the bear too.

India has two dedicated sanctuaries, Daroji in Karnataka and Jessore in Gujarat, and a conservation reserve is proposed in Uttar Pradesh. Managing hotel waste keeps bears out of towns and cuts accidental attacks. Wildlife SOS runs the Agra Bear Rescue Facility for bears freed from the dancing trade.

Relationship with humans

In absolute numbers the sloth bear attacks more people than any other bear. It seems to treat a person as it treats a tiger: it roars, then retreats or charges. It rarely bluffs, and it often strikes at the head and face. In Madhya Pradesh attacks killed 48 people and injured 686 between 1989 and 1994. In part of Chhattisgarh 137 attacks between April 1998 and December 2000 caused 11 deaths, most in gardens and fields during the monsoon.

The bear of Mysore killed 12 people and mutilated 24 before Kenneth Anderson shot it. Yet the bear rarely eats people, and in Mount Abu residents have not retaliated against bears that raid the town's bins. That restraint is thought to reflect Hindu reverence for animals.

Dancing bears date from the 13th century, and the Kalandar community staged bear shows at Mughal courts. India banned the practice in 1972, but about 800 dancing bears still walked the roads late in the 20th century. Cubs were bought at six months, their teeth knocked out at a year, and a rope run through the nose. A seven-year campaign freed the last Kalandar bear in 2009 by finding the handlers other work. Bear fat and gall bladders are still used in traditional medicine.

In culture and myth

In Hindu tradition, Jambavan rules the bears and was born from a yawn of Brahma. In the Ramayana he counsels Rama, and it is he who tells Hanuman that he has the power to leap the sea to Lanka. In the Mahabharata he fights Krishna in his cave for weeks over the Syamantaka jewel, then yields and gives his daughter Jambavati in marriage. The texts do not name a species, but the sloth bear is the common bear of the subcontinent, so Jambavan is probably a sloth bear.

Baloo in Rudyard Kipling's The Jungle Book is probably a sloth bear. No other bear lives in the Seoni district where the story is set. Kipling called him a sleepy brown bear, and his diet of roots, nuts and honey fits the black bear better. Charles Catton drew the animal in 1788 and called it the Petre bear.

In Sri Lankan tradition, the bear's baculum was once carried as a charm against barrenness. British officers in India kept cubs as pets, and Kenneth Anderson's wife raised one named Bruno that learned tricks. The Sanskrit word for the animal, rksha, is the root of the bear's name in many Indian languages.