The sloth bear (Melursus ursinus), also known as the labiated bear, is an insectivorous bear species native to the Indian subcontinent. The sloth bear evolved from ancestral brown bears during the Pleistocene and shares features found in insect-eating mammals through convergent evolution. The population isolated in Sri Lanka is considered a subspecies. Compared to brown and black bears, sloth bears have lankier builds, long, shaggy coats that form a mane around the face (similar to that of a lion), long, sickle-shaped claws, and a specially adapted lower lip and palate used for sucking insects. Sloth bears breed during spring and early summer and give birth near the beginning of winter. They feed on termites, honeybee colonies, and fruits. Sloth bears sometimes attack humans who encroach on their territories. Historically, humans have drastically reduced their habitat and diminished their population by hunting them for food and products such as their bacula and claws. These bears have been used as performing pets due to their tameable nature. The sloth bear is listed as Vulnerable by the IUCN due to habitat loss and poaching.
Naming and etymology
Initially thinking it to be related to the South American sloths, Shaw and Nodder in 1791 called the species Bradypus ursinus, noting that it was bear-like, but giving weight to the long claws and the absence of upper middle incisors. Meyer (1793) identified it as a bear and called it Melursus lybius, and in 1817, de Blainville called it Ursus labiatus because of the long lips. Iliger called it Prochilus hirsutus, the Greek genus name indicating long lips, while the specific name noted its long and coarse hair. Fischer called it Chondrorhynchus hirsutus, while Tiedemann called it Ursus longirostris.
Local names
- Gujarati: રીંછ rīn̄cha; also rinchh
- Hindi: à¤à¤¾à¤²à¥, bhÄlu; also rinch and adam-zad
- Odia: à¬à¬¾à¬²à, bhÄlu
- Bengali: শà§à¦²à¦¥ à¦à¦¾à¦²à§à¦•, Å›latha bhaluka; kÄlÅ bhÄluka; also bhaluk
- Sanskrit: ऋकà¥à¤·, á¹›ká¹£a; also rikspa
- Kannada: ಕರಡಿ, karaá¸i; kaddi
- Tamil: கரடி, karaá¹i; kaddi
- Malayalam: തേൻകരടി, tÄ"nkaraá¹i; also pani karudi
- Telugu: à°Žà°²à±à°—à±à°¬à°‚à°Ÿà°¿, elugubaṇá¹i; also elugu
- Marathi: असà¥à¤µà¤², asvala; also aswal
- Gond: yerid, yedjal and asol
- Kol: bana
- Oraon: bir mendi
- Sinhalese: වලසà·, valasÄ; also usa
Evolution
Sloth bears may have reached their current form in the early Pleistocene, the time when the bear family specialized and dispersed. A fragment of fossilized humerus from the Pleistocene, found in Andhra Pradesh's Kurnool Basin is identical to the humerus of a modern sloth bear. The fossilized skulls of a bear once named Melursus theobaldi found in the Shivaliks from the early Pleistocene or early Pliocene are thought by certain authors to represent an intermediate stage between sloth bears and ancestral brown bears. M. theobaldi itself had teeth intermediate in size between sloth bears and other bear species, though its palate was the same size as the former species, leading to the theory that it is the sloth bear's direct ancestor. Sloth bears probably arose during the mid-Pliocene and evolved in the Indian subcontinent. The sloth bear shows evidence of having undergone a convergent evolution similar to that of other ant-eating mammals.
Physical description
Sloth bears are distinguished from Asian black bears by their lankier builds, longer, shaggier coats, pale muzzles, and white claws. Adults are medium-sized bears weighing around 130 kg (290 lb) on average, though weight can range variously from 55 to 124 kg (121 to 273 lb) in females and from 80 to 192 kg (176 to 423 lb) in males. They are 60â€"90 cm (2.0â€"3.0 ft) high at the shoulder, and have a body length of 1.4â€"1.9 m (4.6â€"6.2 ft). Females are smaller than males, and have more fur between their shoulders.
Sloth bear muzzles are thick and long, with small jaws and bulbous snouts with wide nostrils. They have long lower lips which can be stretched over the outer edge of their noses, and lack upper incisors, thus allowing them to suck up large numbers of insects. The premolars and molars are smaller than in other bears, as they do not chew as much vegetation. In adults, the teeth are usually in poor condition, due to the amount of soil they suck up and chew when feeding on insects. The back of the palate is long and broad, as is typical in other ant-eating mammals. The paws are disproportionately large, and have highly developed, sickle-shaped, blunt claws which measure 10 cm (4 in) in length. Their toe pads are connected by a hairless web. They have the longest tail in the bear family, which can grow to 15â€"18 cm (6â€"7 in). Their back legs are not very strong, though they are knee-jointed, and allow them to assume almost any position. The ears are very large and floppy. The sloth bear is the only bear with long hair on its ears.
Sloth bear fur is completely black (rusty for some specimens), save for a whitish Y- or V-shaped mark on the chest. This feature is sometimes absent, particularly in Sri Lankan specimens. This feature, which is also present in Asian black bears and sun bears, is thought to serve as a threat display, as all three species are sympatric with tigers. The coat is long, shaggy, and unkempt, despite the relatively warm environment in which the species is found, and is particularly heavy behind the neck and between the shoulders, forming a mane which can be 30Â cm (12Â in) long. The belly and underlegs are almost bare.
Behaviour
Adult sloth bears may travel in pairs, with the males being gentle with cubs. They may fight for food. They walk in a slow, shambling motion, with their feet being set down in a noisy, flapping motion. They are capable of galloping faster than running humans. Although they appear slow and clumsy, both young and adult sloth bears are excellent climbers. They climb to feed and to rest, though not to escape enemies, as they prefer to stand their ground. Sloth bear mothers carry cubs up to 9 months old on their backs instead of sending their cubs up trees as the primary defense against attacks by predators, such as tigers, leopards, and other bears. They are capable of climbing on smooth surfaces and hanging upside down like sloths. They are good swimmers, and primarily enter water to play. To mark their territories, sloth bears scrape trees with their forepaws, and rub against them with their flanks. Sloth bears have a great vocal range. Gary Brown, in his Great Bear Almanac, lists over 25 different sounds in 16 different contexts. Sounds such as barks, screams, grunts, roars, snarls, whickers, woofs, and yelps are made when angered, threatening, or when fighting. When hurt or afraid, they shriek, yowl, or whimper. When feeding, sloth bears make loud huffing and sucking noises, which can be heard over 100 m away. Sounds such as gurgling or humming are made by bears resting or sucking their paws. Sows emit crooning sounds to their cubs. The species is the most vociferous when mating, and make loud, melodious calls when doing so. 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 are the most nocturnal of bears, though sows become more active in daytime when with cubs.
Reproduction
The breeding season for sloth bears varies according to 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. Sows gestate for 210 days, and typically give birth in caves or in shelters under boulders. Litters usually consist of one or two cubs, or rarely three. Cubs are born blind, and open their eyes after four weeks. Sloth bear cubs develop quickly compared to most other bear species: they start walking a month after birth, become independent at 24â€"36 months, and become sexually mature at the age of three 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 two to three years.
Dietary habits
Sloth bears are expert hunters of termites, which they locate by smell. On arriving at a mound, they scrape at the structure with their claws till they reach the large combs at the bottom of the galleries, and disperse the soil with violent puffs. The termites are then sucked up through the muzzle, producing a sucking sound which can be heard 180 m away. Their sense of smell is strong enough to detect grubs 3Â ft below ground. Unlike other bears, they do not congregate in feeding groups. They rarely prey on other mammals. Sloth bears may supplement their diets with fruit and plant matter; in March and April, they eat the fallen petals of mowha trees and are partial to mangoes, sugar cane, jackfruit, and the pods of the golden shower tree. Sloth bears are extremely fond of honey. When feeding their cubs, sows are reported to regurgitate a mixture of half-digested jack fruit, wood apples, and pieces of honeycomb. This sticky substance hardens into a dark yellow, circular, bread-like mass which is fed to the cubs. This "bear's bread" is considered a delicacy by some of India's natives.
Relationships with other animals
The large canine teeth of sloth bears, relative to both its overall body size and to the size of the canine teeth of other bear species, and the aggressive disposition of sloth bears may be a defense in interactions with large, dangerous species such as tigers, elephants, and rhinoceroses.
Bengal tigers occasionally prey on sloth bears. Tigers usually give sloth bears a wide berth, though some specimens may become habitual bear killers and it is not uncommon to find sloth bear fur in tiger scats. Tigers typically hunt sloth bears by waiting for them near termite mounds, then creeping behind them and seizing them by the back of their necks and forcing them to the ground with their weight. One tiger was reported to simply break its victim's back with its paw, then wait for the paralysed bear to exhaust itself trying to escape before going in for the kill. When confronted by tigers face to face, sloth bears charge at them, crying loudly. A young or already sated tiger usually retreats from an assertive sloth bear, as the bear's claws can inflict serious wounds, and most tigers end the hunt if the bears become aware of the tiger's presence before the pounce. A female bear with cubs was observed to stand her ground and prevail in a confrontation against two tigers (one female, one male) in rapid succession. Sloth bears may scavenge on tiger kills. As tigers are known to mimic the calls of sambar deer to attract them, sloth bears react fearfully even to the sounds made by deer themselves. Indian leopards can also be a threat, as they are able to follow sloth bears up trees. Sloth bears occasionally chase leopards from their kills.
Sloth bears are sympatric with Asiatic black bears in northern India, and the two species, along with the sun bear, coexist in some of the national parks and wildlife sanctuaries. They are also found together in Assam, Manipur, and Mizoram, in the hills south of the Brahmaputra River, the only places occupied by all three bear species. The three species do not act aggressively toward each other. This may be because the three species generally differ in habit and dietary preferences.
Dhole packs may attack sloth bears, though they are not a usual prey item. When attacking them, dholes try to prevent the bear from retreating into caves. In one case, a golden jackal (a species much smaller and less powerful than a sloth bear and not generally a pack hunter as is the dhole) was seen to aggressively displace an adult bear which passively loped away from the snapping canid, indicating the sloth bear does not regard other carnivores as competition.
Asian elephants apparently do not tolerate sloth bears in their vicinity. The reason for this is unknown, as individual elephants known to maintain their composure near tigers have been reported to charge bears. The Indian rhinoceros has a similar intolerance for sloth bears, and will charge at them.
Subspecies and range
Status and conservation
IUCN estimates that less than 20,000 sloth bears survive in the wilds of the Indian subcontinent and Sri Lanka. The sloth bear is listed in Schedule I of the Indian Wildlife Protection Act, 1972, which provides for their legal protection. International trade of the sloth bear is prohibited as it is listed in Appendix I of the Convention on International Trade in Endangered Species.
To address the human-bear conflict, people may be educated about the conservation ethics, particularly among locals. To resolve this conflict, the basic issue of deteriorating habitat, which is the reason for the conflict between people and bears, improvements through government or community-based reforestation programmes, may be promoted.
The population of sloth bears grows when they live in high-profile reserves that protect species, such as tigers and elephants. Directly managed reserves could conserve the sloth bear, hence such reserves must be supported.
The government of India has banned use of sloth bears for entertainment, and a 'Sloth Bear Welfare Project' in the country has the objective of putting an end to their use for entertainment. However, their number in such activity is still large. Many organizations are helping in the conservation and preservation of sloth bears in safe places. Major sloth bear sanctuaries in India include the Daroji bear sanctuary, Karnataka.
Relationships with humans
Attacks on humans
Sloth bears likely view humans as potential predators, as their reactions to them (roaring, followed by retreat or charging) are similar to those evoked in the presence of tigers and leopards. Their long claws, ideally adapted for digging at termite mounds, make adults less capable of climbing trees to escape danger, as are other bears such as Asian black bears. Therefore, sloth bears have seemingly evolved to deal with threats by behaving aggressively. For the same reason, brown bears can be similarly inclined, accounting for the relatively high incidence of seemingly nonpredatory aggression towards humans in these two bear species.
According to Robert Armitage Sterndale, in his Mammalia of India (1884, p. 62):
[The sloth bear] is also more inclined to attack man unprovoked than almost any other animal, and casualties inflicted by it are unfortunately very common, the victim being often terribly disfigured even if not killed, as the bear strikes at the head and face. Blanford was inclined to consider bears more dangerous than tigers...
Captain Williamson in his Oriental Field Sports wrote of how sloth bears rarely killed their human victims outright, but would suck and chew on their limbs till they were reduced to bloody pulps. One specimen, known as the sloth bear of Mysore, was singlehandedly responsible for the deaths of 12 people and the mutilation of 24 others before being shot by Kenneth Anderson. Although sloth bears have attacked humans, they rarely become man-eaters. Dunbar-Brander's Wild Animals of Central India mentions a case in which a sow with two cubs began a six-week reign of terror in Chanda, a district of the Central Provinces, during which more than one of their victims had been eaten, while the sloth bear of Mysore partially ate at least three of its victims. R.G. Burton deduced from comparing statistics that sloth bears killed more people than Asian black bears, and Theodore Roosevelt considered them to be more dangerous than American black bears. In Madhya Pradesh, sloth bear attacks accounted for the deaths of 48 people and the injuring of 686 others between 1989 and 1994, probably due in part to the density of population and competition for food sources. A total of 137 attacks (resulting in 11 deaths) occurred between April 1998 and December 2000 in the North Bilaspur Forest Division of Chhattisgarh. The majority of attacks were perpetrated by single bears, and occurred in kitchen gardens, crop fields, and in adjoining forests during the monsoon season. One Mr. Watts Jones wrote a first-hand account of how it feels to be attacked by a sloth bear, recalling when he failed to score a direct hit against a bear he had targeted:
I do not know exactly what happened next, neither does my hunter who was with me; but I believe, from the marks in the snow, that in his rush the bear knocked me over backwards in fact, knocked me three or four feet away. When next I remember anything, the bear's weight was on me, and he was biting my leg. He bit two or three times. I felt the flesh crush, but I felt no pain at all. It was rather like having a tooth out with gas. I felt no particular terror, though I thought the bear had got me; but in a hazy sort of way I wondered when he would kill me, and thought what a fool I was to get killed by a stupid beast like a bear. The shikari then very pluckily came up and fired a shot into the bear, and he left me. I felt the weight lift off me, and got up. I did not think I was much hurt. ... The main wound was a flap of flesh torn out of the inside of my left thigh and left hanging. It was fairly deep, and I could see all the muscles working underneath when I lifted it up to clean the wound."
In 2016, according to a forest official, a female bear had killed 3 people, and hurt 5 others in Gujarat State's Banaskantha district, near Balaram Ambaji Wildlife Sanctuary, with some of the casualties being colleagues. At first, an attempt was made to trace and cage it, but this failed, costing the life of one official, and so a team of both officials and policemen shot the bear.
Hunting and products
One method of hunting sloth bears involved the use of beaters, in which case, a hunter waiting on a post could either shoot the approaching bear through the shoulder or on the white chest mark if it was moving directly to him. Sloth bears are very resistant to body shots, and can charge hunters if wounded, though someone of steady nerves could score a direct hit from within a few paces of a charging bear. Sloth bears were easy to track during the wet season, as their clear footprints could be followed straight to their lairs. The majority of sloth bears killed in forests were due to chance encounters with them during hunts for other game. In hilly or mountainous regions, two methods were used to hunt them there. One was to lie in wait above the bear's lair at dawn and wait for the bear to return from its nocturnal foraging. Another was to rouse them at daytime by firing flares into the cave to draw them out. Sloth bears were also occasionally speared on horseback. In Sri Lanka, the baculum of a sloth bear was once used as a charm against barrenness.
Tameability
Officers in British India often kept sloth bears as pets. The wife of Kenneth Anderson kept an orphaned sloth bear cub from Mysore, which she named "Bruno". The bear could be fed on almost anything (including motor oil) and was very affectionate toward people. It was even taught numerous tricks, such as cradling a woodblock like a baby or pointing a bamboo stick like a gun.
Dancing bears were historically a popular entertainment in India, dating back to the 13th century and the pre-Mughal era. The Kalandars, who practised the tradition of capturing sloth bears for entertainment purposes, were often employed in the courts of Mughal emperors to stage spectacles involving trained bears. They were once common in the towns of Calcutta, where they often disturbed the horses of British officers.
Despite a ban on the practice that was enacted in 1972, as many as 800 dancing bears were in the streets of India during the latter part of the 20th century, particularly on the highway between Delhi, Agra, and Jaipur. Sloth bear cubs, which were usually purchased at the age of six months from traders and poachers, were trained to dance and follow commands through coercive stimuli and starvation. Males were castrated at an early age, and their teeth were knocked out at the age of one year to prevent them from seriously injuring their handlers. The bears were typically fitted with a nose ring attached to a four-foot leash. Some were found to be blind from malnutrition.
In 2009, following a seven-year campaign by a coalition of Indian and international animal welfare groups, the last Kalandar dancing bear was set free. The effort to end the practice involved helping the bear handlers find jobs and education, which enabled them to reduce their reliance on dancing-bear income.
Cultural references
In Rudyard Kipling's The Jungle Book, Baloo "the sleepy old brown bear" teaches the Law of the Jungle to the wolf cubs of the Seeonee wolf pack, as well as to his most challenging pupil, the "man-cub" Mowgli. Robert Armitage Sterndale, from whom Kipling derived most of his knowledge of Indian fauna, used the Hindustani word bhalu for several bear species, though Daniel Karlin, who edited the Penguin Classics reissue of The Jungle Book in 1989, stated, with the exception of colour, Kipling's descriptions of Baloo are consistent with the sloth bear, as brown bears and Asian black bears do not occur in the Seoni area where the novel takes place. Also, the name "sloth" can be used in the context of sleepiness. Karlin states, however, that Baloo's diet of ".. only roots and nuts and honey" is a trait more common to the Asian black bear than to the sloth bear.
References
External links
- Field Trip Earth â€" Field Trip Earth is a conservation education website operated by the North Carolina Zoological Society.
- Sloth Bear at Animal Diversity Web