Sloth Bear (Melursus ursinus)
Order: Carnivora, Family: Ursidae
Native: Oriental. Melursus ursinus is found throughout India, Sri Lanka, and further north into Bangladesh, Nepal, and Bhutan. This species was fairly common in India and Sri Lanka until as recently as 20 years ago, now they are harder to find.
I. GEOGRAPHIC RANGE
II. PHYSICAL CHARACTERISTICS
- Native: Oriental. Melursus ursinus is found throughout India, Sri Lanka, and further north into Bangladesh, Nepal, and Bhutan. This species was fairly common in India and Sri Lanka until as recently as 20 years ago, now they are harder to find.
III. FOOD HABITS
- Mass: 55 to 140 kg.
- Length: 1.5 to 1.9 m.
- Sloth bears have a shaggy black coat, especially over the shoulders. Brown and grey hairs found on the coat give the appearance of a cinnamon color on some bears. This heavy coat may be an adaptation to deal with cold. These bears have long snouts, which are similar to but less elongate than those of anteaters. Their teeth are small and they lack upper incisors. The molars are broad and flat, representing a trend away from carnivory. The body structure of M. ursinus is awkward with huge feet and enormous claws. Sloth bears are nevertheless capable of galloping faster than a person can run. Compared to the body, the face appears naked and grey. They have extremely large tongues, a mobile snout, and they can voluntarily open and close their nostrils, all of which prove helpful with their diets. These bears have a light "U" or "Y" shaped patch on their chests. The color of these markings varies from white to yellow to chesnut brown. Females can weigh between 55-95 kg. Males are 30-40% heavier than females and can weigh between 80 and 140 kg. Adults measure 60-90 cm at the shoulder.
- Sloth bears are highly insectivorous, but their diet includes leaves, honey, flowers, and fruits. During the months of March through June, fruits are more common and on occasion may make up 50% of these bears' diet. They prefer termite or bee nests and will do everything to get at them. While raiding termite nests these bears insert their long snouts into the nest, rip open the nest with their long claws, blow away the earth and dust, then feast on their prize by vacuuming the termites into their mouths. This sucking action is also accompanied with a series of puffings and belchings which can be heard up to 185 m away. The ability to voluntarily open and close the nostrils prevents the inhalation of dust during this process. Termites are a very secure food source, as they are present all year round. When nearby populated areas sloth bears feed on cultivated crops like sugar cane and maize.
- Information on the reproductive behavior of M. ursinus varies. Some studies have them mating mostly between May and July, whereas others report mating and giving birth at any tiime of year. These differences may be due to the location of the bears studied. Field studies in India found sloth bears to mate mostly in June. On the other hand, field studies in Sri Lanka discovered they mate over a greater part of the year. In captivity, a pair only mates for about 1-2 days. Most births occur from September to January. Pregnancy lasts between 6-7 months. One to two offspring are usually born, rarely three, but it does occur. Females usually search for a cave or a ground shelter in which to give birth.
- Sloth bears tend to be very noisy during mating.
- After birth (usually in a ground shelter of some sort), sloth bears are blind for about 3 weeks. Following a period of about 4-5 weeks the young leave the den. The cubs stay with their mother until they reach adulthood at about 2-3 years of age. Cubs often ride on the mother's back.
- Sloth bears are mainly nocturnal. Their sense of smell is well developed but their sight and hearing are poor. These bears are generally not aggressive, but their poor eyesight and hearing allows humans to draw near, and when feeling threatened these bears will defend themselves. Surprisingly, these bears are described as shy. For example, they live in the tropics but have long, dark, shaggy coats suggesting they are susceptible to cold stress. They are excellent climbers, but do not climb trees to escape danger. During the day they sleep in caves, especially caves by river banks. Not much is known about their social systems but evidence suggests they are solitary except for mothers with cubs. They do not hibernate, but do have a period of inactivity during the rainy season.
VII. ECONOMIC IMPORTANCE FOR HUMANS
- Sloth bears live mainly in tropical areas. They can be found in forested areas and grasslands. They are more frequently found at lower elevations and seem to prefer drier forests and areas with rocky outcrops.
- Tropical; savanna or grassland, forest, scrub forest
The gall bladders and fat of M. ursinus are used in traditional medicine.
Sloth bears will enter crop fields such as maize. They also have a reputation for being unpredictable and aggressive (although this may be an unfair description) toward humans. They are quite possibly the most dangerous wild animal in Central India. When they are in human territory, or vice versa, numerous human casualties occur. One study found that between April 1989 and March 1994, there were 735 victims of sloth bear assaults and 48 were fatal.
IX. OTHER COMMENTS
- As is the case for many species, the destruction of sloth bears' habitats is a major cause for their rapidly declining numbers. Sri Lanka has lost about 1.85 million hectacres of natural high forest between 1956-1983. Reasons for the destruction include agricultural and developmental plans. An indirect threat to this species is the destruction of termite mounds for fine soil for tennis courts. Termites are a main source of food for these bears. These bears have also been hunted because of their reputation for aggression and crop destruction.
- IUCN: Endangered
- U.S. ESA: No special status
- U.S. MBTA: 1
- CITES: Appendix I
- Captive sloth bears have lived up to 40 years.
- These bears only risk predation from large predators such as tigers and leopards. Female sloth bears with cubs will occasionally vary from their nocturnal tendencies to avoid these nocturnal predators.
- Predators: leopards, other bears, tigers
- Since these bears include some fruit in their diet, they disperse the seeds of the fruit they eat. Also, by feeding on numerous amounts of termites, they keep the termite populations in check.
- Early explorers observed that M. ursinus hung upside down in trees. This gave rise to the name "bear sloth." Sloth bears were trained by Qualanders, a nomadic group that roamed India and entertained crowds with performing animals and circus acts, and were the original dancing bears.