The sun bear is found primarily in the rainforests of Southeast Asia and is believed to be in the following countries: India, Bangladesh, Myanmar (formerly Burma), Thailand, Cambodia, Vietnam, Indonesia, Malaysia, Brunei , and Laos. Laos is thought to be one of the last strongholds for the sun bear because of its rugged terrain, scarcity of human population, and abundance of forested area. The sun bear used to inhabit China. However, that is now thought to be doubtful. The one subspecies of sun bear (Helarctos malayanus euryspilus) is found only on the island of Borneo.
The size of the sun bear's territory depends a lot on the concentration of food sources. They spend a good portion of the day sleeping and sunbathing in nests or platforms that they build in trees.
The sun bear is roughly half the size of the American black bear. The average adult weighs from 60 to 145 pounds and measures from 48 to 60 inches in length. Males are 10 to 20 percent larger than females. Like other bears, it stands on its hind legs to view distant objects or when it senses a potential enemy.
Their black fur is short and dense and repels rain, mud, and other debris rather efficiently. The color of the bear's short muzzle varies in color from light gray to orange which often extends slightly above their beady eyes. The sun bear's ears are smaller and more rounded than most bears, though they have excellent hearing. Their feet are turned inward, giving them a distinctive pigeon-toed walk, similar to that of the sloth bear. Their bare soles and long sharp claws make them excellent tree climbers.
Sun bears have an extremely long narrow tongue which they use to extract honey from hives and insects from deep crevices in trees. Their teeth are flatter compared to other bears' teeth. Although the sun bear isn't extremely carnivorous, its canine teeth, which are used by many animals to tear meat, compare favorably with those of lions and tigers. Just like with a tree, a sun bear's age can be determined by the number of rings in its teeth.
The sun bear is known to be exceptionally aggressive and will attack without cause. Having such large canines, extremely strong jaws and long claws, it is said to be one of the most dangerous animals to encounter in the jungle.
The Malayan sun bear is omnivorous. In the jungle, food can be spread out very thinly over a large area. Sun bears are nocturnal animals, usually setting out at dusk in search of anything edible. They have a large variety of foods in their diet such as, fruits, honey, snails, eggs, lizards, birds, rodents, and other small animals. They also enjoy the young tips of palm trees, nests of bees, sprouts, roots, termites, and other insects. They have no problem breaking open nuts with their strong jaws or tearing open termite mounds with their long claws. The Bornean sun bear relies on fruits from the Moraceae, Burseraceae and Myrtaceae family to make up over half its diet.
The diet of the Thailand sun bear is very similar to that of the Asiatic black bear since their habitat overlaps.
Because they do not hibernate, sun bears are capable of reproducing year-round and have been observed breeding at various times of the year. The mating period lasts anywhere from two days to a week. It is described as a boisterous occasion, similar to sloth bears, with the bears engaging in hugging-like behavior, mock fighting, head bobbing, head nuzzling and barking. Copulation takes place in a manner similar to members of the canine (dog) family.
The gestation period is usually about 95 days. However, it has been observed to last as long as 240 days which suggests delayed implantation. Usually 1, but sometimes 2 cubs are born while the mother sun bear nests deep in the forest undergrowth. Climate and food supply are important determinants to the size of the litter.
At birth, the cubs are blind, hairless and very tiny. Their approximate weight is 7 ounces. Their skin is virtually transparent. Helpless at birth, the cubs develop quickly, and within 1 or 2 months they are able to forage with their mother.
There are reports of sun bears forming monogamous pairs in the wild but this is, at present, unsubstantiated. Pairs of adults have been observed to be in the company of cubs. However, sun bears are usually solitary creatures except during mating season and females raising their offspring. The cubs usually stay with their mothers until they are nearly full grown. Females reach maturity at about 3 years, and males 4 years.
The two major threats to sun bears are habitat loss and commercial hunting. They are hunted mainly for their meat and for use in medicines. They are also hunted for their fur and even to sell as exotic pets. Killing of the bear is prohibited by national wildlife laws. However, enforcement of these laws is rare. Though the size of their population is unknown, it is estimated that it has declined over 30 percent in the last 30 years.
They have been on the IUCN's Red List of Endangered Species since 1978, and are listed as vulnerable. Their lifespan in captivity is 25 to 28 years. Though their lifespan in the wild is unknown, it is thought to be about 12 to 24 years.