Along with being the smallest bear species in the world, the sun bear (Ursidae Helarctos malayanus) is also one of the rarest. The sun bear's name is derived from the golden colored crescent shaped patch of fur on its chest. It is also known as the honey bear because of its extreme fondness of honey, the dog bear because of its size, and the Malay bear for its geographical location.
Out of all species of bears, the least is known about the sun bear because they are so rare.
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.
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 diet of the Thailand sun bear is very similar to that of the Asiatic black bear since their habitat overlaps.
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.
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.