Asiatic Black Bears (Selenarctos thibetanus)
Description: The
Asiatic Black Bear can easily be distinguished from the sun bear by its very
long pelage. 
It
is about twice as heavy as the sun bear, and has relatively longer ears. The
black bear has long hair and a wide white "V" shaped mark from the upper breast
to both shoulders. It often weighs over 100 kg and in captivity can reach weights
up to 160 kg.
Distribution: Southern and Eastern Asia: Japan, China, Taiwan, Hainan, Tibet, Nepal, Burma, Thailand. Found in hill areas.
Habitat and Behavior: The Asiatic black bear usually stays alone and pairs only during the breeding season. It prefers forested hills and mountains, but may also be found at lower levels. Generally, nocturnal, sleeping during the day in hollows of trees, caves, or crevices of rocks, and coming out at night to feed. However, it is also seen feeding or moving about in the daytime when favored fruits are ripening. It is an expert climber and marks of its claws are often seen on tree trunks where it has climbed for fruit, berries, or beehives. It usually walks on all fours, but when on attack it often stands on its hind legs and uses its paws to scratch and pound at the foe.
Diet: Their diet is widely varied depending on what is locally available. Besides the normal bear diet of fruit, buds, invertebrates, and small vertebrates, Asian black bears will also take animals as large as adult buffalo, killing them by breaking the neck. They will also eat carrion.
Reproduction: The gestation period is 7-8 months and usually two cubs are born in a cave or hollow tree in early winter. The eyes of the cubs remain closed for about a week after birth. A short time after the eyes are open, the young begin following the female as she forages, staying with her until they are nearly full grown or until the mother is in estrous again; females have been seen with two sets of cubs. Breeding begins at the age of about three years, and the lifespan in captivity may be as much as 33 years.
Malayan
Sun Bear (Helarctos malayanus)
Description: The Malayan Sun Bear is the smallest bear in the world. The hair is short and black all over except the muzzle and the "U" shaped marking on the upper breast. The white muzzle is more conspicuous than that of the Black Bear and in most cases the white area extends far above the eyes. The ears are small and round, and the forehead and areas behind the ears have whorls of hair, which is lacking in the Selenarctos. Sun bears weigh about 27-65 kg, though any weight over 50 kg should be considered heavy in the wild.
Distribution: From Burma and Thailand through Malaysia to Borneo and Sumatra, possibly found in southern China. Found in jungles all over Thailand, but they are more common in the south.
Habitat and Behavior: The Sun Bear is generally nocturnal but is also seen during the day, often traveling in pairs. It inhabits dense forests of all elevations in Thailand and is an excellent climber. These bears normally sleep in a tree nest, probably built just before retiring. Like other bears, it often stands on its hind legs to get a better view of a distant object, or when it encounters an enemy. It is said to be one of the most dangerous animals for jungle people to meet. Besides biting with its sharp canines and powerful jaws, it uses its strong paws and sharp claws to tear the skin of the head and makes severe wounds on the face and body of its victim. It is one of few animals that will charge without apparent warning or cause. On the attack it barks loudly, "How, how!"
Diet: Food habits are roughly similar to that of the Asiatic black bear, but with insects, especially bees, termites, and earthworms, forming a considerably greater proportion of the diet. They also like to eat the heart of coconut palms. Sun bears are known to do serious damage to coconut plantations, destroying numerous trees in a single night and returning to the plantation until all trees have been affected.
Reproduction: Breeding seems to be throughout the year, usually two cubs are born blind and hairless after a gestation of 95-96 days. The cubs stay with their mother until nearly grown. The adult dentition is complete by the age of 18 months, and lifespan in captivity may be 20 years.
Source: "Mammals of Thailand" by Boonsong Lekagul & Jeffrey A. McNeely
