Sun bear

Name and taxonomy

Stamford Raffles described the species from Sumatra in 1821 as Ursus malayanus. Thomas Horsfield gave it a genus of its own, Helarctos, in 1825 when he described a bear from Borneo. The genus name joins the Greek words for sun and bear. It is the only species in Helarctos, within the bear family Ursidae and the order Carnivora.

Two subspecies are recognised: Helarctos malayanus malayanus on the mainland and Sumatra, and the smaller Helarctos malayanus euryspilus of Borneo. The genetic difference between them is slight, and some authors treat the species as a single form. Other English names include Malayan bear, honey bear and, in some lists, dog bear.

Evolution and relatives

The sun bear is one of eight living bears and belongs to the subfamily Ursinae. Nuclear gene studies show that the sun bear and the sloth bear branched off first among the ursine bears. Both sit outside the genus Ursus. The sun bear line probably split from the two black bears between about 6.26 and 5.09 million years ago. The species hybridises with the sloth bear in captivity, and the offspring are fertile.

Fossils show the sun bear lived further north in the Pleistocene, and as far south as Java. Its inturned front feet, flat chest and heavy forelimbs are thought to be adaptations for a life of climbing. The Asian black bear shares its mainland range and carries a similar cream chest mark.

Appearance

The sun bear is stocky, with a big broad head, a short snout and small rounded ears. Head and body measure 100 to 140 centimetres, and the shoulder stands about 70 cm high. Adults weigh 25 to 65 kilograms, and the tail is only 3 to 7 cm long. Males are larger than females by roughly 10 to 20 percent, less than in most bears. The Bornean subspecies is markedly smaller than the mainland form.

The fur is the shortest of any bear, silky and fine, and usually jet black, though it can shade to grey or red. Two whorls sit on the shoulders, and the hair radiates out from them. The muzzle is grey, silver or orange. The chest patch is usually a U shape, from orange or ochre through buff and cream to white, and a few bears lack it. The shape never changes through a bear's life, so researchers use it to recognise individuals.

The paws are large with bare soles, which probably helps in climbing. The front claws are long, heavy and sickle-shaped. The tongue is exceptionally long and reaches into hives and nests. The canine teeth are very large, and a 50 kg bear bites with a force of 1907.3 to 2020.6 newtons on the rear molar.

Habitat and range

The range runs from north-east India and Bangladesh through Myanmar, Thailand, Laos, Cambodia and Vietnam to Malaysia, Brunei and Indonesia. A sighting in Yingjiang County confirmed the bear in Yunnan, China, in 2017. The Brahmaputra bounds the range in the north-west and the Red River in the north-east. The species is extinct in Singapore and has gone from most of Thailand. GBIF holds records from 20 countries, a count that includes zoos.

North of the Isthmus of Kra the bear lives in deciduous and seasonally evergreen forest, alongside the Asian black bear. In Sumatra, Borneo and Peninsular Malaysia it lives in wet evergreen dipterocarp rainforest and peat swamp. It also uses mangroves and oil palm plantations when better forest lies close by. Most bears live below 1,200 metres, but in India they have been recorded up to 3,000 m, probably because lowland forest is gone.

Home ranges run from 7 to 27 square kilometres in Borneo and Peninsular Malaysia. Density varies from 4.3 to 5.9 bears per square kilometre in Khao Yai National Park to 26 in the Harapan Rainforest of Sumatra. The bear avoids heavily logged forest and villages, though it will raid orchards and plantations.

Diet and feeding

The sun bear is an omnivore that leans toward insects. It eats more than 100 insect species, mainly termites, ants, beetles and bees, plus honey and bee larvae. The bear specialists' association puts the diet at roughly 70 percent animal and 30 percent plant food. Earthworms, small rodents, birds, lizards and tortoises are taken when found, and it scavenges tiger kills.

Fruit matters most in a masting year, when many trees fruit at once. In Kalimantan figs and the fruits of the Burseraceae and Myrtaceae make up more than half the fruit diet. When fruit fails the bear turns back to insects. It eats the heart of coconut palms, crushes acorns and other oily seeds, and raids bananas and oil palm fruit near farms.

Its jaws and claws rip open hollow hardwood trees to reach wild bees. At a termite mound it breaks the crust, holds the pieces in its forepaws and licks up the insects. Much of its foraging is done at night.

Behaviour and social life

No bear spends more time in trees. The sun bear climbs to feed when fruit is plentiful. It rests 2 to 7 metres up, sometimes on a nest of bent branches and leaves. On the ground it beds in hollow logs, tree cavities and the spaces under roots. It swims well.

Radio collars show bears far from roads are active mainly by day. Near roads and oil palm estates they turn nocturnal, so camera traps catch them at night. It does not hibernate, probably because food is available all year. Adults are solitary apart from a mother and cub, though bears sometimes gather at a rich food source.

To look around or catch a distant scent the bear stands on its hind legs. When threatened it rises and shows its chest patch to look bigger. It is clever: a captive bear watched sugar being locked in a cupboard and later opened the lock with a claw. A 2019 study found that sun bears copy each other's facial expressions with a precision seen otherwise in gorillas and humans.

Communication and senses

Smell is the main sense, and the bear uses its nose and its touch to find and handle food. It probably tracks mates by scent as well.

Foraging bears grunt and snuffle. In the breeding season a male roars in a voice that has been compared to a male orangutan. A surprised bear gives short barks. The raised chest patch is a visual threat, and the patch's shape marks out one bear from another.

Reproduction and life cycle

The sun bear is the only bear with no clear breeding season, and cubs are born in every month. A female comes into heat for five to seven days. Pregnancy is short for a bear, about 95 days in zoos. With delayed implantation it can stretch to 240 days.

The mother gives birth in a hollow tree to one cub, sometimes two, each weighing about 325 grams. Cubs are born deaf and blind. The eyes open at about 25 days, but full sight and hearing take about 50 days. The mother keeps her cubs on the buttress roots of a tree until they can walk and climb, and she defends them fiercely.

Cubs stay with their mother for nearly three years. Both sexes mature at two to four years. A captive bear has lived 35.9 years, and most captive bears pass 20. The wild lifespan is unknown.

Predators and threats

The tiger is the main predator, and dholes and leopards take a few bears. In one fight a tiger and a sun bear both died. A large reticulated python swallowed an adult female in East Kalimantan. Adult males sometimes kill cubs.

People are the real danger. Southeast Asia lost almost 12 percent of its forest between 1990 and 2010 to farms, logging and fire. Wire snares set for bears have been found even inside protected areas such as Nam Ha in Laos. Farmers shoot or poison bears that raid coconut and snakefruit plantations in East Kalimantan.

Bears are caught alive for farms in Laos, Vietnam and Myanmar, where bile is drained for traditional medicine. A survey of 128 medicine shops across Sabah and Sarawak, run in 2018 and 2019, found bear parts on sale in a quarter of them. Cubs are sold as pets and outgrow their owners within a year or two.

Population and conservation

The IUCN lists the sun bear as Vulnerable, and CITES lists it in Appendix I, which bans international trade. No reliable count exists because the bear is secretive and its forest is dense. The IUCN Bear Specialist Group estimates a fall of 35 percent since the 1990s. Numbers are lowest in Bangladesh and China, and Vietnam's bears may lose 50 to 80 percent in the next 30 years.

Every range country protects the bear by law except Sarawak and Cambodia, but enforcement is weak. A 2014 report found poaching and trade in Sarawak worse than anywhere else in Malaysia. A conservation action plan appeared in 2019, and Sabah adopted a ten-year plan for 2025 to 2034.

Zoos run a Species Survival Plan for the bear in North America and a European studbook at Cologne, both since 1994. Wong Siew Te founded the Bornean Sun Bear Conservation Centre in Sabah in 2008 with eight confiscated bears. It held 42 rescued bears in 2025 and started soft releases of cubs at Tabin in 2023.

Relationship with humans

The sun bear seldom attacks a person unless it is cornered, hurt or with cubs. Its shy nature led people to tame cubs as pets, though an adult is far too strong to keep. A bear surprised in the forest can still be fierce.

Villagers see it as vermin when it eats oil palm shoots, coconuts and bananas or takes poultry. A survey in the Lower Kinabatangan found people feared the bear, yet bearded pigs, elephants and macaques did far more crop damage. Hunters take bears for meat and for gall bladders, paws and claws, which have no proven medicinal value.

Sanctuaries in Malaysia, Indonesia, Cambodia and Laos now hold bears seized from traders. Many arrived as cubs and cannot go back to the wild. The bear draws tourists to Sabah, and it appears to have become a symbol for forest protection in Borneo.

In culture and myth

In Malay and Indonesian tradition, the animal is beruang madu, the honey bear, named for its raids on wild hives. In Bornean tradition, the chest patch resembles the glow of a sun not yet risen above the mountain. That story is one explanation of the English name. The scientists who named it reached for the same image: Helarctos means sun bear in Greek.

In Chinese tradition, bear bile has been a medicine for centuries, and that belief drives the bear farms of Laos and Vietnam. Science finds no medical value in it. Some Bornean communities are thought to have hunted the bear for its meat and claws as trophies. Today the bear appears on conservation posters and in school programmes across Sabah as the face of the shrinking forest.