SUN BEARS: CHARACTERISTICS, BEHAVIOR AND CONSERVATION

SUN BEARS

sun bear at a national park in Thailand

Sun Bears (Helarctos malayanus) are also known as honey bears and Malayan sun bears. They are the only truly tropical bear in Asia. Relatively small and elusive, they are found primarily in the lowland tropical rainforests in Southeast Asia, northeast India, Bangladesh, southern China and the islands of Sumatra and Borneo. The largest population of them is thought to be in Borneo. The bears are named after the reddish “sun” patch on their chest that varies in shape from a U-shape to a circle to an irregularly-shaped spot — and sometimes is not present at all. Each bear’s patch is unique, like a fingerprint, and can be used to identify individual bears.

Sun bears are the smallest bears in the bear family (Ursidae). They are stocky and have have doglike body. This and their small size have earned it the local name dog bear. They range as far north as the eastern Himalayas and Sichuan Province in China and are found in fragmented habitats in Myanmar, Southeast Asia and the Malayan peninsula. On the Sabah-Sarawak border of Borneo, sun bears have been reported living at 2,300 meters (7,545 feet).

Sun bears are commonly found climbing in trees. The paws are fairly large with sickle-shaped claws with naked soles which are thought to be helpful in climbing trees but give them an awkward walk in which all four legs are turned in while walking. In captivity sun bears live 24 years or longer. One captive individual was 35.9 years old when it died. [Source: LeeAnn Bies, Animal Diversity Web (ADW) /=]

Adult sun bears have few predators except humans, due to their fierceness and formidable teeth. Occasionally, they may be overwhelmed by a tiger or large reticulated python. Other possible predators include leopards, clouded leopards, and the sun bear's larger relative, the Asiatic black bear. The sun bear's loose skin on its neck allows it to wriggle its body inside its skin fast enough to turn around and bite its attacker when grabbed. It addition to biting it can rip at attackers with its sharp claws. Some locals say a sun bear is the most dangerous animal a person can encounter in the forest and even tigers keep their distance. There have been reports of unprovoked attacks on other animals, with the sun bear barking as it attacks.

There are two subspecies: 1) the Malayan sun bear (H. m. malayanus), which occurs on the Asian mainland and Sumatra, and is smallest member of the bear family; and 2) the Bornean sun bear (H. m. euryspilus), which occurs only in Borneo and has a skull that is smaller than that of the Malayan sun bear. They play a crucial role in their rainforest ecosystems. “Sun bears are forest engineers,” says Roshan Guharajan, a researcher with the conservation organization Panthera in Malaysian Borneo. Wong Siew Te, founder of the Bornean Sun Bear Conservation Center, calls them “forest doctors.” Alex Fox wrote in Smithsonian magazine: They use powerful jaws and canines as large as a polar bear’s to bite chunks out of trees to access beehives, slurping the honey with a tongue that can stretch to ten inches long. The hollows they create provide new habitat for other arboreal forest dwellers such as flying squirrels or hornbills. Their short, muscled limbs and four-inch claws can break apart rotting logs for grubs and beetles, and dig for worms, boosting decomposition and cycling nutrients in the thin topsoil. And when fruits such as figs or even spiky durian are available, the bears feast on the cornucopia and disperse the seeds in their droppings as they roam, helping the forest regenerate. When fruit isn’t in season, they ransack termite nests, protecting the trees from the destructive insects. [Source: Alex Fox, Smithsonian magazine, April-May 2024]

Sun Bear Characteristics

Sun bear range in length from 1.2 to 1.5 meters (3.9 to 4.9 feet) and stand 60 to 78 centimeters (24 to 28 inches) at the shoulder, making them the smallest member in the bear family. They range in weight from 27 to 65 kilograms (59 to 143 pounds). A bear that is over 50 kilograms is considered big. Their tail is 1.2 to 2.8 inches (3 to 7 centimeters ) long. Sexual Dimorphism (differences between males and females) is present: Males tend to be 10 to 45 percent larger than females. Males normally weigh between 30 and 70 kilograms (66 and 154 pounds) and females between 20 and 40 kilograms (44 and 88 pounds).

sun bear range in 2010: brown – extant; black – former; dark grey – presence uncertain

Sun bear possess very long sickle-shaped claws that are relatively light in weight. These claws and large paws with naked soles are adaptions for tree climbing. Their inward-turned feet make the bear's walk pigeon toed, but also assist it in climbing which it does by hugging the tree with its front limbs and hauling itself up with its teeth. The claws are also used to dig for worms and insects, to tear up bark and old logs to get at termites and remove honey from bee’s nests.

Sun bears have short, wide, flat heads; small, round ears and a stout snout. They possess a very long, slender tongue, ranging from 20 to 25 centimeters (8 to 10 inches) in length. The bear uses it to extract honey from beehives and gather grubs from deep inside holes. Loose skin around its neck allows it to turn and fight even if a predator such as a tiger seizes it by the neck.

Their s coat is entirely black except for the patch on the chest and a grey to faintly orange muzzle. The yellowish or white chest patch may exaggerate bears' sizes during fights. Young are born with soft, shiny coats. Unlike other bears, the sun bear's fur is short and dense and appears sleek but is is rather coarse. These traits are probably adaptations to the lowland climates it inhabits. The dense fur which you think might be a handicap in dense forests is actually quite good at shedding rain and mud. Dark black or brown-black fur covers its body, except on the chest, where there is a pale orange-yellow marking in the shape of a horseshoe. Similar colored fur can be found around the muzzle and the eyes. These distinctive markings give the sun bear its name.

Sun Bear Feeding

Sun bears are opportunistic omnivores (eat a variety of things, including plants and animals). Animal foods include birds, mammals, carrion, insects, terrestrial worms. Among the plant foods they eat are fruit. Bees, termites, and earthworms comprise the main part of their diet. Fruit is eaten when available.

Being omnivores sun bears eat a wide variety of foods including small vertebrates, such as lizards, birds, and turtles, eggs, the young tips of palm trees, nests of bees, grubs, berries, sprouts, roots, and coconuts. In fact, sun bears have been observed to eat over 100 insect species and over 50 plant species. Sometimes it feeds on termites by placing its front paws alternately in a termite nest, licking off the insects with it long tongue when they crawl on his claws.

sun bear tongue

Despite being able to eat many leaves, the sun bear has certain favorite food sources. This was demonstrated in a study where termites, ants, beetles and beetle larvae made up the majority of the invertebrates eaten, whilst figs were the most important fruit source consumed. They eat termites by thrusting their paws into termite mounds and licking them off their paws. Fruit is picked in the trees. Fallen fruit is collected on the ground, The sun bear's fondness for honey gives rise to its alternative name of the 'honey bear'. In Malay and Indonesian, it is known as 'Beruang Madu' which translates to honey bear.

The sun bear’s powerful jaws can crack open nuts. Its long, powerful claws are used to break into tree trunks and fallen logs to access honey, grubs and termites. Much of the sun bear's food must be detected using its keen sense of smell, as its sight is poor. Because food supplies in rains forest are scattered and rot quickly bears often have to cover a lot of ground and move quickly doing so to locate food.

Their incredibly long tongue, measuring up to 25 centimeters (10 inches) according to Guinness World Records, are helpful for obtaining insects from trees, termites from their nests, and digging deep into beehives to extract honey.
When the opportunity present itself, sun bears scavenge tiger kills. In human populated areas their diet may include rubbish, livestock, and agricultural fruit such as bananas. [Source: LeeAnn Bies, Animal Diversity Web (ADW) /=]

Sun Bear Behavior

Sun bears are scansorial (able to or good at climbing), terricolous (live on the ground), nocturnal (active at night),motile (move around as opposed to being stationary), sedentary (remain in the same area) and solitary but little is known about it. It spends much of its time in trees and sometimes rests or even sleeps on rough nests made of bent-over broken branches. The fact that so few bears are found even in relatively undisturbed rain forests has led scientists to surmise they need very large territories to survive.

Being a primarily nocturnal creature, sun bear tends to rest during the day on lower limbs not far above the ground. They sleep and sun bath in trees at heights from two to seven meters. Their nests resemble those made by orangutans but are closer to a tree’s trunk. These beard do not hibernate (the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal’s energy requirements), probably because they live in tropical areas and their food sources are present year round. [Source: LeeAnn Bies, Animal Diversity Web (ADW) /=]

While studies of Sun Bears in the wild indicate they live solitary existence, most likely due to competition for food, in captivity they exhibit social behavior. Sun bears sometimes travel in pairs and often leave scratch marks on trees, presumably to mark their territory or declare their presence in an area.

Sun bears sense using vision, touch, sound and chemicals usually detected with smell and communicate with sound and chemicals usually detected by smelling. Like other bear species, they have a keen sense of smell. Bears tend to use their senses of smell and touch to find and manipulate food. They probably use olfactory cues to find potential mates and use some vocalizations. Adult sometimes make loud roars and grunts. /=\

One sun bear in captivity demonstrated extraordinary intelligence. He took the rice that was given to him for food and scattered it on the ground. There were also chickens in this bear's area. The scattered rice attracted these chickens, which the bear then captured and ate. /=\

Sun Bear Mating, Reproduction and Offspring

sun bear

Female sun bears mate at about once every three years any time of the year. Courtship lasts two days to a week, during which time sun bears display behaviors like hugging, mock fighting, head bobbing and even kissing. There is some suggestion that sun bears might be monogamous. There have been sightings of sun bear couples with young. Captive male sun bears have been observed placing their paws over their heads, in a human-like frustration pose, after losing battle with their “bossy” wives, who sometimes steal their food.

Because sun bears do not hibernate they can reproduce year-round. The offspring reach sexual maturity after three to four years and may live up to 30 years in captivity. A female sun bear usually produces one or two but occasionally there are three. .

Sun bears undergo a roughly 96 day gestation period after which the 300 to 400 gram cub is born blind and hairless with nearly transparent skin. According to Animal Diversity Web: There is evidence of delayed implantation (a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months). Some sun bear pregnancies in a zoo in Fort Worth lasted 174 to 240 days. A sun bear at the Berlin Zoo actually gave birth two times in one year in 1961, first in April, then again in August, but this is rare. [Source: LeeAnn Bies, Animal Diversity Web (ADW) /=]

Like other bear species, sun bear females invest large amounts of energy raising their young. Pre-weaning provisioning and pre-independence provisioning and protecting are done by females. There is an extended period of juvenile learning. Cubs are initially totally dependent on their mother and suckling can continue for about 18 months. After one to three months, young cubs can run, play and forage near its mother. Cubs stay with their mothers until fully grown. They like to suck their paws, often making a “humming” nose when they do so. On average males and females reach sexual or reproductive maturity at three years.

Sun Bears, Humans and Conservation

On the International Union for Conservation of Nature (IUCN) Red List sun bears are listed as Vulnerable. In CITES (Convention on International Trade in Endangered Species of Wild) they are in Appendix I, which lists species that are the most endangered among CITES-listed animals and plants.[Source: LeeAnn Bies, Animal Diversity Web (ADW) /=]

Sun bears are known to cause damage to crops such as oil palms, coconuts, and bananas. Their gall bladders, bile and body parts have been used in folk medicines. Habitat destruction to create coffee, rubber and oil palm plantations and slash-and-burn agricultural settlement has caused bears to live in smaller and more isolated fragments of habitat.

A decline in the sun bear population in the 2000s and 2010s was largely attributed to the hunting of "nuisance bears" that destroyed crops and widespread poaching driven by the market for their fur and for their bile, which is used in Chinese medicine. Sometimes mothers are shot by poachers for their body parts and the cubs are sold as pets. Because it spends so much time in trees, the sun bear can sometimes cause damage to property. It has been known to destroy coconut palms and cacao trees on plantations. They like palm hearts — whose removal can kill a tree — and sometimes return to the same place on successive nights, inflicting heavy damage. The biggest threat to the sun bear is habitat destruction as a result of deforestation caused by slash-and-burn agriculture, logging and rubber and palm oil plantation development.

Sometimes, sun bears are captured or bred to be domestic pets — a role for which they are considered desirable, due to their relatively inoffensive nature and small size in comparison with other bears. Cubs are very playful and adorable. Poachers in Borneo use logging roads to gain access remote tracts of forest and scan the forest with searchlights — an illegal technique in the U.S. called “jacklighting” — to locate bears and other animals by the bright glow of their eyes and stun them long enough to blast them out of the trees with a shotgun. The IUCN classified the sun bear as "vulnerable" in 2007.

Studying and Trying to Counting Sun Bears

Sun bears are very hard to find in the wild and precious little is known about them. Alex Fox wrote in Smithsonian magazine: The bears are woefully understudied. With no reliable estimates of their global population or current distribution, conservationists are sometimes forced to guess where to protect rainforest habitat or crack down on poaching. That’s why in 2024 members of the IUCN's Bear Specialist Group launched an initiative to create an updated range map for this little-studied species. [Source: Alex Fox, Smithsonian magazine, April-May 2024]

The effort combined new data from camera traps, field surveys and input from hundreds of experts across Southeast Asia to determine local sun bear presence. It also used confirmed bear sightings to create a computer model that predicts where else bears “should be” by looking for environmental commonalities — attributes such as tree cover, tree species, forest age and elevation, and the locations of roads and protected area boundaries.

The specialist group will use the resulting updated range map to identify the highest-priority areas for sun bear conservation — for example, flagging emerging deforestation threats, identifying dangerously small populations and spotting corridors that could connect isolated bear habitats. “Sun bear populations could be blinking out in many small forest patches unbeknownst to us,” Dave Garshelis, co-chair of the specialist group, says. “We need this information to highlight where direct conservation actions should be focused.”

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated January 2025