Mammals: Sun Bear

Range: Thailand, Cambodia, Vietnam, Laos, Burma, the Malay Peninsula, Sumatra, and Borneo in Asia. Habitat: dense tropical and subtropical forest

Small but mighty

The sun bear is the smallest of the world's eight bear species, about half the size of the American black bear. Its name comes from the white or yellowish crescent marking on its chest, which many people think looks like the rising or setting sun.

The sun bear’s teeth are flatter than those of other bears, and their canine teeth are long enough to stick out a bit between their lips. Their ears are smaller and rounder than those of other bears, yet they can hear very well. They have a distinctive pigeon-toed walk, a clue to their arboreal lifestyle.

Tree, sweet tree

In the Malay language, sun bears are called basindo nan tenggil, which means “he who likes to sit high.” Sun bears certainly live up to that reputation! They like to make their homes in the branches of trees. Their small size, four-inch-long (10-centimeter-long) claws, and large paws with hairless soles help them move about with ease high up in trees. And since the sun bear is nocturnal, those branches also make a nice place to build a nest for resting or sunbathing during the day.

A tropical forest buffet

The omnivorous sun bear uses its front paws for most of its dining needs as its long claws rip open trees in search of insects or sap. Other food choices include small birds, fruit, honey, lizards, rodents, and soft parts of palm trees. Strong jaws and teeth even help this bear open coconuts!

The sun bear’s especially long tongue is perfectly suited for getting at honey and insects inside trees and other tight places. Its appetite for coconuts, oil palms, and other commercial crops have led to a lot of trouble between sun bears and humans.

At the San Diego Zoo, the sun bears eat fruits, vegetables, and an omnivore pellet that’s a lot like dog kibble. They also receive bones to gnaw on twice a week and, for enrichment, an assortment of goodies like mealworms, crickets, and even peanut butter!

Built-in protection

Sun bears have all the tools necessary to protect themselves. Those claws and canine teeth are handy weapons in a fight. If a predator were to latch on during a struggle, the sun bear can turn in its loose skin and bite its attacker. And even though they live in a hot, humid climate, their fur is unusually thick and dense to protect the bears against twigs, branches, falls, and heavy rain.

Cub scouting

Because sun bears are often spotted in pairs, it is thought that they are monogamous. Sun bears don’t have a particular breeding season. Nests have been observed in leafy vegetation on the ground or in hollow logs. Cubs are born hairless and helpless, unable to hear or smell, and are completely dependent upon their mother (sow) for food, warmth, and protection. Sows sometimes walk upright and carry their babies in their arms to move them from place to place. The youngsters are able to run and play at about two months of age, and they are weaned at four months of age. They will stay with their mother, however, for more than two years.

Uncertain times for sun bears

Sun bears are an endangered species. It is unknown how many are left in the wild, since their secretive nature makes them hard to study. In the wild, sun bears are getting fewer and fewer, due mainly to habitat loss from farming and logging, poaching (both for meat and use in medicines), and even the pet trade. The Association of Zoos and Aquariums (AZA) has a Species Survival Plan (SSP) for sun bears, of which the San Diego Zoo is a participant.