Sun Bear

The sun bear is the smallest, least-known, and most tropical of the world’s bears — a compact, black, tree-climbing animal of the Southeast Asian rainforest, named for the golden mark on its chest and known locally for its love of honey.

Overview

Sun bears live in the lowland and hill forests of Southeast Asia, from the foothills of the eastern Himalaya through mainland Indochina to the islands of Sumatra and Borneo. They are forest specialists, dependent on intact tree cover for food and shelter, and are among the least-studied bears because they are secretive, thinly spread, and live in dense, hard-to-survey habitat.

Physical characteristics

A sun bear has short, sleek black fur — no shaggy coat is needed in the tropics — with the pale chest crescent and often a pale muzzle. It is powerfully built for its size, with a stocky body, large paws, long inward-curving claws, and a broad head with a strong bite. Relative to body size, its canine teeth are the largest of any bear, useful for cracking hard nuts and prising open bark and wood.

The skin is notably loose, especially around the neck. A sun bear grabbed by a predator — a tiger, a leopard, a python — can rotate inside its own hide and turn to bite.

Diet and the forest’s plumber

Sun bears are omnivores whose diet shifts with what the forest offers: fruit when trees are in season (they are important seed dispersers), and insects, honey, and small animals the rest of the year. With their claws and jaws they tear open rotten logs, dig into the ground, and rip apart tree cavities and beehives, then use the long tongue to extract termites, ants, beetle grubs, and honey.

In doing so they open up nest holes and cavities that other animals — birds, flying squirrels, civets — go on to use, and they aerate the soil and thin out insect populations. Where sun bears disappear, parts of the forest food web change.

Behaviour and life cycle

Sun bears are mostly solitary and, in areas with people, largely nocturnal. They are excellent climbers, building nests of bent branches in the canopy to sleep and sunbathe in, sometimes 20 m up.

Breeding can happen at any time of year in the aseasonal tropics. After a pregnancy of about 95 days — occasionally much longer, if implantation is delayed — the female gives birth to one or two tiny cubs in a ground den. Cubs stay with her for around two years.

Threats and conservation

The sun bear is Vulnerable and declining across its range:

• Deforestation. Southeast Asia’s lowland forests are being cleared for oil palm, rubber, and timber faster than almost anywhere on Earth, removing the fruiting trees and hollow logs sun bears depend on.
• Poaching. Sun bears are hunted for their gallbladders and bile, used in traditional Asian medicine and sometimes “farmed” from captive bears, and for their paws and meat.
• The pet trade. Cubs are taken from the wild — usually after the mother is killed — and kept as pets or tourist attractions.

Rescue centres in Malaysia and Indonesia rehabilitate confiscated sun bears, and protecting large connected areas of lowland forest is the key to the species’ future.