The sun bear (Helarctosmalayanus) is a well-known bear species in the family Ursidae, native to Southeast Asia’s tropical forests.
The sun bear is the most arboreal of all bear species. A sun bear is an excellent climber, so it sleeps or sunbathes in trees 7 – 23 ft (2 – 7 m) above the ground.
It is mainly nocturnal, although nocturnality may be expressed in some in certain areas frequented by humans.
Sun bears are solitary animals but are often seen in pairs (mother and her cub). Sun bears are threatened by illegal hunting for food & the wildlife trade, and heavy deforestation. Sun bears are listed on the IUCN Red List as Vulnerable.
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It is regarded as the smallest among all bear species, standing nearly 28 in (70 cm) at the shoulder and weighing 55 to 143 pounds (25 to 65 kg).
It is stubbily built, strongly curved claws, large paws, short snout, and small rounded ears. The fur is usually jet-black but can vary from red to grey. The term “sun” in sun bear is gotten from the characteristics cream to orange coloured chest patch.
Its unique morphology includes a flattened chest, inward-turned front feet, and powerful forelimbs with large claws (which are believed to be an adaptation for climbing).
The head and body length is between 39 – 55 in (100 – 140 cm). The snout could be silver, grey, or orange. The hair is fine and silky and is also the shortest among all bear species due to hot tropical habitat.
The common trait among all sun bears is the chest patch, usually U-shaped but sometimes spot-like or circular and it varies from ochre-yellow or orange to cream or buff, or even white. Some individuals may lack the patch.
Infants are born with greyish black fur, with a white or pale brown snout and a dirty white chest patch. The guard hairs are lighter than the underfur in adults. The edges of the paws are brown or tan, with sickle-shaped claws and furless soles.
The tail is 1 to 3 in (3 to 7 cm) long. Sun bears extend their long tongue by 8 to 10 in (20 to 25 cm) to extract honey and insects.
Sun bears give birth throughout the year (polyoestrous). Oestrus lasts 5 – 7 days. Sun bears become sexually mature at 2 – 4 years of age.
The gestation period may last 95 – 240 days. Newborns are born inside hollow tree cavities. A litter usually comprises 1 or 2 weighing around 11 ½ ounces (325 grams) each.
Newborns are born with their eyes closed and are also deaf. Their eyes open on the 25th day, but they remain blind till the 50th day. Their sense of hearing develops during the first 50 days.
The young remain with their mother for nearly the first 3 years of their lives. The average lifespan of sun bears in captivity is 20 years; one specimen lived for 31 years.
Sun bears are omnivorous animals, and they feed on a wide variety of food items such as bees, ants, honey, beetles, termites, and plant material such as fruits and seeds. Vertebrates such as deer, birds, reptiles, and eggs may be eaten often.
Due to the availability of food resources throughout the year, sun bears do not hibernate.
Habitat and distribution
The sun bears range from northeastern India to northern India. It extends from the south to southeast through Cambodia, Bangladesh, Laos, Myanmar, Vietnam, Thailand, Indonesia, Brunei, and Malaysia to the south.
Sun bears are believed to be extinct in Singapore. Sun bears inhabit two types of forests; non-seasonal ever-green forests in Malaysia and Indonesia and deciduous & seasonally ever-green forests to the north of the Isthmus of Kra.
They are usually found at low altitudes, such as below 3,900 ft (1,200 m) in peninsular Malaysia and western Thailand.
The major habitats in peninsular Malaysia and southern Thailand are moist ever-green forests, with heavy rainfall throughout the year, more or less non-varying climate, and montane or low-lying dipterocarp forests.
Sun bears tend to avoid areas close to human settlements and heavily logged forests. However, they have been seen in plantations, farmlands, and orchards. Sun bears have been reported to prey on livestock and poultry.
Population densities vary from 4.3 – 5.9 individuals per 39 sq mi (100 km2) in Khao Yai National Park, located in Thailand, to 26 individuals per 39 sq mi (100 km2) in the Harapan Rainforest located in southern Sumatra.