Sun Bear
The sun bear is the smallest bear. It is stocky, with large paws, strongly curved claws, small rounded ears and a short snout. The head-and-body length is between 100-140 cm, and the shoulder height is nearly 70 cm. Adults weigh 25–65 kg. The snout is grey, silver or orange. The fur is generally jet-black but can vary from grey to red. The hair is silky and fine, and is the shortest of all bear species, suiting their hot tropical habitat.
The characteristic chest patch, typically U-shaped but sometimes circular or spotlike, varies from orange or ochre-yellow to buff or cream, or even white. Some individuals may even lack the patch. Sun bears can expose the patch while standing on their hindfeet as a threat display against enemies. The underfur is particularly thick and black in adults, while the guard hairs are lighter. Two whirls occur on the shoulders, from whence the hair radiates in all directions. A crest is seen on the sides of the neck and a whorl occurs in the centre of the breast patch. The edges of the paws are tan or brown, and the soles are fur-less, which possibly is an adaptation for climbing trees. The claws are sickle-shaped; the front claws are long and heavy. The tail is 3–7 cm long. During feeding, the sun bear can extend its exceptionally long tongue by 20–25 cm to extract insects and honey. The teeth are very large, especially the canines, and the bite force is high relative to its body size for reasons not well understood; a possible explanation could be its frequent opening of tropical hardwood trees with its powerful jaws and claws in pursuit of insects, larvae, or honey. The head is large, broad and heavy in proportion to the body, but the ears are proportionately smaller; the palate is wide in proportion to the skull. The overall unique morphology of this bear—inward-turned front feet, flattened chest, powerful forelimbs with large claws—indicates adaptations for extensive climbing. There are two subspecies; the Malayan Sun Bear which occurs on mainland Asia and Sumatra; Bornean Sun Bear which occurs only in Borneo.
Habitat
Sun bears are found in the tropical forests of Southeast Asia; the range is bound by northeastern India to the north and extends south to southeast through Bangladesh, Cambodia, Myanmar, Laos, Thailand and Vietnam in mainland Asia to Brunei, Indonesia and Malaysia to the south. Their presence in China was confirmed after years in 2017 when they were sighted in Yingjiang County of Yunnan Province (China). Sun bears are extinct in Singapore. These bears dwell primarily in two main types of forests throughout their range: deciduous and seasonally evergreen forests to the north of the Isthmus of Kra, and non-seasonal evergreen forests in Indonesia and Malaysia.
​
They are typically found at low altitudes, such as below 1,200 m in western Thailand and peninsular Malaysia. However, this varies widely throughout the range; in India, larger numbers have been recorded at an elevation of up to 3,000 m than in low-lying areas, probably due to habitat loss at ground level. They occur in montane areas in northeast India, but may not extend farther north into the unfavourable and colder Himalayan region; their distribution might be restricted to the northwest due to competition with sloth bears. The sun bear is sympatric with the Asian black bear throughout the remaining areas in the mainland range featuring a mix of seasonal forest types, with monthly rainfall below 100 mm for a long spell of three to seven months. In mountainous areas, Asian black bears are more common than sun bears, probably due to scarcity of invertebrates to feed on. The major habitats in southern Thailand and peninsular Malaysia are moist evergreen forests, with more or less non-varying climate and heavy rainfall throughout the year, and low-lying or montane dipterocarp forests. Mangroves may be inhabited, but usually only when they are close to preferred habitat types. Sun bears tend to avoid heavily logged forests and areas close to human settlement. However, they have been seen in farmlands, plantations and orchards, where they may be considered vermin.
Diet
Sun bears are omnivores and feed on a broad variety of items such as ants, bees, beetles, honey, termites and plant material such as seeds and several kinds of fruits. Vertebrates such as birds, deer, eggs and reptiles may be eaten occasionally. They forage mostly at night. Sun bears tear open hollow trees with their long, sharp claws and teeth in search of wild bees and honey. They also break termite mounds and quickly lick and suck the contents, holding pieces of the broken mound with their front paws. They consume figs in large amounts and eat them whole. In a study in the forests of Kalimantan, fruits of Moraceae, Burseraceae and Myrtaceae species made up more than 50% of the fruit diet; in times of fruit scarcity, sun bears switched to a more insectivorous diet. A study in Central Borneo revealed that sun bears play an important role in the seed dispersal of Canarium pilosum. Sun bears eat the centre of coconut palms and crush oil-rich seeds such as acorns. Oil palms are nutritious but not enough for subsistence.
Breeding
Sun bears are polyoestrous; births occur throughout the year. Oestrus lasts five to seven days. Sun bears become sexually mature at two to four years of age. Reported lengths for pregnancies vary from 95 to 240 days; pregnancy tends to be longer in zoos in temperate climate possibly due to delay in implantation or fertilisation. Births occur inside hollow tree cavities. A litter typically comprises one or two cubs weighing around 325 grams each. Cubs are born deaf with eyes closed. The eyes open at nearly 25 days but they remain blind till 50 days after birth; the sense of hearing improves over the first 50 days. Cubs younger than two months are dependent on external simulation for defecation. Cubs are kept on buttress roots at the base of trees until they learn how to walk and climb properly. Mothers protect their cubs aggressively. Offspring remain with their mother for nearly the first three years of their lives. Lifespan in captivity is generally over 20 years; one individual lived for nearly 31 years.
Population
According to the IUCN Red List, they are classed as Vulnerable(VU). Their population trend is considered decreasing and the number of mature individuals is unknown. They were last assessed in February 2016.
Threats
Sun Bears are threatened primarily by deforestation and commercial hunting. Killing due to human-bear conflicts is an additional threat, although less obvious in its impact. Active trade in wild Sun Bears and their parts is one of the two most serious threats to Sun Bear populations. Commercial poaching of Sun Bears was reported by regional experts in the Bear Specialist Group to be a moderate to major threat in all range countries except Brunei, for which there are no data. In Thailand, local hunters in one area estimated that commercial poaching reduced the abundance of Sun Bears by more than 40% in 20 years. Poaching pressure is increasing within some Thai Protected Areas, based on encounter rates of poaching signs and poachers, though bears are not usually targeted as much as other species. In northeastern India, where Sun Bear populations occur naturally at low densities, bears are still caught and poaching is said to have reached "critical" levels. In southern Lao PDR, sign surveys indicate that Sun Bear populations have been reduced to extremely low levels relative to other sites in Southeast Asia, with declines attributed to historically high poaching levels.
Of major concern is a widespread trend of wildlife snaring throughout much of the Sun Bear range. In northeastern Lao PDR, hunters use a snaring method that specifically targets bears and threatens to wipe out local populations. Large and small mammal snares were detected in numerous protected areas throughout the county. Although not always specifically targeting bears this represents a major ongoing threat. Farmers affected by wildlife crop damage frequently set snares around the perimeter of crop fields, and in some instances catch bears. In Peninsular Malaysia and Indonesia camera traps increasingly record bears with missing paws (apparent snare injuries) and in a radio-collaring study in Peninsular Malaysia, three out of five captured Sun Bears had missing paws, indicating high snaring pressure using cable snares. Enforcement of domestic and international wildlife laws is severely lacking in most cases and is failing to deter illegal bear trade. Low risk of being prosecuted and high potential profits mean that the incentive to poach bears is very high. The value of bear parts on the illegal wildlife market has increased notably over the past two decades.
Other motivations for killing bears include preventing damage to crops and livestock, subsistence use such as wild meat consumption, and fear of bears near villages. The rapid loss and fragmentation of forests across the Sun Bear range may bring bears closer to humans and thus increase the likelihood of human-bear interactions. In Lao PDR, where bear crop-raiding occurs annually in many parts of the country, farmers showed a general reluctance to report crop-raiding events to management authorities and may be more inclined to hunt bears that enter fields instead of seeking non-lethal mitigation methods. Incidences of sun bear attacking humans are rare and usually result as an act of self-defence—under normal circumstances, Sun Bears avoid humans.
As Sun Bears are a forest-dependent species, population declines are likely to be associated with deforestation rates. Deforestation increased dramatically during 1990-2005 and in recent times Southeast Asia has experienced the highest annual rate of forest cover change in the world. Some estimates project an extremely high loss of natural forests and of biodiversity of up to 75% and 85% respectively by 2100. Rate of forest loss is not uniform throughout the range, however, with some discrepancies among published estimates of forest loss due to varying analytical techniques. Deforestation in the Sundaic region is largely attributed to extensive clear-cutting for plantations (i.e., oil palm, rubber), unsustainable logging practices, legal and illegal logging, and forest fires. Conversion of natural habitat to oil palm plantations is most extensive on Borneo and Sumatra. Protected areas are not exempt from deforestation; 40% of the forest lost in Indonesia during 2000-2012 was lost in areas where logging is restricted, and in Kalimantan alone, 56% of protected lowland forests were cleared from 1985-2001. Given the Sun Bear’s affinity for primary and relatively mature, heterogeneously structured forests, along with its strongly frugivorous diet, such forest loss and fragmentation will exert significant effects on the bear’s regional and global populations along with its genetic and demographic structure and viability. Based on deforestation rates and increasingly fragmented range, and evidence of increasing trade of bears and their parts, it is likely that many isolated populations face a real threat of extirpation.
Conservation
Measures to reduce habitat loss and poaching throughout the entire Sun Bear range are key actions needed to conserve Sun Bears. In areas with the highest deforestation rates, such as Indonesia and Malaysia (two globally leading oil palm producers), immediate action should be taken to protect remaining high conservation value forests from conversion to other land-uses, eliminate unsustainable logging, and effectively manage forest fires. Additionally, new protected areas should be established and effectively managed in order to preempt land conversion and protect critical Sun Bear habitat.
In conjunction with primary forest protection, degraded habitats and forest remnants in human-modified landscapes should be enhanced, through reforestation programs, corridor planning and elevated protected status. Additionally, there is a need to establish buffer zones and prevent further agricultural expansion surrounding protected areas. Achieving these measures requires increased levels of resources, the support of conservation constituencies in civil society, and strengthened government commitments to conservation. In Malaysia and Indonesia, the two main producers of palm oil, it will be difficult to stop forest conversion, given the impacts of their economies in the world markets. Furthermore, in present conditions the effective management of already established protected areas, let alone the addition of new protected areas and land management outside of protected areas, has proven a highly challenging task.
Sun Bears are legally protected domestically and internationally from hunting and trade throughout most of their range. However, deficiencies in law enforcement are recognized as major ongoing weaknesses. Some successes are evident where dedicated agencies operate with steady technical and funding support. For example, in Cambodia, a dedicated Wildlife Protection Mobile Unit, run by Forestry Officials and Military and funded by international NGOs, has confiscated more than 100 Sun Bears and Asiatic Black Bears since 1998. Similar initiatives exist in parts of Malaysia and Indonesia but the action is limited. Establishment of more focused wildlife protection/crime units is recommended for other range countries, where possible funded by local authorities responsible for wildlife law enforcement. Reduction of mortality by a clearing of snares from bear habitat is urgently needed throughout much of the range, and long term measures are needed to prevent the problem reoccurring. Efforts to do so are underway in several protected areas throughout the region, by park authorities often in collaboration with foreign NGOs. However, these projects usually do not extend throughout a protected area and can face difficulties in maintaining long-term funding and political support. To combat the growing impacts of human-bear conflict, funding and technical support are needed to promote non-lethal mitigation, especially in low-income regions where the incentive to hunt bears may outweigh incentives to stop conflict from occurring.
Non-government organizations (NGO’s) have established bear dedicated rescue centres in Cambodia, Vietnam, Lao, Thailand, Malaysia and Indonesia with the primary aim of providing sanctuary to bears confiscated from the illegal wildlife trade. Bear rescue centres can play a key role in raising local awareness on the threats to sun bears and the conservation value of ecological services provided by bear habitat. Some centres operate dedicated outreach teams, providing structured learning programs that can reach tens of thousands of people each year. Likewise, centres support the capacity building of local conservationists and facilitate in-situ and ex-situ research and conservation. Rehabilitation of ex-captive Sun Bears is another potential role. However, this is rare and fraught with challenges, as most potential release sites are still threatened by forest loss and poaching. For example, in Cambodia, a pilot project to rehabilitate two Sun Bears that had been confiscated from the illegal wildlife trade ended after both bears were trapped in snares within two months, despite over two years of intensive snare-patrolling in the area prior to the release. Ultimately, reducing the trade in bear parts would be one of the most highly beneficial steps for the persistence and recovery of Sun Bears throughout their range, especially as trade is increasingly moving towards the last strongholds for Sun Bears in Malaysia and Indonesia. Understanding consumer motivation, and educating and changing the behaviour of potential consumers of bear products, could be an incredibly effective tool. This is especially important given that law enforcement is generally underfunded and unfocused.
Increasing our scientific knowledge of Sun Bear ecology, population distribution, status and effects of threats is also needed. Aside from a now-outdated Global Status Survey and Conservation Action Plan for this species, only one range country (India) has developed a National Conservation Action Plan for Sun Bears. Range mapping efforts, ongoing since 2006, have suffered from lack of presence data. But in 2014, the Bear Specialist Group mapped the current range-wide distribution of Sun Bears based on collation of more than 2000 presence points from throughout the range and with input from numerous experts. This has resulted in the most up to date range map for the species. The veracity of Probable range depicted by experts remains unclear. Habitat modelling approaches generate maps of potential distribution and may thereby help direct field surveys to promising locations to ascertain bear status; however such models are often generated with bear presence data from a small area and extrapolated broadly, and should thus be treated with caution. There remain large areas for which sun bear status is uncertain, most noticeably in Myanmar, where further research is needed. Furthermore, it is important to establish the geographic distribution of Sun Bears at finer scales, taking into consideration habitat and fragmentation within and between countries, in order to better direct conservation actions and monitor habitat changes accurately (i.e., forest loss and fragmentation).
In 2006 The Bear Specialist Group mapped important habitat blocks for the long-term survival of Sun Bears (Bear Conservation Units-BCUs). Anti-poaching efforts and forest boundary protection efforts within BCUs should be a high priority. Presently no BCUs receive support just for bears, but BCUs in some countries coincide with protected areas that receive substantial conservation support for other species (such as tigers), and bears benefit as a result. The possibilities to link bear conservation with that of other species should be explored and promoted more widely.
Efforts are currently underway to develop a standard methodology with which to monitor occurrence, relative abundance and trends of Asian bear populations through repeat sign transects. To this end, methodologies to distinguish Sun Bear claw marks from Asiatic Black Bear claw marks and to age claw marks have been developed. Surveys using this technique have been completed in Lao PDR and are planned for Vietnam and Cambodia. Trends in bear occurrence and relative abundance within the aforementioned BCUs should be monitored using standardized sign surveys and camera trapping by local government, communities, and NGOs. Results of such monitoring could indicate which management or ecological conditions promote successful bear conservation, and which do not, and provide a means to assess the results of conservation efforts (e.g., future range expansion and/or increased bear density being indicative of effective conservation efforts). Additional field studies would also be helpful in this regard, as few intensive studies have been conducted on Sun Bears.