Bears are a group of carnivores that attract the attention of wildlife photographers almost as much as the wild cats and wolves. There is a deep fascination with these large lumbering omnivores that can, when needed, move surprisingly fast and most species can even pull-down a sizeable prey. All the bear species show some level of torpor during cold periods, with the northern species like the female polar bears and brown bears spending a significant proportion of their life in deep hibernation. Indeed, the lives of most bears is defined by the needs of hibernation, so they must build up their pre-hibernation reserves by concentrating on energy rich food sources such as spawning salmon or a flush of caterpillars and then recover from hibernation by eating the protein rich sedges that start growing in the spring. All bears are solitary, but these eruptions of rich food sources result in aggregations of bears, usually just before or after hibernation. The collective noun for these grouping is a “sloth of bears”. The irony is that Sloth Bears (Melursus ursinus), the subject of this article, only occasionally aggregate on rich food sources to form a sloth of Sloth Bears.
Bears that live further north hibernate for longer periods, in these ecosystems the availability of food is greatly reduced during the winter months so they have little choice but to hibernate. Of course, male polar bears break this pattern by going out onto the winter sea ice and hunting seals during the winter darkness. In contrast, the tropical species do not suffer from the seasonal lack of food and so the Spectacled Bears of South America, the Sun Bears of Malaysia and the Sloth Bears of the Indian subcontinent do not hibernate. Even so, I am always astonished that despite the fact they inhabit warm areas these Sloth Bears have a thick shaggy coat of hair but lack the thick under-hair coat that keeps the polar bears so well insulated when swimming through the freezing oceans of the arctic. Both the Sloth Bears and the Asiatic Sun Bears have a bright white blaze across their chest, but the Sloth Bears also have very long claws on their front legs for digging …. somewhat reminiscent of sloths, and this anatomical similarity with sloths is the derivation of their name.
Sloth Bears are somewhat special. They are the only species of bear that is well-adapted to feeding on termites, ants, and fruit. Like other species adapted for ant-eating (known as myrmecophagous mammals), they have very long claws on their front feet that are good for digging but not for climbing trees, and live in relatively small home ranges. They have also lost some of their front incisors, developed an ability to close off their nose while digging and developed their lips so they can lick up and suck up ants, without them going up their nose. Unlike the other bear species, they are not carnivorous but are the most aggressive bear species and attack people more than any other bear. One explanation is that this is because of their adaptation to eating ants and termites, which makes them vulnerable to attack when they are feeding and attack is their only form of defense since they can’t climb trees. Typically, the attacking bear stands on its hind legs and will run at the aggressor.
Breeding Biology of Sloth Bears
Mating and birthing in sloth bears can occur in most months, although mating usually occurs in June and cubs are born towards the end of the year. Like the other bear species, the female gives birth in a den and then remains in the den with the cubs for almost two months. They usually have one or two cubs and sometimes three, there is some speculation that three might be more common and then the cubs suffer early mortality since the females carry the young on their backs until they are nine months old, and they can’t carry more than two. The cubs stay with the female until they are almost two years of age so females breed at two or three-year intervals. Interestingly, and good for photographers, the females with cubs are more active during the day, maybe as an adaptation to avoiding nocturnal predators and other bears.
Sloth Bear Status
Like most large carnivores Sloth Bears suffer from habitat destruction and persecution. The IUCN lists the Sloth Bear as Vulnerable although there is insufficient data to really know much about the rate of decline over each generation (10 years) and I suspect that once these data are available, and a new review is undertaken, we shall see the status increased to Endangered.
The current world population of adult sloth bears is not clear, recent estimates come up with 5,00 bears in protected areas so the total population maybe around 15,000 to 20,000, but there are large inaccuracies around these figures and all we can say is that numbers are currently falling. In the past, the population was continuous and almost uninterrupted from the southern tip of India up into Nepal and east towards the Myanmar border. Now the population is fragmented, and bear populations are being lost and are no longer connected and this makes the isolated populations even more vulnerable.
Threats to Sloth Bears
Like most carnivores, Sloth Bears are threatened by the combination of habitat destruction, which limits the extent of the population and reduces dispersal between the habitat patches, and also issues of persecution that reduces density within the patches. The degradation of forest habitats into scrub often results in the loss of their main food sources including termites, so the bears switch to crop raiding and causing conflict. Issues of habitat destruction are not just an issue facing bears but also tigers and other animals, so the impressive recovery of tigers in India through habitat management and connecting protected areas with corridors will have also helped bears.
In India, poaching of bears is still an issue, in particular when bears are killed for their body parts, in particular their gall bladders which are exported to Singapore, Honk Kong and onward to Japan and China. Added to this, in some parts of India, mother bears are killed and the young taken and trained as performing bears or pets, although this was made illegal in 1972 and has been reduced greatly.
Sloth Bears are listed in Appendix I of CITES and are completely protected under Schedule I of the Indian Wildlife Protection Act of 1972. The killing of nuisance bears is still legal. On the one hand, we may expect this to increase with habitat destruction and fragmentation as bears outside protected areas have little food and are brought into closer contact with people. On the other hand, it is gratifying to see how more parks are including buffer areas around parks, education of bears is increasing and people living in these areas are finding ways of living with the bears.
