Why killer sloth bears have become hyper-aggressive towards humans

The sloth bear’s aggressiveness could be explained by the species’ early coexistence with tigers, according to a new study.

Sloth bears are considered one of the most dangerous animals in Asia. Although there are around 20,000 or fewer left in the wild, bears are known for their attacks on humans, which have increased in recent years – the species kills more than a dozen people each year, according to a 2020 report National geographic report.

Human-wildlife conflicts occur on a global scale, however, most predators only attack if provoked – for example, an animal may attack if it senses its territory is under threat. And while the numbers are on the rise, deaths remain relatively rare.

However, researchers have long suspected that sloth bears are more likely to attack than other species. In June, a sloth bear killed and maimed a man and a woman in India before feasting on their remains for hours.

sloth bear
A file photo shows a sloth bear. It is one of the most dangerous animals in Asia.

Wildlife SOS, a non-profit conservation organization based in India, undertook a study to assess why the species is prone to such behavior.

The study, published on Nature.com, assessed the sloth bear conflicts that occur in the Indian state of Karnataka and the Deccan Plateau, a preferred bear habitat of mostly rocky scrub forest. The study recorded 180 sloth bear attacks in the area.

The researchers noted that the aggressiveness of bears could be due to evolutionary factors. They may be more prone to “innate defensive-aggressive responses to surprise (sudden) encounters” because they co-evolved with tigers, the study says – a predator that preys on sloth bears opportunistically.

Sloth bears are not often hunted by other animals. The study noted that cubs can be preyed upon by wolves or leopards, however, their only “natural predator” and realistic adversary is the Bengal tiger. According to studies of tiger feces, 2% of a Bengal tiger’s diet may consist of sloth bears.

“Since [sloth bears] can’t outrun tigers and can’t climb trees fast enough to escape tigers, sloth bears evolved aggressive behavior to fight off tigers,” said study lead biologist M. Swaminathan. Newsweek. “While tigers can always have the upper hand over sloth bears that share their habitat, their aggressive behavior sometimes makes tigers think they’re just not worth it.”

The study indicated that tigers no longer live on the Deccan Plateau, however, the wide range of caves in the region “have undoubtedly historically benefited sloth bears, perhaps facilitating a higher density than would have been otherwise possible”.

Although aggressive tendencies potentially stem from their evolution, the study noted that there are other factors at play when it comes to conflict.

In the Deccan Plateau region, researchers found that sloth bear attacks were more common during the winter months. At this time of year, more and more locals are busy in the forest, as the monsoons have ended.

Similarly, previous studies in central India have shown that attacks are more common during the monsoon season, which is usually when local people are active outside of agriculture and protecting crops.

The study noted that there are a greater number of attacks when human activity is at its highest in their habitats.

“We conclude that seasonal bear activity plays a much smaller role in attack rates than seasonal human activity. Consistent with findings from other studies, human incursion into bear habitat is the main factor responsible for precipitating conflicts,” the study said.

Despite their reputation, Kartick Satyanarayan, co-founder and CEO of Wildlife SOS, said Newsweek that sloth bear attacks occur when the animal feels threatened.

“There has been an increase in human-slot bear conflicts where in some cases sloth bears behave aggressively towards humans when threatened,” Satyanarayan said. “Human activity and encroachment into and out of protected areas results in a high frequency of human-slotch bear conflicts and limits the movement of sloth bears and other wildlife among fragmented forest patches.

“This species is also threatened by habitat loss and poaching for body parts,” he said.

“In various regions, people fear these animals due to their aggressive and unpredictable nature. Sloth bears are often referred to as ‘problematic’ or ‘pest’ animals. Local communities respond to crop damage by attacking sloth bears. in retaliation. Such incidents not only result in injury and, in some cases, death, but instill insensitivity and a negative perception of wildlife.”

Leave a Reply

Your email address will not be published.