The social life of bears

The Daroji Bear Sanctuary near Hospet in Karnataka turned out to be a wonderful place to see sloth bears (Melursus ursinus). I’d never noticed the long sickle shaped claws and sharp teeth in such detail before. Their long and curved claws led to their mis-classification as sloths in the 18th century, hence their “common” name. There is nothing sluggish about them. Bears being the secretive animals they normally are, I don’t expect to see their behaviour in so much detail elsewhere.

A mother and child made an appearance on the hillside first. The cub was old enough to pad along with its mother, exploring around its mother’s path. Cubs remain with their mothers until they are two years old. In this part of the country they are born in winter, so this one was probably not more than a year old.

I always wonder why the bears have this thick coat. The sloth bear evolved in the Deccan plateau, the same region where I was now watching them, perhaps less than 5 million years ago. This is a period during which the weather cooled on the average, and forests were replaced by grasslands and scrublands. On the other hand, the Indian Ocean monsoon had already set in, so the interior of India would perhaps been dry and warm when it was not wet and warm. As I watched the mother and child feeding, I wondered how they could stand the weather.

A solitary juvenile made an appearance without upsetting the mother and cub. I’d always thought of sloth bears as solitary creatures, so this was a little surprising to me. These bears become sexually active at about the age of three, so there is a year when they have left their mother but are not seeking mates. The new bear approached quite close to the cub without the mother being perturbed. I wondered whether the adult female was the mother of this juvenile, but there was no way to tell.

After a while another adult and a cub appeared. The two cubs started playing together without the adults becoming aggressive. This was a complete surprise to me. Cubs of sloth bears remain with mothers; the father does not play a role in rearing the cubs. So this was not a family group; it was two different families, and a third juvenile, perhaps an older offspring of one of the two adult females. I have no idea whether such groups have been recorded.

There is a lot of literature on the foraging and feeding behaviour of sloth bears, but assemblies of so many of them in one place is not mentioned. Is it so common that no one remarks on it? Unlikely, since some sources remark about their solitary habits. Has the relatively small size of this sanctuary changed their behaviour, and made them more social? Possible, since territorial behaviour is not mentioned in any article on sloth bears. It would be interesting to see whether any field scientists are studying this population of bears.