Wild bear uses a stone to exfoliate

05 March 2012 by Michael Marshall

IT IS impossible not to scratch an itch, so it's no wonder this brown bear reached for some help. It was seen scratching its skin with rocks – the first bear definitively known to use a tool.

In July 2011, Volker Deecke of the University of Cumbria, UK, was on holiday in Alaska's Glacier Bay national park when he spotted a brown bear in shallow water. The animal picked up a small, barnacle-covered rock, turned it around a few times then rubbed the rock over its face for a minute. It repeated this with another rock (Animal Cognition, DOI: 10.1007/s10071-012-0475-0).

The bear was moulting, and had big patches of fur hanging off its skin. Moulting bears often scratch themselves with their claws, or rub their bodies against trees or rocks. "The barnacles," Deecke says, "may have given that exfoliating feeling."

Brown bears may not be the only bears to use tools, says Euclid Smith of Emory University in Atlanta, Georgia. A 1972 report suggested that a polar bear might have clubbed a seal over the head with a chunk of ice (Yearbook of the Norwegian Polar Institute, p 177). But the researchers did not see the event, and the behaviour has never been seen since.

Deecke points out that bears have large brains for their body size, suggesting they are clever, though too few tests of bear cognition have so far been carried out to say for sure.

http://www.newscientist.com/article/dn21537-wild-bear-uses-a-stone-to-exfoliate.html