Grizzly Uses Rock to Exfoliate Skin, Becomes First Bear to Use Tools

03/06/2012

Bears might look like they're all brawn, but they've also got some brains. Case in point, a wild grizzly in Glacier Bay National Park recently became the first bear known to definitively use tools.

Scientist Volker Deecke witnessed the behavior while on vacation in Alaska. During a hike, he caught sight of a large brown bear wading in shallow water. Deecke watched in amazement as the bear carefully picked up a barnacle-covered rock and meticulously proceeded to rub it across its face. After about a minute, the bear then repeated the behavior with another rock.

According to Deecke, it looked exactly like the bear was using the rock to comb its hair and exfoliate the skin.

It might just sound like a vain bear; but if Deecke's description is accurate, this behavior amounts to something much more. Other than humans and a few other primates, only four species of non-primate mammals have ever been definitively proven to use tools. This bear's vanity would not just be a giant leap for bearkind, but a big step for science's understanding of tool use in non-human animals.

Deeke describes the event in a recent article published in the journal Animal Cognition. Of course, the bear wasn't really preening itself out of vanity. The behavior was witnessed at a time when bears are moulting. The animal was likely trying to rub off itchy patches of fur that were falling out. The rock being used was likely chosen because it contained a fair amount of rough-edged barnacles.

"The barnacles," Deecke told New Scientist, "may have given that exfoliating feeling."

Deeke also noted that the bear exhibited considerable motor skills when manipulating the rocks, likely indicating that this wasn't the first time the bear wielded a rock as a tool. Such tool-use may even be one explanation for why bears have the largest brains relative to body size of all carnivores.

In fact, tool use in bears has been speculated about in the past. A 1972 report in the Yearbook of the Norwegian Polar Institute suggested that a polar bear was seen using a chunk of ice to club a seal over the head, but the behavior was never confirmed by researchers.

Very little has been done to study the cognitive skills of bears, so it's impossible to make any generalized claims about bear tool-use based solely on this one encounter. But Deeke hopes the event may soon prompt new research initiatives.

Photo: Ha-Wee/Flickr

Comments

[William]

This is an amazing news. I never thought that Grizzly would come up with using rocks. Bears are surely smart.

[Nike TN]

A 1972 report in the Yearbook of the Norwegian Polar Institute suggested that a polar bear was seen using a chunk of ice to club a seal over the head, but the behavior was never confirmed by researchers.

[Spicoli]

That would depend on your definition of tool. The object wasn't modified for a purpose. That's just using what's laying around like using a tree as a back scratcher.

[Cristy]

That is really a cool way to exfoliate. I love it, and it works so well.