Do polar bears wield ice blocks to kill walruses?

This illustration from an 1865 book by adventurer Charles Francis Hall depicts a polar bear using a rock as a tool to kill a walrus. Recent research suggests such behavior is real, but rare.
Credit: Charles Francis Hall/Library of Congress

In the eastern Canadian Arctic and Greenland, Inuit have told stories for centuries of polar bears using rocks and blocks of ice to bludgeon walruses to death. Naturalists discounted such tales as myths, but new research suggests the phenomenon is likely real, but rare.

Researchers reviewed historical reports from Inuit hunters to explorers and naturalists as well as recent observations by hunters and researchers and documented observations of polar bears (Ursus maritimus) and brown bears (Ursus arctos) using tools to access food in captivity. Their findings suggested that, while infrequent, polars bears do use tools to hunt walruses (Odobenus rosmarus), which are very difficult for the bears to kill.

“It’s been my general observation that if an experienced Inuit hunter tells you that he’s seen something, it’s worth listening to and very likely to be correct,” Ian Stirling, a polar bear biologist at New Zealand’s University of Canterbury, and lead author of the study published in the journal Arctic, told Science News.

Read more from Science News, and read the Arctic paper here.