Polar Bears Take Down Walruses by Hurling Rocks and Ice

New research corroborates Inuit knowledge of the animals cleverly using new tools

An engraving of a polar bear hurling a rock at a walrus
An engraving of a polar bear hurling a rock at a walrus from Charles Francis Hall's 1865 book Arctic researches, and life among the Esquimaux. Smithsonian Libraries/Public Domain

In 1865, Arctic explorer Charles Francis Hall published an Inuit account of a polar bear attacking a walrus with a rock on Baffin Island in Canada. He even included an engraving of the bludgeoning in his book Arctic researches, and life among the Esquimaux.

“The bear mounts the cliff, and throws down upon the animal’s head a large rock, calculating the distance and the curve with astonishing accuracy, and thus crushing the thick bullet-proof skull,” Hall describes in his book.

Scientists have long dismissed these centuries-old claims of polar bears smashing the skulls of walruses with rocks and chunks of ice as myth and legend. Now, Canadian researchers have found evidence to corroborate the Indigenous knowledge.

Reviewing Inuit accounts over the past 200 years, lead author Ian Stirling, a biologist at the University of Alberta, Edmonton, and his team report in a new study that while rare, these attacks likely do occur. Published in the peer-reviewed journal Arctic, the research concludes that “polar bears may occasionally use tools to hunt walruses in the wild.”

“I have always been impressed with the accuracy and reliability of the observations of animals reported by experienced Inuit hunters, so I thought it was likely the accounts might not just be myths but the result of reporting of actual observations, even though the behavior itself is likely quite rare,” he tells Mindy Weisberger of Live Science.

The Inuit accounts describe polar bears picking up rocks and chunks of ice to throw at the heads of unsuspecting walruses. The large marine mammals are occasional prey, though their size—male walruses can weigh in excess of 2,500 pounds—thick skulls and dangerous tusks make it difficult for unarmed bears to bring them down, reports Kristine De Abreu of ExplorersWeb.

Polar Bear Collar Cam B-Roll 2014, 2015, 2016

Stirling and his colleagues determined that polar bears clobbering walruses made sense. Their study cites the example of a five-year-old male polar bear named GoGo using objects as tools to get food in a Japanese zoo. The bear used sticks—as well as throwing a large tire—to knock down meals placed on inaccessible perches. According to the study, “GoGo demonstrated an exceptional and previously undocumented degree of conceptual creativity to facilitate access to a food item hanging from the air.”

“The most significant part of this is that a bear is able to look at a situation, think of it in a three-dimensional sense, and then figure out what it might have to do to be successful,” Stirling tells Ginella Massa of “As It Happens” on CBC Radio.

In another example, researchers in Alaska videotaped polar bears in the wild throwing chunks of ice at seals. One account collected by the United States Geological Survey’s Alaska Science Center Polar Bear Research Project shows a bear sliding a large lump across the frozen surface to an open hole to ambush its prey.

Previously, scientists didn’t know polar bears were capable of using tools. Now, they suggest it could happen in the right circumstances, especially if the hunter is faced with a formidable foe like the walrus.

“An occasional adult polar bear might be capable of mentally conceptualizing a similar use of a piece of ice or a stone as a tool,” the study states.

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