Another detail into one of the Arctic’s top predators is being filled in, with a new study on how they behave after killing their prey.
Scientists have always thought of polar bears as fast eaters, chowing down on the choicest cuts of seal, walrus and whale right after they’ve killed it.
But that’s not always the case, as some decide to hoard their kills for later, similar to a behaviour common among their grizzly bear cousins.
That’s the conclusion from a new paper co-authored by Ian Stirling at the University of Alberta. It was published this week in Arctic Science and lists nearly 20 different sightings of polar bears hoarding their kills over the past 30 years.
That’s something Stirling hasn’t seen or heard of the bears doing in his 49 years of studying them. Though it’s uncommon behaviour, it illustrates the evolutionary link between polar bears and grizzlies, he explained.
“Polar bears only separated from grizzly bears and became different animals about a half-million years ago,” he said. “In evolutionary time, that’s just a blink of an eye.”
Stirling says it appears most polar bears have stopped hoarding their food because they simply don’t need to as the apex predator on the sea ice. But that instinct is there when they need it to be.
Polar bears cover their food, the purpose of it, is for the meat or blubber to be cooled off, after it cools, the bear will eat it-David Iqaqrialu, Inuk elder, Clyde River
“The main thing they’re trying to do is reduce [the chance] of other bears seeing it and coming over,” Stirling said. “One of the things the bears cue in out on the sea ice is anything that’s dark or stands out in contrast with the snow.”
“By putting some snow over a carcass along the shoreline, they’re trying to keep some competitors from maybe trying to take it away from them,” Stirling said.
During Stirling’s time working with Inuit hunters, this type of hoarding behaviour never came up in discussions, which made him curious about whether the bears actually did it.
“I’m not suggesting for a moment that hunters haven’t seen this from time to time, I just haven’t heard them talk about it,” he said.
‘This is for survival’
David Iqaqrialu, a well-respected elder from Clyde River, Nunavut, says he’s not surprised the scientists observed this behaviour.
He’s spent much of his life on the land with the bears and knows it’s happened before
“Polar bears cover their food, the purpose of it, is for the meat or blubber to be cooled off, after it cools, the bear will eat it,” he said in Inuktitut.
“If the meat that the polar bear ate isn’t finished, [the bear] will go back to it, return to it and eat the remains,” he said. “This is for survival.”
Iqaqrialu said polar bears play a major role in Inuit life and it remains important for humans to respect them.
“Our ancestors used polar bears, way back then it was important traditionally,” he said. “Even to this day, polar bears are important to Inuit.”
But Lennie Emaghok, a hunter and elder from Tuktoyaktuk, N.W.T., says he’s never seen the hoarding before, supporting Stirling’s findings that this is rare behaviour.
In his experience, polar bears often move from place to place, rarely staying in one spot for long, Emaghok said.
Stirling’s take on the research is that it’s another piece of information — like a brush stroke in a painting — that may not be a major discovery now, but could prove important in our understanding of polar bears in the future.
“Down the road, you end up finding a remarkable number of these kinds of things fit into a bigger puzzle and help you understand the animals better,” he said.