Polar bears share their prey U of M research underscores importance of species to future of Arctic By: Katie May Posted: 6:30 PM CDT Tuesday, Oct. 28, 2025

Polar bears are generous hunters whose leftovers feed many other animals, new research shows, casting the protected species as a major provider, not just a vulnerable predator in a province that attracts thousands of polar bear watchers every fall.

Arctic foxes, wolverines, eagles, hawks, gulls and even younger bears are among at least 11 species who feast on the prey left behind by polar bears. The latest study calculates the leftovers: 7.6 million kilograms per year in picked-over seal carcasses left on sea ice.

That’s a conservative estimate, said biologist and University of Manitoba PhD candidate Holly Gamblin, lead author of the study published Tuesday in the journal Oikos from the Nordic Ecological Society.

“A bunch of my co-authors are in that polar bear research world and have been thinking about investigating (this issue), knowing that it’s this really under-represented and under-studied component of the story, when we think about polar bears as apex predators,” said Gamblin, who has studied Arctic foxes. “They had had this idea for a while and I was just sort of in the right place at the right time.”

The research, a collaboration between the U of M and the San Diego Zoo Alliance, with contributions from the University of Alberta and Environment and Climate Change Canada, lays the foundation for fieldwork to document how polar bears support the subarctic and Arctic ecosystems in Churchill and Pond Inlet, NT.

The study used data modelling to estimate how much the bears leave behind after they feast on ringed seals.

Because they are “blubber specialists,” Gamblin said, the bears eat much of the seal fat, but unlike some other carnivores, they don’t guard or hoard their prey. Dragging their prey — seals or even narwhals — up onto the sea ice helps scavengers survive.

“What our research group is interested in doing is showing that when we lose sea ice, we’re losing this energy source for all kinds of different species.”

Even rare scavengers, such as grizzly bears and snowy owls, have come to the table for the spoils of a polar bear’s hunt, the study found. Previous research from Gamblin’s lab at U of M has found the Arctic fox population is directly linked to polar bears’ “hunting success.”

This study points to the importance of conservation efforts.

“This just highlights one other potential impact of climate change, but it really comes down to making changes on a global scale that will reduce the loss of sea ice,” Gamblin said.

The ecological benefits provided by the bears are irreplaceable, she said.

“We already know how the Arctic is warming at a rate of four times the rest of the world, and we know that we’re experiencing loss of sea ice, and so what our research group is interested in doing is showing that when we lose sea ice, we’re losing this energy source for all kinds of different species,” she said.

“It has the potential to impact much further down into the food web.”

The issue of climate change hits home in the polar bear capital of the world.

There are fewer polar bears in and around Churchill: one study, published in 2022, estimated there are roughly 600 — half of the number of polar bears that roamed the area 35 years earlier, according to Polar Bears International. The bears attract thousands of tourists to Churchill each year: more than 25,000 travellers visited in 2023. Tourism in Churchill contributes $99.8 million to Manitoba’s economy, a 2024 economic impact study shows.

“It’s always good to see knowledge like this formalized, but I think it will come as no surprise to anyone who’s spent some time watching bears that they have a very important role in supporting ecosystems and everything that lives around them,” said Drew Hamilton, co-owner of Discover Churchill Tours.

Polar bear season in the northern town, traditionally in October and November, has recorded above-seasonal temperatures this year.

When Hamilton looked out his window Tuesday, it was raining, not snowing.

“It’s the talk of the town; everybody’s wondering what the next couple of months are going to hold… as the sea ice comes or it doesn’t, these bears stick around. The tourists all leave, but the bears stick around. So then, you have to take a hard look at what it takes to co-exist with polar bears,” Hamilton said, pointing to practical concerns such as the need for a bear-proof trash management system in town.

Hamilton, who has worked in Churchill for about a decade and said he’s “been in the bear business” since the late ’90s in Alaska and other areas, said he and other Churchill residents are witnessing the realities of climate change, and they need systems in place to protect the bears, both for the environment and the economy.

“This is changing before our eyes, and hopefully that sparks some urgency in both looking at polar bear conservation and confronting climate change,” he said.

katie.may@freepress.mb.ca