Some grizzly bears in the Northwest Territories are travelling far north of their usual habitat — 500 kilometres farther north, in fact, according to scientists who spotted one this summer on Melville Island.

On June 23, biologist Charles Francis and his team were flying back to their base camp on the uninhabited island when they saw what Francis said looked like "an awfully dirty-looking polar bear" on the snow-covered landscape. He said he took a photograph as their helicopter circled the large creature.

Biologists on Melville Island in June initially thought this grizzly bear was a dirt-covered polar bear or a polar-grizzly hybrid.
(Photo courtesy Charles Francis)

"Our first thought was that maybe we had one of those hybrids, because we knew we'd heard about grizzly-polar bear hybrids," Francis, a bird biologist with the National Wildlife Research Centre, told CBC News in an interview done Friday.

"When we examined the photographs afterward, we realized that it was a grizzly bear.... Certainly not something I expected to see up there."

Francis's sighting was the latest in a number of documented grizzly bear sightings on the islands of the Canadian Arctic archipelago, at 500 kilometres north of their traditional homes.

The last sighting of a grizzly on Melville Island was in 2004, according to an article last month in the northern research journal Arctic.

According to the article, geological research parties photographed and took genetic samples from grizzly bears on the island. The authors noted that those sightings make up "the most northerly observations made of this species in North America."

"Our evidence and review suggest that, at a minimum, transient grizzly bears are now regular visitors to the Canadian Arctic archipelago," the article read.

Population in good shape, says biologist

Andrew Derocher, a University of Alberta biologist who studies bears, said the recent grizzly sightings may signal a boom in southern bear populations.

"What's happening is that the mainland population of grizzly bears is probably in fairly good shape," Derocher said.

"They produce a surplus of young bears, and some of these males eventually take off. And some of them that just cross the sea ice in the spring eventually set up a territory or a home range up on these Arctic islands."

Derocher also suggested that a warming climate may be making the Arctic a more comfortable habitat for the bears, but added more research is needed to determine whether that's true. Regardless of what's happening with the climate, he said grizzly bears can learn to adapt to the harsh High Arctic environment.

"It's surprising in some ways because we don't think of this as being normal grizzly bear habitat," he said.

"We could speculate that maybe he's making some living off of marine resources — perhaps hunting seals like polar bears do — or perhaps scavenging dead marine mammals as well."