Wandering polar bears a sign of climate change: expert

Climate change likely played a role in three polar bears wandering hundreds of kilometres south to the Northwest Territories community of Dline, says a Canadian polar bear expert.

Residents in the community of 525, located along the southwest tip of Great Bear Lake, were shocked to get up close to the mother and two cubs when they lumbered into their community Wednesday afternoon wandering more than 400 kilometres away from their usual habitat on the Beaufort Sea.

The local RCMP, which started getting calls about the unusual visitors around 3 p.m. MT, said the polar bears appeared thin and hungry. An officer shot and killed the bears, out of safety concerns for residents and local dogs.

It's not the first time that polar bears have travelled south recently: a polar bear made not one, but two trips towards Fort McPherson, N.W.T., last summer.

Andrew Derocher, a University of Alberta biologist who studies polar bears, saidthe animals haveto cope with a dramatic reduction in the amount of sea ice on the Beaufort Sea.

"What we've seen over the last number of years is more increased numbers of incidences of bears that are not being able to maintain contact with the ice through the winter," Derocher told CBC News in an interview Thursday.

"They're having to jump off because the ice breaks up."

Some residents concerned

The Dline bears both excited and troubled many residents, about 100 of whom ran outside Wednesday afternoon to take photographs and videos.

"The mother bear looked like it was protecting the cubs, but it's pretty amazing to see," resident Christina Gaudet told CBC News on Wednesday.

"I've lived in Dline all my life, and I've never seen a polar bear; this is the first time."

Const. Jim Craig said RCMP had no choice but to shoot the bears, given they were harassing and threatening dogs nearby. Their proximity to people was also a factor, he added.

"The mother bear, when I shot it was I'm having a guess here probably 15, 20 feet [about 4.6 to six metres]away from me," Craig said.

"There was people everywhere behind me out of their trucks, running around behind me, everyone taking pictures and videos. And I'm just concerned for the safety of the people in the community, and for the pets that are tied up outside."

The mother was shot and killed first. However, the sound of Craig's shotgun did not disturb the cubs, as they continued to harass nearby dogs after their mother was shot. They were killed next.

Bears likely looking for food since summer

Derocher said he believes the bearsthat came toDline probably lost contact with the sea ice last summer, andhad beenlooking for foodthe land since then.

Last August, a polar bear wandered south into the hamlet of Fort McPherson, N.W.T., which is 570 kilometres northwest of Dline.

Wildlife officials captured the bear and, with Derocher's help, brought it back to the Arctic Ocean. Butseveral weeks later,it made a second trip south, appearing 100 kilometres north of Fort McPherson.

"When we start to see a pattern like this, it's probably an indication of something changing broadly over an ecosystem," Derocher said.

"We're seeing a lot more bears summering on land in Alaska. We're not seeing a lot of that yet in the Canadian Arctic, on the Beaufort Sea side, but it's certainly an indication that things are changing. The bears are trying to find ways to make a living on land, and of course they're nowhere near as effective as grizzly bears."

Wildlife officers with the territorial government are travelling to Dline on Thursday to examine the carcasses, which are being stored in a local cold storage area.

The officers hope to determine the health, size and age of the bears.