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This article was published 10/7/2019 (754 days ago), so information in it may no longer be current.
Summer has come to Churchill, and the polar bears are back in town.
It’s a great time of year for people such as Evan Roberts, program co-ordinator for the Churchill Northern Studies Centre, west of Wapusk National Park.
"The bears are back — we care about the bears so much," said Roberts. "They’re here. They’re certainly a way that people make a little bit of income out here, so it’s a fun time of year to be up here for sure."
He spotted his first bear of the season July 5 while out with a group — it seemed young, well-fed and didn’t pose a threat, even though with the bears coming off the rapidly melting ice, bear protocols are back in season.
That includes keeping a vehicle parked close to the door of the CNSC for quick escapes and making sure all fieldwork is done under the watch of a dedicated bear monitor — who carries a gun with both deterrent and lethal rounds, as a last resort.
Roberts said he is happy to see the bears looking healthy and fat, and doesn’t anticipate any problems.
"We live in polar bear country, we live in their turf, so it’s just the way it is," he said.
University of Alberta polar bear researcher Andrew Derocher said it’s a bit early in the season for bears to head off the ice, but not too early — meaning this might be the year bears get a respite from shorter seasons and a chance to rebuild their population.
While the population has declined 30 per cent in recent years, the fact bears had from mid-November until mid-July to fatten up on the ice bodes well for a good crop of cubs in the spring of 2020, he said.
"Collectively, the bears should do really well this year, but whether it’s going to be enough to recruit a bunch of cubs into the population remains to be seen," Derocher said.
For the last three years, Derocher’s team has stepped up its efforts to put ear-tag trackers on the animals, one of the most vulnerable polar bear populations in the world.
"We have concerns that this population probably won’t persist until mid-century — the rate of loss we’re seeing in sea ice is too fast," Derocher said.
The western Hudson Bay bears are losing about one day on the ice per year as sea ice patterns change. But some areas, such as Norway, are losing sea ice three times faster, up to 30 fewer days per decade.
It takes about four good, "at least reasonable," seasons to see a change in cub numbers, Derocher said.
In August and September, Environment Canada officials will count the number of cubs, but from his monitoring, it looks like there’s a very small cohort of cubs coming ashore this year, he said.
"Whatever happened out on the sea ice in the spring of 2018, females that should have been pregnant didn’t or weren’t healthy enough to keep cubs going."
It’s not breeding that’s the problem — Derocher said it’s relatively easy for a female bear to have the fat stores to get pregnant and give birth, usually around December — it’s keeping the cubs alive to yearling age.
"It’s a lot more challenging to keep (the cubs) alive for 2 1/2 years," he said. When bear mothers don’t have enough food, they stop lactating, he said.
On land, Derocher said bears lose about a kilogram of mass, largely fat but also some muscle, every day. So if they come to shore with 150 kg of fat stores from a good hunting season — like this spring — they’re fine foraging for a few blueberries, bird eggs or seal carcasses to keep going for 150 days.
He said he’s worried about the year days on land push above 200 — which could precipitate a mass mortality event.
"If Churchill gets a really hot summer, the bay really heats up, it can take a lot longer for the bay to refreeze in the autumn, and that’s when we start to see a lot more problem bears."