Grizzly bear numbers in this region are stable, if not slightly increasing.
That’s according to the latest DNA census in the province’s bear management area five (BMA5) – an approximately 10,000 square kilometre area from the Trans-Canada Highway south to Crowsnest Pass, which includes Canmore and Kananaskis Country.
There’s an estimated 16 grizzlies per 1,000 square kilometres in the northern portion of the management area, which takes in K-Country, and 12 grizzly bears per 1,000 sq km in the southern region.
Based on DNA results and modelling programs, researchers have come up with an estimate of 96 grizzlies – 52 females and 43 males – in the 6,000 sq km northern section and approximately 35 bears – 22 females and 12 males – in the south.
John Paczkowski, an ecologist with Alberta Environment and Parks, said grizzly bear density varies with food availability, noting differences in density estimates between years may reflect shift in their range rather than changing density.
And, he said, there can’t be a direct comparison made to previous census work because of different methodologies.
“But the takeaway message is the population is stable, or slightly increasing,” said Paczkowski at a WildSmart Speaker Series presentation on Tuesday (March 20).
“What’s interesting since the last census is that the population is expanding eastward.”
Grizzly bears rub on trees, fence posts and signposts, and this behaviour – primarily thought to be a form of communication – is used to collect hair from the animals for genetic analysis. Through extraction of DNA from hair follicles, researchers can identify species, sex, and individual identity of the bears.
Researchers coated lure on known rub trees and set up cameras in the northern section of the bear management unit to attract bears, while the southern section had sites that included posts and fences, not just rub trees and no bait was used.
“We know bears like to rub on things and when they rub on things they naturally leave hair behind,” said Paczkowski.
“This is a bit of a story about exploiting that natural behaviour in bears in order to facilitate bear management and understanding of bears in Alberta.”
Paczkowski said cameras set up at the sites indicate bears aren’t staying too long at these rub trees.
“About nine minutes is the longest duration, and often it’s a few seconds or minutes,” he said.
Grizzly bears are a threatened species in Alberta. The province’s recovery strategy recommends that the seven grizzly bear management units be re-evaluated every five years to keep an eye on population numbers and distribution.
The previous bear count in BMA 5 was completed in 2006 as part of a province-wide DNA count. The population estimate at that time was 90 grizzly bears, or a density of 12 bears per 1,000 square kilometres.
In the recent census, the bear management unit was divided into two regions – 2,900-sq. km. extending from Highway 3 to the southern end of Kananaskis Country and the northern 6,000 sq. km. portion to the Trans-Canada Highway, which includes K-Country.
However, differences in the way the two counts were done, such as sampling methods and different time frames, means the two numbers can’t be added together to come up with an overall population estimate for the entire area like in 2006.
For example, a lure was coated on rub trees to attract bears and cameras were set up at each site to make sure all bears were being recorded in the northern study – and the work was done two years apart.
“I kind of equate it to when you have a ratchet wrench and you’re trying to get a bolt and you look in the kit and the half inch ratchet isn’t there,” Paczkowski said.
“You know the metric one, the 12mm one will work, it’ll get the nut off; it’s not exactly the right tool, but it’s pretty damn close.”
Paczkowski said Kanansksis Country is more or less at carrying capacity for grizzly bears, noting more than half of the bears are females.
“We’re kind of full and I guess one of the signs we’re at carrying capacity is when we start to see females with cubs and those cubs are getting killed by other bears,” he said.
“The bears are regulating their own population because they’re at a certain density. It’s kind of counter intuitive, but that’s certainly a sign we’ve got a healthy bear population.”
Interestingly, Paczkowski said, DNA data as well as ongoing telemetry work from satellite collars on some grizzly bears shows the population is expanding toward the east compared to 2006.
“There are K-Country bears we think are local bears and they disappear on us for a few days and some of them are moving out there,” he said.
“That being said, there are a bunch of resident bears out there as well, so it’s not just our K-Country bears moving back and forth.”
Paczkowski said the change in distribution isn’t coming without its challenges, noting some bears are looking to make their way in the world in areas where there are grain bins, chicken coups and cattle – and no bear-proofing.
“There’s rich, rewarding food opportunities out there in terms of cattle and other things, but I think it’s a high-risk lifestyle,” he said.
“I think that’s where people of Alberta and the government of Alberta are going to say, ‘right, how are we going to make this work now?’ That’s the future challenge.”
Meanwhile, in neighbouring Banff, researchers have found Banff’s grizzly population has remained relatively unchanged since a 2006-08 DNA study. Population density is estimated to be approximately 13 bears per 1,000 square kilometres.
Researchers used information from grizzly bears captured as part of the Parks Canada-Canadian Pacific Railway joint plan, as well as images from cameras located throughout the front country and backcountry.
“We found that the population of grizzly bears is stable, which is important for conservation of grizzly bears throughout the Rockies,” said Jesse Whittington, a Banff National Park wildlife ecologist who led the study.
