Wolves and Disease Slowly Decimating Banff’s Elk Population

In addition to the beautiful mountains and landscape, the picturesque town of Banff, Alberta is also known for the majestic wildlife that call this world famous town home. A recent report published by the good folks out of Parks Canada painted a bleak picture for the area's elk populations as researchers are reporting population declines of about 54 percent over the last six years.

Performing fall elk classification counts each year, Parks Canada has been eying the disturbing trend that has been going anywhere but up since 2018. With just 123 elk counted in the Bow Valley between Castle Mountain and Banff National Park last year, it’s a stark contrast to the 267 elk counted just six short years ago.

“Over time, what we’ve noticed is this is definitely sliding off,” said Blair Fyten, human-wildlife coexistence specialist for Banff National Park. “We do know that our population is going down … that’s a 54 per cent decrease in population since 2018.”

With such an alarming trend forming, researchers set out to determine the root cause of the declines and found that two main factors seemed to be affecting the region's elk. Looking first at calf survival rates, researchers identified cow-calf ratios to determine whether or not the winter seasons were negatively affecting the herd. With harsh winters making it difficult for calves to survive, it’s often a leading cause for mortality in elk and other ungulates. 

But the numbers from this past fall painted a stronger-than-expected picture of calf survival. Researchers found that for every 100 cows they surveyed, 57 of them were with calves that had survived the winter season. In what is considered a high percentage (57%), researchers then turned to predation and disease.

Noting that tracking down these fatalities and causes are certainly more difficult than calf survival rates, Parks Canada ended up locating 16 known elk mortalities as part of the study. Of the 16 elk, they found that disease was the leading cause of death followed closely by predation. 

Five of the affected elk were found to have been infected by necrotic hepatitis rather than the usual suspect, chronic wasting disease - although it has reared its head in other regions of the province.

“We’re definitely picking up some of these animals that are succumbing to infectious necrotic hepatitis,” Fyten said. “Our most recent case of that was we had an elk in November die on the golf course so we know it’s occurring here.”

Specialists also concluded that while predation ranked second in terms of the 16 animals they were able to locate, many suspect the number of elk killed by wolves and cougars is far higher than what they were able to uncover. Given the fact that these elk are often consumed or cached, running into one of these predation events is admittedly a stroke of luck for researchers.

“Our wolves have been pretty active in the valley here and there’s been good numbers this past year, and past few years, so definitely the wolves are taking a lot more elk than we know of,” Fyten said.

Even with a few collared wolves roaming the landscape, Fyten and others stated that the actual population of wolves in the area remains unknown, but is believed to be higher than anticipated. 

As for the strategy moving forward, the Bow Valley’s population target remains at between 150 and 300 elk. Given the sizable holes in the available data, researchers are hopeful that a combination of collared wolves and making adjustments to survey times will help yield larger sample sizes and reveal answers to what continues to plague local elk populations.