In a bid to keep a close eye on the life and death drama between predator and prey, Parks Canada wants to collar additional wolves in a pack that overlaps territory with the new bison herd in a remote region of Banff National Park.
The plan is to have at least two wolves in the Panther-Cascade pack fitted with GPS collars as part of the $6.6 million bison reintroduction program, which saw 16 bison from Elk Island National Park brought to a fenced pasture in the Panther Valley earlier this year.
One wolf from that pack is currently collared, but park researchers say they’re keen to see if wolves will switch up their diet to include bison, a species that has not been present in Banff’s backcountry for 140 years.
“One of the big questions we have is whether or not wolves will be able to predate on bison,” said Jesse Whittington, a wildlife ecologist for Banff National Park, noting staff will monitor predator-prey dynamics and interactions between wolves and bison.
“Understanding wolves are the dominant species in this ecosystem, it’s important for us to understand how they’re travelling on the landscape, what they’re eating and what effect that might have on bison.”
For the past several years, Parks Canada has been visiting GPS cluster locations downloaded from wolf collars to find predation sites. GPS clusters show when wolves have stayed in the same place for a few days, suggesting it may be a kill site.
Whittington said 75 per cent of the species hunted and killed by the Panther-Cascade wolf pack in summer 2016 were bighorn sheep, but this year 75 per cent of predation sites were deer, with far fewer bighorn sheep.
“These are preliminary results and obviously we didn’t get to all the clusters, so we’ll have to do additional analysis to get a more comprehensive picture of their predations,” he said.
“Wolf predation depends a lot on availability and that can change over time.”
Last February, 10 pregnant females and six bulls were brought from Elk Island’s disease-free herd to a soft-release pasture in the backcountry in the Panther Valley, located about 40 kilometres north of the Banff townsite.
Ten healthy calves were born between April 22 and throughout May, bringing the bison herd number to 26. All bison in the herd remain alive and well.
After calving again in spring 2018, the gates to the fenced pasture will open in June to allow bison to wander into a larger 1,200-square-km reintroduction zone in the Panther and Dormer valleys.
“They’ll be released when the calves are robust and strong,” said Whittington.
“It’s also a time when there’s abundant forage for the bison to feed on.”
Research in Yellowstone National Park in the U.S. has shown bison make up about 40 per cent of the wolves’ diet there. It suggests wolves there pick their prey based on the size of the pack. They generally eat elk, but bigger packs will tackle bison.
Hunting is a hazardous business for wolves, but Whittington said they will generally prey on more vulnerable animals like young, old or sick ungulates to reduce their risk of being injured during the kill.
“Obviously, a species like a deer is easier for a wolf to kill than something like an elk or a bison, but those larger animals like elk or bison would have a much larger food reward if they can kill it safely,” he said.
“We really don’t know how long it will take wolves here to learn how to predate on bison and what effects that will have on the wolf population.”
The Panther-Cascade pack has been travelling extensively throughout its range, from Stoney Creek north through the Upper Cascade and Panther valleys, sometimes east outside the park toward Mountain Aire Lodge near Sundre.
At this point, it’s not known exactly how many individuals are in the pack. Parks knows the wolves denned in the Panther Valley last spring and remote camera data showed at least one new pup.
Whittington said the pack has travelled adjacent to the fenced pasture where the 26 bison are being held.
“To our knowledge there have been no direct interactions between the wolves and bison,” he said.
“That’s in part because the bison pasture is fenced and wolves couldn’t get through it.”