It may have taken 15 years, but a wolverine has finally used a wildlife overpass to get across the deadly Trans-Canada Highway in Banff National Park.
As part of long-term highway crossing monitoring, a remote camera snapped the image of this highly elusive creature travelling across the Wolverine Overpass, just west of the Sunshine turnoff, late last year.
It was the first time a wolverine has ever been recorded using one of the multi-million dollar overpass structures, built to reduce wildlife mortality, help animals access critical habitat and keep populations connected.
“We’ve had wolverines using the underpasses before, but never an overpass, and any time a wolverine crosses the highway is big news,” said Trevor Kinley, a Parks Canada wildlife biologist.
“Every time we have one more structure they’re using it increases the chance we will see them crossing the highway enough that the populations on both sides will interbreed. We don’t want them isolated and inbred.”
Wolverines are rare, occur at low density, and move widely within very large home ranges. Because of this, it’s extremely challenging to gather information on their biology, distribution and abundance.
They are also highly sensitive to human disturbance, including transportation corridors like the Trans-Canada Highway, where noisy traffic buzzes by.
Highways pose significant challenges to wildlife by interrupting natural movement patterns, keeping animals from important habitat, causing genetic isolation, and by direct mortality from collisions with motor vehicles.
The first overpass crossing of the wolverine occurred Nov. 16 last year at 1:09 a.m. It is one of more than 200,000 crossings on overpasses and underpasses by wildlife, including grizzly and black bears, wolves and ungulates.
There have been nine previous crossings by wolverine at Banff underpasses – three crossings on the same day in 2005, one in 2008, three in 2010 and two in 2011.
Some of the underpass use has been in Phase 3B of the highway twinning project between Castle Mountain and Lake Louise, an area considered wolverine range in the Canadian Rockies.
Tony Clevenger, a Canmore-based research wildlife biologist in the Western Transportation Institute road ecology program at Montana State University, said it’s interesting to note that more than half of the 10 crossings have occurred in the last two years, suggesting use of the structures by wolverines is a learned behaviour.
“We don’t know a lot about wolverines, but we do know there’s a learning curve, which we’ve seen for grizzly bears and black bears as well,” he said.
“Perhaps this is what we’re seeing, that it’s an initiation of a learning curve, that they’re starting to figure out what these things are and starting to use them.”
Clevenger said 10 years ago he would have predicted wolverines would prefer to use overpasses, given they are extremely sensitive to human disturbance.
“They seem to use just about anything. Maybe it’s got something to do with their attitude; that nobody messes with them. It doesn’t seem to matter whether it’s a pipe or a big overpass. They just go through,” he said.
“Any time a wolverine crosses a highway is cause for celebration. Highways are fragmenters of habitat and any time you can get across is good for the species.”
Kinley said Parks Canada hopes the overpass crossing is the first of many to come by wolverines.
“It was pretty momentous to first see him on camera,” he said.