The number of mammals killed by trains in Canada’s Rocky Mountains could be slashed if the railway reduced speed limits along eight km total of track on either side of the Banff and Lake Louise townsites, according to a study by University of Alberta researchers who used the train mortality record to pinpoint the most dangerous locations.
In collaboration with biologists from Parks Canada, Faculty of Science professor Colleen Cassady St. Clair and her team in the Department of Biological Sciences used the mortality records of 646 animal strikes reported by Canadian Pacific Railway from 1995 to 2018 in Banff and Yoho National Parks.
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Her previous train-strike investigations focused on grizzly bears, which account for less than one per year over the 24-year time period.
“We wanted to know if we could leverage the statistical power of all these collisions to identify the kinds of locations that were most dangerous and suggest mitigation strategies that might make these locations less dangerous,” said St. Clair.
All told, there were 11 species in the study broken into three groups: 59 bears, both black and grizzly; other carnivores that included 27 wolves, cougars, lynx and coyotes; and a category for ungulates made up of 560 moose, elk, sheep and deer – whitetail and mule.
The data showed that the top characteristic of places where there’s a high animal mortality was train speed, followed by proximity to water from the track, amount of water nearby and track curvature.
“We think that train speed and track curvature really impede an animal’s ability to detect trains, and two others we thought had mostly to do with how quickly they could get off the tracks,” said St. Clair.
She noted there are two locations that account for half of the province’s grizzly bear strikes – just west of the Banff townsite and just east of the Lake Louise townsite – that hit all four of these characteristics.
“Both are sites where trains are travelling at a relatively higher speed, the track is curved, they’re adjacent to water and, especially for the most important location near the Banff townsite, there’s a lot of water.”
St. Clair added bears’ mortality peaks in late June, the time of year when water levels are the highest and the animals use the tracks as a travel corridor when water is most impeding.
“We’ve had a hunch about this for some years, and the mitigation for these kinds of sites is already underway,” she said.
Parks Canada has been clearing wildlife trails near sites where there’s been quite a lot of bear mortality as part of a pilot project to see whether making it easier for animals to get off the tracks cuts mortality.
Unfortunately, slowing down the train speed has been a non-starter in discussions with railways over the years, as St. Clair said speed is arguably the railway’s most important determinant of profit margin.
“There’s tremendous resistance to reducing train speed across the board, and I’ve tried to argue over the years that might not be necessary to have a significant reduction in risk.”
Instead, St. Clair has put forth a middle-ground proposal that would see lower speed limits imposed at specific locations that could have quite a small effect on that bottom line.
“In particular, if the speed limit change were moved by just four km farther away from the townsites, where trains slow anyway for human safety, it would have covered those two hotspots of mortality,” she said.
She noted that, as with the rising waters in June, there are specific times of the year a seasonal speed-limit reduction could be effective at reducing mortality on a number of species. For instance, conservation officers responded to four train collisions that killed more than 100 pronghorn antelope between Nov. 9 and Nov. 20 in Saskatchewan.
St. Clair explained the best mitigation for highways has been to put up a barrier fence and perforate it with crossing structures, but that’s not affordable for railways as there’s not a risk of human deaths.
“That’s a pretty speculative use of our results but it’s compelling and, I believe, could be a lot less expensive than a blanket approach to mitigation,” she said, adding this is more than just a bear problem.
“Bear strikes receive attention because bears have a low population density. But the loss of each individual is damaging to any population, whether it’s a common species or a rare one.”
| By Michael Brown for © Troy Media