09/01/2026
https://www.facebook.com/share/p/19YSmVsNuT/
Researchers installed railroad crossing signals for wild animals in Banff National Park. Bells rang and lights flashed 30 seconds before each train arrived. Grizzly bears, elk, wolves, and coyotes fled the tracks 62 percent earlier at sites with the warning system than at sites without it, gaining an extra 360 feet of distance between themselves and the incoming train. The animals were not trained. Nobody conditioned them. The system was installed, the bells started ringing, and the animals figured out what the sound meant on their own.
Jonathan Backs, a PhD candidate in engineering and biological sciences at the University of Alberta, built the device. It is a small box bolted to the rail that detects an approaching train through vibration and changes in the magnetic field. When the sensors fire, the box triggers flashing lights and a bell sound at a location farther down the track where wildlife has been documented using the rail corridor. The warning begins 30 seconds before the train reaches the site. Thirty seconds is enough time for a grizzly bear standing on the tracks to register the sound, decide to move, walk or run off the rails, and clear the corridor before a train traveling 40 miles per hour covers the remaining distance.
Backs installed the systems at four sites along the Canadian Pacific Railway inside Banff in 2016 as part of a five-year grizzly bear research initiative funded by a million-dollar grant from Canadian Pacific. His supervisor, ecologist Colleen Cassady St. Clair, had been studying why grizzly bears were dying on the tracks at an alarming rate since the early 2000s. The railway was built in 1883. Bears and trains coexisted for over a century without significant mortality. Something changed around 2000.
What changed was the tracks themselves. The cleared rail bed became the easiest travel route through deep mountain snow. Walking on packed ballast costs a bear a fraction of the energy that wading through four feet of powder costs. Vegetation grows abundantly along the sunny, disturbed margins of the corridor: buffaloberry, other shrubs, and grasses that attract bears in spring and fall. Grain spills from freight trains leave piles of wheat and canola along the rails. The tracks became a trail system with a built-in cafeteria, and the bears that discovered this used the railway the way they would use any other travel corridor, except this one had trains on it.
Over a nine-month controlled experiment, Backs alternated warning and control treatments among the four sites, switching which sites had the bells and which did not every two to four weeks to account for seasonal variation. Trail cameras recorded every animal that appeared on the tracks before and during train arrivals. He logged 25 large-animal flight sequences and 149 small-animal sequences.
Large animals fled the tracks an average of 6.5 seconds earlier when the warning was operating, increasing their escape time from roughly 10.5 seconds to 17 seconds. That difference translated to 360 additional feet of space between the animal and the train. Small animals gained 3.3 seconds. The results were published in Transportation Research Part D in 2020.
The system does not scare the animals. Backs was specific about this. The purpose is not to frighten bears off the tracks permanently because frightening them would just push them into deep snow where travel costs more energy and survival gets harder. The purpose is to alert them that a train is coming right now so they move off the tracks for the 30 seconds it takes the train to pass and then walk back on. The bears are allowed to use the corridor. They are asked to step aside when the corridor is about to kill them.
Image is for illustration purposes only
Source: Backs, Cassady St. Clair, et al. (2020), Transportation Research Part D / University of Alberta / Canadian Pacific Railway / Parks Canada / CBC News / Science / The Narwhal / The Revelator.
