Banff Alberta - It's well known that grizzly bears eat squirrels, but a team of scientists is trying to determine whether squirrels are also contributing to the death of bears.
 
Researchers are studying the environment and animal behaviour to determine why bears have been dying on the railway tracks in Banff, Yoho, and Kootenay national parks.
 
Bears have been killed as they eat spilled grain along the tracks, but the team has now discovered that red squirrels could also play a role in food-conditioning bears to the grain.
 
"Our preliminary results are that squirrels are actually targeting the grain and taking it back to their middens and they are cacheing it there," said Colleen Cassady St. Clair, a biological sciences professor at the University of Alberta who's leading the research.
 
"We first got an inkling of this last year when we found one of our collared bears was defending what looked to my crew like a hole in the forest full of grain. When I saw it, I knew that's not a hole in the forest, that's a squirrel midden full of grain."
 
The preliminary finding is one of many that could help come up with mitigation measures as part of ongoing research project between Parks Canada and Canadian Pacific to prevent grizzly bear mortality on the transportation corridors.
 
Since 2000, the railway has been the most common threat to bears, with a total of 14 grizzlies killed by trains in the mountain parks.
 
Survival in the national parks is considered critical because there are only about 700 grizzly bears throughout Alberta, leading the province to declare the species threatened.
 
"They are an extremely important indicator species," said Steve Michel, human-wildlife conflict specialist with Banff National Park.
 
"Basically, if we've got grizzly bears on the landscape, we know the entire ecosystem is healthy. I like to think of them as the canary in the coal mine for Alberta's ecosystem. They are very important in Banff National Park, as well as the rest of Alberta. They are under a lot of stress and face a lot of unnatural mortality so that's why we are doing this research work to try to reduce that the best we can."
 
The Parks Canada project, announced in fall 2010 with a $1-million commitment from Canadian Pacific Railway, is in its third of a five-year study.
 
The rail company has made efforts to reduce the amount of grain spilling from its trains, added whistles in high-risk areas, and added on-board camera systems to record collisions.
 
Parks Canada has brought in the teams of internationally recognized experts in the fields of conservation, biology, animal behaviour, transportation research, and bear biology.
 
Cassady St. Clair, the project lead, said the squirrel insight could allow for the treatment of some of the deposited grain with a compound that deters them from cacheing it over the winter and attracting bears to the middens in the spring.
 
Other work includes having remote cameras monitor the rails for signs of bear behaviour, continuing to test electro-mats as a way to deter bears from going on the tracks, and installing a low-cost device that would alert bears that a train is coming, similar to bells at a rural railway crossing.
 
She said they've determined some bears, particularly males, spend a lot of time on the tracks and often are successful in avoiding trains.
 
"We're trying to figure out exactly what it is that makes these bears vulnerable, where sometimes they fail to detect the approaching train," said Cassady St. Clair.
 
"How could we mitigate so they don't fail to detect an approaching train, so they can continue to use all of the resources in the valley bottom where the railway is?"

Colette Derworiz.