Identifying ecological limits of mountain trail use

View of Peyto Lake in Banff National Park. Credit, Tobias Alt.A new study on human impact to wildlife in some of Canada’s most popular national parks has identified limits at which trails can be used before ecological disturbance takes place.

The study, led by University of Calgary Masters graduate, J. Kimo Rogala and published in the journal Ecology and Society, found that wolves and elk were disturbed away from high quality habitat in Banff, Kootenay and Yoho National Parks in areas where human traffic on trails was monitored.

Wolves and elk avoided areas within 50 metres of trail routes travelled by one person per hour or greater and up to 400 metres from trails with human activity above two persons per hour. Such avoidance behaviours are consistent with previous scientific research; however, the identification of threshold levels is new.

Partially funded by Parks Canada, the research conducted between 2005 and 2008 also sheds light on how further ecological changes may be occurring. Results found that at human activity levels below two persons per hour, wolves avoided and conversely, elk were attracted to, habitat areas within 51-400 metres of trails. This suggests a refuge zone for elk from key predators, such as wolves.

“The challenge of parks and reserves is finding the balance between long term ecological integrity and providing visitors with quality experiences and learning opportunities,” says Rogala, who was a student of professor Marco Musiani in the environmental design faculty. “This research increases understanding of how humans impact the national park landscape and provides a tool for park staff to better manage sensitive areas such as wildlife corridors and primary habitat.”

Another recent paper out of Musiani’s lab, by PhD graduate Tyler Muhly, supports the hypothesis that high human activity displaces predators, but not prey species, creating a spatial refuge from predation. The research on Alberta ranchlands found that activity greater than 18 humans per day (also approximately one person per hour, as found in National Parks) had the potential to interfere with predator-prey interactions.

“These two independent publications from a national park area and from a ranchland area both found similar thresholds on wildlife disturbance, suggesting significant ecological consequences,” Musiani says. “Nowadays, human influences are everywhere and we should learn to cope with them.”

--Reprinted from University of Calgary