Peter Thompson explains how, alongside colleagues, the spatial distribution and interactions of grizzly bears (Ursus arctos), grey wolves (Canis lupus), and humans within the central Canadian Rocky Mountains were monitored and assessed in their latest study.
Human recreation and wildlife
The Bow River Valley in Alberta, Canada is a global hotspot for outdoor recreation, attracting millions of visitors annually to enjoy the spectacular landscapes of the nearby mountain parks. Visitation and outdoor recreation have exploded throughout Provincial and National Parks in and near the Bow Valley. This area is world-renowned for its beauty as well as opportunities for hiking, mountain biking, rock climbing, skiing, and many other recreational pursuits.
Both visitors and locals make extensive and increasing use of the trails in the Bow Valley, many of which were built by users without planning or sanction by local land managers. While enjoying these trails, recreationalists might not realize that they are interrupting movement and habitat security for a diverse array of wildlife that includes bears, wolves, cougars, and other wary species that must navigate an intensifying maze of outdoor recreation, habitat modification, and human development. Large ungulates, including moose, elk, and deer must also adapt to both humans and their infrastructure.
As recently as a few hundred years ago, the Bow Valley looked very different than it does now. This east-west valley connects the prairies to the continental divide, affording wildlife with respite from the rugged, energetically draining terrain of Rocky Mountain slopes. The same travel advantages attracted European settlers to the Bow Valley as an ideal pathway to the west coast. For over 100 years, the valley has supported industrial levels of human movement, first via the mainline of the Canadian Pacific Railway and then via the country-crossing Trans-Canada Highway. Associated industrial and urban development destroyed much of the natural habitat in the valley bottom, pushing wildlife out of the most ecologically productive areas.
The study
Conserving a full community of montane species in the Bow Valley along with the ecological processes on which they depend increasingly requires more information about how human recreation – not just human infrastructure – alters use by other species, particularly wary carnivores. Even when natural areas occur in National Parks or are designated as wildlife corridors or critical habitat patches, there are few to no limits on the density of recreational use by people. Managing this use so that humans and wildlife can coexist in this landscape well into the future requires quantitative methods for measuring the effects of human presence on other species, particularly wariest of the large mammals: grizzly bears and wolves.
Using over one thousand camera traps, we found that human recreation on trails displaces grizzly bears and wolves from their natural habitats even when the trails are hundreds of meters away. Camera traps automatically photograph anything that passes in front of them, making them one of the most efficient and effective monitoring tools for biologists studying large mammals. Our camera traps detected grizzly bears and wolves tens thousands of times each and we related their detection patterns to detections of human recreationalists (of which over one million were photographed).
Findings
Our results show that detection rates of grizzlies and wolves decreased at cameras with more human detections, but also at cameras near other high-use trails. Using statistical models, we were able to quantify the exact strength of this interaction, with the strongest disturbance effects take place within 300 m for grizzlies and 600 m for wolves. In other words, high-use recreational trails in the Bow Valley decrease the quality of more than half a kilometer of surrounding habitat for some species.
Our results illuminate the path forward for achieving coexistence between humans and wildlife in the Bow Valley. We learned that large carnivores need space away from high-use recreational trails to move across their extensive mountain ranges. Our work identifies specific thresholds and targets that can be integrated into land use planning efforts, which can reroute trails sufficiently far away from high-quality wildlife habitat.
It also emphasizes the importance of human behavior in wildlife conservation, and we hope that anyone interested in visiting the Bow Valley understands the importance of following rules and regulations associated with recreation in natural areas. We believe that the Bow Valley has room for humans, bears, wolves, and more, but we all must work together to create a landscape that makes coexistence possible.
Read the full article, “Integrating human trail use in montane landscapes reveals larger zones of human influence for wary carnivores” in Journal of Applied Ecology.
