Wildlife crossing design influences effectiveness for small and large mammals in Banff National Park

Abstract

Banff National Park (BNP) is Canada's oldest national park and a very popular one, with both year-round residents and millions of annual visitors. In turn, this means there are several busy road and rail transportation routes throughout the park. These factors can have a number of negative effects on local wildlife. The wildlife crossing structures of the Trans-Canada Highway in BNP have become a key conservation tool to conserve biodiversity in the park and beyond. As the first large-scale operation of highway mitigation of its kind in North America, it is a perfect case for understanding the conservation value of highway overpasses and underpasses for a variety of wildlife species including both large and small mammals. It was determined from the research that there is a vast majority of information available for large mammals compared to small mammals. Small mammals used the crossing structures to avoid predators, while large mammals used the crossing structures to avoid humans. The design of the structure was extremely influential on its effectiveness with black bears and cougars preferring narrow bridges with cover, elk preferring wide, open bridges, and smaller mammals, such as weasels, snowshoe hares, and some mice preferring culverts with vegetation cover.