Rail-based transportation offers considerable efficiency and economy, but it conveys a risk of mortality for people and wildlife that is sometimes high enough to threaten local populations. This situation characterizes grizzly bears (Ursus arctos) in Banff National Park where mortality from train strikes has increased dramatically over the last 15 years without explanation. Risk of mortality is assumed to begin with hypothesized attraction to agricultural products spilled on the rail, natural and invasive edible plants favoured by rail disturbance, the presence of scavenging opportunities from other rail-killed animals, and increased travel efficiency. Mortality risk is presumed to increase both numerically (as a function of frequency) and functionally, from the failure of bears either to detect approaching trains or escape the track bed quickly. The functional effects, in turn, are hypothesized to result from topography, interference from other kinds of human infrastructure or other bears, and exacerbating effects of visibility and weather.
We participated in a five-year project to investigate each of these hypotheses and to identify effective forms of mitigation. In collaboration with biologists from Parks Canada, we measured habitat selection and movement of bears fitted with GPS collars, monitored the distribution, abundance and seasonal changes in each of spilled agricultural products, bear foods, and rail-caused mortality for all wildlife. We also estimated rail use at specific locations by bears and other mammals and assessed several physical attributes of the rail, including the surrounding aspect, slope, hydrology, and magnetic properties. Owing to clear hot spots of mortality, we have developed a train-based warning system that is now being tested. We are synthesizing our more specific research results in a predictive model of mortality risk to support mitigation action at this site and use by others to reduce train-caused mortality for other species and locations.
This project is funded by the Canadian Pacific / Parks Canada Grizzly Bear Conservation Initiative with matching funding from a Collaborative Research and Development Grant Grant, an industrial partnership program of the Natural Science and Engineering Research Council (NSERC) of Canada.