Michael A. Sawaya, Ph.D. (Parks Canada, Sinopah Wildlife Research Associates)
Anthony P. Clevenger, Ph.D. (Western Transportation Institute)
Erin L. Landguth, Ph.D. (University of Montana)
Benjamin Dorsey, M.Sc. (Parks Canada)
Highways and roads within Mount Revelstoke and Glacier National Parks (MRG) in Canada contribute to habitat fragmentation and direct wildlife mortality from vehicle collisions. Anticipated highway expansion will likely increase wildlife mortalities and further contribute to demographic and genetic isolation of certain wildlife species. Site-specific mitigations have reduced wildlife road mortality and increased connectivity across highways. However, traditional highway mitigations in MRG will be challenging due to excessive snow loads and numerous avalanche and avalanche debris events. MRG have a large amount of pre-existing data on highway-related mortality, observations and radiotelemetry-based movements for many species. The data has never undergone a formal review or comprehensive analysis to address highway mitigation needs in the event of a future Trans-Canada Highway (TCH) twinning project. The purpose of this research was to compile MRG wildlife data, review the data for select terrestrial species and use the most statistically robust information to analyse conflicts between wildlife and the TCH, and from analyses of highway-related mortality and regional-scale connectivity, identify key areas for implementing mitigation measures on the TCH.
1) to compile and review MRG wildlife data for select terrestrial species, with emphasis on highway-related mortalities.
2) to analyse patterns of conflict between wildlife and the TCH.
3) to conduct regional-scale landscape resistance connectivity analysis.
4) to identify key areas for implementing mitigation measures on the TCH.
Map of Mount Revelstoke National Park (left) and Glacier National Park (right), the Trans-Canada Highway, and the focal study area in the Columbia Mountains of southeastern British Columbia..
We compiled wildlife-vehicle collision (WVC) data for MRG and found a total of 691 useable records. Mortalities occurred between 1961-2010 and were evenly distributed throughout the national parks. We summarized collision data numerically, monthly and spatially for black bears, caribou, deer, elk, grizzly bears, moose, mountain goats, and wolverines. We used a landscape resistance connectivity model to help identify key areas for highway mitigation. Our comparison of least cost paths and mortality sites identified 24 TCH sites deemed suitable for mitigation measures (i.e. mitigation emphasis sites). For each site, we ranked the importance to regional and local connectivity, the threat posed from road-caused mortality based on road-kill records, and the feasibility of implementing mitigation measures at the site. We ranked each of these four categories, giving higher scores for areas with higher degrees of overlap with WVCs or least cost paths. We developed recommendations for mitigation opportunities at each mitigation emphasis site, from simple to complex, some requiring work off-site (e.g., salt diversion), while others necessitating structural work on the highway (e.g., underpass construction). We discussed each of these sites and their mitigation recommendations in light of their respective attributes associated with local and regional connectivity conservation values and the safety of motorists traveling the TCH.
For more details about our recommendations to Parks Canada, see our final project report (pdf).
Mount Revelstoke & Glacier Highway Mitigation