Individual and Seasonal Variation in Grizzly Bear Selection for a Railway and other Linear Features in Banff National Park, Canada

  • Author / Creator
    Friesen, Alyssa J
  • Mortality caused by collisions with trains affects numerous species globally and has increased recently to threaten the grizzly bear (Ursus arctos) population protected in Banff and Yoho National Parks, Canada. Although train collisions are the ultimate cause of mortality, the more proximate processes that cause grizzly bears to use the railway are unclear. No previous study has assessed the relative strength of grizzly bear attraction to the railway compared to other linear features in the study area, including power lines, a secondary road and the right-of-way along the TransCanada Highway fence. According to local knowledge, male bears make greater use of the rail than females, but there has been no quantitative assessment of this putative tendency. I hypothesized that selection for the railway is strongest in spring and fall, when forage resources are limited. I also hypothesized that male bears would select the railway more strongly than females to increase one or more of forage selection, travel efficiency or access to social dominance and mating opportunities. Using GPS collar data collected by Parks Canada, I modeled individual and population-level resource selection functions to compare selection by feature type and season. I also conducted repeated vegetation sampling in each linear feature type and season to quantify the availability of bear forage. Percent cover of vegetation available to grizzly bears was higher in linear features than adjacent forests, lower on the rail than other feature types and lower in the fall than the spring. At the population level, grizzly bears increased selection for the railway in spring and fall and the power line in summer. I did not find evidence of consistent sexual segregation within or among linear features and selection for linear features was highly variable even within classes of individuals. My results suggest that individual experiences and attributes, as well as temporal and spatial features of local landscapes, have greater effects on attraction to the railway than sex or reproductive status. Logical management extensions include a focus on mitigation during the seasons of highest selection for the railway by grizzly bears (spring and fall). Maintenance of power lines should be scheduled to avoid summer months when selection by grizzly bears is strongest, to decrease the potential for human-bear conflict. Integration of this work with other components of a larger project at the University of Alberta will determine whether it is logical and feasible to target mitigation for specific individuals and locations where rail use is highest.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Biological Sciences
  • Specialization
    • Ecology
  • Supervisor / co-supervisor and their department(s)
    • St. Clair, Colleen (Biological Sciences)
  • Examining committee members and their departments
    • Nielsen, Scott (Renewable Resources)
    • Merrill, Evelyn (Biological Sciences)