Since 2001, the elk population wintering on the Ya Ha Tinda ranch ~5kms east of Banff National Park, Alberta has declined from over 1000 to ~450 elk. The causes and consequences of these changes have been the focus of a long-term study between Dr. Evelyn Merrill at the University of Alberta, Mark Hebblewhite at the University of Montana, and their students. Since 2001 we have captured and radiocollared over 225 adult female elk and tracked their resource selection, movements, survival and migratory patterns. The current project is lead by Scott Eggeman, MS student at the University of Montana and focus on the mechanics of partial migration.
During the last decade, the proportion of elk that migrate into Banff National Park during summer has decreased relative to the population resulting in more elk remaining on the winter range of the Ya Ha Tinda ranch throughout the summer. As partial migrants, fluctuations in the ratio of migrants to non-migrants may be fairly common. However, little is known about the underlying mechanisms responsible for maintaining densities of partially migratory ungulates. It has been hypothesized that the behavior of partial migration results from density-dependence in the relative costs and benefits of migrating or remaining a resident. Scott's research will take advantage of long-term radio-telemetry data to determine whether changes in migratory patterns of the Ya ha Tinda elk herd are a function of a density-dependent response to changes in the population. Scott will determine the migratory nature of this partially migratory elk herd and whether migrants and residents are regulated by top-down or bottom-up forces (e.g. predation or forage).
Hebblewhite, M. & Merrill, E. H. 2011. Fitness balancing in a partially migratory ungulate through risk-forage trade-offs. Oikos, 120(12): 1860 - 1870.
Robinson, B. G., M. Hebblewhite, and E. Merrill. 2010. Are migrant and resident elk (Cervus elaphus) exposed to similar forage and predation risk on their sympatric winter range? Oecologia 164: 265-275.
Hebblewhite, M., & Merrill, E.H. 2009. Trade-offs between wolf predation risk and forage at multiple spatial scales in a partially migratory ungulate. Ecology,90(12): 3445-3454.
Hebblewhite, M., Munro, R. & Merrill, E. H. 2009. Trophic consequences of post-fire logging in a wolf-elk system. Forest Ecology and Management, 257, 1053-1062.
Hebblewhite, M., Merrill, E. H. & McDermid, G. 2008. A mutli-scale test of the forage maturation hypothesis for a partially migratory montane elk population. Ecological Monographs, 78: 141-166.
Hebblewhite, M., & Merrill, E.H. 2008. Modelling wildlife-human relationships for social species with mixed-effects resource selection models.Journal of Applied Ecology, 45: 834-844.
Hebblewhite, M. 2007. Predator-prey management in the National park context: lessons from a transboundary wolf-elk, moose, and caribou system. Transactions of the North American Wildlife Conference, 72, 348-365.
Hebblewhite, M. & Merrill, E. H. 2007. Multiscale wolf predation risk for elk: does migration reduce risk? Oecologia, 152, 377-387.
Hebblewhite, M., Merrill, E. H., Morgantini, L. E., White, C. A., Allen, J. R., Bruns, E., Thurston, L. & Hurd, T. E. 2006. Is the migratory behavior of montane elk herds in peril? The case of Alberta’s Ya Ha Tinda elk herd. Wildlife Society Bulletin, 34: 1280-1295
Scott Eggeman M.Sc./Wildlife Biology
Tom Hurd, Wildlife Biologist, Banff National Park
Anne Hubbs, Alberta Fish and Wildlife
Evelyn Merrill, University of Alberta
Rick Smith, Ya Ha Tinda Ranch Manager
Alberta Conservation Association
University of Montana
University of Alberta
Shikar Safari Club International
Parks Canada, Ya Ha Tinda Ranch