Abstract
The importance of conserving migratory populations is recognized across a variety of ungulate taxa, yet the demographic benefits of migration remain uncertain for ungulate populations that exhibit partial migration. We hypothesized that migratory pronghorn (Antilocapra americana) would experience greater survival compared to residents by moving longer distances to avoid severe winter weather and access higher quality forage. We used a Bayesian time-to-event approach to analyze the fates of 175 radio-collared adult female pronghorn monitored over 8 biological years (2004–2011) in the Northern Sagebrush Steppe ecosystem. Annual survivorship of migratory pronghorn was 7% higher on average compared to residents but not statistically different. Migratory pronghorn had higher survivorship in summer and winter compared to residents, and few mortalities were observed during the short autumn and spring migration periods. Mortality risk for both movement tactics intensified under more severe winter weather; winter weather severity alone best explained annual pronghorn mortality risk. The top model predicted survival rates to decline on average by 56% over the range of observed winter climatic conditions. To minimize human impacts to pronghorn during extreme climatic events, we recommend working with transportation departments and land managers to enhance pronghorn crossings of roads and railroads, and landholders to modify fences to wildlife-friendly standards.
| Original language | English |
|---|---|
| Pages (from-to) | 1114-1126 |
| Number of pages | 13 |
| Journal | Journal of Wildlife Management |
| Volume | 84 |
| Issue number | 6 |
| DOIs | |
| State | Published - Aug 1 2020 |
Funding
This project could not have been accomplished without the dedication of project staff and partners. We thank D. J. Bender, C. C. Gates, J. P. N. Landry‐Deboer, D. H. Eslinger, M. G. Grue, K. Morton, and M. J. Suitor in Alberta; R. Adams, M. Albers, J. C. Carlson, S. Forrest, J. A. Gude, P. T. Gunderson, J. T. Herbert, K. R. Johnson, D. Jørgensen, K. Kunkel, A. Messer, S. Story, M. G. Sullivan, and S. Thompson in Montana; and E. Beveridge, C. Lees, and J. Pogorzelec in Saskatchewan for field assistance and logistical support. We also thank Quicksilver Air, D. Hitch, Bighorn Helicopters, Pathfinder Helicopter Wildlife Management, and Allison Air Service for excellent capture and surveillance of pronghorn during the study. We thank P. R. Krausman, M. Wisdom, and 2 anonymous reviewers for helpful suggestions that greatly improved our manuscript. Funding for this project was provided by the Alberta Antelope Guides, Alberta Conservation Association (ACA), Alberta Fish and Game Association (Zone 1), Alberta Professional Outfitters Society, Alberta Sport Recreation Parks and Wildlife Foundation, Canadian Forces Base Suffield, Counter Assault, Foundation for Northern American Wild Sheep—Eastern Chapter, Mitacs–Accelerate Program, Montana Chapter of The Wildlife Society, Montana Fish, Wildlife & Parks (FWP), National Fish and Wildlife Foundation, Petro‐Canada Sustainable Grasslands Applied Research Program, Safari Club International, Safari Club International Alberta Chapter and Northern Alberta Chapter, Sagebrush Science Initiative (a collaboration between the U.S. Fish and Wildlife Services and Western Association of Fish and Wildlife Agencies), Saskatchewan Ministry of Environment, University of Calgary, University of Montana, United States Bureau of Land Management (BLM), and World Wildlife Fund (WWF). Additional in‐kind support was provided by The Miistakis Institute, FWP, ACA, BLM, and WWF. This project could not have been accomplished without the dedication of project staff and partners. We thank D. J. Bender, C. C. Gates, J. P. N. Landry-Deboer, D. H. Eslinger, M. G. Grue, K. Morton, and M. J. Suitor in Alberta; R. Adams, M. Albers, J. C. Carlson, S. Forrest, J. A. Gude, P. T. Gunderson, J. T. Herbert, K. R. Johnson, D. J?rgensen, K. Kunkel, A. Messer, S. Story, M. G. Sullivan, and S. Thompson in Montana; and E. Beveridge, C. Lees, and J. Pogorzelec in Saskatchewan for field assistance and logistical support. We also thank Quicksilver Air, D. Hitch, Bighorn Helicopters, Pathfinder Helicopter Wildlife Management, and Allison Air Service for excellent capture and surveillance of pronghorn during the study. We thank P. R. Krausman, M. Wisdom, and 2 anonymous reviewers for helpful suggestions that greatly improved our manuscript. Funding for this project was provided by the Alberta Antelope Guides, Alberta Conservation Association (ACA), Alberta Fish and Game Association (Zone 1), Alberta Professional Outfitters Society, Alberta Sport Recreation Parks and Wildlife Foundation, Canadian Forces Base Suffield, Counter Assault, Foundation for Northern American Wild Sheep?Eastern Chapter, Mitacs?Accelerate Program, Montana Chapter of The Wildlife Society, Montana Fish, Wildlife & Parks (FWP), National Fish and Wildlife Foundation, Petro-Canada Sustainable Grasslands Applied Research Program, Safari Club International, Safari Club International Alberta Chapter and Northern Alberta Chapter, Sagebrush Science Initiative (a collaboration between the U.S. Fish and Wildlife Services and Western Association of Fish and Wildlife Agencies), Saskatchewan Ministry of Environment, University of Calgary, University of Montana, United States Bureau of Land Management (BLM), and World Wildlife Fund (WWF). Additional in-kind support was provided by The Miistakis Institute, FWP, ACA, BLM, and WWF.
| Funders |
|---|
| Lukuru Wildlife Research Foundation |
| Hornocker Wildlife Institute/Wildlife Conservation Society |
| World Wildlife Fund |
| Bureau of Land Management |
| Alberta Conservation Association |
| Mitacs Canadian Science Policy Fellow |
Keywords
- Alberta
- Antilocapra americana
- Bayesian
- Montana
- Saskatchewan
- adult female survival
- movement tactics
- pronghorn
- winter severity
