Date of Award:

8-2026

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Wildland Resources

Committee Chair(s)

Kezia Manlove

Committee

Kezia Manlove

Committee

Mary Conner

Committee

Tal Avgar

Committee

Jim Powell

Committee

Tom Stephenson

Abstract

The places animals choose to live affect the food they find, the dangers they face, and the weather conditions they experience. These experiences influence whether individual animals survive and reproduce, which in turn affects the size and health of animal populations. Although scientists have long believed that animal movements play an important role in population trends, there has been limited real-world evidence showing this connection. Advances in GPS tracking technology now allow researchers to follow animals over long periods and better understand how movement influences survival. Using 20 years of GPS tracking data from the endangered Sierra Nevada bighorn sheep (Ovis canadensis sierrae), we examined how snow conditions affect where these bighorn choose to live, and how those decisions influence their chances of survival. Our goal was also to help wildlife managers prepare for future changes in snow conditions caused by a warming climate. First, we studied how snow influences seasonal movements up and down the mountains and investigated how bighorn sheep decide when to move. Next, we examined how these movements change the amount of snow the sheep experience and how that affects their survival. We then estimated how the snow conditions encountered by bighorn sheep may change in the future if their movement patterns remain the same. Finally, we predicted how survival is likely to change under future snow conditions while accounting for the possibility that the bighorn may adjust their movements. We found that Sierra Nevada bighorn sheep actively change where they live and travel in ways that reduce their exposure to difficult snow conditions, improving their chances of survival. Future changes in snowpack, combined with the bighorn's ability to adapt their movements, are expected to further improve survival. This study provides clear evidence that animal movement can shape population outcomes and offers practical tools that wildlife managers can use to better understand and protect species using GPS tracking data.

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

Download

Share

COinS

Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .