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Cougar predation in a multi-prey system in west-central Alberta

  • Author / Creator
    Knopff, Kyle
  • Predation by cougars (Puma concolor) variously can structure ecosystems and preserve biodiversity, engender conflict where livestock and pets are killed, and even drive prey populations to extinction. Effective management requires a firm grasp of the ecological drivers of predation, but these remain poorly understood due to difficulty obtaining sufficient data. My objective was to test hypotheses about drivers of predation in a population of wild cougars foraging in a multi-prey system in west-central Alberta, Canada. To obtain necessary data, I began by refining Global Positioning System (GPS) telemetry cluster techniques to monitor predation. I found that models alone were insufficient and that field visitation was required to estimate kill rate and prey composition accurately, but logistic regression models could direct field-work to improve efficiency, permitting continuous monitoring of cougar predation and generating large sample sizes. I assessed the role of scavenging as a foraging strategy and found that cougars scavenged opportunistically, reducing predation when carrion availability was high. Scavenging also made cougars susceptible to incidental snaring at wolf bait stations, and survival analysis revealed important consequences for cougar population trajectory and harvest management. I evaluated competing hypotheses about the magnitude of cougar predation and the influence of season and prey vulnerability on kill rate and prey composition. Cougars were effective predators, killing ungulates at rates near the upper end of the previously reported range. Cougar kill-rate increased by a factor of 1.5 in summer and cougars shifted prey composition seasonally as predicted by the juvenile and reproductive vulnerability hypotheses. Analysis of a multi-species functional response (MSFR) revealed that cougar impact on small populations of endangered prey is reduced by a tendency towards prey-switching but can be aggravated by the presence of individual specialists. Contrary to expectation, cougar MSFR was not driven by prey density, but rather by cougar demography and relative abundance of various prey. Finally, I reject the notion that cougars are nocturnal ambush predators, demonstrating instead that they hunt actively and make kills frequently during the day, exhibiting activity patterns loosely tied to those of their prey. I discuss the application of my findings for management and conservation.

  • Subjects / Keywords
  • Graduation date
    2010-11
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/R3H33P
  • 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
    English
  • Institution
    University of Alberta
  • Degree level
    Doctoral
  • Department
    • Department of Biological Sciences
  • Supervisor / co-supervisor and their department(s)
    • Boyce, Mark (Biological Science)
  • Examining committee members and their departments
    • Cassady St. Clair, Colleen (Biological Science)
    • Boutin, Stan (Biological Science)
    • Foote, Lee (Renewable Resources)
    • Bowyer, R. Terry (Biological Sciences, Idaho State University)