Evaluating a Mechanistic Home Range Model for Elk (Cervus elaphus)

  • Author / Creator
    Seidel, Dana P
  • Stable home ranges can emerge in a generic forager using a two-part memory system and rules derived from optimal foraging theory. My objective was to evaluate the underlying assumptions of this promising theoretical model using data from two populations of elk. Using a spatiotemporal scan statistic, I identified discrete foraging patches in GPS relocations of elk, thereby supporting the first assumption of the model that foraging occurs in discrete patches rather than diffusely across the landscape. Moreover, the model assumes that foraging patches have higher attractive value than other areas of the home range. During the 2012 growing season I identified patches based on GPS relocation data and sampled vegetation within each patch to estimate forage biomass. Points along elk paths not used for foraging were sampled identically for comparison. Using a matched-pairs conditional logistic regression on "patch" and "nonpatch" data points, I demonstrated foraging selection differences across herd, sex, and season and compared results to herd-scale resource selection functions for the area. Generally elk selected patches with higher biomass, cover, slope, and lower traffic on the nearest road; selection priorities that were mirrored at the larger scale. Exploring intra-home range movements in comparison to those predicted by the model, I used negative binomial regression to assess environmental characteristics that affect the frequency of returns, and thereby characterize the most successful patches. I found that elk return to known patches regularly over a season, on average after 15.4 (±5.4 SD) days. Patches in less-rugged terrain, farther from roads and with high productivity were returned to most often when controlling for the time each patch was known to each elk. My results demonstrate empirical support for the primary assumptions behind a mechanistic home range model and offer insight into the physiographic and anthropocentric features that define a successful foraging patch. These findings offer important insights that may be used to understand the movements, space use, and home range formation in free-ranging ungulates.

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  • Degree
    Master of Science
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    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.