Date of Award:

8-2023

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Wildland Resources

Committee Chair(s)

Larissa L. Yocom

Committee

Larissa L. Yocom

Committee

Tal Avgar

Committee

Peter Adler

Abstract

The Rocky Mountain elk (Cervus elaphus nelsoni) is an ecologically and culturally important wildlife species in the Intermountain West, but it is facing habitat changes caused by increasing fire activity. Wildfire frequency is projected to continue to change into the future, yet increases in annual area burned and increases in area burned at high severity may actually represent opportunities for some species. Large herbivores like elk may benefit from increased access to regenerating areas where forage abundance and quality are often elevated. Therefore, effective management of wildlife populations may depend on quantifying how large ungulates, like elk, alter their behavior in the context of rapidly shifting fire regimes. In order to evaluate elk foraging activity in previously burned areas, my research examined differences in severity and habitat types. I used two sampling methods to understand elk behavior and habitat selection post-fire. First, I ran a Hidden Markov Model (HMM) on GPS collar data to assign one of three behavioral states (‘resting’, ‘foraging’, or ‘commuting’) to each of the approximately 730,000 elk positions located in a previously burned fire perimeter. I statistically tested whether the probability of an elk position being assigned a ‘foraging’ state depended on fire severity and time since fire, while controlling for other potential behavioral drivers (remote-sensed vegetation type, cover, and productivity). I then used camera data from 40 camera traps, stratified by fire severity (unburned, low, moderate, and high severity), to monitor elk use of burned areas. Results suggest that elk probability of foraging in burned areas peaks 3-4 years post-fire in conifers, but peaks between 7-9 years in aspen. Also, elk have higher probabilities of being in a foraging state in areas where aspen is burned at high severity. From camera data, I found that the post-fire abundance of herbaceous biomass is the strongest driver of elk abundance, and abundance is highest at higher burn severity. Combined, this research provides information on wildfire’s influence on elk behavior and abundance and can help inform management decisions for elk on increasing fiery landscapes in the western United States.

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