Date of Award:

12-2024

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Wildland Resources

Committee Chair(s)

Julie K. Young

Committee

Julie K. Young

Committee

Justin A. Dellinger

Committee

Tal Avgar

Committee

Karen H. Beard

Committee

Edd Hammill

Abstract

Wild pigs are an introduced species in the Americas that negatively affect ecosystems in many ways. Previous research has documented their negative effects on water quality and vegetation and their potential to spread disease among wildlife, domestic animals, and humans. However, how wild pigs affect predator-prey interactions between native wildlife has received little attention. This research explores multiple interactions between wild pigs, a native predator (cougars), and a native prey (black-tailed deer). First, I studies cougar diet to understand how frequently pigs are used as prey. During this project, I also placed wildlife cameras at cougar killed prey to monitor scavenging behavior by pigs. Second, I monitored tagged pigs to measure their survival rates and determine causes of mortality. Finally, I evaluated the potential for competition for resources between pigs and deer to determine if deer are negatively affected by pigs. I observed that pigs, especially young pigs, are an important alternative prey item for cougars, but that native deer remain the primary prey. Pigs also regularly scavenged at cougar killed prey and rarely stole kills from cougars. Pig survival was similar to other areas in the US, and cougars were only a cause of mortality for juvenile and subadult pigs, suggesting that adults are not vulnerable to cougar predation. Finally, I observed high overlap in space use, activity periods, and diet of deer and pigs, but did not find any negative effects of pigs on deer reproduction or body condition. This suggests pigs have minimal negative effects on deer through competition. Combined, these results provide a clearer picture of how pigs affect the native cougar-deer system through multiple interactions with each species.

Creative Commons License

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

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