Theses and Dissertations

ORCID

0009-0006-2340-1546

Advisor

Morin, Dana

Committee Member

Conner, L.

Committee Member

Royle, J.

Committee Member

Wang, Guiming

Committee Member

McConnell, Mark

Date of Degree

8-12-2026

Original embargo terms

Immediate Worldwide Access

Document Type

Dissertation - Open Access

Major

Forest Resources (Wildlife, Fisheries & Aquaculture)

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Forest Resources

Department

Department of Wildlife, Fisheries and Aquaculture

Abstract

Disturbances shape communities through population responses and species interactions. However, the effects of these inter-related factors on primary consumers and their predators are relatively understudied. Therefore, I used a long-term experimental dataset to assess direct and indirect effects of prescribed fire and mesocarnivore removal on community interactions within small mammal populations. Earlier research revealed no major changes in small mammal abundances following mesocarnivore exclusion, but cotton rats (Sigmodon hispidus) had increased home-range sizes and greater body mass in the exclosures. My research specifically focused on examining behavior and population dynamics of cotton rats and cotton mice (Peromyscus gossypinus) as a factor of effects of fire and mesocarnivore exclusion and inter-specific interactions. First, I investigated changes in microhabitat use (evaluated using detection probability) due to competition, fire, and mesocarnivore exclusion. I found evidence that predation risk shaped cotton rat microhabitat use, with use being greater in the exclosures. On the other hand, competition with cotton rats reduced cotton mouse microhabitat use, suggesting cotton mice expand their realized niche following predation-induced declines of cotton rats post-fire. Second, I assessed the relative importance of fire, rainfall, mesocarnivore exclusion, competition (with cotton rats), and density-dependence on cotton mice demographics. Cotton mouse survival and post-fire recruitment were density dependent and influenced by the interaction between fire and rainfall. Further, cotton mouse recruitment was positively correlated with cotton rat abundance within mesocarnivore exclosures but negatively correlated in controls (i.e., ambient predator abundance), suggesting stress-induced reduction in recruitment or greater emigration due to apparent competition with cotton rats. Finally, I evaluated how mesocarnivore exclusion, fire, weather, small mammal abundances, and vegetation altered predation risk using multi season, multi-year giving-up densities (GUD) at three different temporal scales. Giving-up densities were largely unaffected by mesocarnivore exclusion and fire but showed high seasonal variation. Importantly, direction and magnitude of all covariate effects varied, indicating that GUDs are context dependent and affected by a multitude of factors acting simultaneously. Together, my results demonstrate the complexity of population responses, the role of community interactions, and prey foraging behavior in advancing understanding of the relationships between predators, prey, and fire.

Sponsorship (Optional)

The Jones Center at Ichauway; College of Forest Resources, Forest and Wildlife Research Center, and Department of Wildlife, Fisheries and Aquaculture, Mississippi State University

Download

Share

COinS