Revisiting Mesopredator Release: Carnivore Dynamics Along A Gradient of Landscape Disturbance
Open Access
- Author:
- Townsend, Andrew Thomas
- Graduate Program:
- Geography
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 07, 2014
- Committee Members:
- Robert P Brooks, Thesis Advisor/Co-Advisor
Joseph Alan Bishop, Thesis Advisor/Co-Advisor
Thomas L Serfass, Thesis Advisor/Co-Advisor - Keywords:
- spatial ecology
mesopredator
predation
landscape gradients
riparian corridors
Appalachia
ecological cascades - Abstract:
- Human induced habitat loss and predator persecution caused severe declines in apex carnivores throughout the North American continent. Removal of apex predators allowed smaller, lower rank predators from the Order Carnivora to become prominent. These "mesopredators" flourished, destabilizing ecosystems by driving many prey species toward extinction. However, some suggest that mesopredators still benefit from contemporary vegetation changes and fragmentation by thriving in disturbed areas. Many worry the versatility of these mesopredators could further threaten their prey species by leading to increased predation in anthropogenically-disturbed areas. This study seasonally sampled predator distributions along land cover gradients in forested, riparian corridors in Appalachia to identify whether landscape modification results in changes in carnivore community structure in the region. The study area consisted of randomly generated sites along streams in central Pennsylvania. I gathered data from camera traps and field surveys to catalogue the spatial ecology of mesopredators. I analyzed these data with landscape metrics to test the hypothesis that as forest contiguity decreases, both the abundance and richness of the predator community increases, possibly adding pressure on vulnerable prey populations. Through the analysis of these habitat metrics and carnivore occurrence data, this study found that carnivore species richness and abundance do generally increase with human disturbance in rural settings. However, this pattern is not due to the behavior of every species as many mesopredators are present across these rural landscapes and exhibit different responses to disturbance. Nevertheless, a few important generalists, namely the canids and raccoons, do show preferences toward more human disturbed areas and thus, are most accountable for this observed pattern.