THE EFFECTS OF ENVIRONMENTAL CONDITIONS ON THE POPULATION DYNAMICS OF A REMNANT BOTTOMLAND CYPRESS-TUPELO WETLAND AMPHIBIAN COMMUNITY

Author

Jacob M. Hutton, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2025

Degree Name

Doctor of Philosophy

Department

Zoology

First Advisor

Brown, Jason

Abstract

The conservation of semi-aquatic amphibians in wetland systems requires a comprehensive understanding of how environmental factors shape population dynamics across different life stages and habitats. This dissertation addresses key ecological challenges affecting amphibian occupancy, detection, and movement across three complementary studies. First, I investigated detection challenges in post-metamorphic, nonbreeding Cope’s Gray Treefrogs (Hyla chrysoscelis) using tree-mounted PVC refugia. I found that prior occupancy state was a strong predictor of future occupancy, while temperature and extended dry periods positively influenced detection. Additionally, distinct age-sex groups exhibited specific microhabitat preferences. Second, I evaluated the effectiveness of passive integrative transponder (PIT) tags in tracking Lesser Sirens (Siren intermedia). High tag loss rates in juveniles underscored the need for size-specific telemetry approaches and standardized survey methodologies for large pond habitats. Finally, I examined how habitat characteristics and biotic interactions influenced a larval amphibian community across a heterogeneous wetland landscape. My findings indicated that canopy cover promotes salamander occupancy, while predation pressure suppresses overall abundance. Collectively, these studies provide critical insights into community- and species-specific responses to environmental variation, highlight key habitat features influencing amphibian populations, and propose methodological improvements essential for amphibian conservation in dynamic wetland ecosystems.