DOI
https://doi.org/10.25772/CW5Y-EV53
Defense Date
2021
Document Type
Thesis
Degree Name
Master of Science
Department
Biology
First Advisor
Dr. Derek M Johnson
Abstract
Spotted turtles (Clemmys guttata) use a complex of wetland and terrestrial habitats for survival and reproduction. Precipitation expands and creates larger and more numerous ephemeral pools available to spotted turtles on the landscape. In this study, I investigated the effects of precipitation on movement patterns and ephemeral pool usage by spotted turtles in southeastern Virginia. I conducted a 4-month capture-mark-recapture study alongside a telemetry study to estimate population size and to quantify movement of spotted turtles across the landscape during the breading season. A change point analysis was used to detect discrete changes in turtle behavior and whether changes in behavior were related to precipitation events. Synchronized increase in population size estimates and changes in movement behavior are consistent with the hypothesis that spotted turtles either synchronously emerged from hibernation and/or synchronously immigrated to breeding aggregations in ephemeral pools. The changes in movement behavior in most of the spotted turtles was correlated with a large precipitation event. Spotted turtles within this study were never observed aestivating, likely due to the abnormally high levels of precipitation in spring 2018, which maintained ephemeral pools inundated with cool water. The foregoing of aestivation along with a steep late season decline in survival probability suggests that after the breeding season spotted turtles dispersed out of trapping plots. Distances traveled by spotted turtles were significantly longer on days with precipitation, suggesting that precipitation increased connectivity of wetlands. This study demonstrates the causal effects of within-season variation of precipitation on spotted turtle movement and aestivation behaviors.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-13-2021