This dissertation investigates the behavioral ecology of green and loggerhead sea turtles by analyzing site fidelity, movement behavior-based life stages, and the impacts of long-term climatic changes. Using a 47-year capture-recapture dataset from turtles entrained in the intake canal of the St. Lucie Nuclear Power Plant, this research proposes to develop probabilistic models to predict habitat utilization and site fidelity based on size and temporal habitat covariates. These models will estimate the likelihood of turtles being in specific movement behavior-based life stages—nomadic, resident, or migratory—and assess changes in these likelihoods over time. We hypothesize that capture probabilities will vary by life stage, with nomadic stages showing lower capture rates, residents showing higher rates, and migratory adults exhibiting variable rates depending on breeding cycles. Survival models will examine trends in survival rates, integrating life stage likelihoods derived from the probabilistic models. We predict that survival rates differ by life stage and have shifted over time due to environmental changes. Finally, long-term climatic data will be analyzed to understand their influence on life stage transitions and survival rates. This research aims to provide insights into how environmental factors shape sea turtle behavior and survival, potentially contributing to more effective management strategies for these long-lived, wide-ranging marine species.
Ryan Welsh
Adivsor: Dr. Mansfield
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