Date of Award
Spring 4-17-2025
Document Type
Thesis
Degree Name
Master of Biological Science (MBioSci)
Department
Biological Science
First Advisor
Dominic DeSantis
Second Advisor
Bruce Snyder
Third Advisor
Al Mead
Abstract
Temperate non-avian reptiles are under selective pressure to minimize the costs of low winter temperatures. For high latitude or high elevation snake populations, this has often favored communal overwintering behavior, while lower latitude populations typically overwinter solitarily. Timber Rattlesnakes (Crotalus horridus) are distributed across a wide latitudinal gradient in North America and represent ideal models for exploring how variable winter selective regimes might favor different overwintering strategies. We studied a unique population of C. horridus from central Georgia, USA, that maintains both communal and solitary overwintering behavior. Through time-lapse videography, temperature datalogging, radio telemetry, and accelerometry, we quantified the potential costs and benefits of communal and solitary overwintering while assessing variation in individual plasticity in strategy. Migration distance (mean ± s.e.) among communal rattlesnakes (561.41 ± 86.74 m) was significantly greater than solitary rattlesnakes (334.71 ± 50.48 m). Communal individuals might trade-off this cost for increased winter basking opportunities, as they exhibited greater activity levels and a reduced dependency on ambient temperature for activity relative to solitary snakes. However, there were no differences in basking frequency, body temperatures, and environmental temperatures between communal and solitary sites. We documented individual plasticity in overwintering strategy, with several males and females shifting between communal and solitary sites across years. Our results only partially explain the simultaneous maintenance of both overwintering strategies in this population. We suspect that multiple lurking variables related to individual condition are at play, such as disease (Ophidiomycosis) status and inclusive fitness benefits to communal snakes.
Recommended Citation
Powers, John, "Behavioral and Thermal Correlates of Alternative Overwintering Strategies in a Southeastern Population of Timber Rattlesnakes (Crotalus horridus)" (2025). Biology Theses. 43.
https://kb.gcsu.edu/biology/43