Date of Award
Spring 5-14-2026
Document Type
Thesis
Degree Name
Master of Biological Science (MBioSci)
Department
Biology
First Advisor
Dr. Dominic DeSantis
Abstract
Understanding how consistent among-individual differences in behavioural and physiological traits shape the ecology and evolution of populations is hindered by the relatively limited subset of research that involves wild-ranging animals. Advanced animal-borne datalogging technologies (biologgers) have recently transformed our ability to obtain long-term and high-resolution repeated measures from individuals living in wild populations, even among smaller-bodied and highly secretive species. We leveraged recently validated biologging protocols for snakes in a multivariate framework to quantify among-individual differences in body temperature and activity intensity of wild-ranging Timber Rattlesnakes (Crotalus horridus), while evaluating the effects of sex, body mass, body condition, seasonal motivational state, and ambient temperature. We also aimed to test a thermal-activity syndrome hypothesis in these ectothermic mesopredators, for which we expected positive covariance between body temperature and activity behavioural types. In line with our predictions, we found evidence for consistent among-individual differences in thermal (r = 0.40) and activity (r = 0.54) trait types, as well as positive covariance between these traits (r = 0.51) to form a continuum of cool-inactive to hot-active individuals. Among males and females, body mass (but not body condition) was negatively related to body temperature and activity during the foraging season, possibly indicative of distinct body size-mediated foraging tactics. However, among males, this trend was lost during the breeding season when larger males exhibited a greater relative increase in activity driven by the motivational state shift to mate-searching behaviour. Our project is the first to quantify among-individual differences in behavioural and thermal traits of wild-ranging snakes, paving the way for investigations into variation in fitness outcomes across thermal-activity types, the potential for state-dependent shifts in trait types, and their role in key population-level processes such as metapopulation dynamics, dispersal, and migration.
Recommended Citation
Stubbs, Amber A.; Gulotta, Nickolas A.; Powers, John R.; and DeSantis, Dominic L., "LONG-TERM BIOLOGGING REVEALS A THERMAL-ACTIVITY SYNDROME IN WILD-RANGING ECTOTHERMIC MESOPREDATORS (TIMBER RATTLESNAKES, CROTALUS HORRIDUS)" (2026). Biology Theses. 50.
https://kb.gcsu.edu/biology/50