Effect of Sex and Personality on Thermoregulatory Behaviors and Microhabitat Selection of Brumation Sites in Fall and Winter Months in Eastern Box Turtles (Terrapene carolina carolina)

Abstract

Consistent individual variation in behavior within a population is commonly referred to as personality across animal taxa. As our understanding of animal personality increases, researchers can gain better insight into the way personality may affect different behaviors. Research has shown correlations between personality and productivity, population density, stability of populations, dispersal, colonization, distributions within habitats, and disease transmission. Because personality apparently impacts so many attributes of the lives of various species, research on personality variation in different species is especially important. Eastern Box Turtles, Terrapene carolina carolina, are a long-lived species with a distribution across much of the eastern United States. Past studies have shown that Eastern Box Turtles exhibit two personality variations, bold and less bold, which affect movement rate, home range size, date of emergence from brumation, and thermoregulation. Research has also shown that sex may affect home range size, movement distances, utilization of developed habitats, and thermoregulation. Little research, however, has been done to determine the effect of personality and sex on either thermoregulation during fall and winter, or brumation site selection in Eastern Box Turtles. This study examined whether sex and boldness influence thermoregulation during the fall and winter, and brumation site microhabitat selection in wild Eastern Box Turtles. Bold turtles maintained higher body temperatures than less bold turtles at all times of day regardless of sex. Females maintained higher body temperatures when compared to males when boldness was not accounted for. When the interaction of sex and boldness was measured, the four combinations of sex and boldness (e.g., bold female, bold male, less bold female, less bold male) in turtles were found to be significantly different from one another in how they thermoregulated. Bold male turtles exhibited the warmest temperatures overall, whereas less bold male turtles exhibited the coolest temperatures overall. Bold and less bold male box turtles differed dramatically in how they thermoregulated (average maximum difference of ~1.5°C); bold and less bold females also differed but the difference was more subtle (average maximum difference of ~0.5°C). Brumation site microhabitat selection was not found to differ for sex, boldness, or their interaction. This likely means that brumation site selection is dependent on factors other than sex or personality or could be relatively stochastic within their tolerable range. Further research into the interactions of sex and boldness on thermoregulatory behaviors in different portions of the range of Eastern Box Turtles would help elucidate the proximate mechanisms and functional consequences of personality.