SREL Reprint #3457

Effects of canid damage on thermal characteristics of Gopher Tortoise (Gopherus polyphemus) burrows at the northern extent of the species' range

Michael Small1, James W. Dillman1, Kurt A. Buhlmann2, Tracey D. Tuberville2, and James B. Kesler1

1South Carolina Department of Natural Resources, 1000 Assembly Street,
Columbia, South Carolina 29201, USA
2University of Georgia’s Savannah River Ecology Laboratory, Drawer E,
Aiken, South Carolina 29802, USA

Introduction: Ectothermic species have evolved a wide variety of adaptations for thermoregulatory behavior (Bogert 1949; McGinnis and Voight 1971). Among the most common is the use of burrows to provide shelter from unfavorable temperatures (Brattstrom 1965; Douglass and Layne 1978; Kinlaw 1999). These refugia can be necessary for the survival of these species particularly for populations at higher latitudinal extremes of their range. During winter months, burrows may provide relative temperature stability, allowing for hibernation or extended torpor (Anderson 2001; DeGregorio et al. 2012; Harris et al. 2015). Burrows also provide protection from potential predators (Witz et al. 1991).
...Gopher Tortoises are mostly likely to be adversely affected by modifications to their thermal environment during winter dormancy, when they experience rather stable burrow temperatures, emerge infrequently, if at all, and do not generally move between burrows (Diemer 1992; DeGregorio et al. 2012). Any adverse effects would be most pronounced at the northern limit of the species’ range where winter ambient temperatures are lowest and the dormancy period is presumably longest (DeGregorio et al. 2012). Thus, we sought to characterize the winter temperatures of Gopher Tortoise burrows with different canid disturbance histories at the northern edge of the species’ range. Specifically, the objectives of our study were to compare temperature profiles among three types of adult Gopher Tortoise burrows: 1) intact (undisturbed) burrows, 2) burrows damaged by digging activity from dogs, and 3) burrows that had been damaged but which we reconstructed or repaired.

SREL Reprint #3457

Small, M., J. W. Dillman, K. A. Buhlmann, T. D. Tuberville, and J. B. Kesler. 2018. Effects of canid damage on thermal characteristics of Gopher Tortoise (Gopherus polyphemus) burrows at the northern extent of the species' range. Herpetological Review 49(2): 224-229.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).