Date of Award
M.S. in Biological Science
Turtles are one of the most threatened taxa worldwide. In addition to direct anthropogenic impacts such as hunting and pollution, unintentional indirect human disturbance affects poikilothermic turtles by disrupting thermoregulatory basking behavior. In this thesis I assess the behavioral and physiologic impacts of high boat traffic, reductions of basking structures, and environmental factors on basking behavior, rates of disturbance, thermoregulation, parasite load, shell condition, and population recruitment in two populations of the endangered ringed sawback (Graptemys oculifera), also known at the ringed map turtle, on the Pearl River outside Jackson, MS. Basking behavior was influenced by availability of basking structures, boat traffic, zone (wake or no wake), boat type, air temperature, weather, and Julian day. Mathematic simulations of anthropogenically disturbed and undisturbed adult female ringed sawbacks showed a decrease in body temperatures due to disturbance, an effect which was magnified in higher probabilities of disturbance and in the months of May and June compared to July and August. Parasite load did not differ between populations, despite apparent differences in human disturbance. Shell condition was poorer in the population near urban development, and fewer juveniles and young adults were found in the population subject to higher boat traffic. This study explores the effect of unintentional human disturbance on ectothermic riverine turtles and provides management recommendations for the conservation of an endangered, endemic species.
Heppard, Jessica Mary, "Impact of Human Disturbance on the Behavior and Physiology of the Endangered Ringed Sawback Turtle (Graptemys oculifera)" (2018). Electronic Theses and Dissertations. 1277.