Effects of Temperature on Voluntary Locomotion of the Eastern Box Turtle, Terrapene carolina carolina

Abstract

We examined voluntary locomotion of Terrapene c. carolina in a laboratory racetrack at six temperatures ranging from 9.7-31.9 C. The mean number of strides and stops, velocity, fastest non-stop velocity, total time stopped and body mass were recorded for each turtle. We did not observe acclimation or training effects and neither time of year nor prolonged captivity affected locomotor performance. Stride length increased with body mass. The mean number of strides, and the mean total time stopped in the first meter, decreased as temperature increased. Both the mean velocity and the mean fastest non-stop velocity increased with increasing temperature. Body temperatures of turtles in the field, monitored via radiotelemetry, ranged from -1.4-34.9 C (rarely exceeding 31.9 C) and clustered about the simultaneous ambient temperatures. Both laboratory and field data suggest that locomotion is strongly temperature dependent. Voluntary locomotion in the laboratory appeared to be maximal at body temperatures between 24 and 32 C; however, the existence of an 'optimal' temperature remains uncertain. Although the voluntary speeds of turtles are much slower than the sprint velocities of squamates, they are comparable to the speeds of urodele amphibians and to voluntary speeds of lizards and snakes.