Between a Rock and a Hard Place: The Responses of Eastern Box Turtles (Terrapene carolina) When Trapped Between Railroad Tracks
Yurii Kornilev, Steve Price, Michael Dorcas

Picture by Joy Hester

Anecdotal accounts of eastern box turtles (Terrapene carolina) found dead between railroad tracks suggest that their populations might be negatively impacted by such structures. To investigate the potential impacts of railroads on box turtles, we recorded the number of climbing attempts, the distance moved, the overall speed of travel, and the exit behavior of 12 adult animals experimentally trapped for 1 hr between railroad tracks. Additionally, we examined the temperatures box turtles experience between rails. Only one individual escaped by climbing over a rail. The total distance moved by the majority of tested turtles was less than 100 m during the observation period. When presented with the option to leave at a railroad crossing, 3 turtles stayed between the tracks, 4 exited and headed towards an adjacent parallel road with moderate traffic, and 5 headed in the opposite direction towards a vegetated field. The mean distance between railroad crossings in our study area is 379 m; more than 50% of the crossings are separated by more than 200 m. Thus, at least two hours would be necessary for a box turtle consistently moving in its original direction to get from one railroad crossing to another. However, on a mild day (air temperature = 24 C) the core body temperatures of turtles trapped on railroads may reach lethal temperatures within this time. Railroads, like other human transportation infrastructures, likely serve not only as sources of direct mortality, but as barriers to turtle dispersal, leading to population declines and fragmentation.