THE IMPACT OF RAILWAYS ON GOPHER TORTOISES

RHETT M. RAUTSAW

PhD Student

Clemson University

Welcome to my website! I am a PhD student in Dr. Christopher Parkinson's lab and I am interested in evolution, ecology, genetics, and conservation. My current ongoing research spans this broad spectrum to examine everything from Gopher Tortoise movement ecology and conservation to rattlesnake venom evolution through transcriptome sequencing. 

ABSTRACT

Stopped dead in their tracks: The impact of railways on Gopher Tortoise (Gopherus polyphemus) movement and behavior

Habitat fragmentation is one of the leading causes of biodiversity decline and most commonly results from urbanization and construction of transportation infrastructure. Roads are known to negatively impact species, but railways often cause similar effects. Certain taxa are more vulnerable to railways than others due to limitations in mobility, mainly turtles. Here we used Gopher Tortoises (Gopherus polyphemus) as a model system to study the impacts of railways on turtle movement and behavior. First, we used radio-telemetry to determine the frequency of railway crossings and compared this to correlated random walk (CRW) simulations. Second, we measured behavior for one hour to assess a tortoise’s crossing ability and tested for behavioral differences associated with the familiarity of the railways using principal component analysis. Lastly, we tested the effectiveness of trenches dug underneath the rails as a management strategy to alleviate the impact of railways on tortoises. We found that railways significantly impacted the movement of Gopher Tortoises, as tortoises crossed the railway less often than what would be expected by unhindered movement. During behavioral trials, there were no behavioral differences associated with rail familiarity. Additionally, no tortoise was capable of crossing the rails. Using game cameras, we demonstrated that trenches dug underneath the rails and between the ties was an effective management strategy to enable passage and escape of tortoises, while maintaining rail functionality. We suggest trenches be dug to alleviate the impact of railways on turtles and that more studies focus on the impacts of railways on wildlife.