On the Road Again: Assessing the Use of Roadsides as Wildlife Corridors for Gopher Tortoises (Gopherus polyphemus)

Small populations resulting from the impacts of habitat fragmentation are prone to increased risks of extinction because of a lack of population connectivity. Roads increase habitat fragmentation, but properly managed roadsides may be able to function as wildlife corridors. Here we use radiotelemetry to observe movement patterns of Gopher Tortoises (Gopherus polyphemus) along potential roadside corridors at the John F. Kennedy Space Center (KSC) in Florida, USA, to determine if tortoises use roadsides as movement pathways between larger habitat patches or as residential habitat. Additionally, we translocated tortoises to study the feasibility of roadsides to function as movement corridors. We found that roadsides are not used as a movement pathway but rather as an apparent long-term residential habitat. Only one tortoise was observed exiting the roadside corridor, and minimum convex polygon (MCP) home range sizes and distances traveled remain similar to those exhibited by tortoises in larger habitat patches. Following translocation, we observed a failure to return home, either by direct paths or by corridor use, for all but one tortoise. Instead, most tortoises remained along roadsides after only a brief period of exploration. Overall, we find that roadsides act as independent, residential habitat instead of as a movement corridor. Future studies should focus on understanding the actual suitability of roadsides, as they may function as ecological traps given their attractiveness but high risk of mortality. While we urge caution, current management should treat roadsides as residential locations for Gopher Tortoises and focus on reducing road mortality.