Genetic Patterns Among Rare and Common Turtle Species

Population genetic studies that incorporate life history information are important for informing management and conservation actions that seek to maintain biodiversity and preserve multiple species. The goal of this study was to use a comparative approach to evaluate population genetic patterns among rare (Emydoidea blandingii, Clemmysguttata) and common (Chrysemys picta, Chelydra serpentina) freshwater turtle species persisting in highly modified habitats across northeastern Illinois. These species differ in traits expected to modulate genetic structure across heterogeneous landscapes. Here, we employed microsatellite DNA analysis to investigate patterns of genetic structure and project future loss of genetic diversity for each species. Rare species exhibited more genetic divergence among populations compared to common species. However, a past bottleneck was only detected in C. guttata. Further, simulations showed that long-term loss of genetic diversity is inevitable in all four turtle species, but particularly imminent in E. blandingii and C. guttata. Differences in genetic patterns are likely attributed to a variety of factors including population size, dispersal capacity, habitat specialization, generation time, reproductive strategies, and historical processes. Lack of gene flow and genetic drift within species is potentially masked by long-generation times and relatively recent landscape modification. In addition to protection of habitats, long-term management should focus on maintaining gene flow, potentially considering actions such as translocation or head-start programs.