Many different types of wildlife around the globe are facing increasing pressure from development and loss of native habitat as human populations continue to expand. One of the most pressing issues facing wildlife populations is the broad-reaching direct and indirect effects that roads have on them. Roads prevent wildlife from moving from one habitat patch to another, change animal behavior, and most devastatingly often lead to animals getting hit and killed by vehicles. The Susquehannock Wildlife Society in collaboration with Towson University has just published a new study investigating the impact that road mortality has on a population of Spotted Turtles in Central MD.
Spotted turtles are beautiful black turtles speckled with bright yellow spots. The small turtle is found in various wetland ecosystems across the Eastern seaboard from Ontario down to central Florida. This new study shows that a population of Spotted Turtles, despite residing on protected land, are declining in size, even without the effects of road mortality. With the effects of road mortality included into the models, the population has a greater than 90% chance of reaching an extinction threshold within the next 150 years. This striking result highlights how damaging road mortality can be to turtle populations and makes it clear that preventing road mortality in other turtle populations will be a critical component of any long-term conservation plan that seeks to conserve turtle populations in developed areas. The study represents one of the first attempts to quantify the direct effect that roads have on freshwater turtle population viability. One of the implications of the study is that even populations that have persisted for long time periods and appear relatively stable from opportunistic sampling, in fact, may be on a ‘‘slow glide path’’ to extinction.
This decline may be caused by just road mortality, but turtle populations around the globe are also facing threats from poaching by humans, habitat loss and fragmentation, and increased rates of nest predation from increased prevalence of small predators (raccoons, foxes, etc.). Protecting these unique organisms in the future will require a broad approach to mitigating various threats, long-term monitoring to measure the efficacy of these practices, and constant updating of practices to achieve the best outcome possible. These results further the cause for federal listing of Spotted Turtles as an imperiled species and will hopefully spur more population research and data driven management. This study supports the growing body of evidence that freshwater turtle populations rest in a perilous position and that anthropogenic causes, such as road mortality, may have even more devastating consequences on long-term population viability than previously expected.
For more detailed information please read our recent publication in the Journal of Herpetology – https://www.researchgate.net/publication/331059434_The_Effects_of_Road_Mortality_on_Small_Isolated_Turtle_Populations
