Houston ChandlerViews:
The Orianne Society began working with Spotted Turtles in Georgia all the way back in 2014. At that time, little was known about this species in the southeastern U.S. Most of the published research on Spotted Turtles came from the northeast, and the only available data in the southeast was from Dr. Jackie Litzgus’ dissertation research in South Carolina. Over the last 10 years, Spotted Turtles have become one of our primary focal species, with work stretching across Florida, Georgia, and South Carolina. We have studied turtle movements and home ranges (Chandler et al. 2019), reproductive ecology (Chandler et al. 2022), conservation genetics (Brown et al. 2023), and temperature profiles (Chandler et al. 2020), as well as conducted surveys for previously undocumented populations. Spotted Turtles are currently a candidate for federal listing under the Endangered Species Act, and there is significant momentum to continue conservation projects aimed at understanding this species in the southeastern U.S.
Spotted Turtle distribution in the southern states, despite multiple years of survey work. This new effort aims to fill these gaps by surveying for turtles across the southeast. The Orianne Society will be responsible for surveys in Florida, Georgia, and southern South Carolina, while partners at North Carolina State University and the Smithsonian Conservation Biology Institute will conduct surveys in northern South Carolina, North Carolina, and Virginia. As part of this project, we plan to not only conduct additional survey work but also examine the available sampling methodologies to design better survey protocols for Spotted Turtles in the southeast, where they are notoriously difficult to detect. As part of this effort, we are collecting Spotted Turtle observations from the study area. If you see a Spotted Turtle in the southeast, please report it to us or one of the other project partners!
The fieldwork for this project began last month as we sampled our two long-term Spotted Turtle monitoring sites in Georgia. This marked the 10th and 11th consecutive year of sampling at these sites, and we plan to use these datasets to better understand the population dynamics of Spotted Turtles in the southeast (a 3rd primary objective of the current project). In just eight days of sampling across these two sites, we encountered 46 individuals, accounting for approximately 26% of all marked turtles in these two populations. Remarkably, we continue to catch new individuals at both sites, highlighting how difficult Spotted Turtles can be to detect. The larger of the two populations now has a total of 116 marked individuals, while the smaller population has 58 total individuals marked. Every year that we sample at these sites, it is rewarding to see some turtles that we have now been observing for close to a decade.
Our second new Spotted Turtle project on the horizon is being funded by the Department of Defense’s Strategic Environment Research and Development Program. This project will examine the effects of climate change and the thermal landscape on the sex ratios of Spotted Turtle hatchlings. This is a significant conservation issue for Spotted Turtles because they undergo temperature dependent sex determination, where higher incubation temperatures produce more female turtles (Roberts et al. 2023). The fieldwork for this project will begin during summer 2024. We will install environmental sensors to measure the available thermal landscape at select sites, one in the southeast and one in the northeast. Then we will locate Spotted Turtle nesting sites in Spring 2025 as we have done in previous seasons so that we can monitor the sex ratios produced under various thermal conditions. This project is partially a proof of concept but will also have important implications for how we understand the effects that climate change is having on Spotted Turtle populations.
Over the next three years, there will be a significant increase in the amount of Spotted Turtle research being conducted as part of the Science Initiative. These projects will directly improve our understanding of this species’ ecology and provide tangible benefits to future conservation efforts. Spotted Turtles have been one of my favorite species to work with over the last several years, despite the inherent challenges in much of the survey work. I am excited to see where these research projects take us by the end of 2026.
Literature Cited
Brown, G., J. D. Mays, H. C. Chandler, B. S. Stegenga, B. Kreiser, and D. J. Stevenson. 2023. Spotted Turtle (Clemmys guttata) population genetics in the southeastern United States. Chelonian Conservation and Biology 22:127–136.
Chandler, H. C., B. S. Stegenga, and D. J. Stevenson. 2019. Movement and space use in southern populations of Spotted Turtles (Clemmys guttata). Southeastern Naturalist 18:602–618.
Chandler, H. C., B. S. Stegenga, and D. J. Stevenson. 2020. Thermal ecology of Spotted Turtles (Clemmys guttata) in two southern populations. Copeia 108:737–745.
Chandler, H. C., B. S. Stegenga, and J. D. Mays. 2022. Compensating for small body size: The reproductive ecology of southern Spotted Turtle (Clemmys guttata) populations. Ichthyology & Herpetology 110:268–277.
Roberts, H. P., L. L. Willey, M. T. Jones, T. S. B. Akre, D. I. King, J. Kleopfer, D. J. Brown, S. W. Buchanan, H. C. Chandler, P. G. deMaynadier, M. Winters, L. Erb, K. D. Gipe, G. Johnson, K. Lauer, E. B. Liebgold, J. D. Mays, J. R. Meck, J. Megyesy, J. L. Mota, N. H. Nazdrowicz, K. J. Oxenrider, M. Parren, T. S. Ransom, L. Rohrbaugh, S. Smith, D. Yorks, and B. Zarate. 2023. Is the future female for turtles? Climate change and wetland configuration predict sex ratios of a freshwater species. Global Change Biology 29:2643–2654.
Willey, L.L., M.K. Parren, and M.T. Jones. 2022. Status Assessment and Conservation Plan for Spotted Turtles in the Eastern United States. Technical Report to the Virginia Dept. of Wildlife Resources and the U.S. Fish and Wildlife Service.
