Integrating the thermal dependence of sex ratio into distribution models to predict suitable habitats for the invasive freshwater pond slider turtle, Trachemys scripta

Biological invasions represent one of the main anthropogenic drivers of global change with a substantial impact on biodiversity. Traditional studies predict invasion risk based on the correlation between species' distribution and environmental factors, with little attention to the potential contribution of physiological factors. In this study, we incorporated temperature-dependent sex determination (TSD) and sex-ratio data into species distribution models (SDMs) to assess the current and future suitable habitats for the world's worst invasive reptile species, the pond slider turtle (Trachemys scripta). First, occurrence records of T. scripta from online databases and published scientific literature were identified. Then, climatic variables representing current (1976–2013) and future (2060–2080) climate scenarios were extracted and combined with sex-ratio records to create hybrid-SDMs with which to assess the current and future suitable habitats for T. scripta. It was found that T. scripta has potential suitable habitat in 136 countries at present. Under the four climate change scenarios (ssp126, ssp245, ssp370 and ssp585) that were modeled, the distribution of T. scripta is predicted to decrease in 78–93 countries but increase in the northern hemisphere. This confirms that there is a greater likelihood that this species will increase in more developed countries. Incorporating the thermal dependence of sex ratio into hybrid-SDMs can be an important addition to detect the invasion risk of TSD species and to develop region-specific invasion management strategies to prevent and/or control invasive species such as T. scripta.