Meeting Abstract

4.5  Jan. 4  The influence of climate on offspring sex ratios in Painted turtles SCHWANZ, L.E.*; BOWDEN, R.M.; SPENCER, R.-J.; JANZEN, F.J.; Iowa State University, Ames; Illinois State University, Normal; CRC for Invasive Animals, University of Canberra, Australia; Iowa State University, Ames schwanz@unm.edu

In many reptiles, the sex of an individual is determined permanently early in embryonic development by the temperature at which the embryo is incubated. Temperature-dependent sex determination may have evolved in response to unique selective pressures and has marked consequences for population dynamics. We analyzed data collected over 19 years from a population of Painted turtles (Chrysemys picta) to examine the relationship between ambient air temperature and annual cohort sex ratios of hatchlings. We found that the strong relationship between air temperature during embryonic development and cohort sex ratios has been altered in recent years due to changes in climate. We discuss the importance of these results for population dynamics and population persistence in the face of potential climate change in the future.