JMIH 2016: Late-season Lizards Hatch More Quickly and Run Faster

Previous research in the Warner lab has shown that temperature during egg development influences fitness and performance in Anolis sagrei. In particular, a warmer incubation temperature increases sprint speed. The breeding season of A. sagrei spans from March through October, with lower temperatures early in the season and higher temperatures late in the season. Phil Pearson, a masters student in the Warner Lab, conducted an experiment to test whether embryos are developmentally adapted to their incubation temperature. He collected eggs from two temporally-separated cohorts and incubated them under two different temperatures, simulating seasonal temperature differences. He found that late season hatchlings had higher egg survival when incubated under late season temperature. Regardless of incubation temperature, late season embryos had higher sprint speed, larger body size and longer tails. This might compensate for the late start, since they are competing with early cohort individuals in the population.

Late season hatchlings have higher sprint speed regardless of incubation temperature

Overall, this suggests that timing of oviposition has greater effect on morphology and performance than incubation temperature. Future analysis will show whether timing of oviposition affects survival. Phil released the hatchlings on small islands to measure fitness using a mark-recapture approach and will hopefully present his findings at future meetings.