SICB 2019: Recreating Nest Temperatures in the Lab May Be Easier than Previously Thought

Many biologists are interested in understanding how temperature affects animals throughout ontogeny. Egg incubation experiments are often done to examine how nest temperatures influence embryo development. However, the information gleaned from these experiments are only useful when comparing ecologically relevant thermal regimes.

Mallory Turner, an undergraduate researcher in the Warner lab at Auburn University, examined how embryo development differs between incubator thermal regimes in Anolis cristatellus and A. sagrei. Nest temperatures peak at different times of the day due to differences in the local environment (e.g., habitat structure, shade, etc.). Turner examined how incubator thermal regimes that were uncentered and peak-centered influenced development. Nest temperature data were used to create two 24-hour diel cycles. Anole eggs were incubated in incubators programmed to mimic hourly nest temperature data with temperatures either uncentered (uncentered regime), or with hourly nest temperature data aligned temporally at thermal peaks (peak-centered regime). She examined how thermal regimes impacted incubation duration and offspring phenotype. Incubator thermal regime did not impact incubator duration, mass, or SVL in either anole species. Uncentered thermal regimes have lower maximum incubation temperatures compared to peak-centered regimes, although interestingly enough these differences do not appear to influence development.