Developmental environments do not affect thermal physiological traits in reptiles: an experimental test and meta-analysis

Abstract

On a global scale, organisms face significant challenges due to climate change and anthropogenic disturbance. In many ectotherms, developmental and physiological processes are sensitive to changes in temperature and resources. Developmental plasticity in thermal physiology may provide adaptive advantages to environmental extremes if early environmental conditions are predictive of late-life environments. Here, we conducted a laboratory experiment to test how developmental temperature and maternal resource investment influence thermal physiological traits (critical thermal maximum: CT max and thermal preference: T pref ) in a common skink ( Lampropholis delicata ). We then compared our experimental findings more broadly across reptiles (snakes, lizards and turtles) using meta-analysis. In both our experimental study and meta-analysis, we did not find evidence that developmental environments influence CT max or T pref . Furthermore, the effects of developmental environments on thermal physiology did not vary by age, taxon or climate zone (temperate/tropical). Overall, the magnitude of developmental plasticity on thermal physiology appears to be limited across reptile taxa suggesting that behavioural or evolutionary processes may be more important. However, there is a paucity of information across most reptile taxa, and a broader focus on thermal performance curves themselves will be critical in understanding the impacts of changing thermal conditions on reptiles in the future.

Maternal investment and early thermal conditions affect performance and antipredator responses

“…Fifteen minutes before each performance measure, lizards were placed in an incubator at 28 °C to ensure constant body temperature across lizards. Although recent studies have shown that the thermal optimum is slightly higher than 28 °C ( Anderson et al 2023 ; Zhang et al 2023 ) there is substantial individual and species-specific variation with 28 °C being firmly within this range. Animals were then transferred to the racetrack and were chased down toward a terrarium placed at the end of the track.…”