Estimating Thermal Plasticity and Dynamics of Thermal Tolerance in Eublepharis macularius: Implications for Future Climate-Driven Heat Stress

Ecologists expect the intensity and duration of heat waves, as well as average global temperatures, to increase in the coming century due to anthropogenic climate change. Heat waves that lead to physiological stress and reductions in fitness threaten animal life, especially species living in warmer thermal habitats. Species can respond to extreme environmental temperatures by reducing overheating risk via phenotypic plasticity of thermal tolerance (heat hardening), which allows the thermal tolerance limits of the organism to increase over time. While heat hardening occurs in various lizard species, it has yet to be explored in many species of geckos. Geckos occur across several different biomes, including warmer tropical and arid climates, which will become severely impacted by future extreme heat events. Heat hardening capacity can be estimated as the change in the maximum temperature tolerated by the organism over time. In this study, we inferred thermal tolerance and heat hardening capacity in the gecko, Eublepharis macularius, an organism that is quickly becoming a model species for studies on squamates. We found that heat hardening capacity (1) does not depend on the basal thermal tolerance of the organism, (2) was highest after 6 hours since initial heat shock, and (3) was negatively influenced by individual body mass for E. macularius. Our findings show that individuals of E. macularius exhibited similar heat hardening capacity to that of different wild-caught lizard species. These results further support that reptiles can potentially respond quickly to extreme temperatures in the future via thermal tolerance plasticity.

Author

• White, Emma

• Critical thermal maximum
• Geckos
• Heat hardening
• Heat waves
• Reptiles
• Thermal physiology

Identifier

hdl:1920/14108

OAI identifier oai:identifier

oai:MARS:1920/14108