Waitin' on a sunny day: Factors affecting lizard body temperature while hiding from predators

Most animals face predators in their daily life and have evolved antipredator strategies that promote survival while minimizing escaping costs. For example, many animals often hide into refuges when chased. Ectotherms rely on external sources of heat to raise their body temperature, and thermoregulate to keep their body temperature close to the optimal for performance. For many ectotherms living in temperate areas, it can be expected that they pay a cost in terms of heat loss while staying hidden. Indeed, refuges are often more thermally unsuitable than the external environment. Hence, the aim of this study was to assess if and to what extent hiding may result in a decrease of body temperature in a temperate lizard. We used infrared technology to measure the body temperature of a large-sized lizard (Timon lepidus) before individuals escaped from a simulated predation attempt to hide inside a refuge, and after they emerged back from the refuge. We quantified the change of body temperature that lizards experienced while hiding. Results show that while the decrease in body temperature covaried with the time spent hidden, it was also affected by the initial body temperature. Our key finding is that the time spent hidden depends mostly on the temperature inside the refuge. Indeed, lizards hiding in warmer refuges spent more time hidden, likely benefitting from a reduced cooling rate. This suggests that lizards perceive and evaluate the thermal quality of their refuges and integrate this information to react to predation attempts and minimize the potential thermal consequences of hiding.