Plasticity of thermoregulatory behaviour in response to the thermal environment by widespread and alpine reptile species

Phenotypic plasticity plays a central role in determining how organisms respond to environmental change over short timescales. Despite this, we know little about how phenotypic plasticity varies between populations or species. We tested the extent of plasticity in basking behaviour in low- and high-altitude populations of two widespread lowland and two highland species of a cool-climate lizard genus: Niveoscincus. We found evidence of divergence in basking behaviour between populations and species, with highland species and high-altitude populations of all species basking more than the widespread lowland species and low-altitude populations. Furthermore, we found differences in the extent of behavioural plasticity between species. Widespread lowland species altered their basking behaviour depending on basking opportunity whereas the highland species maintained high levels of basking independent of basking opportunity. These differences in basking behaviour were concordant with the diffe...