Fisiologia térmica dos lagartos da Amazônia (Reptilia: Squamata)

We summarize data on the thermal biology data of 69 species of Amazonian lizards including mode of thermoregulation and field-active body temperatures (Tb). We also provide new data on preferred temperature (Tpref), voluntary and thermal tolerance ranges, and thermal performance curves (TPC’s) for 27 species from nine sites in the Brazilian Amazon. We tested for phylogenetic signals and pairwise correlations among the thermal traits. We found that thermoregulating species have the highest mean values of all thermal traits, and broader ranges for Tb, critical thermal maximum (CTmax) and optimal (Topt) temperatures. The thermoconforming species have large ranges for Tpref, critical thermal minimum (CTmin), and minimum voluntary (VTmin) temperatures for performance. Despite these differences, our results show that all thermal characteristics overlap between both groups and suggest that Amazonian lizards do not follow discrete thermoregulatory categories. The traits are all correlated, with the exceptions of (1) Topt, which does not correlate with CTmax, and (2) CTmin, which only correlates with Topt. Weak phylogenetic signal for Tb, Tpref and VTmin indicates that these characters may be shaped by local environmental conditions in addition to phylogenetic relationships. We found that open-habitat species perform well under present environmental conditions, without suffering detectable thermal stress from high environmental temperatures induced in lab experiments. For forest-dwelling lizards, we expect warming and drying trends in Amazonia to induce thermal stress, as temperatures surpass the thermal tolerances for these species.