Thermal balance in Andean lizards: A perspective from the high mountains

High Andean lizards in the Andes face numerous challenges in high-altitude environments characterized by significant temperature, spatial and temporal variations. These factors greatly influence their thermal characteristics and adaptive strategies for coping with temperature fluctuations. This study aims were to investigate the thermal biology of high mountain lizards (>2000 m) inhabiting the Andes Mountain range, using information from existing literature, and to identify the potential impacts of the original climate change scenarios developed in this study. Within the Andes, high-altitude species are primarily found in families like Liolaemidae, Gymnophthalmidae, Tropiduridae, Anolidae and Leiourisauridae. Notably, we found in the literature that the higher body temperatures and maximum critical temperatures in southern species compared to those closer to the tropics. Typically, diurnal and seasonal temperature variations have a significant impact on the body temperature of these high-altitude lizards, but their adaptive behaviours and physiological mechanisms enhance their resistance to extreme temperatures. Populations situated below the equator often exhibit higher body temperatures and maximum critical temperatures, largely due to their exposure to higher ambient temperatures during summer. With all global warming scenarios indicating temperature increases in latitudinal regions, tropical high-altitude lizards, historically less thermally adaptable, may be particularly susceptible to these temperature rises. It is crucial to consider that additional factors, such as species activity patterns, thermal resource availability and diminishing suitable thermal habitats, will also play a pivotal role in shaping the future of these lizard species, making the situation even more complex and challenging.