Behavioral and physiological thermoregulation of Atacama desert-dwelling Liolaemus lizards

The behavioral and physiological thermoregulation of three Atacama desert-dwelling Liolaemus lizards was studied and compared with previous data on Liolaemus from other ecosystems. The thermoregulatory mechanisms of the desert-dwelling species differed from those of the others, a consequence of differences in the habitat structure of the species. Desert species have higher critical thermal minima and, contrary to expectations, lower selected body temperatures than Liolaemus from Mediterranean environments. Results of the rate,, of thermal time constants suggest mechanisms to cope with the fast decrease of environmental temperature that occurs in the desert during the mid-afternoons. Finally, the manner in which selection of low body temperatures may allow survival in desert conditions is discussed. Keywords: thermal time constants, operative temperature, physiological and behavioral thermoregulation.