Season-sex interaction induces changes in the ecophysiological traits of a lizard in a high altitude cold desert, Puna region.

ABSTRACT

Functional traits are those characteristics of organisms that influence the ability of a species to develop in a habitat and persist in the face of environmental changes. The traits are often affected by a multiplicity of species-dependent and external factors. Our objective was to investigate thermal biology of Liolaemus ruibali in a high altitude cold desert at the arid Puna region, Argentina. We address the following question do sex and seasonal variations in environmental temperature induce changes in the ecophysiological traits? We measured and compared the operative temperatures between fall and spring; and between sexes and seasons, we compared the ecophysiological traits of lizards, microenvironmental temperatures and thermoregulatory behavior. Air and operative temperatures were different between seasons. We found an effect of season-sex interaction on field body temperatures, preferred temperatures, panting threshold and thermal quality. The voluntary and critical temperatures presented seasonal variation in relation to changes in environmental temperatures, suggesting thermal acclimatization. We note behavioral changes between seasons, with the substrate being the main resource for gaining heat in spring. We conclude that Liolaemus ruibali is an efficient thermoregulator; it is a eurythermic lizard and presents phenotypic plasticity in different ecophysiological and behavioral traits induced by sex and seasonality. In addition, we predict that this population could buffer the effects of projected global warming scenarios.