RESUMEN
The immune state is an essential component of survival as it directly influences physiological performance and health status. Variation in the leukocyte profile, a significantly increase in body temperature, and a detriment of the eco-physiological performance are among the possible consequences of an unhealthy state. In this study we analyse and discuss how field body temperature, preferred body temperature, the speed for sprint and long runs, locomotor stamina, and body condition can be affected by the immunological state (i.e. leukocyte profile) in a wild population of Liolaemus sarmentoi. Juveniles and adult males with a high percentage of eosinophils, basophils, and a low percentage of monocytes preferred higher body temperatures in a thermal gradient, while pregnant females maintained thermal preferences independently of leukocyte profile. Although juveniles with a high percentage of heterophils showed less locomotor stamina, adult males and pregnant females showed no differences in locomotor performance in relation to leukocyte profile. This study represents a starting point in eco-immunology of a wild lizard population of Liolaemus in cold and temperate environments of Patagonia where the southward shift in the geographic ranges of pathogen populations due to global warming represents a threat to resident host populations.