Effects of reproductive condition on body mass and thermal ecology in the female Mesquite Lizard, Sceloporus grammicus, in a population from central Mexico

Reproductive condition influences ecophysiological traits in viviparous female lizards, which may have various effects on their fitness. In this study, the effects of reproductive condition on body mass and thermal ecology were evaluated in females from a central Mexico population of Sceloporus grammicus . Sampling was conducted during pregnancy and postpartum periods, recording body mass, snout-vent length (SVL), body temperature, and substrate and air temperatures. The data were analyzed using linear mixed and general linear models to evaluate differences between reproductive conditions. The study included repeated measurements from recaptured individuals, allowing intra-individual comparisons across reproductive conditions. After controlling for body size, pregnant females had a significantly higher body mass than postpartum females. Despite this higher mass, pregnant females had a significantly lower body temperature than postpartum females. These results suggest that changes in body mass and thermal ecology are associated with the reproductive condition of S. grammicus females.