Precipitation and Temperature‐Dependent Locomotor Performance Drive the Abundance of a Neotropical Lizard

ABSTRACT Understanding the factors influencing the dynamics of natural populations is essential for mitigating the impacts of anthropogenic changes. Here, we investigate the effects of climate, microclimate, and ecophysiology on the demography of Tropidurus oreadicus , an endemic lizard found in the Brazilian Cerrado savannas. In a vegetation gradient, we monitored the lizards monthly for 4 years using a mark‐recapture protocol with pitfall traps. We conducted ecophysiological experiments with 20 individuals and used microclimatic temperatures to estimate hours of activity and locomotor performance for each trap and month. Throughout this period, we made 598 captures and recaptures of 372 individuals. Environmental variables could not explain the determinants of population growth, such as survival and recruitment. Instead, these demographic parameters appear to fluctuate due to the size‐structured seasonal variation of the population each year and negative density dependence relationships. We identified a strong correlation between recruitment and the rainy months, with peaks occurring in December and January. Precipitation and locomotor performance were good predictors of capture probability and abundance of T. oreadicus . We captured more lizards in the driest months, while abundance increased in the rainy season when locomotor performance was at its highest. Thus, our results suggest that the seasonal availability of microhabitats that optimize locomotor performance is a key selective pressure that has shaped the reproductive timing of T. oreadicus , a mechanism likely crucial for other ectotherms. Stochastic and anthropogenic changes in precipitation and microclimatic temperatures may hinder T. oreadicus abundance, jeopardizing the local population's persistence.