Elevational Variation in Reproductive Strategy of a Widespread Lizard:High-Elevation Females Lay Fewer but Larger Eggs

Identifying how reproductive strategies such as the trade-off between clutch size versus egg mass vary with elevational gradients is essential for our understanding of life-history evolution.We studied lacertid lizards(Eremias argus)in China,from six populations at different altitudes,to assess elevational variation in reproductive strategy.We found significant between-population variation in maternal body size and clutch mass,but these variations were not explained by elevational differences.However,high-elevation females tended to produce smaller clutches of larger eggs compared with their low-elevation counterparts,demonstrating an elevational change in the trade-off between egg size and number.The egg size-number trade-off is a reproductive strategy that may favor large offspring,better enabling them to survive severe and unpredictable environments found at high elevations.