Climate warming and temporal variation in reproduction strategies in the endangered meadow viper

Here, we used more than three decades of mark-recapture data in a natural population of the endangered meadow viper (Vipera ursinii ursinii) to unravel the patterns of temporal variation in reproductive traits, local climatic determinants of inter-annual variation in reproduction and the potential buffering effects of life cycle on population growth rate. We found significant inter-annual variation in annual body growth, gestation length, post-parturition body condition, clutch success and offspring traits at birth, but little temporal effects in reproductive effort. Temperature during gestation was the most influential local climatic determinant by shortening gestation length, and increasing clutch success and post-parturition body condition. Neither air humidity nor insolation was found to influence reproduction.