Countergradient variation has been detected in diverse taxa. In a common manifestation, individuals from colder environments develop faster than conspecifics from warmer environments when placed in a common garden. Where such a pattern exists, it implies a tradeoff: individuals from warmer environments have intrinsic rates of development lower than those demonstrated by other individuals of the same species. We explored a tradeoff between development rate and locomotor performance in the wood frog (Rana sylvatica), an amphibian for which countergradient variation has been well documented. We reared wood frogs from 10 populations under two temperature regimes, bracketing the temperatures observed in local natural ponds. Individuals reared under warmer conditions developed more rapidly but exhibited burst speeds 20% lower than individuals reared under colder conditions. The shape of the relationship was consistent across the 10 populations and thus, we found no evidence of countergradient variation in performance. Burst speed assays of wild-caught tadpoles from the same populations showed a similar but nonsignificant trend, with greater variability among ponds. Overall, our findings support the existence of a tradeoff that may be of broad importance and which may help explain widespread occurrence of countergradient variation.

Please see the methods section of our manuscript for details on data collection. The README file includes details about processing for specific variables. For further questions, please contact the authors: kaija.gahm@aya.yale.edu.