Climate and Morphology Drive Breeding Periods in Frogs

Abstract

Climate can have profound effects on reproductive behavior and physiology, especially in ectothermic animals. In amphibians, the evolution of breeding period due to climate has received little attention despite its direct connection to fitness and relevance to amphibian conservation. We used phylogenetic comparative methods to analyze a global dataset of frog breeding periods, climate, body size, and microhabitat for 497 species across 41 of 54 families. We found support for the hypothesis that breeding periods are longer in the warmer, wetter, aseasonal tropics and shorter in the colder, dryer, seasonal temperate zone. However, this latitudinal reproduction gradient is more complex than expected, as the effect of climate depends on body size. Additionally, breeding periods were similar across microhabitats. Overall, our model describes ~20% of variation in breeding periods and these results are robust to phylogenetic uncertainty. Our results set within an eco-physiology framework have broad implications for more targeted priorities in amphibian conservation.