Environmental drivers of body size variation in the lesser treefrog (Dendropsophus minutus) across the Amazon-Cerrado gradient

Environmental variation between habitats may impose divergent selection pressures resulting in phenotypic divergence that can lead to reproductive isolation, especially if these same traits are favoured by sexual selection. Anuran body size is an important trait in male mating success and can affect the spectral traits of calls that female frogs use in mate choice. Environmental differences in water availability and temperature influence anuran body size and may result in reproductive incompatibility between populations. We investigated the importance of environmental differences between the Amazon and the Cerrado in driving phenotypic variation in the lesser tree frog (Dendropsophus minutus). In the present study, we tested the relationship between body size and environmental variables (precipitation and temperature). The results obtained show that body size increases in a more seasonal climate. Precipitation seasonality is the most important variable in explaining body size variation. If environmental variables can be used as a proxy for phenotypic variation, our results suggest that environmental differences between habitats may be an important driver of intraspecific divergence. Thus, this divergence across the Amazon and the Cerrado suggests the early stages of the ecological speciation continuum. (C) 2016 The Linnean