Anuran mating systems: the role of climate, life history traits, and sex ratio

There is a great diversity of mating systems in anurans, but the factors driving this diversity remain unclear. Here, using phylogenetic comparative methods, we explore which factors are related to the presence of certain mating systems in anurans and examine evolutionary patterns. We collected data for 717 anuran species and evaluated the effects of climate, temporal breeding pattern, sex ratios, terrestriality, and fecundity on their mating systems. Scramble competition and simultaneous polyandry occur more in species with aquatic oviposition sites, which have larger clutches, in habitats with high temperature seasonality, and low annual temperature/precipitation. Direct benefits occur often in species with terrestrial larger eggs and smaller clutches, which have terrestrial or sheltered oviposition sites, and in habitats with lower temperature seasonality. Only lek and polygyny were correlated with sex ratios. Most mating systems are strongly influenced by shared evolutionary history and are linked to the evolution of reproductive modes. Climate and sex ratios seem to play a role in the plasticity of mating systems, as a species can have more than one. Finally, our study represents a considerable advance toward understanding the anuran mating system evolution.