Male breeding success is predicted by call frequency in a territorial species, the agile frog (Rana dalmatina)

Abstract

Calling behaviour and the characteristics of the male call are important for both female mate choice and male mating success in anurans. As with most other ranid frogs, males of the agile frog (Rana dalmatina Fitzinger in Bonaparte, 1839) emit advertisement calls during the mating period. However, since males occupy and defend territories, it is not clear whether the calls serve to defend a territory and (or) to attract a mate. We investigated the relationship between male call characteristics and male breeding success in a field study by relating individual males' call parameters (viz. call duration, number pulses, pulse rate, and fundamental frequency) with their breeding success as indicated by the number and size of egg clutches in the territories of males. We found that the number and size (in number of eggs) of clutches in the territories of males increased with decreasing fundamental frequency of calls. We found no correlation between territory characteristics and breeding success, suggesting that the observed correlation between male call characteristics and mating success is not likely to be explained by differences in territory quality, but by female potential preference for males calling with low fundamental frequency. © 2008 NRC.