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In acoustically advertising anurans the male courtship call elicits species-typical responses from conspecifics - usually phonotactic approach and mate choice in gravid females and an evoked vocal response in adult males. Males in several species, however, are also known to perform phonotaxis, sometimes with the same acoustic preferences as females. Female túngara frogs are known to update their phonotactic approach as male advertisement signals change dynamically in attractiveness. Here we show that males also perform such temporal updating during phonotaxis in response to dynamic playbacks. While males exhibit slower phonotactic approaches than females, their responsiveness to dynamic changes in call complexity does not differ significantly compared to females. These results demonstrate that males are sensitive to the location of preferred call types on a moment-to-moment basis and suggest that similarities between male and female sexual behaviour in anurans might often be overlooked. We suggest that anuran phonotaxis is more widespread and serves different functions in reproductive females and males. Lastly, these temporal updating results suggest that male frogs are highly selective about site selection in a chorus. [ABSTRACT FROM AUTHOR]

The human music faculty might have evolved from rudimentary components that occur in non-human animals. The evolutionary history of these rudimentary perceptual features is not well understood and rarely extends beyond a consideration of vertebrates that possess a cochlea. One such antecedent is a preferential response to what humans perceive as consonant harmonic sounds, which are common in many animal vocal repertoires. We tested the phonotactic response of female túngara frogs (Physalaemus pustulosus) to variations in the frequency ratios of their harmonically structured mating call to determine whether frequency ratio influences attraction to acoustic stimuli in this vertebrate that lacks a cochlea. We found that the ratio of frequencies present in acoustic stimuli did not influence female response. Instead, the amount of inner ear stimulation predicted female preference behaviour. We conclude that the harmonic relationships that characterize the vocalizations of these frogs did not evolve in response to a preference for frequency intervals with low-integer ratios. Instead, the presence of harmonics in their mating call, and perhaps in the vocalizations of many other animals, is more likely due to the biomechanics of sound production rather than any preference for 'more musical' sounds. [ABSTRACT FROM AUTHOR]