The matched filter hypothesis proposes that the tuning of auditory sensitivity should match the spectral character of calls, suggesting that sender calls and receiver auditory systems have co-evolved. However, studies provide mixed evidence, and in some species, this match is imprecise. Here, we analyzed the acoustic characteristics of male calls and both male and female hearing sensitivity in an explosive-breeding toad Duttaphrynus melanostictus to test the matched filter hypothesis.Male toads emitted a series of multisyllabic calls that were composed of single notes with a dominant frequency of 1494 ± 80 Hz. The dominant frequency reflected body size and was static between males, suggesting it may be under stabilizing selection and used in species recognition. Sexual dimorphism in peripheral auditory sensitivity was also observedas females exhibited lower auditory thresholds than males across 600–2400 Hz frequency range. The relationship between vocalizations and hearing corresponded to the matched filter hypothesis, suggesting that male call spectral structure and hearing sensitivity in males and females may have co-evolved under sexual selection in D. melanostictus.
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