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Numerous models have attempted to explain the evolution of extravagant male ornaments found in many species. Inter‐sexual indicator models postulate that male ornaments evolved as signals of quality, and that females use these signals to select the highest quality males. These models involve three traits – male quality, male signals and female preferences – and have specific expectations about the relative strengths of the phenotypic relationships between these traits. Using data from anuran species, we assessed the relative strengths of the phenotypic relationships using meta‐analysis. The relative strengths of these phenotypic correlations were as expected by indicator models, providing support for indicator models of inter‐sexual selection. We also found much variation in our data, suggesting that additional, untested factors may mediate inter‐sexual interactions in this taxon, such as differences in the importance of quality signalling between species. These factors require investigation, in order to improve our understanding of inter‐sexual selection.

In many species, male animals produce costly signals to attract females. Intersexual indicator theories propose that these signals are indicative of male quality, whereas individual recognition models are based on the idea that male signals are used primarily to allow for individual discrimination. These two types of models make differing predictions about the nature of male signals. In particular, these models’ predictions differ in the information about a male’s quality that will be included in his signal, the frequency distributions of male signals in a population, and the ways in which the different traits that make up a signal will covary. Calls from the Australian frog Litoria chloris were tested for consistency with the predictions of intersexual indicator models and individual recognition models. The calls were found to contain minimal information on male quality, and the covariance between different signal traits was consistent with the individual recognition models. However, the frequency distributions of male signal traits agreed with intersexual indicator models. In addition, this study found evidence that the information content of calls may instead mediate intrasexual interactions, although more research is required to determine if this is the case.