“Punch or argument?” Is the acoustic dominance behavior of Tettigonia viridissima males reflected in their acoustical and physical strength?

Any signal involved in intrasexual competition may indicate the physical strength of individuals, allowing males to gauge a competitor’s fighting ability and avoid costly injuries. Tettigonia viridissima is an aggressive predatory bush-cricket in which males produce loud songs and engage in physical fights during choruses. This study tested whether males could assess rivals’ fighting ability through acoustic signals and without physical interaction. This study hypothesized that larger males produce lower mean carrier frequencies and exhibit greater acoustic competitiveness than smaller rivals, which would be reflected in acoustic dominance behavior. Individual male calls were recorded, morphological traits were measured, and acoustic competitiveness was evaluated in a laboratory setup. Paired Wilcoxon signed-rank tests revealed no significant relationship between acoustic competitiveness and either body size or mean carrier frequency. These null results demonstrate an evolutionary asymmetry: While acoustic and morphological traits are favored by intersexual female choice, they operate independently during intrasexual male competition. Future work should evaluate alternative acoustic parameters and non-physical behavioral contexts.