No evidence for song evolution influencing speciation patterns in honeyeaters

Abstract

AbstractBirdsongs are well-known acoustic signals and are thought to play a key role in sexual selection. Despite the established role of birdsong in sexual selection and reproductive isolation at microevolutionary scales, its macroevolutionary impacts on speciation and diversification remain largely unexplored. Here, we test the hypothesis that song influences speciation on macroevolutionary scales, using honeyeaters, a diverse clade of songbirds restricted to Australasia. Using song data for 163 honeyeater species, we employ phylogenetic comparative models of trait evolution to detect shifts in optima for song evolution and use hidden state speciation and extinction models to assess the influence of these shifts on diversification. Contrary to theoretical expectations, we find no evidence that song influences speciation or diversification rates, and models suggest other factors play a role. Overall, song does not significantly contribute to speciation in honeyeaters, likely due to other ecological factors including range size and dispersal ability.