Song evolution, speciation, and vocal learning in passerine birds

Abstract

Phenotypic divergence can promote reproductive isolation and speciation, suggesting a possible link between rates of phenotypic evolution and the tempo of speciation at multiple evolutionary scales. To date, most macroevolutionary studies of diversification have focused on morphological traits, whereas behavioral traitsincluding vocal signalsare rarely considered. Thus, although behavioral traits often mediate mate choice and gene flow, we have a limited understanding of how behavioral evolution contributes to diversification. Furthermore, the developmental mode by which behavioral traits are acquired may affect the rates of behavioral evolution, although this hypothesis is seldom This article is protected by copyright. All rights reserved. 2 tested in a phylogenetic framework. Here, we examine evidence for rate shifts in vocal evolution and speciation across two major radiations of codistributed passerines: one oscine clade with learned songs (Thraupidae) and one suboscine clade with innate songs (Furnariidae). We find that evolutionary bursts in rates of speciation and song evolution are coincident in both thraupids and furnariids. Further, overall rates of vocal evolution are higher among taxa with learned rather than innate songs. Taken together, these findings suggest an association between macroevolutionary bursts in speciation and vocal evolution, and that the tempo of behavioral evolution can be influenced by variation in developmental modes among lineages.

Ecological drivers of song evolution in birds: Disentangling the effects of habitat and morphology

“…More recently, Mason et al. () found that body size was more important than habitat in the evolution of song in tanagers (Thraupidae), but no information was available regarding beak size. Thus, we still have only a limited understanding of the relative roles of these mechanisms, partly because comprehensive information on phylogenetic relationships, signal design, morphology, and ecology are rarely available for large radiations.…”

“…Moreover, in common with other tracheophone suboscine passerines (Tobias & Seddon, ; Tobias et al., ; Touchton, Seddon, & Tobias, ), their songs appear to be innate with song learning limited or absent. This minimizes the effect of cultural processes on song evolution (Mason et al., ; Weir & Wheatcroft, ) and means that ovenbird songs are relatively simple and amenable to acoustic analysis (Tobias et al., ).…”

Genomic divergence in allopatric Northern Cardinals of the North American warm deserts is linked to behavioral differentiation

“…Relative to the accumulation of novel genetic markers or other traits, behavioral evolution via exchange of learned song can be rapid (Allender, Seehausen, Knight, Turner, & Maclean, ; Duckworth, ; West‐Eberhard, ). Further, species that learn their song evolve new dialects particularly quickly (Mason et al, ; but see Freeman, Montgomery, & Schluter, ). Rapid evolution of songs could mediate and/or supplement divergences across the Cochise Filter Barrier.…”

Can animal culture drive evolution?

“…In both cases, song evolves over time as it passes through generations. Evolutionary biologist Elizabeth Derryberry of the University of Tennessee, Knoxville, and Nicholas Mason, a doctoral candidate in ecology and evolutionary biology at Cornell University, studied two families of birds: the tanagers (Thraupidae) that learn song and the ovenbirds (Furnariidae) that are innate singers (12). What they found suggests that culture could play a sizeable role.…”

“…Derryberry and Mason (12) acknowledge that they don't know whether bird song evolution drives speciation or vice versa. In one scenario, bird song could diverge first, which would prevent individuals with different songs from mating together, setting their lineages on the path to becoming distinct species.…”