Correlated evolution of distinct signals associated with increased social selection in female white-shouldered fairywrens

Authors

John Anthony Jones, Tulane University
Karan J. Odom, Cornell University
Ian R. Hoppe, University of Nebraska - LincolnFollow
Doka Nason, Porotona Village, Papua New Guinea
Serena Ketaloya, Porotona Village, Papua New Guinea
Jordan Karubian, Tulane University

ORCID IDs

John Anthony Jones

Karan J. Odom

Ian R. Hoppe

Jordan Karubian

Date of this Version

11-2-2021

Citation

Jones, J. A., Odom, K. J., Hoppe, I. R., Nason, D., Ketaloya, S., & Karubian, J. (2021). Correlated evolution of distinct signals associated with increased social selection in female white-shouldered fairywrens. Ecology and Evolution, 11, 17352–17363. https://doi.org/10.1002/ ece3.8370

Comments

OPEN ACCESS

Abstract

Conspicuous female signals have recently received substantial scientific attention, but it remains unclear if their evolution is the result of selection acting on females independently of males or if mutual selection facilitates female change. Species that express female, but not male, phenotypic variation among populations represents a useful opportunity to address this knowledge gap. White-shouldered fairywrens (Malurus alboscapulatus) are tropical songbirds with a well-resolved phylogeny where female, but not male, coloration varies allopatrically across subspecies. We explored how four distinct signaling modalities, each putatively associated with increased social selection, are expressed in two populations that vary in competitive pressure on females. Females in a derived subspecies (M. a. moretoni) have evolved more ornamented plumage and have shorter tails (a signal of social dominance) relative to an ancestral subspecies (M. a. lorentzi) with drab females. In response to simulated territorial intrusions broadcasting female song, both sexes of M. a. moretoni are more aggressive and more coordinated with their mates in both movement and vocalizations. Finally, M. a. moretoni songs are more complex than M. a. lorentzi, but song complexity does not vary between sexes in either population. These results suggest that correlated phenotypic shifts in coloration and tail morphology in females as well as song complexity and aggression in both sexes may have occurred in response to changes in the intensity of social selection pressures. This highlights increased competitive pressures in both sexes can facilitate the evolution of complex multimodal signals.