Odom, Karan J.Cain, KristalHall, MichelleLangmore, NaomiMulder, RaoulKleindorfer, SoniaKarubian, JordanBrouwer, LyanneEnbody, ErikJones, John AnthonyDowling, Jenelle L.Leitao, Ana V.Greig, Emma I.2023-07-052023-07-05Odom, K. J., Cain, K. E., Hall, M. L., Langmore, N. E., Mulder, R. A., Kleindorfer, S., Karubian, J., Brouwer, L., Enbody, E. D., Jones, J. A., Dowling, J. L., Leitão, A. V., Greig, E. I., Evans, C., Johnson, A. E., Meyers, K. K.-A., Araya-Salas, M., & Webster, M. S. (2021). Sex role similarity and sexual selection predict male and female song elaboration and dimorphism in fairy-wrens. Ecology and Evolution, 11, 17901–17919. https://doi.org/10.1002/ece3.83782045-7758http://hdl.handle.net/1885/293974Historically, bird song complexity was thought to evolve primarily through sexual selection on males; yet, in many species, both sexes sing and selection pressure on both sexes may be broader. Previous research suggests competition for mates and resources during short, synchronous breeding seasons leads to more elaborate male songs at high, temperate latitudes. Furthermore, we expect male–female song structure and elaboration to be more similar at lower, tropical latitudes, where longer breeding seasons and year-round territoriality yield similar social selection pressures in both sexes. However, studies seldom take both types of selective pressures and sexes into account. We examined song in both sexes in 15 populations of nine-fairy-wren species (Maluridae), a Southern Hemisphere clade with female song. We compared song elaboration (in both sexes) and sexual song dimorphism to latitude and life-history variables tied to sexual and social selection pressures and sex roles. Our results suggest that song elaboration evolved in part due to sexual competition in males: male songs were longer than female songs in populations with low male survival and less male provisioning. Also, female songs evolved independently of male songs: female songs were slower paced than male songs, although only in less synchronously breeding populations. We also found male and female songs were more similar when parental care was more equal and when male survival was high, which provides strong evidence that sex role similarity correlates with male–female song similarity. Contrary to Northern Hemisphere latitudinal patterns, male and female songs were more similar at higher, temperate latitudes. These results suggest that selection on song can be sex specific, with male song elaboration favored in contexts with stronger sexual selection. At the same time, selection pressures associated with sex role similarity appear to favor sex role similarity in song structure.Funding was provided by: a Cornell Lab of Ornithology Rose Postdoctoral Fellowship and a U.S. National Science Foundation (NSF) Postdoctoral Research Fellowship in Biology to KJO (grant no. 1612861), NSF grant number 1354133 to JK, NSF grant number 1701781 to JK and EDE, National Geographic Society Young Explorers Grant to EDE, Nature Foundation of South Australia Grand Start Grant and Holsworth Wildlife Research Endowment awarded to CE, Australian Research Council DECRA to LB (DE130100174), Australian Research Council Discovery Grant DP110101966 to RAM and NEL (DP150101652), Australia & Pacific Science Foundation to RAM and MLH (APSF1406), and Birdlife Australia grant to AVL. Funding for purple-crowned fairy-wren data collection was also provided to Anne Peters by the Max Planck Society Minerva Program, the Australian Research Council (FT10100505 & DP150103595) and Monash University.application/pdfen-AU© 2021 The Authorscomplexitydimorphismlife historyMalurussex roles2021-12-0710.1002/ece3.83782022-04-10Creative Commons Attribution License