The traditionally-defined wren genus Thryothorus is notable for its diversity of singing styles with some species producing highly coordinated duets or choruses in various formats while, at the other extreme, songs are performed almost exclusively by males. In this comparative study, we document the singing styles of almost all of the 27 or so species in this group, relating these to a molecular phylogeny in an effort to identify the conditions that have led to the evolution of duetting and chorus singing. In a previous study, we used molecular data to demonstrate that Thryothorus is actually paraphyletic, leading us to propose its splitting into three genera (one newly described) in addition to Thryothorus. Here we show that most species within each of these four genera usually sing with the same style, and that these styles tend to differ between the genera. We also show that a few species have songs that differ markedly from those most typical of their genus. We argue that these exceptional cases will provide important insights into the origins of duetting behavior, and tentatively suggest factors that may have played a role in determining the extent to which male and female birds combine their vocalizations together.
Bibliographical noteFunding Information:
We would like to thank the Leverhulme Trust for funding the study and the following organisations and field stations for facilitating our field research. In Ecuador: Fundación Probosque and the Bosque Protector Cerro Blanco, Fundación Maquipucuna, Fundación Natura and the staff at Pasochoa, the community at the Playa de Oro Reserve, Esmeraldas, Rio Palenque Science Station, Universidad San Francisco de Quito and staff at the Tiputini Biodiversity Station (especially David and Consuelo Romo and Kelly Swing). In Panama: Autoridad Na-cional del Ambiente and The Smithsonian Tropical Research Institute, also Ancon Expeditions of Panama and the staff at Cana Field Station, Darien National Park. In Costa Rica: Depto. Evaluacion Recursos Biologicos, Estación Biológica La Suerte, the staff at Manuel Antonio National Park, Carara Biological Reserve and the Universidad la Paz, for facilitating our work at the El Rodeo Forest Reserve. In Mexico: Ministry of Ecology (SEMARNAT), In-stituto de Biologia at the Universidad Nacional Autonóma de México (UNAM), Estación de Biología Chamela, El Eden Ecological Reserve, also thanks to Marcela Osorio for organising accommodation with a community adjacent to the Reserva de la Biósfera Sierra de Huautla. We are also very grateful to the following for contributing sound recordings: The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York; British Library Sound Archive, London; Clementina Gonzalez, Cindy Hogan, Olaf Jahn, Donald Kroodsma and John Moore. Finally, we thank David Logue and an anonymous referee for helpful comments on the manuscript.
- Comparative study
- Song evolution