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The Vitelline Warbler (Setophaga vitellina) is an understudied species endemic to a few islands in the western Caribbean. Little is known beyond its phylogenetic relationship to other New World warblers. We used island-wide surveys and bioacoustic recordings to investigate the distribution, vocalizations, and ecology of S. vitellina across a significant portion of the species’ range on Little Cayman Island. We recorded 417 songs from 91 individuals and analyzed the length, frequency, and shape of various song components. We observed and characterized high variation in the composition and character of songs.
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Genomic divergence, demographic histories, and male territorial response reveal asymmetric reproductive barriers in allopatric eastern versus western Nashville warbler subspecies ( Leiothlypis ruficapilla )
Abstract In song-learning birds, vocalizations are species recognition signals and may act as premating reproductive barriers; for allopatric taxa, testing how the signals can influence the speciation processes is quite challenging. This study aims to understand genomic divergence and species recognition via songs in 2 allopatric taxa, eastern and western Nashville warblers (Leiothlypis ruficapilla ruficapilla vs. Leiothlypis ruficapilla ridgwayi). We performed playback experiments to assess their reciprocal behavioral responses, which suggests an asymmetric barrier: the eastern L. r. ruficapilla discriminates between the 2 songs, but the western L. r. ridgwayi does not. Using whole-genome sequencing, we also examined the extent of the taxa’s genomic divergence and estimated their demographic history. We identified dozens of highly differentiated genomic regions, as well as fluctuations in historical effective population sizes that indicate independent demographic trajectories during the Pleistocene. To contextualize the magnitude of divergence between L. ruficapilla subspecies, we applied the same genomic analyses to 2 additional eastern-western pairs of parulid warblers, Setophaga virens vs. Setophaga townsendi and Setophaga coronata coronata vs. Setophaga coronata auduboni, which have existing behavior studies but are not in strict allopatry. Our findings provide insights into the role of vocalizations in defining within-pair relationship and the important legacy of isolation during the Pleistocene.
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- Award ID(s):
- 2131469
- PAR ID:
- 10647595
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Evolution
- ISSN:
- 0014-3820
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Harris, Bert (Ed.)The Vitelline Warbler (Setophaga vitellina) is an understudied species endemic to a few small islands in the western Caribbean. Little is known beyond its phylogenetic relationship to other New World warblers. We used island-wide surveys and bioacoustic recordings to investigate the distribution, vocalizations, and ecology of S. vitellina across a significant portion of the species’ range on Little Cayman Island. We recorded 417 songs from 91 individuals and analyzed the length, frequency, and shape of various song components. We observed and characterized high variation in the composition and character of songs within the Little Cayman population. We also describe the call of the species and use sound files from across the species’ range to compare vocalizations between islands. Vitelline Warbler abundance is highest in dry forest and dry scrub habitats, suggesting that these habitats are most important for the species. Elaboration of the vocalizations of understudied species like the Vitelline Warbler has the potential to further our understanding of avian evolution and behavior. As much still remains to be learned from this species, action must be taken to protect its critical habitats, especially dry forests, among other conservation measures.more » « less
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