Madagascar is known as a biodiversity hotspot, providing an ideal natural laboratory for investigating the processes of avian diversification. Yet, the phylogeography of Madagascar's avifauna is still largely unexamined. In this study, we evaluated phylogeographic patterns and species limits within the Rufous Vanga, Schetba rufa, a monotypic genus of forest-dwelling birds endemic to the island. Using an integrative taxonomic approach, we synthesized data from over 4000 ultra-conserved element (UCE) loci, mitochondrial DNA, multivariate morphometrics, and ecological niche modeling to uncover two reciprocally monophyletic, geographically circumscribed, and morphologically distinct clades of Schetba. The two lineages are restricted to eastern and western Madagascar, respectively, with distributions broadly consistent with previously described subspecies. Based on their genetic and morphological distinctiveness, the two subspecies merit recognition as separate species. The bioclimatic transition between the humid east and dry west of Madagascar likely promoted population subdivision and drove speciation in Schetba during the Pleistocene. Our study is the first evidence that an East-West bioclimatic transition zone played a role in the speciation of birds within Madagascar.
Bibliographical noteFunding Information:
This study was funded by NSF grant DEB-1457624 awarded to SR. Funding was also provided by the Pritzker Laboratory for Molecular Systematics and Evolution, operated with support from the Pritzker Foundation. We gratefully acknowledge the Field Museum of Natural History, the American Museum of Natural History, and the Mention Zoologie et Biologie Animale at the Université d'Antananarivo for access to specimens and tissue samples. We are thankful to Robert Lauer for his assistance preparing sampling maps, and to Chris Kyriazis and Dylan Maddox for their molecular laboratory work. The Illumina short reads are available from the NCBI sequence read archive (PRJNA548994) and Sanger sequences are available from GenBank (MN081772 - MN081795). JY collected, analyzed, and interpreted the data, wrote the manuscript, and participated in conceiving and designing the study. PD carried out phylogenetic analyses, AN conducted ecological niche modeling, TOH collected the morphometric data. MJR collected genetic samples. SMG collected genetic samples, and participated in interpreting the data and conceiving the study. SR conceived and designed the study, and carried out morphometric analyses.
© 2019 Elsevier Inc.
- Ecological niche modeling