Patterns of genetic and morphological divergence reveal a species complex in the Plain Wren (Cantorchilus modestus)

Abstract

ABSTRACT We used morphometrics, plumage color, and mitochondrial DNA to reconstruct the phylogeography of the Plain Wren (Cantorchilus modestus), an abundant bird species of low to middle elevations throughout Central America. Sampling the full geographic range of C. modestus, we uncovered significant phenotypic structure in size, shape, and plumage color that mirrored deep genetic divergences in mitochondrial DNA. This structure was mostly concordant with the 3 most broadly recognized subspecies of Plain Wren (C. m. modestus, C .m. zeledoni, and C. m. elutus), but a potentially undescribed taxon exists in the highlands of Central Belize. We also found evidence of a cryptic phylogeographic break on the Pacific Slope of Costa Rica, between the southernmost populations and the widespread northern populations. This latter discovery likely represents a significant expansion of the known range of the traditionally Panamanian subspecies C. m. elutus, corresponding to a transition between major ecoregions. Topol...