Molecular Systematics of the Red-Bellied and Golden-Fronted Woodpeckers

Abstract

The Red-bellied Woodpecker species group (Melanerpes carolinus and relatives) is composed of five morphologically similar species whose limits have been unclear. The relationship of the Golden-fronted Woodpecker (M. aurifrons) to the remainder of the group is particularly uncertain. We used mitochondrial DNA sequences to examine the phylogeny of this group and its close relatives. We sequenced 872 bp, including fragments of the genes for ND2, ND3, COIII, and tRNAmet, of 11 species of Melanerpes. We constructed trees from combined sequences by using the maximum likelihood and Bayesian inference approaches. We found that M. aurifrons is not monophyletic but rather consists of two clades, one comprising tropical populations (M. santacruzi), the other, consisting of northern populations, being sister to M. carolinus. The Caribbean species, M. superciliaris, is sister to the carolinus—aurifrons clade. The group as a whole appears to have diversified into multiple lineages in response to several episodes of vicariance, perhaps associated with glacial—interglacial cycles. As a result of these findings, major taxonomic changes in the group are needed.