Comparative phylogeography and genetic structure of Vanuatu birds: control region variation in a rail, a dove, and a passerine

We examined variation in mitochondrial control region (Domain I) sequences in three distantly related species of birds found on multiple islands in Vanuatu: the Buff-banded Rail Gallirallus philippensis (n=21, 433bp), the Emerald Dove Chalcophaps indica (n=21, 513bp), and the Streaked Fantail Rhipidura spilodera (n=17, 326bp). Nucleotide and haplotype diversity were similar in all three species and showed little to no geographic structure within Vanuatu. Estimates of demographic parameters, tests for excess rare alleles, and the structure of both haplotype networks and pairwise mismatch distributions support a hypothesis of recent colonization and subsequent expansion in C. indica and R. spilodera but not in G. philippensis. Phylogenetic analyses suggest that G. philippensis samples from Vanuatu are polyphyletic, and further indicate that this species has had a more complex history of colonization than do the other two species. Estimated divergence times of alleles sampled in Vanuatu suggest there may be slight differences among species in the timing of colonization of Vanuatu despite differences in flight ability and presumed dispersal ability. In all three species, current populations probably derive from colonists that arrived several million years after the islands formed. Our comparisons illustrate the potential of direct genetic analyses of to highlight historical differences among co-distributed species with similar levels of phenotypic variation.