Patterns of Molecular and Morphological Variation in Some Solomon Island Land Birds

Abstract

The Solomon Archipelago is the largest and most biologically complex archipelago in northern Melanesia. We collected tissues and voucher specimens from codistributed bird species found on five island groups that provided the first opportunity to apply molecular methods to this avifauna. Using the mitochondrial marker ND2, we constructed a series of intraspecific phylogenies for 23 ecologically and taxonomically diverse species (13 families from 5 orders). Intraspecific comparisons across islands revealed a broad range of genetic differentiation, from 0% in widespread dispersive species such as Eurystomus orientalis and Nectarinia jugularis, to as high as 4–8% in species such as Ceyx lepidus and Dicaeum aeneum. Fifteen of the 23 species had well-supported phylogeographic structure, and for many of these, endemic and otherwise, molecular phylogenetic relationships closely matched those delineated by morphology. However, degrees of genetic differentiation appeared to be inconsistent across taxonomic designations, and the monophyly of some endemic taxa was not well supported. The data reveal the limits of morphology in tracking complex evolutionary histories and suggest that taxonomic revision of some Solomon Islands birds is warranted. As the first molecular analyses of this avifauna, results presented here create a platform for further biogeographic and evolutionary studies of bird diversity in this influential region.Patrons de variation moléculaire et morphologique chez quelques oiseaux terrestres des îles Salomon