Phylogenetic Relationships of Micronesian White-Eyes Based on Mitochondrial Sequence Data

Abstract

Using mitochondrial sequence data, we estimated phylogenetic relationships and genetic divergence among selected species of white-eyes (Zosteropidae). We focused on taxa endemic to islands in Micronesia, specifically Zosterops conspicillatus, Z. semperi, Z. hypolais, Rukia oleaginea, and Cleptornis marchei. We also included in our data set five additional species of Zosterops from the Indo-Australian region and three species from Africa, as well as additional passerine outgroups. Our mitochondrial sequence data revealed substantial genetic divergence (5.7 to 7.3%) among Z. conspicillatus, Z. semperi, and Z. hypolais, three taxa that formerly were treated as a single species. In addition, a sequence divergence of 6.5 ± SE of 1.7% was found between the population of Z. conspicillatus from Rota and “conspecific” populations on Guam, Tinian, and Saipan. The distinctiveness of the Rota population suggests that this taxon should be recognized as a distinct species, a result that bears on the conservation of this population because it has been declining dramatically in recent years. All optimal trees based on analysis of the mitochondrial sequence data place Rukia oleaginea within the genus Zosterops. In all optimal trees, Cleptornis marchei positions as the sister taxon to a clade including all other zosteropids included in this study. The trees based on our data strongly contradict the traditional classification of Cleptornis as a honeyeater (family Meliphagidae). Our data cannot resolve with any confidence the sister relationships of the insular endemic white-eyes, although the optimal trees suggest multiple colonizations of Micronesia by more than one white-eye lineage.