Phylogeny and biogeography of Oriolidae (Aves: Passeriformes)

Understanding oscine passerine dispersal patterns out of their Australian area of origin is hampered by a paucity of robust phylogenies. We constructed a molecular phylogeny of the oscine family, Oriolidae, which is distributed from Australia through to the Old World. We used the phylogeny to assess direction and timing of dispersal and whether dispersal can be linked with the well-documented movements of geological terranes in the Indonesian Archipelago. We sampled 29 of 33 species of Oriolidae from fresh tissue and from toe pads from museum specimens, and examined two nuclear introns and two mitochondrial genes. Model-based phylogenetic analyses yielded strong support for clades that generally mirrored classical systematics. Biogeographical analyses and divergence time estimates demonstrated that the family originated in the Australo-Papuan region from where it dispersed first to Asia and then onwards to Africa and the Philippines before back-colonising Asia and the Indonesian archipelago. Thus, contrary to several other avian families in the region, Oriolidae represents a sequential dispersal pattern from Australia to Africa via Asia. However, it is noteworthy that the Pacific islands and archipelagos remain uncolonised and that members inhabiting Wallacea are recent colonisers suggesting that Oriolidae are poorly adapted to island life.