Mitogenomes resolve the phylogeography and divergence times within the endemic New Zealand Callaeidae (Aves: Passerida)

The biogeographical origins of the endemic birds of New Zealand (Aotearoa) are of great interest, particularly Palaeogene lineages such as Callaeidae, a passerine family characterized by brightly coloured wattles behind the beak and, in some cases, extreme sexual dimorphism in bill size and shape. Ancestral representatives of Callaeidae are thought to have split from their closest relatives outside New Zealand in the Oligocene, but little is known about the timing of divergences within the family. We present a fully dated molecular phylogeny of Callaeidae mitogenomes and discuss the biogeographical implications. Our results suggest that formation of Pliocene marine seaways, such as the Manawatu Strait, are likely to have played a significant role in the differentiation of North Island and South Island kokako (Callaeas spp.) and saddlebacks/tieke (Philesturnus spp.).

Automated summary

The biogeographical origins of the endemic birds of New Zealand, particularly the Callaeidae family, have attracted great interest. The formation of Pliocene marine seaways, such as the Manawatu Strait, is likely to have played a significant role in the divergence of North Island and South Island kokako and saddlebacks/tieke.