Complete mitochondrial genomes offer insights into the evolutionary relationships and comparative genetic diversity of New Zealand's iconic kiwi (Apteryx spp.)

Kiwis (Apterygidae) are an enigmatic family of flightless birds endemic to New Zealand. Apterygidae is made up of a single genus,Apteryxwith five species, four of which are characterised as at risk of greater by the New Zealand Department of Conservation. These five species are further separated into two morphologically and genetically distinguishable clades, containingA.haastii, and A.oweniiin one andA.rowi, A.mantelli,andA.australisin the other. We reconstructed 17 kiwi mitochondrial genomes from previously published genomic data, nine fromA.rowiand eight fromA.owenii. Mitochondrial diversity analyses uncovered low levels of genetic diversity consistent with their reduced ranges and conservation concern. We further used one of the assembledA.rowimitochondrial genomes together with mitochondrial genomes fromA.haastii, A.owenii, A.mantelli,and several other individuals from Palaeognathae to estimate the within and between clade divergence times of kiwis. Our study exemplifies how available published data can be used in novel ways to provide new and complementary evolutionary insights to previous studies.