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

ABSTRACT

Kiwis (Apterygidae) are an enigmatic family of flightless birds endemic to New Zealand. Apterygidae is made up of a single genus, Apteryx with 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, containing A.haastii, and A.owenii in one and A.rowi, A.mantelli, and A.australis in the other. We reconstructed 17 kiwi mitochondrial genomes from previously published genomic data, nine from A.rowi and eight from A.owenii. Mitochondrial diversity analyses uncovered low levels of genetic diversity consistent with their reduced ranges and conservation concern. We further used one of the assembled A.rowi mitochondrial genomes together with mitochondrial genomes from A.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.

KEYWORDS:

• Kiwi
• mitochondrial genome
• genetic diversity
• phylogeny
• divergence
• Apteryx

Acknowledgements

We would like to acknowledge the Kaitiaki o Kapiti Trust, Te Rūnanaga Ngāi Tahu, Port Nicholson Block Settlement Trust, Te Ātiawa Manawhenua Ki Te Tau Ihu Trust, Te Rūnanga o Makaawhio, and Waiorua Bay Trust, who provided guidance to the authors of the studies that published the original genomic data, on which our study is based. We would also like to thank Lara Shepherd and one anonymous reviewer for their insightful comments which allowed us to improve the quality of the manuscript.

Data availability statement

All newly assembled mitochondrial genomes can be found under the Genbank acession codes MT437231-MT437247.