Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev Mitogenomic evidence of close relationships between New Zealand’s extinct giant raptors and small-sized Australian sister-taxa Michael Knapp a, ⁎ , Jessica E. Thomas b,c,1 , James Haile c,1 , Stefan Prost d,e , Simon Y.W. Ho f , Nicolas Dussex a,g , Sophia Cameron-Christie a , Olga Kardailsky a , Ross Barnett c , Michael Bunce h , M. Thomas P. Gilbert c,i , R. Paul Scofield j a Department of Anatomy, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand b Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, UK c Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark d Research Institute of Wildlife Ecology, Vetmeduni Vienna, Vienna, Austria e Department of Integrative Biology, University of California Berkeley, Berkeley, USA f School of Life and Environmental Sciences, University of Sydney, Sydney, Australia g Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden h Trace and Environmental DNA Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia i Norwegian University of Science and Technology, University Museum, 7491 Trondheim, Norway j Canterbury Museum, 8013 Christchurch, New Zealand ARTICLE INFO Keywords: Ancient DNA Climate change Extinction Island gigantism New Zealand megafauna Trans-Tasman dispersal ABSTRACT Prior to human arrival in the 13th century, two large birds of prey were the top predators in New Zealand. In the absence of non-volant mammals, the extinct Haast's eagle (Hieraaetus moorei), the largest eagle in the world, and the extinct Eyles' harrier (Circus teauteensis) the largest harrier in the world, had filled ecological niches that are on other landmasses occupied by animals such as large cats or canines. The evolutionary and biogeographic history of these island giants has long been a mystery. Here we reconstruct the origin and evolution of New Zealand’s giant raptors using complete mitochondrial genome data. We show that both Eyles’ harrier and Haast’s eagle diverged from much smaller, open land adapted Australasian relatives in the late Pliocene to early Pleistocene. These events coincided with the development of open habitat in the previously densely forested islands of New Zealand. Our study provides evidence of rapid evolution of island gigantism in New Zealand’s extinct birds of prey. Early Pleistocene climate and environmental changes were likely to have triggered the establishment of Australian raptors into New Zealand. Our results shed light on the evolution of two of the most impressive cases of island gigantism in the world. 1. Introduction New Zealand’s geographic isolation and lack of non-volant mam- mals has led to a unique avifauna but one that suffered an extinction rate of ∼50% following human arrival (Worthy and Holdaway, 2002). Among the most remarkable examples are New Zealand's avian apex predators, Haast's eagle (Hieraaetus moorei; formerly Harpagornis moorei) and Eyles' harrier (Circus teauteensis previously referred to as C. eylesi). Both species have long been recognized as examples of island gigantism and filled ecological niches that are on other landmasses occupied by animals such as large cats or canines. Haast’s eagle was the largest known eagle in the world and is estimated to have weighed up to 15 kg, significantly more heavy than the largest extant eagle, the harpy (Harpia harpyja) at about 9 kg (Worthy and Holdaway, 2002). Haast’s eagle remains have so far only been found in the South Island of New Zealand. As an adaptation to the mostly forested New Zealand en- vironment prior to human arrival, its wings were likely broad but with a limited wingspan of about 2.5–3m (Worthy and Holdaway, 2002). Haast’s eagle likely preyed on various large moa species, and adaptation to this previously unoccupied niche is thought to have driven the evolution of the giant body size. Eyles’ harrier was a much lighter bird than Haast’s eagle, but with a weight of ∼3–3.5 kg it was still the largest known harrier in the world. Its wingspan probably reached 2 m. Unlike Haast’s eagle, Eyles’ harrier https://doi.org/10.1016/j.ympev.2019.01.026 Received 3 October 2018; Received in revised form 22 January 2019; Accepted 31 January 2019 ⁎ Corresponding author. E-mail address: michael.knapp@otago.ac.nz (M. Knapp). 1 These authors contributed equally to this work. Molecular Phylogenetics and Evolution 134 (2019) 122–128 Available online 10 February 2019 1055-7903/ © 2019 Elsevier Inc. All rights reserved. T