New research challenges the claim that kiwi and moa are late arrivals from Australia, instead suggesting these iconic New Zealand birds have been important parts of our island’s ecosystems for many millions of years. Discover the amazing history of these wonderful species as well ass the supporting fossil and genetic evidence that is available.
Ancient Roots in Zealandia
New Zealand is a land of birds, many millions of years presence. In fact, the idea that kiwi, and more recently moa, are recent immigrants from Australia upset many New Zealanders who had long seen these birds as such an intrinsic part of their country’s geological and biological history.
It was part of Zealandia, the name given to a territorial mass three times the size of Britain that broke away from Gondwana 85 million years ago. The proto-New Zealand probably teemed with many recognisable animals; among them would have been the endemic silent frogs, the tuatara and an array of invertebrates. Tens of millions of years and countless populations later, a wealth of plant and animal species eventually spread across the area, etching out a dense history within the fossil record as well as in genetic data.
Piecing Together the Past
To work out when species arrived in New Zealand is a labyrinthine problem that needs to be teased apart using a mixture of fossil evidence and genetic dating techniques. Fossils offer important clues to the past as their ability to pass down information over millions of years far exceeds any DNA molecules can. As we look further back in time, the likelihood of finding fossils diminishes and thus genetic studies become vastly important.
The roots of these bird species reach back some 4 million years in New Zealand, where genetic analyses have previously shown that ancients such as the purple swamp hen or pukeko (Porphyrio porphyrio), black stilt or kakī (Himantopus novaezelandiae) and Haast’s eagle (Hieraaetus moorei), among others, descended from open-habitat dwellers travelling across the Tasman Sea from Australia. New Zealand wrens are the primative of all perching birds, and gene studies show that their ancestors split off from its closest relatives 50−60 million years ago. Likewise, the common ancestors of moa and kiwi are thought to have colonized Zealandia independently some 50-60 million years ago.
Conclusion
“However, the evidence is contrary to this; both moa and kiwi are not late immigrants from Australia.” These include species like the iconic Moa — giant flightless birds of which there were at least 12 different types in New Zealand — and which had been a part of NZ’s biological heritage for millions of years, evolving and aside from the malévolence they thought up when it came to surviving over millennia living in harmony within specific ecosystems throughout Zealandia. We celebrate one of the world’s most remarkable avian faunas, and in doing so allow the rest of the natural history story for Aotearoa New Zealand to continue.
