Science or sideshow? Race to resurrect giant moa raises questions

The controversial effort to revive New Zealand’s extinct giant moa is moving from theory to technology, but scientists remain divided over whether de-extinction is possible, ethical or even necessary, writes Patrick Drennan.

THE LARGEST BIRD that ever existed, the South Island giant moa, became extinct about 600 years ago. The first humans who arrived in New Zealand in about 1300 CE, the Polynesian islanders who became known as the Māori, devoured the nine species of moa within 200 years of arriving.

On 8 July 2025, American company Colossal Biosciences announced a $US50 million (AU$69.7 million) project to revive the flightless bird through gene editing and surrogate hatching. Backers include the Māori Ngāi Tahu tribe and billionaire filmmaker Peter Jackson.

On 19 May 2026, Colossal announced they had created an artificial egg, a 3D-printed lattice structure, to hatch the moa.

The closest living genetic relative to the giant moa is the South American giant tinamou, although the moa is nine times larger. The moa’s natural egg is about four times the size of a giant tinamou egg — 240mm (9.45 inches) in length, compared to 60mm (2.4 inches) in length.

Colossal plans to fertilise the artificial egg by harnessing the genes from moa bones and matching them with the giant tinamou genome. Artificial embryos are not new, but Colossal says the shell-less incubation platform can carry embryos from early development through to hatching without a biological eggshell or supplemental oxygen. The real issue will be scaling up the process.

Colossal plan: Moa to walk the Earth again by 2033

Backed by Peter Jackson and Māori leaders, a U.S. biotech firm plans to revive the colossal South Island moa – the largest bird that ever lived – within eight years.

Controversy

Several academic critics do not believe Colossal will be able to recreate a real giant moa, but merely a hybrid. While admiring the technology, others, including some local Māori, question the ethics of reintroducing a creature to an overall ecosystem that no longer exists.

On the other hand, New Zealand still has rainforests that contain the plants moa consumed, such as fern spores, flax, tree daisies and southern beech.

Colossal spokesperson Emily Lowe Mailaender advises me that preliminary work will happen in Dallas, Texas, but as the project progresses, incubation will occur in New Zealand. She is confident that the resulting bird, while not the same, will be as close to an original moa as possible.

However, Professor Philip Seddon, of the University of Otago, told me:

‘The creation of an artificial egg is a solution in search of a problem. There is no current genetic engineering pathway that can truly restore a lost species, especially one missing from its ecological and evolutionary context for hundreds of years.’

Many scientists are concerned that the findings have not been published in a peer-reviewed scientific journal.

Nevertheless, geneticist Professor Michael Knapp, also of the University of Otago, declared:

“The innovation is real and the progress is real and it's done with money, which I'm fairly certain would otherwise not have been available for conservation research.”

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Efforts should be made to prevent the extinction of species rather than playing God and trying to bring them back.

Where will the giant moa live?

New Zealand has several large bird sanctuaries surrounded by predator-proof fences. They protect some of the world’s rarest birds, including the kiwi, takahē, and kākāriki — a red-crowned parakeet. In the wild, introduced pests like possums, rats, stoats and feral cats prey on these birds and their eggs, or eat the plants and seeds these creatures need to survive. The existing deep-dug sanctuary fences are not likely to constrain a giant moa.

Colossal claims that their artificial egg membrane is groundbreaking and may be used for many living birds on the edge of extinction. It confronts the problem for modern conservationists of the limited gene pool of these rare birds. This technology could be very helpful for low-breeding species such as kākāpō — the world’s largest parrot.

Still, Professor Seddon contends that averting extinction might be a better application of so-called de-extinction science than trying to recreate long-lost species.

In a television interview, Paul Scofield of Canterbury Museum, a partner of the Colossal project, described the giant moa being kept in a Jurassic Park-style enclosure that people will pay to view. It doesn’t sound like it has much to do with science or conservation, but it certainly stirs the imagination.