how close are we to the return of this long extinct bird?

US biotech company Colossal Biosciences says it has finally managed to keep pigeon cells alive in the lab long enough to tweak their DNA – a crucial step toward its dream of recreating the dodo.

The firm has grown “primordial germ cells”^[1] (early embryonic cells) from Nicobar pigeons, the dodo’s closest living relative, for weeks at a time. This is an achievement avian geneticists^[2] have chased for more than a decade^[3].

But the breakthrough’s real value lies in its potential to protect wildlife that is still living.

Those cells, once edited, Colossal Bioscience spokespeople say, could be slipped into gene-edited chicken embryos, turning the chickens into surrogate mothers for birds that vanished^[4] more than 300 years ago.

The breakthrough arrived with a bold deadline. Colossal Bioscience’s chief executive, Ben Lamm, said the first neo-dodos could hatch within “five to seven years^[5]”.

He also spoke of a goal to eventually release thousands on predator-free sites in Mauritius, where dodos lived before they became extinct. The promise sent the start-up’s valuation past US $10billion^[6] (£7.4 billion), according to the company’s website.

Almost everything we know about bird gene editing comes from chickens, whose germ cells (cells that develop into sperm or eggs) thrive in standard lab cultures^[7]. Pigeon cells typically die within hours^[8] outside the body.

Colossal Biosciences says it tested more than 300 combinations of growth factors (substances that stimulate cell multiplication) before finding one that works. Now those cells can be loaded with reconstructed stretches of dodo DNA and molecular “switches” that control skull shape, wing size and body mass.

If the edits take, the modified cells will migrate to an early-stage chicken embryo’s developing ovaries or testes so the surrogate lays eggs or produces sperm carrying the tweaked genome.

That process may create a bird that looks like a dodo, but genetics is only half the story. The draft dodo genome was pieced together from museum bones and feathers. Gaps were filled with ordinary pigeon DNA.

Due to the fact it is extinct and cannot be studied we still don’t know much about the genes behind the dodo’s behaviour, metabolism and immune responses. Recreating the known DNA regions letter by letter would require hundreds of separate edits.

The labour involved would be orders of magnitude more than any agricultural breeding or biomedical programme has ever attempted^[9], although it seems that Colossal Biosciences are willing to throw enough money at the problem.

There is also the matter of the chicken surrogate. A chicken egg weighs much less than a dodo egg would have. In museum collections there exists only one example^[11] of a Dodo egg, and that is similar in size to an ostrich egg.

Even if the embryo survived the early stages, it would soon outgrow the chicken eggshell and be forced to hatch before full development – much like a premature baby that needs intensive care. A chick would therefore need round-the-clock care to reach the historical dodo weight of 10–20kg.

Gene-edited “blank-slate” hens have successfully^[12] laid the eggs of rare chicken breeds, showing that germ-cell surrogacy works in principle, but scaling that idea up to a larger, extinct species remains untested.

These caveats are why many biologists prefer the term “functional replacement” to “de-extinction”. What may hatch is a hybrid: mostly Nicobar pigeon, spliced with fragments of dodo DNA, gestated in a chicken.

It might peck and waddle like a dodo and even spread the large fruit seeds that once depended on the original bird. But calling it a resurrection is a marketing exercise rather than science.

The tension between promise and practice has dogged Colossal Bioscience’s earlier projects^[13]. The “dire wolf” puppies unveiled in August 2025^[14] turned out to be grey-wolf clones with a few genetic tweaks. And conservationists have warned^[15] that such announcements tempt society to treat extinction as something that is reversible, meaning it is less urgent to prevent endangered species disappearing.

Even so, the pigeon breakthrough could pay dividends for living species. Roughly one in eight bird species is already threatened with extinction, according to BirdLife International’s 2022 global assessment^[16]. Germ-cell culture offers a way to bank genetic diversity without maintaining huge captive flocks, and eventually to reintroduce that diversity into the wild.

If the technique proves safe in pigeons, it could help rescue critically endangered birds such as the Philippine eagle or Australia’s orange-bellied parrot. The latter’s wild flock now numbers around 70 birds^[17] and dipped to just 16 in 2016^[18].

A spokeswoman for Colossal Biosciences said they remain on track with their scientific milestones but that securing appropriate elephant surrogates and eggs for their woolly mammoth project “involves complex logistics beyond out direct control” and “we prioritise animal welfare throughout, which means we won’t rush critical steps”.

She also said that the firm’s research suggests de-extinction work increases urgency around protecting endangered species. She added: “Critically, we are expanding conservation resources and public engagement, not replacing traditional efforts.

"Our work brings entirely new funding streams into conservation from sources that previously weren’t investing in biodiversity protection. We’ve attracted hundreds of millions in private capital that wouldn’t otherwise go to conservation efforts. Additionally, the genetic tools we develop for de-extinction are already being applied to help endangered species today.”

For Mauritius, any return of dodo-like birds must start with the basics of island conservation. It will be necessary to eradicate rats (which preyed on dodos), control invasive monkeys and restore native forest. Those tasks cost money and need local support but yield immediate benefits for the existing wildlife. Colossal Bioscience must follow through on its commitment to long-term ecological stewardship^[19].

But in the strictest sense, the actual 17th-century dodo is beyond recovery. What the world may see by 2030 is a living experiment, showing how far gene editing has come. The value of that bird will lie not in nostalgia, but in whether it helps us keep today’s species from following the dodo into oblivion.

References

1. ^{^} has grown “primordial germ cells” (www.theguardian.com)
2. ^{^} avian geneticists (pubmed.ncbi.nlm.nih.gov)
3. ^{^} decade (pubmed.ncbi.nlm.nih.gov)
4. ^{^} birds that vanished (theconversation.com)
5. ^{^} five to seven years (www.theguardian.com)
6. ^{^} past US $10billion (colossal.com)
7. ^{^} standard lab cultures (pubmed.ncbi.nlm.nih.gov)
8. ^{^} hours (pmc.ncbi.nlm.nih.gov)
9. ^{^} has ever attempted (pmc.ncbi.nlm.nih.gov)
10. ^{^} Lobachad/Shutterstock (www.shutterstock.com)
11. ^{^} one example (journals.co.za)
12. ^{^} successfully (vet.ed.ac.uk)
13. ^{^} Colossal Bioscience’s earlier projects (theconversation.com)
14. ^{^} unveiled in August 2025 (theconversation.com)
15. ^{^} conservationists have warned (www.vox.com)
16. ^{^} BirdLife International’s 2022 global assessment (datazone.birdlife.org)
17. ^{^} 70 birds (pmc.ncbi.nlm.nih.gov)
18. ^{^} 2016 (pubmed.ncbi.nlm.nih.gov)
19. ^{^} commitment to long-term ecological stewardship (colossal.com)