Genetic breakthrough paves the way for the return of the dodo bird

Colossal Biosciences says it has cleared a major hurdle toward bring the dodo bird back from extinction. The dodo was a large, flightless island bird known for its rounded body, sturdy legs, and calm behavior around humans.

The team reports growing pigeon reproductive cells and preparing gene-edited chickens to carry them, with the goal of releasing flocks within five to seven years.

The scale is ambitious. The plan is to build enough healthy birds to survive in the wild while avoiding the mistakes that erased the species once before.

How the dodo bird can return

The work was led by Anna Keyte, Ph.D., at Colossal Biosciences. Her research focuses on avian genome engineering and reproductive technologies.

Scientists are starting this resurrection process with primordial germ cells – the embryonic precursors of sperm and eggs – which can be collected and expanded in the lab. In birds, these cells can be transplanted into embryos so that the host later makes donor sperm or eggs.

Engineers then edit DNA so the offspring match dodo traits, including body and head shape, a bundle of features biologists call the phenotype, the observable result of genes and environment. Nicobar pigeons supply the starting template because they are the closest living relatives known.

Chickens serve as the surrogate host – a substitute animal that carries another species’ reproductive cells. Colossal says it has produced chickens engineered to accept pigeon germ cells and pass them on to their offspring.

Bird cloning is not practical because bird embryos develop inside hard to access eggs. That is why germ cell transfer pairs with CRISPR to make precise edits that pass to offspring. Genome.gov

Genetic analysis places the Nicobar pigeon near the dodo on the pigeon family tree. That closeness makes it easier to edit specific sites so a hatchling develops dodo-like features instead of pigeon features.

What the new data did

A new study describes how researchers kept pigeon germ cells dividing for months, then showed those cells can migrate to the gonads of both pigeons and chickens.

The team also reports a recipe that adjusts insulin, adds insulin like growth factor and epidermal growth factor, and limits signals that push cells to mature too soon.

One finding centered on the retinoic acid receptor, a protein switch that turns on genes when it senses vitamin A derivatives.

Blocking this switch, while keeping vitamin A available for other needs, helped the cells keep multiplying without losing their identity.

The group also saw a boost from pleiotrophin – a growth factor protein that can spur cell division at low doses. Under those conditions, cultures expanded with a doubling time of roughly 35 hours.

Researchers confirmed identity by checking for well known germ cell markers in culture. They then injected labeled cells into embryos and tracked the cells as they homed to the future testes or ovaries. 

The recipe matters because birds differ widely in their cell signaling. What worked for chickens did not keep pigeon germ cells healthy over the long term, so the team tuned each ingredient. 

Promises, pitfalls, and Mauritius

One estimate suggests the first releases could occur in five to seven years rather than decades. The same source also noted that teams are already looking for rat free areas in Mauritius where the birds could safely return.

Company scientists emphasize a measured pace. They say the reintroduction will be staged, with ecological monitoring and fail safes so that any harm can be stopped quickly. 

History matters in this story. Museum records note the last confirmed sighting in 1662, and the causes of loss included hunting and invasive animals that raided ground nests. 

Mauritius today has reserves, but predators and competitors remain a threat. Any release will need strong biosecurity, layered measures that keep rats and other nest raiders from gaining a foothold.

What counts as a dodo bird?

Some researchers welcome the technical advance but warn against overpromising. One described the current progress as “some remarkable progress,” and questioned whether the final birds would be authentic dodos or engineered pigeons.

This debate turns on the genomic architecture, the way many genes and their controls interact to produce complex traits. Recreating traits without recreating the original genome raises questions about where to draw the line.

Others raise ethical risk. If the public believes extinct species can be rebuilt, they argue, it could weaken support for habitat protection that living species need right now.

Why this could help living birds

Bird genetics has lagged behind mammal genetics for years, partly because bird eggs are opaque and hard to manipulate.

Reliable culture of germ cells unlocks biobanking, storing living cell lines long term so threatened birds can be rescued later. 

The same toolkit can support the germline, the cells that pass genes to the next generation, by restoring lost variation to tiny populations. That could help island pigeons and doves that are declining today, not only a charismatic bird from the past.

Genetic rescue is not a substitute for habitat protection or invasive species control. It is a tool for cases where breeding alone cannot rebuild healthy variation in time.

Diversity will be essential if birds ever fly free again. Building broad genetic diversity, the range of DNA differences in a population, lowers the risk that a single disease or heat wave wipes out the effort.

Any field plan will need to share decisions openly with local communities. Trust matters as much as technology when people live alongside a returning species.

The study is published in bioRxiv.

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