By
Published: Saturday, 02 November 2024 at 09:53 AM
As scientists plot to bring back the dodo, Helen Pilcher asks whether we should – and what would happen if we did
If ever there were to be a poster child for extinction, it has to be the dodo. This makes them an obvious choice for de-extinction. Bring back the dodo and axe the adage; give the flightless, ground-dwelling pigeon another shot at existence.
Dodos lived happily in their island paradise of Mauritius for hundreds of thousands of years. They were big, chunky birds, with greyish-brown body feathers, a white tail plume, and a large, curved beak, which they probably used for foraging and defending their territory.
The evolved in an environment that was free of predators, so when 16th century seafarers arrived and started clubbing them to death to make stew, the birds were nonplussed. They weren’t stupid, as if often quipped. They were just naïve.
Settlers later brought rats, pigs and other non-native species, which further compounded the dodo’s misery. They trashed its habitat, ate its eggs and generally out-competed it. The dodo went extinct in 1681.
In 2022, geneticist Beth Shapiro from the UC Santa Cruz, who is a scientific advisor to Colossal Biosciences, decoded the dodo’s genome. Scientists at Colossal are now determining the sequences which they will edit into cells collected from the dodo’s closest living relative, the Nicobar pigeon. Then, just as for the passenger pigeon, the edited cells will be used to create adult birds that create dodo sperm and eggs.
This is not a trivial amount of science, but it’s another great example of how research being done for de-extinction, can trickle down into the conservation space. If scientists can tweak the biology of one bird species so that it can lay the eggs of another – as they are doing for both the dodo and the passenger pigeon projects – then the method could be used to help living, endangered birds.
If this sounds far-fetched, think again. Sperm from the threatened houbara bustard have been grown inside chickens and used to make live houbara chicks.
What would happen if we did bring the dodo back?
Perhaps the biggest challenge for the dodo project, however, will come after the first dodo hatches. Modern pigeons produce a nutrient-dense paste in their crops, which they feed to their newly hatched offspring. Dodos probably did this too, so how to ensure the first dodo squabs are well fed?
Then there’s the question of where they would live. The goal is to reintroduce them to Mauritius, but since the dodo’s demise, the island has lost more than 60% of its native forest cover. The invasive species that saw it off the first-time round are still there, so if dodos were to be released, it would need to be in predator-free enclosures or satellite islands.
Even then, however, the dodo’s ecological impact would still be uncertain, as, like so many other extinct species, no one really studied it before it disappeared.
There’s one last key issue that straddles all de-extinction projects. De-extinction projects are generating insights that are helpful to conservation, but very often, this involves research on wild animals and their cells.
Bringing back the woolly mammoth involves research on elephants. Bringing back the thylacine involves research on other carnivorous marsupials. The passenger pigeon project involves studies of the band-tailed pigeon, and the dodo de-extinction involves the study of the Nicobar pigeon.
So, let’s finish by thinking about the Nicobar pigeon. This is a small, stunning, iridescent bird, hunted for the pet and food trades, and threatened by habitat loss. Although it is listed as ‘near threatened’, numbers are declining. It’s not a laboratory animal, but there are captive populations that could be used for research purposes.
The question, then, is should we be able to ‘use’ one wild species to bring back or help another? And who gets to decide?
For now, these and other ethical conundrums, remain a live issue…whilst the dodo remains ‘as dead as.’
- “99 per cent of the species that have ever lived have gone extinct”: Why life needs extinction and how it can be a force for good
- The Sixth Extinction: what it is, what is causing it – and how many species we are losing
- Humans to blame for 600 bird extinctions – causing untold damage to ecosystems…
Top image by Roelant Savery, Public domain, via Wikimedia Commons