The dodo, a flightless bird native to Mauritius, has long captivated the imaginations of scientists and the public alike. Known for its large size and seemingly clumsy appearance, the dodo became a symbol of extinction after its rapid disappearance in the late 17th century following human colonization of its island home. Despite its notoriety, much about the dodo remains shrouded in mystery, with early descriptions based largely on sailors’ accounts rather than scientific observation. Over the centuries, the dodo’s image has been distorted by myths and artistic interpretations, leaving significant gaps in our understanding of its true biology and role in its ecosystem.
Dr. Neil Gostling, an evolutionary biologist with the University of Southampton, is seeking to correct these historical inaccuracies and bring clarity to the dodo’s story. His recent study focuses on re-examining the taxonomy and evolutionary history of the dodo and its closest relatives, including the now-extinct Reunion Island solitaire. By revisiting historical records, analyzing fossil evidence, and applying modern scientific techniques, Dr. Gostling aims to reconstruct the dodo’s place within its ecosystem and provide new insights into its behavior, biology, and the factors that led to its extinction. This Q&A delves into his research, exploring the broader implications for conservation and the field of paleontology.
What motivated you and your team to undertake this review of the dodo and the Rodriguez Solitaire?
That’s an excellent question. We’re at the beginning of a really big project. We’ve been looking for funding, and we have a great project coming up. Hopefully, we’ll be able to share more in the future. Before we can explore the biology of the dodo, one of the most described and written-about birds ever, we need to address some foundational issues.
The dodo has been extensively discussed in both popular literature and the scientific world, but there’s still so much we don’t know about it. The dodo disappeared about 100 years before the rules of taxonomy were finalized and formalized in 1758. It went extinct in 1662, well before the modern classification system was established. This creates half the problem we’re facing now.
In order to consider the biology, relationships, and connections to other members of the pigeon family and wider bird groups, we need to understand what we’re talking about. We’ve gone through 400 years of literature to determine where the dodo fits in because, since it went extinct before Linnaeus, the rules for naming species weren’t set in place.
For every species described in the literature today, there’s a representative specimen housed in a museum, which allows us to know the characteristics associated with that species. However, with the dodo, we’ve had to rely on the accounts of Dutch sailors from a time before science was well-established. While many of these accounts are brilliant, some are more tenuous.
For example, there’s an account of a white dodo and another of something called the Nazarene dodo. The Reunion Island solitaire, which was once thought to be related, isn’t even a pigeonโit’s an ibis, a completely different bird. I believe it’s extinct now. When humans arrived, they brought rats, cats, goats, and pigs, which hunted the local wildlife. We didnโt eat the dodo because it was described as disgusting, fatty, and horrible. We tried it once, but that was it. The pigs and rats ate the eggs, and the cats ate the eggs and chicks. So yeah, it wasnโt great. Then the goats just generally stamped all over everything.
The problem is that the nomenclature up to this point has been entirely based on sailors’ accounts because there were no real specimens. But when the names were formalized, it turns out some of those accounts werenโt very accurate. For example, weโve got the white Dodo, the Nazarene Dodo, which didnโt actually exist. The Dodo itself became a subject of interest in the mid-1800s, nearly 200 years later. There were bones and some bits and pieces, but not much, and it was almost as if the dodo and the solitaire were mythical, like the Phoenix. People just didnโt really understand them.
The reason weโre interested in this is that we want to understand its biology, particularly how the dodo functioned in its ecosystem. We need a formal taxonomic structure in place so we know how it’s related to everything else, and we know what the animal is. Once we understand that, we can hopefullyโthis is the project weโre moving intoโfigure out how it operated and what it did in its ecosystem. The dodo was a major part of its ecosystem because there werenโt any large mammals. For example, thereโs a fig plant called the Calvaria fig, and there are no young treesโall of them are about the same age as when the dodo went extinct. We think the dodo ate the fruits, which then passed through its digestive system and germinated. No dodos, no figs, and thatโs it.
Understanding these animals and their role in their ecosystem, their biology, and their function is crucial. Hopefully, this will help us mitigate further habitat loss and decline, not just in Mauritius, but with other animals as well. The trouble is, when the dodo was discovered in 1598, we were in a pre-scientific world where religion was the primary way we explained the world around us. People didnโt believe they could affect Godโs creation. And by “Godโs creation,” I mean the world as they understood it then. Someone didnโt put quotation marks around that phrase in a newspaper article, so it looked like I, a serious scientist, was talking about it literally. But 400 years ago, we didnโt think we could change something put in place by the Almighty.
Weโve since proved thatโs not the case at all. I think the dodo, as the first animal we recorded as being somewhere and then recorded its disappearance, is an absolute icon for conservation. Even after 400 years, we havenโt changed our behavior, and we need to. We need to tread lightly on the planet because, at the moment, the whole planet is like an island. We donโt have anywhere else to go, and humans really need to figure out what weโre going to do if weโre going to survive.
Can you elaborate on the significance of this correction you’re making in modern zoology? Also, why has it taken so long to even start addressing this correction? It seems like a very basic thing, like fact-checking, right? How has it taken so long?
Okay. I think one of the reasons is that most of the time, I’m working with specimensโtaking fossils, putting them in a CT scanner, and describing them. But thereโs something really interesting, though a bit more esoteric, about nomenclature and taxonomy. The way all of this works and fits together is really beautiful. It underpins everything else. If we don’t have this classification system, we canโt talk about how things relate to other specimens, taxa, or species.
Thatโs the first thingโI think itโs really fascinating. The second thing is, I just think people, in general, arenโt particularly bothered by it. Itโs quite an esoteric issue, just looking at a couple of pigeons because thatโs what they areโthe dodo is a pigeon, and the solitaire is a pigeon. Theyโre the most closely related species to each other. The next closest relative is the Nicobar pigeon, a glossy green, shaggy-feathered pigeon that flies around. We’ve lost this branch with the dodo and the solitaire gone, so weโve grouped them formally into a new group called Rafina, which has a little cross next to it, indicating it’s extinct. Itโs a unique branch on the pigeon lineโthese giant ground doves are gone.
Why hasnโt it been looked at for 400 years?
I just donโt think people thought it was particularly important. Itโs a very specific part of biology. In the case of the dodo, itโs one group thatโs gone extinct, and thatโs that. We specifically focused on it because of the next stage of our project. The dodo is our starting place, and from there, we hope to examine other extinct birds and study their biology and their role in their ecosystems. So the reason we did this is because of what we want to do next. But again, itโs something that needs to be disentangled and explained to understand the biology of this bird in the context of everything else.
In your study, you confirmed that the dodo and the solitaire belong to the Columbidae family, right?
Yes.
What does this tell us about their evolutionary history? What can you deduce from that?
Well, yes. Okay, so they are flighted birds, like any other pigeon. Their appearance and their settling on these islands show that they had no predators. Their loss of flight is a result of this. Island gigantism is something we often see; it can go either way. Very large things become small, and very small things become larger. Itโs all about access to resources. If you’re small, you can’t get a lot of resources; if you’re large, there arenโt enough resources for you. So everything trends to a mean. Small things getting bigger means they can compete with larger things.
On the islands, you’ve got giant tortoises that likely washed ashore, probably rafting, similar to how tortoises reached the Galapagos. So, we see a transition: as these birds made it to the islands, the selective pressure reduced the need for flight but increased the pressure to grow in size. The dodo, for example, had males weighing about 18 kilos and females around 10 or 11 kilos. The solitaire male would have been about 28 kilosโa massive bird.
Taking that a step further, the release hints that the dodo might have been a fast-moving, active bird, which runs contrary to how we typically imagine it.
Well, thatโs the thing. We have people like Lewis Carroll and Alice in Wonderland to thank for that misconception. People didnโt understand what this bird was, and the paintings made by Savary and othersโhis name escapes me right nowโdepict these fat birds. Part of that is because, number one, I donโt believe any of the paintings were made in Mauritius. There are one or two sketches by Dutch sailors that show a much more slender bird. Additionally, any dodos brought back to Europe would have had to endure the long journey from Mauritius, around the southern tip of Africa, and all the way up to Europe. They wouldnโt have been very happy or well-fed, likely surviving on scraps. So they wouldnโt have been the healthiest-looking birds when they arrived, appearing sickly and not at their best.
Thereโs also been a misrepresentation through the artโnot to blame the artists, but they were working with what they had. Another issue is that weโve ignored some Dutch sailors’ journal entries. Not many people in the late 16th and early 17th centuries could write, so anything written down would have been important. From one of the very first missions in the early 1600s, thereโs an entry from a Dutch sailor that says, and I paraphrase: “When the dodo is out in the open, itโs easy to catch because itโs not afraid of anyone, but when it gets in among the trees and rocks, itโs very fast and agile.” Thatโs not how we typically imagine the dodo, but thatโs what was observed.
Interestingly, Iโve had the opportunity to look at some bones as well. Birds walk on their toes, and what looks like a backward knee is actually their ankle. If you stand on your toes, the thigh is buried in the body, the lower leg (the drumstick) comes down to the ankle, and then it goes into a bone called the tibiotarsus, which is all fused together. Thereโs a tendon that runs down this bone to close the toes. When you look at a dodo tibiotarsus, the shaft is about 12 mm in diameter, and the groove where the tendon would run is also about 12 mmโmassive. Itโs the same size as the bone, indicating a very powerful foot. When we look at living birds with a similar ratio of tendon to bone, these are large, fast, climbing, and agile birds.
But people havenโt looked closely at this beforeโtheyโve just relied on the paintings. The dodo is gone, and those images have shaped our perception. So, this is part of the ongoing project to better understand these animals because, as I said, itโs one of the most widely written-about birds, but itโs one of the least well-described.
So, as you mentioned, the dodo is extinct, and the nomenclature aspect is a bit esoteric for most people. Bringing this to today, how does understanding the taxonomy and nomenclature of the dodo contribute to current conservation efforts?
The dodoโs gone, but it was an absolutely key part of its ecosystem, and we donโt know much about it. If we want to understand what happened and move forward with the next stage of our projectโreconstructing it as a living organismโwe need to know about its taxonomy and nomenclature. We need to understand the framework within which it sits to better comprehend its evolution and the shift from being a flying bird to a terrestrial one.
Understanding where the dodo came from and how it fits into the larger picture is crucial. We know about the Nicobar pigeon, but we need to move forward, do the biomechanics, and study this further. Having the basic framework and understanding how theyโre related is essential for placing its biology in the context of the rest of the group, which will allow us to describe it more accurately.
Okay, now going from thereโand this is my last question, somewhat relatedโwhat are the broader implications of your study on the field of paleontology and the debate over how to classify extinct species?
One of the key points is that, in paleontology, a species is often defined by the person describing it. This new specimen is a species, according to that person. As we move further back in time, it becomes more difficult for paleobiologists to get all the information needed to classify things the way we classify living animals or plants today. We donโt have all the characters, so we canโt run them through computer modeling systems to generate the evolutionary trees weโre interested in.
So, the implications for this are that we need to be very clear about what weโre talking about. The problem with the dodo is that over the last 400 years, weโve seen changes in the taxonomic system, new models, and new codes. As these underlying models for classification have changed, along with a lack of information, things have become muddled. In the broader context of paleontology, we have to be very careful about this. We need to ensure that when we name something, we thoroughly review the literature and understand what weโre talking about. We need to go as deep into the literature as is reasonably practical because often, someone has described one specimen here and then described another of the same thing elsewhere, leading to multiple names for the same taxon.
So, itโs about taking your specimens and ensuring that the model youโre using is as accurate and legitimate as possible. This provides a solid basis for understanding what we have.
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