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 pigeon—it’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 didn’t 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 wasn’t 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 weren’t very accurate. For example, we’ve got the white Dodo, the Nazarene Dodo, which didn’t 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 didn’t really understand them.
The reason we’re 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 hopefully—this is the project we’re moving into—figure out how it operated and what it did in its ecosystem. The dodo was a major part of its ecosystem because there weren’t any large mammals. For example, there’s a fig plant called the Calvaria fig, and there are no young trees—all 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 that’s 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 didn’t believe they could affect God’s creation. And by “God’s creation,” I mean the world as they understood it then. Someone didn’t 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 didn’t think we could change something put in place by the Almighty.
We’ve since proved that’s 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 haven’t 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 don’t have anywhere else to go, and humans really need to figure out what we’re going to do if we’re 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 specimens—taking fossils, putting them in a CT scanner, and describing them. But there’s 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 can’t talk about how things relate to other specimens, taxa, or species.
That’s the first thing—I think it’s really fascinating. The second thing is, I just think people, in general, aren’t particularly bothered by it. It’s quite an esoteric issue, just looking at a couple of pigeons because that’s what they are—the dodo is a pigeon, and the solitaire is a pigeon. They’re 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 we’ve grouped them formally into a new group called Rafina, which has a little cross next to it, indicating it’s extinct. It’s a unique branch on the pigeon line—these giant ground doves are gone.
Why hasn’t it been looked at for 400 years?
I just don’t think people thought it was particularly important. It’s a very specific part of biology. In the case of the dodo, it’s one group that’s gone extinct, and that’s 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, it’s 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. It’s all about access to resources. If you’re small, you can’t get a lot of resources; if you’re large, there aren’t 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 kilos—a 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, that’s the thing. We have people like Lewis Carroll and Alice in Wonderland to thank for that misconception. People didn’t understand what this bird was, and the paintings made by Savary and others—his name escapes me right now—depict these fat birds. Part of that is because, number one, I don’t 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 wouldn’t have been very happy or well-fed, likely surviving on scraps. So they wouldn’t have been the healthiest-looking birds when they arrived, appearing sickly and not at their best.
There’s also been a misrepresentation through the art—not to blame the artists, but they were working with what they had. Another issue is that we’ve 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, there’s an entry from a Dutch sailor that says, and I paraphrase: “When the dodo is out in the open, it’s easy to catch because it’s not afraid of anyone, but when it gets in among the trees and rocks, it’s very fast and agile.” That’s not how we typically imagine the dodo, but that’s what was observed.
Interestingly, I’ve 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. There’s 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 mm—massive. It’s 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 haven’t looked closely at this before—they’ve 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, it’s one of the most widely written-about birds, but it’s 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 dodo’s gone, but it was an absolutely key part of its ecosystem, and we don’t know much about it. If we want to understand what happened and move forward with the next stage of our project—reconstructing it as a living organism—we 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 they’re 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 there—and this is my last question, somewhat related—what 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 don’t have all the characters, so we can’t run them through computer modeling systems to generate the evolutionary trees we’re interested in.
So, the implications for this are that we need to be very clear about what we’re talking about. The problem with the dodo is that over the last 400 years, we’ve 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 we’re 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, it’s about taking your specimens and ensuring that the model you’re using is as accurate and legitimate as possible. This provides a solid basis for understanding what we have.
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