In the novel "Alice's Adventures in Wonderland," released in 1865 by British writer Lewis Carroll, there is a truly strange bird. It suggested running a race by simply circling around to dry their wet bodies. There was no starting signal or rules, and it was a chaotic race where everyone ran and stopped as they wished. This bird is the dodo, which in Portuguese means fool.
The dodo, which lived on Mauritius in the Indian Ocean, disappeared after 1662, less than 100 years after it became known in Europe. Because it did not flee when people approached, it was recklessly slaughtered. When scientists from Canada and Australia analyzed its skull with medical imaging, they found, contrary to expectations, that the dodo did not have lower cognitive abilities than other birds.
◇ Cognitive ability similar to pigeons, sensory system differs
A research team led by Andrew Iwaniuk of the University of Lethbridge in Canada and Vera Weisbecker of Flinders University in Australia analyzed, with computed tomography (CT), the dodo skulls that remain in complete form, one each in the United Kingdom, Denmark and Mauritius. The findings were published on the 5th (local time) in the international journal "Zoological Journal of the Linnean Society."
The Linnean Society is named after Swedish botanist Carl von Linnaeus, known as the "father of taxonomy." In 1766, he gave the dodo the scientific name "Dodus ineptus," cementing its foolish image. The name means "foolish dodo" in Latin. The researchers have now shown that, contrary to Linnaeus' view, the dodo did not have a fool's brain.
CT compiles hundreds of cross-sectional images taken by passing X-rays through from multiple angles to view the interior of the body in three dimensions. The team used CT images of the dodo skull to determine the internal brain structure. The analysis showed that the forebrain, related to cognition and memory, was no different from that of its close relative, the pigeon. In other words, it had intelligence similar to pigeons, which have excellent navigation abilities, enough to find their way home from far away.
Where the dodo differed from pigeons was in the sensory system, especially vision. The optic lobe, the region of the dodo brain that first processes visual information, was abnormally small. This was true even when compared with the Nicobar pigeon, its closest living genetic relative, as well as another extinct bird, the Rodrigues solitaire. The Rodrigues solitaire, endemic to Rodrigues Island east of Madagascar in the Indian Ocean, like the dodo, was a flightless bird.
◇ Avoided competition with reptiles and was active at night
A small optic lobe appears in nocturnal birds such as owls and kiwis. In dark environments, the ability to detect small amounts of light is more important than distinguishing fine details. The researchers suggested that the dodo's small optic lobe may have been related to such sensory changes. They estimated that the dodo may have been active at dawn or dusk, even into the night.
Why, unlike today's pigeons, would the dodo have been active in the dark? The researchers pointed to the giant tortoises that once lived in large numbers on Mauritius. The tortoises, like the dodo, ate fruit and plants. As ectotherms, tortoises' metabolism and muscle movement slow when temperatures drop. The dodo may have avoided competition for food by being active later, when temperatures were lower.
The team inferred that the dodo compensated for reduced vision with its sense of smell and tactile sensation in the beak. The olfactory bulbs, the part of the brain that processes smell, were four times larger than those of the Nicobar pigeon. The dodo was not foolish; it sensed the world differently from what we assume.
The researchers explained that the dodo did not run away when people approached because it was adapted to an isolated environment. As is common among island species without predators, there was simply nothing to fear before humans arrived. The team said the dodo should be imagined not with a foolish image but roaming the dim forests of Mauritius at dusk or dawn, exhibiting intelligence on par with its pigeon relatives today.
A chance is approaching to see with our own eyes whether the dodo was truly nocturnal and how it behaved when it saw people. U.S. bio corporations Colossal Biosciences is pursuing a dodo restoration project. Strictly speaking, it is an effort to modify a modern bird to be more like a dodo.
Colossal scientists decoded DNA information from dodo remains and compared it with that of the Nicobar pigeon, its closest genetic relative, to identify differences. Next, they plan to alter the Nicobar pigeon's genes to match the dodo's form. If cells with edited genes are injected into a surrogate's embryo, a bird with dodo characteristics could be born.
References
Zoological Journal of the Linnean Society (2026), DOI: https://doi.org/10.1093/zoolinnean/zlag123