The dodo has been extinct for more than 300 years, wiped out within decades of humans arriving on its home island of Mauritius, but it lives on in the public imagination.Source: Phys.org
This famous flightless bird has become a symbol of extinction. Its demise is often portrayed as almost inevitable: a supposedly foolish creature that naïvely approached the sailors who killed it.
Early accounts even describe people holding a captured dodo and letting it cry out so others would wander over. In the 18th century, Swedish naturalist Carl Linnaeus dubbed the species Dodus ineptus after its reputation for dim wits and silliness.
But new research shows this image is misleading. The dodo was likely no less intelligent than any modern bird. It may also have possessed a rare and overlooked ecological trait: an adaptation to life in low light.
A closer look inside a vanished bird's head
With a team of collaborators across Canada, Australia, the United States, Europe and the UK, our new study looked in detail at the reconstruction of the dodo's brain.
There are only three completely preserved dodo skulls in existence. Using high-resolution CT scans of all three, we could reconstruct the shape of the dodo skull and get a detailed idea of the size and shape of its brain.
This also allowed us to digitally measure the structures associated with vision, smell and cognition (or "smarts"). These scans can also be shared with the research community.
The dodo was a member of the pigeon family, so its living relatives include the pigeons in our cities and the doves whose calls accompany mornings around the world. Pigeons are famous for their navigational skills and are widely used by scientists to study animal cognition.
Is there any indication that the dodo's brain was much different? When we compared the dodo's brain to that of pigeons, we found that the dodo's forebrain, linked to cognition and memory, was similar in proportion to that of other pigeons when compared to the rest of the brain.
In other words, there is no evidence the dodo was less intelligent than any other pigeon. This is also backed up by previous research suggesting that brain size relative to body mass was similar to that of other pigeons.
So we think the dodo's trusting behavior was because it simply had nothing to fear until humans arrived, as is common for island species with no predators.
A giant pigeon with an unexpected twist
Where the dodo does differ dramatically from other pigeons is in its sensory systems, particularly its vision. The dodo's optic lobes, the brain region that first processes visual information in the bird brain, are unusually small—not just compared to pigeons, but also compared to another extinct flightless relative, the Rodrigues solitaire.
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