The large dodo bird (Raphus cucullatus), which is now long-extinct, has been described as quirky, clumsy, and bumbling. However, it has now been discovered it was actually fairly smart.
The centuries-long reputation of being a stupid flightless bird has just been proven unfounded in a new study from the American Museum of Natural History (AMNH). The study suggests they were likely to have been as smart as modern pigeons, and had a better sense of smell.
The study, which was published in the Zoological Journal of the Linnean Society, discovered that the overall size of the dodo’s brain in relation to its body size was the same as its closest living relatives — pigeons, a bird that has the ability to be trained, which implies a moderate level of intelligence.
It was also found to have an enlarged olfactory bulb; this is the part of the brain that is responsible for smelling. This is an uncharacteristic trait for birds, where most of their brainpower is concentrated on their eyesight.
The dodo lived on the island of Mauritius in the Indian Ocean, and was last seen in 1662. Eugenia Gold, lead author of the paper, a research associate, and recent graduate of the American Museum of Natural History’s Richard Gilder Graduate School, said:
“When the island was discovered in the late 1500s, the dodos living there had no fear of humans and they were herded onto boats, and used as fresh meat for sailors.
“Because of that behavior and invasive species that were introduced to the island, they disappeared in less than 100 years after humans arrived. Today, they are almost exclusively known for becoming extinct, and I think that’s why we’ve given them this reputation of being dumb.”
According to the American Museum of Natural History:
“To examine the brain of the dodo, Gold tracked down a well-preserved skull from the collections of the Natural History Museum, London, and imaged it there with high-resolution computed tomography (CT) scanning.
“In the American Museum of Natural History’s Microscopy and Imaging Facility, she also CT-scanned the skulls of seven species of pigeons — ranging from the common pigeon found on city streets, Columba livia, to more exotic varieties.
“Out of these scans, Gold built virtual brain endocasts to determine the overall brain size as well as the size of various structures. Gold’s colleagues at the Natural History Museum of Denmark and National Museum of Scotland sent her the endocast for the dodo’s closest relative, the extinct island-dwelling bird Rodrigues solitaire (Pezophaps solitaria).”
When the researchers compared the size of the birds’ brains to their body sizes, they found that the dodo was “right on the line.”
Gold said in a statement:
“It’s not impressively large or impressively small — it’s exactly the size you would predict it to be for its body size.
“So if you take brain size as a proxy for intelligence, dodos probably had a similar intelligence level to pigeons. Of course, there’s more to intelligence than just overall brain size, but this gives us a basic measure.”
The study furthermore revealed that the dodo and the Rodrigues solitaire (recently became extinct because of human activity) both had large and distinguished olfactory bulbs. The authors have also suggested, because dodos and solitaires were ground-dwellers, they would have relied on smell to find food.
An unusual curvature of the dodo’s semicircular canal, which is the balance organs located inside the ear, was also discovered, however there are no good hypothesis for this atypical feature.
Co-author Mark Norell, the Macaulay Curator of Paleontology and Chair of the Division of Paleontology at the American Museum of Natural History, said:
“It is really amazing what new technologies can bring to old museum specimens.
“This really underscores the need for the maintenance and growth of natural history collections, because who knows what’s next.”