The extinct dodo, Raphus cucullatus, well-known for its stupidity that many point to as the reason for its disappearance form the Earth, might have been smarter than we thought, according to a new study by scientists from Stony Brook University.
The large, flightless bird lived on the Mauritius island in the Indian Ocean and was last seen in 1662. The new study reveals that the overall size of the dodo's brain in relation to its body size was roughly equal to that of pigeons, which are its closest living relatives. Given the ability of pigeons to be trained, this implies that the dodo possessed at least an average level of intelligence.
Furthermore, the team discovered that the dodo had an oversized olfactory bulb, which is the part of the brain that deals with smell and is an unusual trait for birds given their tendency to concentrate their brainpower on sight.
"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," Eugenia Gold, lead author of the study, said in a press release. "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."
In order to examine the dodo brain, Gold and her team took a well-reserved dodo skull from London's Natural History Museum and put it through high-resolution computer tomography (CT) scanning. Additionally, she used the same technique on the skulls of seven other pigeons and also examined the reconstructed brain of the Rodrigues solitare, the dodo's closest relative, in order to compare data.
"I digitally filled in its braincase to recreate and endocast of the dodo," Gold said "We also performed a regression of brain volume to body size and found that the dodo has a brain completely in proportion to its body size."
"It's not impressively large or impressively small - it's exactly the size you would predict it to be for its body size," Gold added. "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 findings were published in the Feb. 23 issue of the Zoological Journal of the Linnean Society.
