CT scans of the world's only two known complete dodo skulls suggest the extinct flightless bird had a far sharper sense of smell, a more sensitive beak and a more capable brain than its centuries-old reputation as a lumbering "bird brain" suggests.
The research, led by Sara Citron and Andrew Iwaniuk of the University of Lethbridge in Canada with Vera Weisbecker of Flinders University in Australia and museum researchers in Denmark, scanned the two intact dodo skulls known to survive: one held at the Natural History Museum Denmark, the other at the Oxford University Museum of Natural History. The team digitally reconstructed the space once occupied by the dodo's brain and compared it against endocasts from 36 living pigeon and dove species, the dodo's closest relatives.
The scans pointed to an enlarged olfactory region, the part of the forebrain that processes smell, unusually large compared with the solitaire, the dodo's closest extinct relative, and other pigeons. Combined with evidence of a highly sensitive beak, likely rich in touch-sensitive nerve endings, researchers say the dodo may have relied heavily on smell and touch to locate fallen fruit on the forest floor of its native Mauritius.
Not the dim-witted bird of legend
The skulls also showed unusually small optic lobes, the brain regions that process vision, paired with comparatively large eye sockets, a combination researchers say resembles the sensory setup of owls and other birds adapted to low light. That points to a dodo that may have been active at dawn, dusk or even at night, rather than strictly through the middle of the day.
Perhaps most notable, researchers found no evidence that the dodo's forebrain, the region tied to learning and memory, was disproportionately small for its body size once compared fairly against living pigeons. That undercuts the popular caricature of the dodo as a uniquely stupid animal, an image cemented by cartoonish 17th-century illustrations and its rapid extinction within decades of European sailors reaching Mauritius. The findings were published in the Zoological Journal of the Linnean Society.
There is no evidence that the dodo was any less intelligent than its relatives — and we know that pigeons are pretty smart.
Andrew Iwaniuk, University of Lethbridge
Because so little of the dodo survives beyond scattered skeletal remains and a handful of skulls, researchers say every new specimen examined in this kind of detail meaningfully expands what is known about the bird's biology. The team hopes future scans of other partial dodo remains, along with closer study of the Rodrigues solitaire, will sharpen the emerging picture of a bird that was well adapted to its island home rather than simply doomed by its own dimness.
