An article published in the journal “Proceedings of the Royal Society B: Biological Sciences” describes a digital reconstruction of the brain of two species belonging to the family of what are called elephant birds. Christopher Torres of the University of Texas at Austin and his colleague Julia Clarke subjected skulls belonging to the species Aepyornis maximus and Aepyornis hildebrandti to CT scans to analyze the structure of their brains concluding that they were nocturnal and perhaps blind animals.
Elephant birds are those belonging to the Aepyornithidae family. Today they’re extinct but centuries ago they were widespread in Madagascar in various species that became extinct over time, perhaps also because of human activities. The nickname perhaps derives from a description by Marco Polo, who mentioned giant birds seen in Madagascar.
Today there are few descriptions of elephant birds and their remains and we know very little about them. In the case of the genus Aepyornis there were also various discussions over time concerning the exact number of species that existed within it and their classification could change again. The authors of this research considered valid the existence of the species Aepyornis maximus and Aepyornis hildebrandti.
They were flightless birds and scientists generally believed that their behavior was similar to those of other large birds such as emus and ostriches. Christopher Torres and Julia Clarke tried to study the structure of the brains of two species that could even exceed 3 meters in height, Aepyornis maximus and Aepyornis hildebrandti.
Bird skulls are an excellent object of study because they wrap tightly around their brains with the consequence that the bone curves reproduce the brain structure. The ones examined in this research showed that the optic lobe was very small and almost absent in the species Aepyornis maximus, similar in particular to that of the kiwi, which is a much smaller bird and is practically blind.
On the contrary, the olfactory bulb, the part of the brain that processes the sense of smell, was large in Aepyornis maximus. It’s a feature typical of animals living in forests. Aepyornis hildebrandti had a smaller olfactory bulb and this suggests that it lived on grasslands and was perhaps more active at dusk than at night.
These results are surprising and can help reconstruct Madagascar’s ecological history. Not many centuries have passed since elephant birds lived in an environment that has changed and it would be useful to understand how much influence human activities had to provide more information to better predict future changes.
