(CNN) – You may have thought Big Bird would be unrealistically gigantic, but he's still not the biggest bird that ever lived on Earth. This honor applies to the elephant birds that were three meters tall at the foot of Madagascar thousands of years ago.
For reference, the "Big Bird" Sesame Street at 8 feet, 2 inches.
New research indicates that the giant is flightless Birds that died out 500 to 1,000 years ago were also nocturnal and blind. An analysis of two elephant skulls of two species was published on Tuesday in the journal Proceedings of the Royal Society B.
"Almost 500 years ago, nearly blind, giant flightless birds plummeted around the forests of Madagascar in western Madagascar, nobody expected," said Julia Clarke, co-author of the University of Texas Jackson School of Geosciences.
It has been believed that these birds resemble emus and ostriches; They are also large, flightless birds, but they are active during the day and have good eyesight. However, this new research highlights that elephant birds are closer to kiwis ̵
Since bird skulls fit tightly around their brains, the shape of the skull correlates with the structures of the brain. Brain reconstruction studies on elephant birds have shown that their optical eyes, the nerves that control vision, were incredibly small and almost non-existent. This is very similar to the kiwi.
"The most surprising thing was how small the eyeballs of the elephant bird were," said Christopher Torres, co-author of the study and Ph.D. Candidate at the University of Texas at Austin. "The few studies that speculated on what their behavior looked like explicitly stated that they were active during the day, and once we had established the connection to night activity, we were overwhelmed, which meant the elephant's attempts to kill the elephant Reconstruct more than a century of revise lifestyle. "
How did elephant birds become nocturnal?
"A nocturnal lifestyle is often an evolutionary reaction, either when it's too dangerous to come out during the day or when something is eaten at night," Torres said
But elephant birds had no known predators and were herbivores.
In this case, night activity is likely to be an ancestral trait shared by elephant birds and kiwis. And sometimes, competition between species can lead to extreme developments.
The researchers identified a pattern in which these birds go through a nocturnal phase, which is caused by photosensitivity, which allows them to see in low light conditions, said Torres. In flightless birds their vision is reduced, and they rely on other senses.
They also looked at the larger group of birds, including ostriches, emus, cassowaries, rhesis, kiwi, moa, and tinamous, which had a connection between the development "19659003" species in this group that live in forests seem relying on a well-developed sense of smell that helps them look for conditions in which visual stimuli could be obstructed, "Torres said.
The next mystery concerns the extinction of elephant birds and remains unresolved, but scientists have indications Hunting and destruction of human habitat and climate change.
At that time, Madagascar's climate was still changing, and man had not reached the point where he could affect global climate change.  "Recent Studies have shown that elephant birds have survived contact with humans for many thousands of years, based on tool marks, d They were observed in radiometrically dated remains, "Torres said.
And knowing that elephant birds were nocturnal also explains why this was possible to co-exist so long with humans. Other birds were not so lucky. The Moa, nine species of flightless birds, apparently disappeared within a few centuries after humans made it to New Zealand, he said.
Torres wants to look closely at the strange evolutionary stories of living things like elephants birds.
"The study of brain shape is a really useful way to connect ecology – the relationship between the bird and the environment – and the anatomy," said Torres. "Discoveries such as these give us tremendous insights into the lives of these bizarre and poorly understood birds."