[ad_1]
For reference, "Sesame Street's" Big Bird stands at 8 feet, 2 inches.
"As recently as 500 years ago, they were flying in the darkness of the forest," said Julia Clarke, study co-author and professor at the University of Texas Jackson School. of Geosciences.
It had been believed that these birds were similar to emus and ostriches; they're also big, flightless birds, but they're active during the day and have good eyesight. But this new research sheds light on the elephant birds as being closer to kiwifruit – also nocturnal with poor vision. Kiwis, which are about the size of chickens, live in New Zealand.
Because bird skulls fit tightly around their brains, the shape of the skull correlates to the structures of the brain. Brain reconstruction research in elephant birds revealed that their optic lobes, the nerves that control eyesight, were incredibly small and almost absent. This is very similar to the kiwi.
"Certainly, the most unlikely was the elephant bird's optic lobes were," said Christopher Torres, a study co-author and Ph.D. candidate at the University of Texas at Austin. "The few studies that have been made to be more effective than ever before." Then, we made the connection to nocturnality, we were blown away. lifestyle. "
So how did elephant birds become nocturnal?
"A nocturnal lifestyle is often an evolutionary one when it's too dangerous to come out during the day when you eat at night," Torres said.
But elephant birds had no known predators and were plant-eaters.
In this case, nocturnality is probably an inherited feature of the ancestor shared by elephant birds and kiwis. And sometimes, competition between species can cause extremes in evolution.
The researchers recognized a pattern in which these phenomena undergo nocturnal phase, caused by a sensitivity to light, that allows them to see in low-light conditions, Torres said. In flightless birds, their visuals are reduced, and they rely on other senses.
They also include ostriches, emus, cassowaries, rheas, kiwifruit, moa and tinamous, in which a relationship between the development of the sense of smell and habitat preference formed.
"Species in this group are likely to be obstructed," Torres said.
The next mystery is about why elephant birds went extinct, and it remains unsolved. But scientists have clues pointing to hunting and habitat destruction by humans, as well as climate change.
At the time, the climate was changing, and humans had not reached the point where they could affect global climate change.
"Recent studies have suggested that elephant birds remain in contact with humans," said Torres said.
And knowing that elephant birds were nocturnal also helps explain why they were able to coexist with humans for so long. Other birds were not so lucky. The moa, nine species of flightless birds, were apparently made in New Zealand, he said.
Going forward, Torres wants to take a look at the strange evolutionary stories of creatures like elephant birds.
"Studying brain shape is a really useful way of connecting ecology – the relationship between the bird and the environment – and anatomy," Torres said. "Discoveries like these give us tremendous insights into the lives of these weird and poorly understood birds."
Source link
