Islands grow strange animals. Isolated from the rest of the world, these ecosystems often produce beings that are unique to…
Islands grow strange animals. Isolated from the rest of the world, these ecosystems often produce beings that are unique to their idiosyncratic environments. Nations like Madagascar and New Zealand can thus support strikingly similar lives despite different climates.
So while most of the world have birds that are mainly dependent on vision, Madagascar and New Zealand have a few strange additions. Or in some cases had .
Although the phrase “elephant bird” probably produces images of an emu or ostrich, a new study published in the Society of the Royal Society B suggests that these extinct giants had more in common with kiwi. Both were volatile and, according to the new research, were mostly blind and nightly. This fits into how you might think of a kiwi. They are diminutive, with small fluffy brown feathers and incredibly large eggs in comparison to their bodies ̵
1; you can even call them stupid. The fact that they barely can see and wander around New Zealand’s bushes at night looking for grubs jives with their image.
But elephant birds were huge. Standing 10 meters tall and weighing in half a ton – it’s more than two SUVs – it was the world’s largest birds ever . Imagine Big Bird, but make him more than two meters longer and make him more reptilian, then keep him in a tight woodland at night, walk around blindly. That was what elephants were. (A species of elephant birds is literally named for the Malagasy word for “big bird.”)
Most of this is a revelatory revelation. Fossils from this extinct family are rare, and it was not until scientists at the University of Texas in Austin digitally reconstructed brains from two elephant bird skulls that they realized that the birds might have been the most blind. They came to this conclusion by looking at the olfactory bulbs and optic lobes, where smells and images are processed respectively, and finds that the balance was harmless compared to your average bird. Most bird species are primarily dependent on the vision of navigating and chasing bytes, so their optical lobes are well developed in comparison to their olfactory lamps. This also applies to nocturnal species. Owls chase at night, and their evolutionary strategy has been to increase their night vision capabilities to see in the dark.
However, elephant birds, like kiwi, have much more odor bulbs in proportion to their optical lobes, which indicates that they depend more on odor than on sight. In fact, they have virtually no optical lobes. This means that the birds would have been almost blind.
Although the thought of a huge bird that crashes in the underbrush is quite hilarious, the odds are that these behemots had no trouble navigating the forest. As the authors of this new document point out, some wild kiwi are completely blind but have no reduction in their overall skill. They have as complex somatosensory, olfactory and auditory systems as they can get around perfectly in the dark, much like bats (except son’s sons). The researchers suspect that elephant birds may not have been entirely the evolutionary essays of kiwis, but were obviously well adapted enough to survive. Elephant birds even managed to hold on to the early human settlement of Madagascar, a performance that many birds who are native to islands like New Zealand’s moa fail to achieve. Some combinations of human intervention and food loss seem to have slaughtered them in the late 1700s, although none are completely safe.
Nevertheless, no one had ever suspected that a large bird would be blind. We have quite a lot to learn.
This discovery will help researchers figure out the evolutionary tree that raised kiwi, elephant birds, emus, cassowaries, moas, rheas and tinamous (a family of birds living in Mexico and Central and South America). The group, Palaeognathae is the sister blade of all other living birds, making them useful tools to understand how all birds came.
They are also just odd. “Palaeognath evolution has been characterized by repeated gains of gigantism, airlessness, island demos and crepuscularity / nocturnality,” notes the authors. They continue to explain that losing sight of olfaction can be a feature available only for terrestrial birds on predatory islands, as “only volatile nightly birds on islands are known to reduce the visual system for the benefit of other senses.” Without large mammals or reptiles around to eat them, birds could develop to feel their change in other ways – without worrying about having to discover a potential predator.
However, we still know very little if this huge weirdos and scientists hope their discoveries will stimulate more investigation of several species of elephant bird. Who knows what surprises can trick under all these springs.