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Hank: The animal kingdom is full of all sorts of weirdos and evolutionary outliers, but with their long necks, huge judgy eyes, and beautiful eyelashes, ostriches are probably some of the oddest. They also happen to be incredibly well adapted to life as a huge lumbering ball of feathers. Ostriches are part of the group of large flightless birds called ratites which includes birds like emus and rheas and cassowaries and the now extinct moas. These birds probably all evolved from a common ancestor, but one that could fly, then once their flying ancestors dispersed they evolved flightlessness independently. And it makes sense that lots of different birds would evolve flightlessness because flying takes a lot of energy.

So not flying is an advantage for birds as long as they can avoid being eaten while they're stuck on the ground. To make up for it they tend to evolve other adaptations to keep themselves safe, which is probably why ostriches are the fastest creatures to run on two legs. This may come as a bit of a shock considering, let's face it, they look as awkward and gangly as a herd of animated dust mops stranded in the middle of a desert. But it turns out that their bodies are basically made to run. Seriously these guys could run a marathon in like 45 minutes. Ostriches can sprint through their native African savannas at nearly 70 KM/h and sustain speeds of over 50 KM/h for longer periods of time, which is how they outrun many of their natural predators.

To help propel themselves forward they walk on their tip toes because each of their two-toed feet has what's essentially a snaggle claw. An extra large talon that gives them great traction. And you don't want to be on the wrong side of that claw because it also happens to work well as a defensive weapon. For an ostrich though, running fast is about more than just toenails, they also have long, lean legs, massive thigh muscles, stable leg joints, and elastic tendons. All those things combine to give them a springy energy efficient step. But ostriches need to be able to do more than just outrun predators, they also need to be able to see them, and boy, do they have the eyes for it.

These birds have bigger eyes than any other vertebrates that live on land. Not compared to their body size - bigger than any vertebrate, we're talking bigger than an elephant's eyes. An ostrich's eyes are bigger than it's brain. And unlike most birds, ostrich eyes are rimmed with long, luxurious lashes. They are not hair though, they're made of short primitive feathers that help shade the bird's eyes from sunlight and protect them from flying sand. But ostriches break records with more than just their eyes. They're also the largest living birds on earth - growing up to two and a half meters tall, sometimes weighing more than 150 kg. Their size helps them store energy and water, but can also make it tough for them to cool off when it gets too hot.

For that they have their messy looking body feathers. They may not be as sleek as the aerodynamic coats of other birds, but the fluffiness helps keep the birds cool. Ostriches can fan out these loose feathers, airing out the skin. So that's what ostriches do when they get hot, but what about when they get scared? Well I can tell you what they don't do, which is bury their heads in the sand. It might sometimes look like they're doing that, but they just have tiny heads compared to the rest of their bodies which are hard to see from a distance. Especially if the bird is like foraging on the ground or nudging eggs around a nest in the dirt. Predator wary ostriches may also lie low and stretch their necks against the ground to minimize their silhouette and try to look more like a clump of earth, rather than a tasty meal.

At some point humans probably saw ostriches doing one of these things and started spreading the idea that these big birds are dumb enough to bury their heads to hide from bad news, which is just not something birds do. It is only something that people do. Thank you for watching this episode of SciShow, and thank you especially to our President of Space, SR Foxley and other Patreon patrons like Alexandra James who help us clear the good names of ostriches everywhere. If you want to help us out you can go to Patreon.com/SciShow, and if you want to keep getting smarter with us you can go to YouTube.com/SciShow and subscribe.

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