The animal kingdom is full of all sorts of weirdos and evolutionary outliers, but with
their long necks, huge, judgey 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, rheas, 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.
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 the desert, but
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 kilometers per
hour, and sustain speeds of over 50 kilometers an hour for longer periods of time, which
is how they outrun many of their natural predators.
To help propel themselves forward, they walk on their tiptoes, because each of their two-toed
feet has what’s essentially a snaggleclaw -- an extra-large talon that gives them great traction.
And you do not 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 the 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 its brain!
And unlike in most birds, ostrich eyes are rimmed with long, luxurious lashes.
They’re 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 and sometimes weighing more than 150 kilograms.
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 their 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 are, 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 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’s only something that people do.
Thanks 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.
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