They have long legs and large thigh muscles. Also, their long necks make it easy to balance whilst running quickly, similar to a tail in other animals.
So it can escape from predators!
No It can run fast but not as fast as an Adult.
Running birds e.g. Ostrich can run fast comparable to horse in a desert .
Ostriches run fast because of 'springy' tendons
an Ostrich's defence is to run fast, an ostrich can run up to 50mph so it can escape its enemy. and another defence is to peck and hit the enemy with it's long beak.
Ostrich
Ostrich and Emu.
Ostrich
Gentoo Penguin
An ostrich can run 40mph and sustain 30mph.
I think why they can run fast is something to do with their feathers.
the ostrich has long legs and stream like feathers