In the wild, ostriches have demonstrated top running speeds of more than 40 mph, according to the National Wildlife Federation. The ostrich is the largest bird in the world and relies on its speed in order to outrun predators.
The average running speed of an ostrich is approximately 30 mph, a speed it is able to maintain for up to 10 miles at a stretch. When threatened or attempting to outrun a predator, the ostrich is capable of reaching even greater speeds. While lions and cheetahs are capable of achieving greater speeds over short distances, ostriches are the fastest two-legged animals in the world.