Why ostriches run so much faster than us
Scientists have discovered how ostriches are able to run so fast, whilst using relatively little energy.
Like us, ostriches walk (and run) on two legs. But they can reach speeds of up to 50km per hour - about twice the speed of the fastest human.
Researchers at the University of Western Australia carried out a "biomechanical" study of ostriches and humans as they ran on a track. This footage shows the data gathered from markers on their joints.
The study revealed that ostriches have "a spring in their step". The birds generate over twice as much power from recoil of elastic energy stored in tendons than humans, so they need less muscle power to run much faster.