I had to laugh when I came across the video clip below. It's taken from a camera car, and shows two participants in the annual Cape Town Cycle Tour trying to get away from an ostrich that appears to be irritated at them. (Ostriches are notoriously short-tempered, particularly if one gets too close to their nest; and they're very well equipped to administer a beating, particularly kicking with their iron-hard claws, which can disembowel their victim and break bones. They're also very territorial, so if you get too close, they're likely to object. Strongly.)
Ostriches can run at up to 30 mph for extended periods, and up to 45 mph in short bursts; and a fully grown adult can weigh as much as or more than the average human being. The cyclists in this video clip were definitely in danger. I'm sure their race time improved measurably as they fled!
(However, ostrich breast makes very good eating, particularly accompanied by scrambled ostrich egg. If a hungry, armed local had been around, and the cameras not, that bird might have ended up on someone's dinner plate.)