Wind. It's easy to break wind - though it's probably a lot faster than an ostrich.
Illogically an ostrich's top speed is 65 km/h (40 mph), (unless you throw it out of a plane, in which case terminal velocity is around 195 km/h (120 mph). Assuming the former; what else travels at 65kmh?
The Reva! But, you say, the answer isn't transport - well many a car enthusiast would argue that a Reva isn't transport anyway. And they do look easy to break.