More proof... In the 1930s this guy chased ostriches in a vehicle for more than 2 hours at speeds up to 70mph...
"Ostrich Running 70 Miles an Hour Bulldogged from Auto."
The Science News-Letter, Vol. 20, No. 536 (Jul. 18, 1931), p. 45
"...After two days of preparation, we started out on the chase. For eight days we just looked for ostriches. Finally we caught sight of a small group of four ostriches, through our telescopes."
"And now the real chase began, at a speed of 115 kilometers [71 miles] an hour. The ground which harbors the Syrian ostrich is so unevenly bumpy that we were constantly in danger of overturning in our overpacked and over-loaded machines. Besides Sheikh Medjhem and Sheikh Chalid, a number of simple tribesmen, who were considered the best shots, accompanied us."
"Fortunately the ostrich always runs in a straight line, but he must be attacked from the flank, because the stones he throws behind him in running fly with such force that the glass windshields of automobiles cannot withstand them. After a wild and bitter chase that lasted over two hours, we managed to get near enough to shoot at one of the ostriches, which, however, made its escape into the mountains, where no auto could follow it. A second ostrich was killed, but we left it lying where it was, so that we could pick it up on our way back..."