TIMED RUNNING SPEED OF A CHEETAH (ACINONYX-JUBATUS)

The cheetah is generally believed to be the fastest running animal, bu t its maximum speed has been uncertain. A widely-quoted speed of 71 mi les per hour (32 m s(-1)) has been discredited: a tame animal was clai med to have run 80 yards (73 m) in 2.25 s, but the enclosure in which the run was made was later shown to be only 65 yards (59 m) long (Hild ebrand, 1959, who also remarks that the time is very imprecise, and th at there is an error of arithmetic). Hildebrand's own (1961) estimate of 56 miles per hour (25 m s(-1)) does not come from a timed run over a measured distance, but was obtained by analysing film, taking the sc ale of distance from an estimated length of the animal's body. The mea surements reported in this paper were made in 1965, but are published only now because the author was not aware that previously published re cords were unreliable.