Fastest mammal on land – over long distances

The pronghorn (Antilocapra americana) of North America is the fastest terrestrial mammal when measured steadily over a long distance. These antelope-like ungulates have been observed to travel continuously at 56 kilometres (35 miles) per hour for as far as 6.6 kilometres (4.1 miles). They are found in western USA, south-western Canada and parts of northern Mexico.

Other observations have recorded pronghorns travelling at even faster speeds over shorter distances (though still far longer than the cheetah can keep up its record-breaking sprinting speed). For instance, a paper by D W Kitchen published in the journal Wildlife Monographs in 1974 notes speeds of 64–72 km/h (39.7–44.7 mph) for 3.2 km (1.9 mi). A book by John A Byers (1997; University of Chicago Press) cites 72 km/h (44.7 mph) over 2 km (1.2 mi); another study documents a pronghorn travelling at 67 km/h (42 mph) for 1.6 km (1 mi); while another report still refers to a pronghorn maintaining 88.5 km/h (55 mph) for 0.8 km (0.5 mi).

The more famous cheetah (Acinonyx jubatus) can obtain higher speeds, but only in short bursts for distances up to 500 m (1,640 ft). When measured over a short distance the cheetah can maintain a steady maximum speed of approximately 100 km/h (62 mph) on level ground. However, research completed by Professor Craig Sharp of Brunel University, London, UK, in 1965 recorded accurate speeds of 64.3 mph (29 m/sec or 104.4 km/h) for a 35-kg (77-lb) adult female over a measured distance of 201.2 m (660 ft). Cheetahs are native to the open plains of sub-Saharan Africa, Iran, Turkmenistan and Afghanistan.