Speed and brakes make the cheetah a champion

Cheetahs are renowned as the fastest things on legs, but just as important as their speed is their ability to brake, enabling them to twist and turn in pursuit of prey, a study published on Wednesday says. British researchers fitted three female and two male cheetahs in Botswana with special collars equipped with GPS, accelerometers and gyroscopes to track their location and movements. The animals were released back into the wild and their activities were archived over the next 17 months, notching up a total of 367 hunts. The top speed recorded during this period was 93 kilometres (58 miles) per hour, just 7 kph (4 mph) off the fastest cheetah ever. It was nearly double the fastest recorded pace set by a human, which was 43.2 kph (27 mph), once reached by Usain Bolt in a 100m race. The cheetahs' average sprint was far lower, though, at 50 kph (31 mph) -- and they sustained this pace for only one or two seconds. Even more impressive was the cheetah's ability to hit the accelerator and then the brake. In a single stride, the animal can speed up by up to three metres (10 feet) per second, or choose to slow by up to four metres (13 feet) by second. This fast-start, sudden-stop ability -- almost double that of polo horses -- is due to the cheetah's remarkable skeleton, which is supplemented by limb and back muscles that account for around 45 percent of its body mass. These are supplemented by ridged footpads and claws that act as cleats, grabbing hold of the ground to provide extra grip for sideways acceleration or deceleration. "We recorded some of the highest measured values for lateral and forward acceleration, deceleration and bodymass-specific power for any terrestrial mammal," says the study, led by Alan Wilson of the Structure and Motion Laboratory at the Royal Veterinary College at the University of London. For all their prowess, the cheetahs still had to work hard for their dinner. Out of 367 hunts, only 94 -- 26 percent -- were successful.