The fastest land animal on Earth depends on more than speed to catch its prey. In order to successfully hunt, cheetahs need to be able to slam on the brakes and turn quickly, according to new research. One of the first efforts to capture the biomechanics of how animals hunt in the wild, the study pushes the limits of how researchers monitor animals.
“It’s going to allow us for the first time to understand what any species is doing in its stride-by-stride activity,” said David Carrier, a comparative biomechanist at the University of Utah in Salt Lake City who was not involved in the work. “This is a big step forward in terms of understanding what animals do in the real world.”
Captive cheetahs have been clocked at more than 62 mph, as fast as many cars on the highway. But how do they perform on African savannas? To find out, biomechanist Alan Wilson of the Royal Veterinary College in London and his colleagues spent 10 years perfecting a radio collar equipped with GPS, as well as gyroscopes, magnetometers, and accelerometers for detecting when a cheetah speeds up, slows down, or turns. The collars incorporated solar batteries, as well as a nonrechargeable backup battery, and, for part of the experiment, were programmed to turn on only when a cheetah started to run during times of the day when it was known to hunt.
When activated, the collar records the animal’s position, velocity, and direction it’s heading up to 300 times a second and relays that data via radio signals to the researchers. Three female and two male cheetahs wore these collars for 18 months, during which 367 hunting “runs” were recorded.
Wilson says that he was surprised how slowly cheetahs went during a hunting run, for example. The fastest hit 66 mph, but much of the time the animals topped out at about 60 percent that speed and maintained that pace for just 1 or 2 seconds as they ran down impala. Instead, hunting success depended on the cheetah’s ability to outmaneuver the prey. By slowing down by 9 mph in a single stride, the cat could reach its target and then quickly decrease its speed to make sharp turns. The rate of speed up and slow down was double that of polo horses, and they accelerated with four times the power of the fastest human sprinters, Wilson and his colleagues reported in Nature.