In the new study, led by Alan Wilson, a professor of locomotor biomechanics at the Royal Veterinary College in London, researchers captured thousands of high-speed runs by fitting five cheetahs, seven impalas, nine lions and seven zebras with custom collars that could record each animal’s location, speed, acceleration, deceleration and turning performance many times per second. They also took tiny muscle biopsies from each animal.
Though cheetahs and impalas were universally more athletic than lions and zebras, both cheetahs and lions had a similar advantage over their prey — they were 38 percent faster, 37 percent better at accelerating, 72 percent better at decelerating and their muscles were 20 percent more powerful.
This makes sense because the predators are always a step behind, Dr. Wilson said. They have to run faster to catch up, but they must also be able to decelerate quickly in case their targets decide to suddenly slow down and turn.
The data also showed that impalas and zebras were typically moving at only half their maximum speed when running from their pursuers. To confirm why, the scientists created a computer model that simulated the last moments of a hunt, after a predator has closed in enough to capture its prey within two strides.
The model showed that impalas and zebras have the best chance of making a getaway if they run at moderate speeds, because that leaves more options for maneuvering away at the last second.
“If you’re running flat out, there’s not much you can do to stop a lion from anticipating exactly where you’re going to be in two strides’ time,” Dr. Wilson said.
Running at a lower speed, however, means an animal can speed up or slow down. It can also make far sharper twists and turns than if it were running at full steam.
The consistent difference in athleticism between the cats and their prey helps maintain balanced numbers of each group in the savanna, Dr. Wilson added. Generally, cheetahs and lions are successful at catching their prey one out of every three hunts.
“This research suggests that these predator-prey pairs have been co-evolving in an evolutionary arms race,” said Talia Yuki Moore, a postdoctoral fellow studying biomechanics at the University of Michigan who did not participate in the study. “One’s trying to eat, and the other’s trying not to get eaten.”