Even domesticated cats seem to behave in this manner. After eying prey, they may slink to position themselves in an optimal way before pouncing, but then tend to walk away if their initial approach is unsuccessful. Hunting requires a lot of energy. In the wild, conserving such energy can be a life or death matter for predators.
Animal experts have often wondered why lions rarely go after impalas. In addition to finding that impalas are actually more athletic than lions, the researchers' computer simulations determined that impalas can usually escape lion pursuits. The findings help to explain why lions catch impalas opportunistically rather than in open pursuits.
Not all predators, however, suffer from endurance problems.
"Wolves, fox hounds, and deer hounds are reported to be endurance hunters," Wilson said.
Nevertheless, there are many instances of zebras and impalas outwitting predators like wolves with unpredictable moves. It would seem that having a lower fight-or-flight response should benefit prey that are still fit and athletic.
Wilson said that is possible, "but there is the counter argument that being too far away to chase is an even better strategy, hence vigilance and detecting a predator that is looking to hunt is important."
The findings could help wildlife conservationists to better determine how animals hunt, what terrain is preferable for both predators and prey, and other key information affecting the animals' survival. Both lions and cheetahs are considered to be "vulnerable" and threatened with extinction, given that their populations have declined over the years. Loss of habitat, lack of prey and their vulnerability to poachers are just some of the human threats they face.
Wilson said that the new study "would be of help in reintroducing animals" to their known habitats.
RELATED: An Animal's Top Speed Is Determined by Its Size, New Equation Reveals
A glitch during the research is that the collars were all supposed to drop off when programed to do so. A few did not, forcing the researchers to re-dart the animals and remove the collars by hand.
"It is an issue with a mechanical unit in a hot, dusty, wet environment," Wilson said, admitting that the commercial drop-off units "are very expensive and their reliability is not very good. It is the only part of the collar we don't design ourselves."
This problem did not affect the findings, though. While the collars look to have been rather large and unwieldy, the researchers performed tests prior to the study to determine what device weights and sizes the animals could tolerate without effecting their normal behaviors.
As for how humans fit into the picture, the jury is out concerning whether our early ancestors were more predators or prey. There is some fossil evidence that early humans were regularly hunted by saber-toothed cats, hyenas, and other large carnivores. It is unclear, however, if these predators merely scavenged early human remains.
On the other hand, Wilson said that additional evidence points to humans "evolving to be endurance hunters."