A new study from researchers at McGill University in Canada has potentially identified a basic, new “law of nature”. Based on their research on lions and hyenas in Africa, when prey are plentiful, there are relatively fewer predators. Moreover, an examination of ecosystems around the world shows that this pattern could in fact be a fundamental law of nature.
The new research was published in the academic journal Science earlier this week.
Details on the new lion study
Ian Hatton, the McGill University wildlife biologist who led the new study, says it seems perfectly reasonable to expect populations of lions, leopards and hyenas to increase proportionately when there are plentiful zebras and antelopes in the environment for them to hunt and eat.
“If you double the prey, you should double the predators,” Hatton noted. “And we found that this was not the case.”
Hatton and his team conducted the study as his PhD project under Prof. Michel Lareau, currently employed by the Centre national de la recherche scientifique in France. The study examined the populations of prey species including zebras and antelopes and predator species such as lions and hyenas in parks and game reserves in Africa with various different climates and environments. The data showed that as that as the number of prey animals increased, the relative number of predators decreased at a predictable rate. The conclusion to be drawn is predator populations grow much more slowly than prey populations. In fact, the growth of predator populations matched a well-known mathematical pattern known as a power law.
This new research means that there are organizational structures in ecosystems that have not been recognized to date. Biologists have been aware of quite regular mathematical laws controlling functions in the body such as metabolism and growth, but no study has ever shown that similar “laws” govern the development of global ecosystem. A number of well-known academics have already suggested that this discovery could be called a new law of nature.
What makes the new study so impressive is the surprising consistency in the relation of predators to prey across all environments, and offers irrefutable proof that instead of the numbers of predators increasing to match available prey in an area, the populations of predators are actually limited by the growth rate of prey populations. “We kept being astonished,” commented Kevin McCann, of Guelph University’s Department of Integrated Biology, a co-author of the study. “This is just an amazing pattern.”