The number of lions in Africa is dwindling at a worrisome rate, despite prime, favorable conditions for the large cats, including a plentiful food supply.
According to experts, the number of lions in Africa has fallen from an estimated 200,000 in 1995, to less than 23,000 today. Particularly, Western Africa has seen the greatest decline in the population of lions. In fact, the devastation of the lion population has been so severe in Western Africa, that experts believe now that they can only be brought back through a truly radical effort.
So, if there is plenty of food available for the lions to eat in Africa, why are the numbers of lions falling? The truth may be in an unusual law of nature that wasn’t previously known of, or at least thought about.
It seems that even when there is abundant food for larger predators – like lions – to eat, the number of predators does not increase.
A new study, which analyzed data going back 50 years and across over 2,260 ecosystems in 1,512 different land and sea locations worldwide, has determined that just because prey is abundant, the numbers of predators didn’t proportionally increase.
The research study determined that instead of predators rising in number to keep up with – or match – the available prey in an ecosystem, the predator populations are limited by the rate at which the prey reproduce. In an ecosystem in which the prey population is crowded, the less young the prey will produce.
Study author, Ian Hatton, a doctoral student at McGill University, spoke about the predator/prey phenomena.
“Until now, the assumption has been that when there is a lot more prey, you’d expect correspondingly more predators. But as we looked at the numbers, we discovered instead, that in the lushest ecosystems, no matter where they are in the world, the ratio of predators to their prey is greatly reduced. This is because with greater crowding, prey species have fewer offspring for every individual. In effect, the prey’s rates of reproduction are limited, which limits the abundance of predators.”
Kevin McCann, a co-author of the study, said this relationship between predators and prey can be mathematically described by something called a “power scaling law.” This law represents how there will always be fewer predators in a prey-rich environment than in prey-poor ecosystems.
Scientists now believe that understanding this predator and prey relationship in various ecosystems will greatly help conservationists monitor and assist endangered species like the African lion.
[Photo by Cameron Spencer/Getty Images]