科學一刻 捕獵越多，天敵越少

　　In the most plentiful prey regions of Africa, lions are much less populous than you'd expect.

　　Prey Tell

　　Where would you expect to find the most predators—where there’s more prey, or less prey?

　　According to a study by scientists at McGill University, areas with more prey do in fact have more predators overall than areas with relatively sparse prey. But lots of prey does not result in as many predators as you’d think. In fact, in the most plentiful prey regions of Africa, lions are much less populous than you’d expect.

　　Herd Mentality

　　If there’s more to eat, you’d expect predators to thrive and have more offspring. But it also turns out that when there’s a lot of prey animals crowded into an area, the prey tend to have fewer offspring per individual, which in turn seems to limit the number of predators.

　　Perhaps that’s because predators tend to prey on the youngest and weakest members of a herd.

　　In any case, this discovery may have revealed not only a curious phenomenon but a full blown law of nature. There’s still lots to learn about exactly how and why the prey–predator relationship works the way it does, but this study has gotten things off to an intriguing start.