One would think that the more prey animals–zebras, antelopes, rabbits, etc.–there are, the more predators there would be, since a larger food supply should support a larger population of animals that eat them. But it doesn’t work that way. According to a new study, predator populations decrease when the prey increases. In fact, this seems to be the case with all animal populations, including herbivores whose “prey” is particular kinds of plants. And the ratios can be described with a specific mathematical formula, suggesting that this discovery constitutes a new law of nature.
Now the obvious layman’s question is whether the causes might be reversed, that a decline in the number of predators allows for a greater population of prey, but apparently this is considered to be a different effect having to do with the fact that predators breed more slowly in more crowded environments. [Read more…]