Biosphere Contents

4. Interdependence

If a species is heavily preyed upon its numbers decline and it becomes harder to find, which typically allows its population to stabilise and recover

The simplest interaction that a predator can have with its prey is that it consumes all available prey until none are left, eliminating the species. This is an extreme interaction which will result in the predator itself dying out unless it can find an alternative food source, but what it shows is that predation has an influence on species populations. Most theoretical work on predator-prey relationships has concentrated on the effects that one species has on another in controlled circumstances. This is useful for providing a theoretical framework but it should be noted that in most natural communities food webs are more complex, which each predator having a range of potential prey species and also predators of its own. The result of this is that any one species is rarely preyed upon too heavily because as numbers decrease the prey becomes harder to find. The predator will then seek a more accessible alternative thus allowing the initial species time to recover.

Do predators typically devour all prey?