This basic model of interacting predators and prey reveals the tension between population growth and decline, and shows the kind of cycling that characterizes predator–prey systems. It has, however, a number of simplifying assumptions that can be relaxed in more detailed studies, including the following:
- The predator lives only on this prey, and perishes without it.
- The prey has no carrying capacity of its own—only that imposed by the predator.
- The environment is homogeneous and prey have no hiding places.
- Growth is continuous, with no age structure, maturation periods, and so forth.
- The number of prey taken is proportional to the number of prey present. In other words, predators are never satiated.
- Genetics are uniform within each species, and there is no evolution.
Relaxing all of these assumptions is a book in itself, but we will relax some of them in sections ahead.