Predator-Prey

What does this Model Represent?

This model represents the populations of predators and prey in a hypothetical ecosystem. In nature, the populations of each species do not remain constant over time; rather, they fluctuate and affect one another. In equilibrium, the populations are stable over time because the cycle tends to be self-sustaining.

What are the elements of this Model?

This model includes the population of predators and prey. Both populations are born and die according to certain constants as well as in relation to one another. For instance, predators eat prey, but if there is not enough prey, the predators begin to die off.

How do I use this Model?

Set the values for the birth and death proportionality constants for predators and prey, and then run the model. The results will be displayed over time on the top graph, and the two populations will be displayed in relation to one another on the bottom graph.

What should I expect?

In the absence of predators, the population of prey will rapidly explode; however, this causes the predator population to increase. This in turn reduces the quantity of prey, which reduces the number of predators, and so on in a cycle. The bottom graph displays this cycle even more clearly by showing how the relative populations of predators and prey make an oval from cycle to cycle.

Download the model file.