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Predator Prey

David Zachmann

This applet simulates a predator-prey system of foxes and rabbits over time, given a set of initial conditions, which the user controls by dragging a point in the plane. The difference equations used to generate the system are

Ri+1 = Ri + G (1 - Ri /500) Ri - .0001 Ri Fi
Fi+1 = Fi + .0001 Ri Fi - .02 Fi

David Zachmann is in the Mathematics Department at Colorado State University.

where the rabbit growth rate G is controlled by a slider. Thus, these equations differ from the classical (discrete) Lotka-Volterra equations by inclusion of intra-species competition for the rabbits.

INTENDED USES: class demo and a starting point for future code development

APPROPRIATE COURSES: Differential Equations, Applied Mathematics, Mathematical Modeling

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Operating systems used in testing: Windows 98, MacOS 9.0.3

Browsers: Internet Explorer 5, Netscape 4.7

David Zachmann, "Predator Prey," Convergence (September 2004)