NetLogo Models Library:
This is a model of a simple predator-prey ecosystem. It uses the System Dynamics Modeler to implement the Lotka-Volterra equations.
The Lotka-Volterra equations are a pair of first order, non-linear, differential equations that describe the dynamics of biological systems in which two species interact.
At each step, the value of the SHEEP-BIRTHS flow is added to SHEEP stock, and the value of the SHEEP-DEATHS flow is subtracted from the SHEEP stock. The same is done for the WOLVES stock. Each flow is calculated in terms of the variables, and stocks that are linked to it.
What happens when the sheep population increases? And the wolves? Why do you think this is the case?
Use the System Dynamics Modeler to change the values of the variables in the system, such as SHEEP-BIRTH-RATE and PREDATOR-EFFICIENCY.
This model uses the System Dynamics Modeler to simulate the Lotka-Volterra equations.
Wolf Sheep Predation Wolf Sheep Predation (Docked Hybrid)
Lotka, A.J. (1956). Elements of Mathematical Biology. New York: Dover.
"Lotka-Volterra equation". From Wikipedia. https://en.wikipedia.org/wiki/Lotka-Volterra_equation
Eric W. Weisstein. "Lotka-Volterra Equations." From MathWorld. http://mathworld.wolfram.com/Lotka-VolterraEquations.html
If you mention this model or the NetLogo software in a publication, we ask that you include the citations below.
For the model itself:
Please cite the NetLogo software as:
Copyright 2005 Uri Wilensky.
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
Commercial licenses are also available. To inquire about commercial licenses, please contact Uri Wilensky at email@example.com.