Name __________________________________
Date ______________ Period ______
Rabbits and Wolves Population Cycles
Go to the web site:
http://www.shodor.org/interactivate/activiti
es/RabbitsAndWolves/
The program will be easier to work with if
you go to View on the Internet Explorer
toolbar, then select Toolbars and uncheck
all the toolbars so you can see more of the
screen.
Description:
This applet allows the user to simulate how nature keeps its balance. This applet shows how wolves
and rabbits would behave in their natural setting. The general rules of this applet are:
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Two rabbits cannot occupy the same section of grass.
Two wolves cannot occupy the same section of grass.
Each rabbit can only eat grass when he has not reached his maximum food capacity. (The
maximum food capacity can be modified).
A wolf will not eat a rabbit if the rabbit will make him surpass his maximum food capacity.
(The maximum food capacity can be modified).
Rabbits and wolves can only reproduce when they reach a certain age and have a sufficient
amount of food. (The age of reproduction and amount of food required to reproduce can be
modified).
A rabbit cannot reproduce if there is a wolf around her.
Rabbits and wolves can only move up, down, left, or right one space at a time.
Rabbits and wolves die if they get too old or if there is insufficient food. (Maximum age can be
modified).
The grass growth rate is 1. (This growth rate can be modified).
Instructions:
Experiment with the settings to build evidence for the answers to the questions below. Read the
Learner and Help tabs for directions about running the simulation. Use the View/Modify
Parameters button on the bottom left to adjust settings (number of rabbits, maximum age of wolves,
etc.) Make sure to View Population Graph during a simulation to see the data plotted on a graph.
Make sure the Forest Border (on the right side of the screen) is set to Toroid.
Watch the simulation in the default speed the first time, then you can adjust the speed to the far right
to go through each simulation quickly. Run through several simulations then answer the questions.
Questions:
1. What would happen if there were lots more rabbits than there are were wolves? Would the rabbits
take over and live forever?
2. What would happen if there were lots more wolves than there are rabbits? Would the wolves live
forever?
Name __________________________________
Date ______________ Period ______
3. How do the rabbits and wolves live in balance in this game (both survive)?
4. If the wolves die off and there are only rabbits left, what happens to the grass? Explain.
5. When the grass has been overgrazed and is almost completely gone (brown background), what
happens to the size of the rabbit population? Explain.
6. Is it possible for the grass population to be completely wiped out, yet come back?
How does this happen in real life? What is this process called?
7. Adjust the reproductive rate of the rabbits by increasing the Rabbit Reproductive Probability or
lowering the Rabbit Reproduction Age. How does this affect the cycles of the rabbits, wolves,
and grass? Explain.
8. Can you create a simulation that runs forever, with all three species? What are the key settings
(reproduction, life span, food, etc.?) that allow this to happen?
9. Try to create a simulation that causes one species to die off quickly. Which species died off
quickly, and what change(s) did you make to the settings for this to happen?
10. Close Internet Explorer. Re-open the program and do not change any of the settings. Set the
speed to maximum. Run the simulation over and over until you get a different result. Why are
the results NOT the same every time? Explain why this would be true for populations in the real
world.