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Predator Prey Simulation Lab
I. Purpose:
In this exercise you will simulate the interactions between a predatory population
of lynx and a prey population of rabbits in a meadow. The 12 generations of predator and
prey will then be graphed to show the interrelations between the two species.
II. Problem: How is the prey population effected by the size of the predator
population?
III. Hypothesis:
Materials:
15 cardboard squares (lynx)
300 construction paper squares (rabbits)
table top (meadow)
calculator
IV. Procedure:
1. Put three rabbits in the meadow. Disperse them so that they are not close together.
2. Toss the lynx into the meadow in an effort to catch a rabbit. Remove any captured
rabbits. In order for the lynx to survive and reproduce, the lynx must catch three
rabbits each generation. At this point in the activity, that is not possible. The lynx
will starve and there will not be any surviving lynx or new baby lynx.
3. Complete the counts for the first generation on your data sheet.
4. For the second generation, double the number of remaining rabbits and record that
number in the chart. Add that number of paper rabbits to the meadow, if you haven’t
already done so. Be sure to disperse the rabbits over the whole area.
5. Assume that a new lynx migrants into the meadow. So record number “1” on the data
sheet in the lynx column.
6. Toss the lynx into the meadow again and remove any captured rabbits. (Lynx are not
allowed to cheat, but they should try to be effective hunters.) Complete the counts for
the second generation on your data sheet.
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7. At the start of each generation double the number of rabbits you have left. There
should always be at least three rabbits at the beginning of each generation. If the
entire rabbit population is wiped out, then three new rabbits will migrant into the
meadow. Toss in the lynx and complete your counts.
8. Eventually the rabbit population increases to a level that allows the lynx to catch 3
rabbits in a single toss. Then it not only survives, but it reproduces too! It has one
baby for every three rabbits it catches. If it catches only 4 or 5 rabbits, it still only
produces one baby. If it catches 6 rabbits it will have two babies, and so on.
9. Toss a lynx into the meadow for each lynx you had survive or born each generation.
Be sure to redistribute the rabbits in the meadow after each toss.
10. Remove the rabbits caught and add new ones as indicated by your data counts.
11. Continue to record population counts for a total of 12 generations.
12. Graphing the data:


Label the vertical axis “Number of Animals” and the horizontal axis
“Generations”. Mark off a scale of 12 generations on the horizontal axis.
Plot the number of rabbits and the number of lynx on the same graph so that the
interrelationships can be easily observed. Use a solid line and a dotted line to
represent the different animals.
V. Data
Generation
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1
2
3
4
5
6
7
8
9
10
11
12
# of rabbits
# of lynx
# of
rabbits
caught
# of lynx # of lynx
starved survivin
g
# of baby
lynx
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VI. Data Analysis:
1. Explain why the rabbit population rises.
2. If this simulation were to continue for 25 generations, what would you predict for the
size of the rabbit and lynx populations?
3. Use the lynx-rabbit curves to explain what is meant by a “population lag”.
4. In a wildlife community, what causes the populations to rise and fall at different
times?
5. What other factors, besides the number of lynx and rabbits, would influence the shape
of the graph in natural meadow?
6. What might result from inefficient lynx?
VII. Conclusion:
Follow the lab report guidelines and use the CEI format.