Predator/Prey Population Study
Purpose: To simulate a predator and prey relationship.
Materials:
 prey – macaroni
 habitat – 0.5m x 0.5m square (taped off on your
desk)
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predator – elastic
data record sheet
graph paper
Procedure:
1. The prey is eaten only in a figurative sense. DO NOT EAT THE PREY!!!
2. Start generation 1 with three prey and one predator in the habitat.
3. Drop the elastic (predator) to see how successful the hunt is.
Rules:
 Each prey within the elastic is considered caught and eaten (removed from the habitat)
 If a predator catches three prey in one drop, it survives and reproduces to form another predator, six prey caught means
two more predators, 9 prey means three move, etc. (anything less still results in 1, e.g. if five prey are caught, it means only 1 predator is
added)
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The total number of predators at the start of a generation determines the number of times the ring or predator is dropped
You must keep track of the number of prey captured with each drop in order to calculate the increase in the predator
population
Each prey that survives (is not captured within the ring) will reproduce one more prey
Make sure you distribute the prey evenly in the habitat at the beginning of each generation
When there is insufficient prey for the predator to survive, assume another predator migrates in to start the next generation
If all the prey are consumed, three individuals migrate in to start the next generation
4. Continue for 25 generations, recording your results as you go.
5. Graph the predator and prey populations (shaded columns) over 25 generations on the same graph, using different colours for
predator and prey.
Questions:
1. Which population increased first? Why?
a. Why was it necessary that this population increased first?
2. Why would a new predator move into the area in the beginning if the one that was there died?
3. How did the populations change over the 25 generations?
4. How do the predator and prey populations control each other?
5. Is it possible for a predator to continue to increase in numbers while its prey is decreasing?
6. Predict what would happen over 25 more generations. Is there a cycle?
7. Explain how density-dependent and density-independent factors could affect the predator and prey populations?
Predator/Prey Population Study Data Table
Generation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
# of Prey
# of
Predators
# of Prey
Caught
# of Prey
Surviving
Total Prey
Next
Generation
Deceased Predators
(Starvation)
Surviving
Predators
New
Predators
Total
Predators