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Predator-Prey Simulation

Objectives:

To investigate how populations are affected by predator-prey relationships over several generations.

Materials:

Instructions:

  1. The game contains a meadow (the playing field) and stacks of reserve cards for lynxes and rabbits. Lynxes and rabbits added to the meadow are taken from this reserve stack.
  2. All animals that are removed from the meadow are placed back in the reserve stacks.
  3. Play the game in groups of four. Work in pairs. One pair manages the prey (rabbit population), and the other pair manages the predators (lynx population).
  4. Record the numbers of rabbits and lynxes in the meadow at the beginning of each round for the 25 generations in the game. Stop after the 25th generation.
  5. Rabbit managers:
    1. The rabbit managers add active rabbits by spreading them evenly in the meadow
    2. To start the game, the rabbit managers distribute three rabbits evenly on the meadow.
    3. The rabbit managers remove rabbits when they are caught by a lynx.
    4. For the beginning of the next generation, double the number of surviving rabbit and place them in the meadow.
    5. If there are no surviving rabbits, a new generation is begun with three new rabbits, which immigrate into the meadow.
  6. Lynx managers:
    1. The lynx managers throw active lynx cards and add or remove active lynxes from the meadow.
    2. The toss must leave a lynx manager's hand outside the meadow area. As long as the lynx square touches a rabbit square, that rabbit is considered to be caught.
    3. Start the game with one lynx. Probably, the first lynx catches fewer than three rabbits and starves.
    4. If a lynx catches three rabbits in a round the lynx survives.
    5. If a lynx cannot catch three rabbits in a round, the lynx starves and is removed from the meadow.
    6. If there are no surviving lynx, the lynx managers get a new lynx that immigrates into the meadow.
    7. If a lynx catches more than three rabbits in a round, each three extra rabbits caught allows the lynx to have a cub. If a lynx catches six (6) rabbits total it has enough energy to have one cub. Nine (9) rabbits caught is two cubs, etc.
 

Interpretations:

  1. Graph your data using the number of individuals as the dependant variable and the number of generations as the independent variable. Use a separate line on the same page for rabbits and lynxes (one graph - two lines).
  2. Study your graph lines for the two populations. How are the lynx and rabbit populations related to each other? How do the sizes of each population affect each other?
  3. Under what modifications can both populations continue to exist indefinitely?
  4. What do you think would happen if you introduced an additional predator, such as a coyote, which requires fewer rabbits to reproduce?
  5. What would happen if you introduced another type of rabbit, one that could run faster and escape its predators? (In the game, you could give the new type of rabbit a chance to escape by tossing a coin after it is caught and letting it live if you got heads.) Which type of rabbit would predominate after many generations of predation?

Applications:

  1. How does this simulation relate to the human population and its interaction with its environment? Are there any predator-prey relationships?
  2. What predator-prey relationships have you observed in your community?
  3. If a population biologist visited your classroom, what are some questions about the human population you could ask?

Source:

Leonard, W.H. and Penick, J.E. 2003. Biology - A Community Context. Glencoe McGraw-Hill.

 
Name:

Predator-Prey Simulation Data Table


 
Generation Rabbits Lynx Rabbits Caught Lynx Starved Lynx Surviving New Baby Lynx Rabbits Left
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25