1. Simulating the Predator-Prey Interaction Lab Introduction

2. Before you begin predict what will happen to the camouflage and visual acuity scores of the prey and predator over 10 generations. Write a hypothesis in your lab notebook.

3. GAME SET UP

4. Choose your character GAME MASTER: – Distributes game pieces – Determines predator/prey interactions – Removes necessary game pieces from board – Organizes game pieces at the end of the round – Takes necessary pictures of game board

5. Choose your character GAME MASTER RANDOMIZER – Reads off a random number table when dispersing animals

6. Choose your character GAME MASTER RANDOMIZER DISTRIBUTOR – Makes game pieces needed (cuts out 1” squares) – Maintains “death bed”

7. Choose your character GAME MASTER RANDOMIZER DISTRIBUTOR RECORDER – Records the results in data table at the end of round

8. 12 32 23 25 34 45 42 12 32 23 25 34 45 42 Data RANDOMIZER GAME MASTER RECORDER DISTRIBUTOR

9. DISTRIBUTOR should cut out 1” squares and label 16 predator cards (green) and 16 prey cards (purple) according to the image below.

10. DISPERSAL

11. RANDOMIZER will read off the random numbers table while the GAME MASTER places the game pieces on the board. Each pair of numbers represents the coordinates of one of the squares on the board. Ex. If the number is 2 5, place the animal in column 2, row 5.

12. 1 2 3 4 5 1 2 3 4 5 4 4

13. RANDOMIZER will read off the random numbers table while the GAME MASTER places the game pieces on the board. Each pair of numbers represents the coordinates of one of the squares on the board. Ex. If the number is 2 5, place the animal in column 2, row 5. Do this until all pieces (32 total) are placed.

14. You’ll be thankful later.

15. PREDATION

16. Each predator now has a chance to eat (only once) and reproduce, but only if there is a prey in the same square with a camouflage score less than the predator’s visual acuity. EX. A predator with a visual acuity of 6 will detect and eat a prey with a camouflage score of 5, but not one with a camouflage score of 7. Remove dead prey immediately Immediately after a predator eats the prey, it then reproduces as described later. YOU MUST GO SQUARE BY SQUARE (1 1; 1 2; 1 3; etc) Each of these steps will be carried out by the GAME MASTER with the help of the DISTRIBUTOR

17. PREDATOR REPRODUCTION

18. When a predator eats it obtains enough energy to produce two offspring. Then it dies and is removed from the board. Remember that in nature parents and their offspring tend to resemble each other but are not identical. To simulate this let one of the two offspring have a visual acuity score greater than the parent by 1 (there in no upper limit to visual acuity). Give the second offspring a score that is one less than the parent, but no lower than 0. The DISTRIBUTER will make the new pieces. Mark each new offspring with the round in which it was born (in this case round 1). But if that predator reproduces again, mark it as the next generation (2). If there is any uneaten prey still in the square the offspring can immediately eat them (and reproduce themselves) if their visual acuity is high enough. Thus, you could have several generations of predators in one round

20. STARVATION

21. Predators that have not been eaten in two rounds will starve and be removed from the board by the GAME MASTER. This will not happen during round 1! See column 1 in table 1 to know whom to remove in subsequent rounds.

22. PREY REPRODUCTION

23. All surviving prey now has the opportunity to reproduce. A prey can reproduce only if no other prey occupies the same square. If two prey occupy the same square there is not enough food to supply the energy needed for reproduction. However, Prey never starves. They survive into the next round. (The presence of predators in the square does not prevent a prey animal from reproducing since predators do not compete for the same food eaten by the prey.) Reproduction by prey is the same as in predators. Each prey is replaced by two offspring, one of which has better camouflage (by 1) and one of which has worse camouflage (by 1), except that camouflage can never drop below 0.

24. RECORD RESULTS

25. At the end of each round calculate the average scores for surviving predators and prey. It is easiest to organize your game pieces according to their camouflage or visual acuity score. The RECORDER should calculate averages. Record the results in Table 1.