30 May PRINCIPLES OF BIOLOGY

PRINCIPLES OF BIOLOGY

                                                             BI 213

                       PREDATOR/PREY EXERCISE

MATERIALS:

200 beans

Spoons

RULES:

1. Students with spoons are the predators.  Predator population at time 0 is 5 (100%).

2. Beans are the prey.  Prey population at time 0 is 200 (100%).

3. Each generation lasts 30 seconds during which predators will attempt to capture as many prey as possible.   Predators may not “herd” prey, and may not use their collecting cups to aid prey capture.  No physical contact is allowed between predators as they compete for prey.

4. At the end of each generation, surviving prey will reproduce three times, up to a maximum of 200 (the carrying capacity of their habitat).  When survival and reproduction of prey results in a population of less than 190, an additional 10 prey will migrate in from surrounding populations. 

5. At the end of each generation, predators reproduce once for every 20 prey they capture.  Those with less than 10 prey starve to death.  If the predator population becomes locally extinct, 1 predator will migrate in from an adjacent population at the end of the next generation (predators will remain at 0 for 2 generations while prey population continues to reproduce and gain migrants).

6. Numbers of predators and prey are tallied at the end of each generation and graphed as a percentage of their starting populations.

ASSIGNMENT:

Write an Introduction explaining the dynamics of predator/prey interactions, give a brief description of Methods, include a graph of the lab Results, and Discuss their relationship to predator/prey dynamics in nature.   Also include any suggestions that may improve this lab.