Predator and Prey

Everyone who has taught ecology knows the diagram of the food web and the glazed faces in front of it. This is the version where people end up out of breath and arguing.

How it runs

1. Choose a real local chain. In the Ardèche: grasshopper → lizard → snake → short-toed eagle. Use species the group can see that week, not lions.
2. Assign roles in a rough pyramid: many at the bottom, one or two at the top. Bands mark the role.
3. Scatter tokens across the area — food and water for the base level.
4. Round one, three minutes. Herbivores must collect three tokens to survive the round. Predators must tag one animal of the level below to survive. Tagged players kneel where they are and become soil — they will re-enter next round as a plant.
5. Count survivors after each round and write the numbers up. Play five or six rounds. Population cycles appear on the board on their own; you do not have to explain them.
6. Change one thing in round four without announcing why: halve the water, or remove the top predator entirely. Play two more rounds. Watch the numbers.
7. Sit down in the field where you finished. Look at the board. Ask what happened, and only then name what you changed.

Facilitator notes

• Safety first: define the boundary, walk it, ban tackling, and check for holes, wire and wasp nests before you start.
• The debrief is the session. Allow at least twenty minutes and hold the temptation to summarise — the numbers on the board are more eloquent than you.
• If the group has a strong competitive streak, the removal round gets emotional. That is the material. Do not smooth it over.