Population Game

In a feeding game, participants find out how many deer can survive in a herd's "home range."

Group Size: This activity is suitable for ten to fifty youngsters.

Suggested Age: 10 and up

Time: Plan for forty to fifty minutes for this activity.

Consider…
Site: A large level or gently sloping grassy area is best.

Safety: No special considerations.

Materials/Prep:
For each youngster: 10 home-range poker chips (one color), 6 new-range poker chips (another color), 4 plastic sandwich bags.
For the group: flagging or cord, timer or watch with a second hand, data board and marker.

Focus question:
How many deer can survive?

• A population is a group of organisms of one kind that lives in the same area.
• The home range is the area where a population lives and forages for food year after year.
• Populations grow through reproduction.
• The carrying capacity is the greatest number of organisms that can be supported by an area without damaging it.
• Too many organisms in an area can damage the resources and can reduce the carrying capacity.
• Sometimes animals will migrate to a new area if there is a shortage of food or other resources in their home range.

Summary:
In this simulation the participants (deer) forage for food (poker chips) to place in the stomach (plastic bag) of a deer. If they are successful in finding enough food in each round, their deer survives. For each stomach (bag) they have, each participant is given an additional bag to fill for the next round. Usually the population size double each of the first two rounds. At this point the home range has been so “damaged” by overpopulation that there are not as many food resources available for round three plus there are more individuals needing those resources. A dramatic die off occurs due to starvation.

This game really brings home the concept of carrying capacity and how overpopulation will reduce the carrying capacity of an area. The idea of migration to a new feeding area is introduced as one way that a population can cope with a shortage of forage.

Extension Activities:
The youngsters may wish to maintain a small population of real animals and observe changes in the population over a short period of time. Guppies are good subjects for population growth experiments. Starting with three of the little fish (one male and two females) in a properly maintained aquarium, youngsters can follow changes in the size of the population over several months.