The Otter Game

The Otter Game Overview This simulation game introduces the idea of carrying capacity and how density- dependent and independent factors can affect the survival rate of river otters. Objectives • Explain how nature regulates otter populations • Describe the relationships between otter populations and their food supplies • Explain the effects of habitat changes on otter populations

Materials • Instructions • Food cards (5 crayfish, 12 fish, 6 snakes, 12 frogs, 4 turtles, 8 invertebrates) • Stop watch • Final questions Procedure 1. Assign one member of your group to be the “dealer.” The rest of the group are “otters.” 2. This game has two separate rounds. Round 1 only involves the dealer and one otter. Round 2 and 3 have 2 otters playing plus the dealer. 3. Dealer: Spread out the food cards face up on the table. 4. Look at the cards to learn about what otters like to eat. Fish and crayfish are otter’s favorite foods, but that they are opportunistic feeders that will eat whatever is available. 5. It is winter and that each otter needs to gather 60 pounds of food to survive for one month. Round 1 o First otter – you have 15 seconds to gather food. You may pick up the cards one at a time and place them in a pile in front of you, but can only use one hand. o When the teacher says ”Go!” have the dealer in each group time the first otter. After 15 seconds, say “Stop!” and count the food cards you’ve collected. . Round 2 o The otter population has increased in size. Now, two students have 15 seconds to gather their food. o When the 15 seconds are up, see who survived and who would be starving.

Round 3 o The water has become polluted and animals often can’t live in it. So take away 3 crayfish cards and 6 fish cards. o Gather as much as you can in 15 seconds. Analysis 1. Define carrying capacity.

2. What happens when a population reaches its carrying capacity in a particular environment?

2. What happens to the population when the water becomes polluted?

3. Define density-dependent factor and explain what that factor was in the Otter Game.

4. Define density-independent factor and explain what that factor was in the Otter Game.