"Oh Deer" Simulation

Introduction

This is an activity that is used by biology teachers to simulate annual fluctuations in deer populations in a habitat. It is designed to show that populations change according limiting factors that are available in the environment. When sufficient factors are available the population can reproduce and the numbers increase. However, when insufficient factors are available animals die and fail to reproduce. When the deer fail to reproduce their population declines. The procedure outlined below is the classroom procedure used by teachers:

Classroom Procedure:

1. Review the definition and 4 essential components of habitat. Habitat is where an animal lives and the essential components are food, water, shelter and space. Remind students that these components need to be arranged so that animals can find what they need within reasonable distances (this varies depending upon the animal used as an example).

2. Ask the students to count off in fours. Have all the ones go to one area and stand about shoulder-width apart. Have all the twos, threes, and fours go together and line up about 20 yards in front of the ones. At this point you should have two groups lined up facing each other.

3. Tell the students that the smaller group will be deer and the larger group will be habitat. Ask the students again what the four components of habitat are: food, water, shelter, and space. Remind students that deer need good habitat in order to survive. For the purposes of this activity we will assume that the deer have enough space in which to live, so all the deer will need is food, water, and shelter. When a deer is looking for food, it should clamp its hands over its stomach. When a deer is looking for water, it should clamp its hands over its mouth. When a deer is looking for shelter, it holds its hands over its head. During each round of the activity, each deer may choose to look for anyone of its needs, but cannot change what it is looking for until the next round.

4. Each student that is habitat should decide which habitat component it wishes to be. Like the deer, the habitat component can change what it wants to be each round, but may not change within the round.

5. Count the number of deer and make a note of each round.

6. Have the two groups (deer and habitat) turn their backs to each other. Each deer should make the sign for the habitat component that it is looking for and each habitat component should make the sign for what it wishes to be. Give the students a few moments to decide what they will be and get their hands in place.

7. When everyone in both groups is ready, have both groups turn around and face each other while continuing to hold their signs.

8. Give them a signal and let the deer run to the habitat and fmd a student who has the same sign. The deer that find what they need will survive and reproduce and need to take the habitat component that they found back to the starting place (habitat component becomes a deer). Deer that do not find what they need die and become habitat (ashes to ashes, etc.) . If more than one deer tries to get the same habitat component, the one to get there first survives.

Note: If you have a student who is unable to participate (wheel-chair, injured; ill, etc.) put them on the sidelines and let them throw the nerf ball at the deer as they run to the habitat. This can represent a hunter or road-kills. Deer hit by the ball become a part of the habitat.

9. Tell the students that this represented one year in the life of this deer population and ask what happened. Most of the deer should have found what they needed and successfully reproduced. This has resulted in an increase in the deer population.

10. Have the students perform this activity for at least 8-10 more rounds (representing 8-10 years). Keep track of how many deer there are at the beginning of each round. There should be drastic changes in the deer population before you are finished. After a round in which many deer die, ask the students what would have happened to the population if we had a hunting season that year and harvested a few deer. (The resulting population would be the same because those deer would have died anyway. )

11. Gather the students at the end of the activity and discuss the changes in the deer population over time. Use the flip-chart or dry-erase board to graph the deer population. Explain that deer populations go up and down naturally in response to limiting factors. Explain the concept of carrying capacity. Carrying capacity is the maximum number of animals that the land can support. Explain that this is important to us as wildlife managers. We try to figure out what the most limiting factor is and manipulate it to increase or decrease the population. Use the bucket analogy. Explain that mortality (death) is natural in wild populations and that wild animals don't die in bed with boots off like they do in the movies.

The Program

Your task is to write a program that simulates the classroom procedure. You will need to design several objects including deer, habitat components, and the habitat. You will need to also have an object that has the main method that runs the program. Most of the program should be in the Habitat Class.

A Deer Class might include methods to define status (alive or dead), define need (shelter/space, food or water can be represented as integers). The Habitat Component Class must have similar methods. I would suggest instantiating these two objects in the Habitat Class and then using arraylists to keep track of the number of each. Since arraylists store objects you will need to cast the object to be able to use it. This can be done by first instantiating an object (Deer or HabitatComponent) within a method, and the assigning the object in the arraylist to this object.. This way you will be able to access the methods and the data for this particular object within the array list.

Ass is previous program, turn in a listing of your source code, and several example runs of up to one hundred generations. If you worked with others, besure to include their names on your program.