|Life Science||Diversity And Adaptations Of Organisms 8H4.00||Science in Society||Personal Needs 4.2 ac|
Sponsored by the National Science Foundation
CONTENT STANDARD: Life Science
CONTENT STANDARD: Life Science
CONTENT TOPIC: Diversity And Adaptations Of Organisms
CONCEPT: Some living things have become extinct and others are endangered.
CONTENT OBJECTIVE: 8H4.00 To understand how endangered species can be protected
INSTRUCTIONAL OBJECTIVES: The learner will:
TN COMPONENT OF SCIENCE: Science in Society
BENCHMARK: People control science and technology and are responsible for its effects.
4.2c Science solves practical problems but may create new problems and needs for an individual.
BENCHMARK: Solutions in one area may have a negative impact in another.
1. Draw animal homes and compare them to places where people live.
2. Instruct students to look for animal homes. They should be cautioned to not bother the animals or their homes in this process.)
Carrying capacity may be defined as the ability of a given unit of habitat to supply food, water, shelter, and necessary space to a wildlife species. It is the largest population the unit can support on a year-round basis, or during the most critical season. Carrying capacity varies from year to year dependent on conditions within the habitat such as rainfall, competition from domestic animals, etc.
An area of bear habitat can support only a specific number of bears, just as a one gallon bucket can hold only one gallon of water. All habitats, for whatever species, vary seasonally and/or yearly in their carrying capacity. Habitats can therefore only support the numbers which can be carried at the lowest ebb of the season or year. Those surplus animals, born during richer seasons, must be lost to some "limiting factor" prior to or during the harsher season. In this activity, we will be talking about black bears. The major purpose of this activity is for students to gain an understanding of "carrying capacity."
1. Cut the paper or poster board into 2" x 2" or 2" x 3" pieces. For a classroom of 30 students, make 30 cards of each color as follows: orange-nuts (acorns, pecans, walnuts, hickory nuts); mark five pieces N-20; mark 25 pieces N-10.
blue-berries (blackberries, elderberries, raspberries); mark five pieces B-20; mark 25 B-10.
yellow-insects (grub worms, larvae, ants, termites); mark five pieces I-12, mark 25 pieces I-6.
red-meat (mice, rodents, peccaries, beaver, muskrats, young deer); mark five pieces M-8; mark 25 pieces M-4.
green-plants (leaves, grasses, herbs); mark five pieces P-20; mark 25 pieces P-10.
The following estimates of total pounds of food for one bear in ten days are used for this activity.
nuts 20 pounds =25%
berries 20 pounds =25%
insects 12 pounds =15%
meat 8 pounds =10%
plants 20 pounds =25%
Total 80 pounds =100% in ten days
Keeping these figures in mind, make and distribute the appropriate number of food cards for your size group of students. There should be less than 80 pounds of food per student so that there is not actually enough food in the area for the "bears" to survive.
2. In a fairly large open area (e.g., 50' x 50'), scatter the colored pieces of paper.
3. Have each student write his or her name on an envelope. This will represent the student's "den site" and should be left on the ground (perhaps anchored with a rock) at the starting line on the perimeter of the field area.
4. Have the students line up on the starting line, leaving their envelopes between their feet on the ground. Give them the following instructions: "You are now all black bears. All bears are not alike, just as you and I are not exactly alike. Among you is a young male bear who has not yet found his own territory. Last week he met up with a larger male bear in the big bear's territory, and before he could get away, he was hurt. He has a broken leg. (Assign one student as the crippled bear. He must hunt by hopping on one leg.) Another bear is a young female who investigated a porcupine too closely and was blinded with quills. (Assign one student as the blind bear. She must hunt blindfolded.) The third special bear is a mother bear with two fairly small cubs. She must gather twice as much food as the other bears. (Assign one student as the mother bear.)"
5. Do not tell the students what the colors, initials, and numbers on the pieces of paper represent. Tell them only that the pieces of paper represent various kinds of bear food; since bears are omnivores, they like a wide assortment of foods, so they should gather different colored squares to represent a variety of food.
6. Students must walk into the "forest". Bears do not run down their food; they gather it. When students find a colored square, they should pick it up (one at a time) and return it to their "den" before picking up another colored square. (Bears would not actually return to their den to eat; they would eat food as they find it.) Pushing and shoving-any competitive activity-is acceptable as long as it is under control. Snatching food right out from under the blind or crippled bear is natural-but stealing from each other's dens is not. Remember that if bears fight (which they seldom do) they can become injured and unable to gather sufficient food; then they starve.
7. When all the colored squares have been gathered, the food gathering and hunting is over. Have students pick up their den envelopes containing the food they gathered and return to class.
8. Explain what the colors and numbers represent. Ask each student to add up the total number of pounds of food he or she gathered-whether it is nuts, meat, insects, berries, or plant materials. Each should write the total weight on the outside of his or her envelope.
9. Using a chalkboard, list "blind," "crippled," and "mother". Ask the blind bear how much food she got. Write the amount after the word "blind". Ask the crippled bear and the mother bear how much food they got and record the information. Ask each of the other students to tell how much food they found; record each response in the chalkboard. Add the poundage gathered by the entire class. This the total amount of food available in this particular bear habitat. How many bears are there? Divide this number of bears into the total pounds available to find out how much is available for each bear. Tell the students each bear needs 80 pounds to survive. Which bears survived? Is there enough to feed all the bears? Would they all starve? How many pounds did the blind bear collect? Will she survive? What about the mother bear? Did she get twice the amount needed to survive? What will happen to her cubs? Will she feed cubs first, or herself? Why? What would happen to her if she fed the cubs? What if she ate first? If the cubs die, can she have more cubs in the future, and perhaps richer years? (The mother bear will eat first and the cubs will get whatever, if any, is left. The mother must survive; she is the hope for a continued bear population. She can have more cubs in her life; only one needs to survive in order for the population to remain static.)
10. Discuss with the class that this area of black bear habitat can only support a certain number of bears. We call that number the "Carrying capacity." Discuss the idea of a one gallon bucket only being able to contain one gallon of water. Carrying capacity also holds true for humans-the earth can only support so many.
11. Wrap up with a discussion of the idea that any piece of land can support only so many plants and/or animals. That is the land's "carrying capacity."
1. Define carrying capacity.
2. Describe some of the factors which determine carrying capacity for a species of animal.
3. Explain why carrying capacity is important for wildlife.
4. Explain why carrying capacity is important for people.
This is the time this file has been accessed since 04/04/98.
The University of Tennessee at Martin is not responsible for the information or views expressed here.
Eighth Grade Science Home Page