IOWA 4-9 SCIENCE PROJECT
Teacher's Guide for: How Many Bears?
Luann Byerly
Ecology.469 Grades 4-6
CONCEPT OBJECTIVE:
Students will be able to define the components of a habitat and identify a limiting
factor.
PROCESS OBJECTIVE:
Students will develop observing, recording, predicting, and evaluating skills.
TEACHER BACKGROUND:
This activity would be best to do after the students have been introduced to the concepts
of animal adaptations and basic survival needs.
Black bears are limited by shelter, food supply, and the territoriality of the bear.
All of the components of habitat are important but it is also important that they
are arranged in a way that is suitable for their needs. The application activity
looks at the 5 kinds of shelter and space the black bear needs. This need for so much space
and so many kinds of shelter can be a strong limiting factor. It may help students
understand why a large area of preserve is needed for the black bear. The statistics on what the bear eats and the shelter they need comes from a study of bears made
in Arizona. It would not be exactly the same for other areas of North America.
Before the class the teacher will need to make a set of cards. For a classroom of
30 students, make 30 cards of each of 5 colors to represent food as follows:( the
colors are only suggestions)
ORANGE - Nuts; mark 5 N-20, 25 N-10.
BLUE - Berries and fruit; mark 5 B-20 and 25 B-10.
YELLOW - insects; mark 5 I-12 and 25 I-6
RED - meat; label 5 M-8 and 25 M-4
GREEN - plants; mark 5 P-20 and 25 P-10.
If you want to include water make an additional 50 squares of light blue with each
stack of 10 cards marked R, L, ST, SP and M representing water from rivers, lakes,
streams, springs, and marshes.
The same squares can be used for the application game, but students will ignore the
letters and numbers on them.
MATERIALS:
set of cards for the class
student activity sheets
an envelope for each student
EXPLORATION:
1. In an open area scatter the colored pieces of paper. This can be outside or in
the classroom if the furniture is moved to the edges of the room. If you do it in
the classroom you may want the students to move around on hands and knees to slow
things down a little.
2. Give each student an envelope to put their name on to be their 'den'. Have the
students find a 'den site' on the edge of the open area. They must leave their envelope
there.
3. Ask for three volunteers. Tell all the students that they are black bears but
these three are bears with special problems. One is a young male bear who has not
yet found his own territory. Last week he met a larger male bear in the big bear's
territory, and before he got away, he was hurt. He has a broken leg. Therefore the student
representing this bear must hunt by hopping on one foot. The second student represents
a bear who investigated a porcupine too closely and was blinded by the quills. That student must wear a blindfold. The third student represents a mother bear who has
2 cubs so she must gather twice as much.
4. Do not tell the students what the different colors represent, instead just tell
them they represent different kinds of food and that bears like a variety of food.
Have them pick up as many as they can but they must take each square to their den
after they eat it. ( This represents the time bears take to eat their food when they find
it not that they take it back to their den.) They also must not run since bears
gather their food not chase it.
5. When all the squares are gathered give the students activity sheet 1 and have
them complete it. Then get the students together and compile the following information.
How many 'bears' survived?
Did the bears with special problems survive?
How many bears had a healthy diet?
Add up everyone's totals and figure out, if all was equal, how many bears the
area could support.
CONCEPT DEVELOPMENT:
Introduce the concept of 'limiting factor' ( anything that limits the number of animals
that survive ex. food, water, shelter, disease, natural disaster etc. ).
What were the limiting factors to these black bears?
What could happen that would make food and water even more limiting? (drought,
plant diseases, etc.) You might want to play the game again with a stress on the
system, drought cuts the amount of water squares in half for instance.
Why don't as many bears live as is possible?
What are some other limiting factors you can think of for animals?
APPLICATION:
1. Play the game again but this time have the different colored squares represent
the 5 areas of shelter or kinds of space the bear needs. Give each student the 2nd
activity sheet to analyze their information. You may discuss it in large group or
in small groups.
2. Have each student or small group pick a different animal and research to find
out what its habitat is. Then they could decide what some limiting factors for the
animal might be.
For more information look in Project Wild "How Many Bears Can Live In This Forest?"
Student Activity Sheet #1
Each of your squares has a letter and number on it. The letter represents a kind
of food that bears eat and the number tells how many pounds of that food you gathered.
The slips without numbers are for water. The letter tells you where the water comes
from.
N = nuts, B = berries and fruit I = insects, M = meat, P = plants, R = river water,
L = lake water, St = stream water, Sp = spring water, M = marsh water
Use the chart to figure out how many pounds of each kind of food you gathered. If
you gathered 80 pounds of food and had at least one water square you survived. If
you had at least the recommended amount of each kind of food, you had a balanced
diet and are a healthy bear.
FOOD | # OF POUNDS | REQUIREMENT TO BE HEALTHY
NUTS | _____ POUNDS | 20 POUNDS
BERRIES | _____ POUNDS | 20 POUNDS
INSECTS | _____ POUNDS | 12 POUNDS
MEAT | _____ POUNDS | 8 POUNDS
PLANTS | _____ POUNDS | 20 POUNDS
TOTAL | _____ POUNDS | 80 POUNDS
1. Did you have a water source?______
2. Did you (as a bear) survive?______
3. Would you be a healthy bear?_______
2nd ACTIVITY PAGE
Separate the cards you picked up into piles by color. Each color represents a different
kind of cover or shelter that a black bear needs.
Bedding Sites: Black bears are usually active in early morning and late evening and
bedded most of the rest of the day and night. Bedding sites are usually in areas
of dense vegetation, steep topography, and/or large trees where the bears feel secure.
Travelways: Bears need corridors of cover (made up of thick vegetation and/or steep
topography) so they can get to areas of food, water, and shelter within their home
range.
Dens: Black bears use dens as shelter for hibernation from November to April in each
year. They use hollow logs, caves, holes in hillsides, under buildings, and even
culvert pipes.
Hiding Cover: Black bears escape danger from predators and other bears by hiding in
thick cover.
Feeding Sites: Bears will feed in areas with less cover than hiding areas or bedding
sites, but they are usually close to areas with cover so they can hide quickly.
You must have at least one of each kind of cover to be able to survive.
1. Would you survive?
2. What would happen if a bear has all types of shelter except a den?
3. What would happen if a bear has all types of shelter except no travelways between
them?
4. How is each of these kinds of cover or shelter a limiting factor?
5. How would you design a habitat for a black bear? Draw a possible habitat. Would
it be a small area or a big area?
6. Could the black bears survive in a preserve in a city park?