Lesson: Competition
Unit: Ecosystems
Purpose: to teach kids about the interactions that happen within ecosystems,
so that they may have a better understanding and appreciation for the
world around them.
Age Level: 4th-6th grade
Time: 45 minutes
Materials: 75 poker chips, chalk and chalkboard (or whiteboard), 30
carpet squares.
Participants: 30
Objectives:
Students will play deer and resources to learn what interspecific competition
is
Students will learn what it feels like to not get what they need to
survive
Students will see how populations sizes fluctuate and how that effects
competition
Students will play squirrels, chipmunks, and nuts to learn what intraspecific
competition is and review interspecific competition
Students will learn definitions of competition, interspecific and intraspecific
competition.
Plan: 5 minutes: definitions
Ask the students if they know what competition is. Tell the students
that animals usually have to compete to get their food. Write the definition
of competition on the board: interaction between individuals, through
a shared requirement for a limited resource. Ask them to tell you an
example of this. Tell them there are two types of competition: interspecific
and intraspecific. Ask them if they have a guess of what either are.
Interspecific: competition between individuals of the same species.
Intraspecific: Competition between individuals of a different species.
20 minutes: Deer and Resources
Deer and Resources: First teach the motions for the resources. The motion
for food is hands on stomach. The motion for water is hands on throat.
The motion for shelter is hands in an upside-down 'v' shape above head.
Split the group in half, and make one half the deer and the other the
resources. Tell students to pay attention to both directions, because
they will most likely play both roles. Tell the students that your will
have them turn their backs to each other and decide. The deer will decide
which resource they need, and the resources will decide which they are.
Tell them when you yell "decide" they need to put their hands
for the motion they are, and that they aren't allowed to turn around
until you yell "go." When you yell" go the deer have
to run to the resource they need. Only one deer to each resource. The
resources that get used by a deer go back with the deer and become more
deer. Tell the students that this is because when the deer get what
they need they can reproduce and their population grows. Tell the students
that the deer who don't get what they need die and become a resource.
Have the students stand in parallel lines about twenty feet apart, with
their backs to the other group. Yell "decide" then "go."
After you have played a couple of rounds there should be a pattern developing.
Ask the students what time of competition this is, interspecific or
intraspecific. It's interspecific. Ask the students if they noticed
a pattern. They should say that the population size of each group alternated
each round. One round there would be a lot of deer and less resources,
so a lot of deer would die. This resulted in the next round there being
a lot of resources, so every deer got what they needed. Tell the students
that each round represents a year. Have the students play again, and
this time secretly go to the resources and tell them they can't be water
because there was a draught. After two rounds of this, tell them that
they can't be food because the drought before wiped out the food. After
a couple rounds of this bring everyone back for discussion. Ask the
deer what happened when they wanted water and there wasn't any. Discuss
how sometimes the environment can make a resource very scarce, which
increases competition. If there is less of a certain resource, it will
be harder for each deer to get because they are competing with each
other.
*introduce them to top-down and bottom-up control. Tell them that top-down
control is when the consumer population controls the producer population.
So if the deer are the consumers, when did their population size effect
the resource size? When there were a lot of deer, they depleted the
resources. So if the resources are the producers, when did their population
size affect the consumers? When there was a drought, a lot of deer died,
because they couldn't get water. This is called bottom-up control.
20 minutes: squirrels, chipmunks, and nuts
Squirrel, chipmunks, and nuts: Give everyone a carpet square, or something
to
signify their home base. Have them stand in a circle. Pick three students
to be squirrels, and all the rest are chipmunks. The squirrels don't
need carpet squares. Tell the students that the poker chips represent
nuts. Have the squirrels stand in the middle of the circle and tell
the chipmunks that their carpet squares is their safe zone. Through
the nuts in the circle. Tell the chipmunks that they are trying to get
as many nuts as they can, but they can only get one at a time. Each
time they get a nut they have to bring it back to their home base. The
squirrels want all the nuts for themselves so they are trying to stop
the chipmunks from getting the nuts. If a squirrel taps a chipmunk,
the chipmunk must drop the nut where they are and go back to their home
base. After they had played for a little while stop the game and add
a twist. Ask the students what kind of competition they were showing.
It was intraspecific, because squirrels and chipmunks are different
species. Have everyone throw the nuts back in the middle. Tell them
that the chipmunks are also competing with each other for the nuts.
Ask them what kind of competition that is. It is interspecific. If a
home base is left unguarded, they can still they nuts from the other
chipmunk, but only one at a time. After they have played for a while,
bring them back together for discussion. Ask the squirrels how it felt
to try and protect their food. Ask the chipmunks how it felt to get
and protect their food. Was it scary? What was their method of getting
nuts and protecting them?
