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Tabizi Pythons
Clendro
Hawks
&
Using Imaginary
Animals to Achieve
Real Knowledge
About Ecosystems
by Michael Rockow
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or a number of years, I taught a unit on food webs
and ecosystems using actual food webs as models.
However, I repeatedly encountered the same problems: The real food webs were either too simplistic
or too complicated, and students complained that my
examples either left out too many organisms or were too
unwieldy to fully understand. Students’ prior knowledge of
ecosystems complicated my assignments, as well. Students
would know, for example, that a particular animal preyed
upon an animal that I had not included in my example.
A few years ago, I solved these problems by making up my
own food web, complete with invented plants and animals.
This allowed me to control the complexity of the food web,
and because the organisms were not
real, students had no prior knowledge to complicate their learning. This approach had another
advantage: Because I designed the
organisms myself, I could create
animals to illustrate specific concepts. For example, when I wanted
to teach about animals’ niches in ecosystems and how animals adapt to their
environments, I invented a number of
birds that each filled a specific niche of
my choosing.
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ART COURTESY OF THE AUTHOR
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In the unit described here,
made-up organisms are used to
teach a variety of topics related to ecosystems—food chains and energy flow, food
webs, limiting factors, carrying capacity,
and the effects of natural and humanmade events on ecosystems.
Teacher preparation
To prepare this unit, I first had to design a template for my
food web (see Figure 1). Then I made up the names and
descriptions of each organism, based on a few real plants and
animals. In some cases, students made up the names based
on the descriptions. For example, Quadralupa was chosen as
the name for the flowering plant because it had four petals
on each flower. Some names, like Bronilla bear, were based
on actual animals (koala bears in that case). However, many
of the names, like Minedras, were completely imaginative.
Students enjoyed the naming and descriptions of animals
because there were no wrong answers. My made-up ecosystem has three types of plants, four herbivores, and a few
carnivores (Figure 2).
Next, I printed cards for each of the organisms, describing its niche in the ecosystem (Figure 3). The cards can
Michael Rockow ([email protected]) is a science teacher at Leslie
Middle School in Salem, Oregon.
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be printed on cardstock or regular copy paper, cut out, and
laminated for long life. I prepared 10 sets of cards (one set for
every group of three students), and placed each set in an envelope along with 30 three-inch pieces of yarn. To keep track
of their sets, students count the cards and place them back in
the envelopes with the yarn at the end of each period.
To help students further explore the food web, I made a
series of cards describing events that might impact this ecosystem, such as a drought or a disease that affects a certain type
of animal (Figure 4). I chose a variety of
events, some that brought constructive
FIGURE 1
changes in the ecosystem and some that
did not, some that were natural, and others that were humanmade.
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ergy in an ecosystem and, therefore, the arrows point from an
organism toward the organisms that eat it and take its energy.
During this part of the activity, I introduce key terms (predator, prey, producer, consumer, herbivore, carnivore, scavenger)
that will be used throughout the activity. The goal for the first
class period is to develop a general food chain on the board.
An outline for the whole unit can be found in Figure 5.
The second day, I assign groups and distribute the envelopes with cards and yarn and have each group of students
The food-web chain
The unit
On the first day of the unit, I introduce
the concept of a food chain by having
students discuss what humans eat and
where our energy comes from, eventually
developing the idea that energy comes
from the Sun and is transferred from one
organism to another. Students often think
food chains show predator-prey relationships and that the arrows in a food chain
point from an animal toward the organism that it eats. During this lesson, I correct these misconceptions and show that
food chains and webs trace the flow of enFIGURE 2
Note: The arrows start from the organism being eaten and the arrowheads point
toward the animal that eats it.
The food web
Note: The arrows start from the
organism being eaten and the
arrowheads point toward the animal
that eats it. Items in blue were added
as part of the final activity dealing with
animals’ niches and adaptations.
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Organism cards
FIGURE 3
Quadralupa
Flowering plants that
produce bright, red flowers
with four petals.
Minedra
Small rodents that burrow.
They eat roots of grass and fruits.
Their predators are the Tabizi
python, the Clendro hawk, and the
Rahpsheraga.
Neumelinda
Pedreaucus
Large, leafy tree that
produces Neumelinda fruits.
A long, green species
of grass.
Tukatume
Rahpsheraga
Small, wild birds that perch on
trees to eat.
Part of the big cat family.
They drink the nectar from the
blossoms of Neumelinda trees.
They eat rodents, like Minedra, and
bigger game, like Pluplenra and
Vulumadai.
Their main predator is the
Tabizi python.
These are apex predators and
have no real predators.
Pluplenra
Bronilla Bear
A species of antelope that lives
in the open.
Small yellow and brown mammals
that are not really bears.
They eat grasses and other
flowering plants.
They eat the delicious stems of
the Quadralupa plant.
Their predator is the Rahpsheraga.
Their predator is the Rahpsheraga.
Tabizi Python
Constrictor snake.
They eat birds and small rodents.
Their predators are mainly Halati.
Vulumadai
Small canines.
They are scavengers that will eat any
animal, including Tabizi pythons
and the Minedra.
Halati
A small, ferocious species of sloth.
They eat Pluplenra, Bronilla bears,
and Tabizi pythons.
Their predator is the Rahpsheraga.
Clendro Hawk
Small hawks that nest in trees.
They eat rodents like Minedra.
Their predator is the Tabizi python.
Their predator is the Rahpsheraga.
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Walaruna
Lilac Tarmal
Red Tarmal
Small, blue songbirds
that climb on trees to eat.
Lilac-colored songbirds that
perch on trees to eat.
Red-colored songbirds that
perch on trees.
They eat the seeds of the
ripening Neumelinda fruits.
They eat bugs and worms that live on
Neumelinda trees.
They eat the seeds of fruits that fall
from Neumelinda trees.
Their main predator is the
Tabizi python.
Their main predator is the
Tabizi python.
Their main predator is the
Tabizi python.
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examine them for the first time. Students should count and
read all of the cards first and then separate the cards into
groups of producers, herbivores, and carnivores. Before having students do so on their own, I construct a simple food
chain with the class on the board to demonstrate the nature
of the task. Students then copy it at their desks, connecting
the cards using pieces of yarn. The yarn should not be taped
to the cards, just placed on top illustrating the connections,
so that the materials can be easily reused. I direct students to
add more food chains to the original chain, eventually reaching the point where a few of the cards are parts of more than
one chain. While students are working, I circulate around
the class and check for understanding, often reminding students that they should start each food chain with a producer.
During this time, I make sure students have read the cards
and know what each organism eats. Students quickly realize
that a food web is made up of many food chains. The class
period ends with students making a food web using all of the
FIGURE 4
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cards and recording the food web
in their notes.
On the third day, we cover
limiting factors and relationships in ecosystems. Students
play “Oh Deer!” (Dalton 1992), an
interactive game that demonstrates what
happens to a population of animals when there
are more animals than the ecosystem can support (see Figure 6 for instructions and explanations of this game). Students sometimes have
the misconception that if the population of a
species declines, extinction will follow. This activity shows students that populations can decline and then
rebound, without leading to extinction. At the end of this
period I talk about the limitations of this activity as a model
for an ecosystem and the class discusses the effects of predators, disease, and hunters on the deer population.
Event cards
A terrible drought occurs in
this ecosystem. Due to the
disaster, most of the grasses
dry up and die.
Lightning storms trigger
wildfires that burn up a lot of
the plants and grasses in
the ecosystem. Trees are
mostly spared.
A strange disease finds its
way to the area. It causes the
fruits of the Neumelinda tree to
fall off before they are ripe.
A rumor circulates among the
native peoples that the teeth of
the Bronilla bear can cure baldness.
This triggers increased hunting
of the animal.
A Rahpsheraga comes
in contact with some local
farmers. The farmers begin
hunting the Rahpsheraga
in large numbers
to protect their herds.
Laws are enacted that place
strict limits on the hunting of
Minedra, previously valued for
their soft, warm fur.
A disease, spread by farmers’
livestock, begins to kill off the
Pluplenra.
People have discovered how
tasty the fruits of the Neumelinda
tree are and have begun spraying
them with pesticides. The pesticides
are causing the eggs of the
Tukatume to become too fragile
and their babies are dying.
Until recently, natives killed
the Clendro hawk for their tail
feathers. They have stopped this
practice after animal rights groups
complained about it.
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Day
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Unit outline
Concept
Food
chains
Food
webs
3
Limiting
factors
4
Human
interaction
with
natural
ecosystem
Questions
What did you eat this morning?
Do you get your energy from the
food you ate?
Where does a cow get its energy?
Where does the grass get
its energy?
What is a food chain and what does
it show?
What is a food web?
What type of animal eats only
plants? Only meat? Both?
What does a Minedra eat?
What predators do Minedras have?
If we remove the Minedra from
the food web, what organisms will
benefit? Why?
What organisms will suffer? Why?
What do plants and animals need
to survive?
What happens to an animal if it
doesn’t get what it needs?
If a species declines in a year, can
it recover?
After the game:
We played this in the classroom;
how would it be different if we
played it in a field?
Would adding predators affect
the results?
Vocabulary
producer,
consumer,
herbivore,
carnivore,
omnivore,
scavenger,
predator, prey,
food chain
food web
limiting factors,
carrying
capacity
Assignment
a. Define the vocabulary
b. Take notes
a. Using three of the organism cards and yarn to
connect them, make a food chain. Put a producer
at the top. Next, find an herbivore that eats that
plant. Connect them with yarn. Next, find a
carnivore that eats the herbivore and connect it
to the herbivore.
b. Make another food chain next to the first,
again with a producer at the top. You may use an
organism that was used in the first food chain.
c. Continue to add food chains until all the
organism cards are used in your food web.
d. Copy the food web you have into your notes.
a. Play “Oh, Deer!” game.
b. Discuss the results of the game.
c. Graph the number of deer in each round.
How can people damage an
ecosystem?
How can we improve an
ecosystem?
What can happen in an ecosystem
if we disturb the balance?
You have been hired as environmental reporter,
assigned to write a news article about an
environmental event that has altered this
ecosystem. Your article should summarize the
event and discuss which organisms are affected
and how they are affected.
What do lions and cheetahs eat?
Does competition help or hurt
those animals?
Can animals live together and avoid
competition?
a. Read section of book on bird adaptations.
b. Identify what shapes of feet are suited for
perching, climbing, and hunting.
c. Identify what shapes of beak are suited for
eating meat, bugs, nuts, and insects.
d. Using descriptions of birds in our ecosystem,
draw any two of them. Students must make sure
the beaks and feet that they draw are appropriate
for the birds’ niche.
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Adaptation
and niche
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niche,
adaptation
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FIGURE 6
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Oh, Deer! (This activity is adapted from Dalton 1992.)
Before you start
To play, make sure you have an odd number of students involved in the game itself. If I have an even number of students, I will
make one a scorekeeper so I have an odd number of students playing. It is important to note that the teacher does not control
the number of deer. As long as there is an odd number of students, the game will continue as long as you want. All students play
every round, sometimes they will be deer and sometimes they will be environment.
Instruction
What it means
Split the class into two groups. Document the number of deer
in a chart on the board. Chart should be a two-column chart
with the number of the round being played in one column and
the number of deer in that round in the other column.
One group represents deer and they stand in the back of the
room. The other group represents factors in the environment
that the deer need and they stand in the front of the room.
All students in both groups are given three 3” x 3” pieces of
colored paper: brown, green, and blue.
Brown represents shelter, green represents food, blue
represents water.
Instruct each student in the deer group to choose one of the three
colors and put the other two squares in his or her pocket.
Instruct each student in the environment group to also select
one of the three colors.
This color represents what the deer needs for survival that
round, and the environmental factor that a particular student
will be during the round.
To play a round, instruct the deer to cross the room and try to
find a student in the environment who has chosen the same
color. Deer are only allowed to match one student and can
only match a student from the environment, not other deer.
If they find a match, they can return to the back of the
room, bringing with them the student from the environment
that they matched. Both of these students are now deer and
will be deer in the next round.
If they do not find a match, they do not return to the
deer side of the room. Instead, they will be part of the
environment in the next round.
If a deer was successful, it was a good year because the
deer found what it needed for survival and reproduced.
If the deer is unable to find a match, the deer dies and
becomes part of the environment for the next round.
Teachers should point out that this means there was not
enough food or water and some deer could not find enough
to survive. This is a good example of a limiting factor.
After the round is over, document the number of deer that
are left in the deer population. Students get ready to play
another round.
The game is played in rounds so that you can observe the
fluctuation in the number of deer from year to year. Each
round represents a year.
Discussion questions
What is a limiting factor? What represented limiting factors in our game?
Describe what happened to the deer population during our game.
During the game, the deer experienced some very good years, when their population was quite large. What happened the
following year? Why?
During the game, the deer experienced some very bad years, when their population was quite small. What happened the following
year? Why?
Did the deer ever go extinct? Why?
We played this in the classroom; how would it be different if we played it in a field?
Would adding predators affect the results? How?
Once students understand limiting factors and food
webs, the next day is spent exploring what events can affect their ecosystem and how it will respond. The class
talks about what might happen if we remove an organism
or if its population increases or decreases. The experience
with the previous day’s game helps students realize that a
population can decrease without leading to extinction.
Next, I randomly distribute different event cards to students and ask them to write a newspaper article describing
the event on the card and explaining the effects of the event.
The cards describe events ranging from changes in pesticide
use to changes in hunting laws to droughts and can be seen
in Figure 4. Students must write a headline, describe the
event they were given by paraphrasing the card, and explain
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the short- and long-term effects of the event. Finally, students suggest ways that people can help ease the situation.
The writing assignment is designed as an assessment tool to
see if students understand how changes to one species can
affect other species in an ecosystem. Teachers who want to
relate this topic to actual ecosystems or modify the unit for
advanced students or classes could assign research on real
events similar to events described on the cards.
In the final activity in this unit, the class looks at animals’ niches in the ecosystem and how they adapt to their
environment. This activity begins with a discussion about
competition in an ecosystem, how it affects organisms, and
how it can be avoided. Lions and cheetahs can be used to
illustrate how animals are affected by direct competition
when they occupy the same niche in an ecosystem, and
birds illustrate how adaptations allow a number of species
to occupy different niches in the same ecosystem.
For example, I have students begin studying birds by
examining pictures of bird beaks and feet. These can come
from textbooks (Bierer and Lien 1984) or from magazines.
The teacher should also make sure that the pictures clearly
show which shapes of bird feet are adapted for perching,
climbing, wading, and hunting (talons). The teacher should
show students pictures of beaks that are adapted to eat nuts,
bugs, worms, fish nectar, and small birds and mammals. I
set up two matching activities, one where students have
to match the correct bird foot shape (e.g., three toes facing forward and one facing back) with the correct activity
(e.g., perching) and another where students match the correct beak design (e.g., sharp and hooked) with the correct
food source (e.g., meat). I then instruct students to use the
descriptions on the organism cards (Figure 3) to sketch two
of the birds in the ecosystem. Because the birds are designed
to have a different niche in the ecosystem, each bird has a
specific beak and foot design. With their newfound knowledge, students should be able to sketch the appropriate beak
and foot shape for whichever birds they choose. Other than
color, which can be specified on the cards, the rest of the
details are up to students’
imaginations. The
goal for this activity is to have students demonstrate that
they know each bird is uniquely adapted to its niche.
Adapting the lesson
This unit is easy to use with English language learners
(ELL) and slow readers because there is not much reading. With these groups of students, it is important to
teach the vocabulary before the unit starts. Once they
know the basic vocabulary, read the cards out loud with
students before they start to work on their own.
The writing assignment on the fourth day can be a problem
for ELL students. Teachers can have ELL students write in their
native language. This writing assignment can also be problematic for students who write poorly. Instead of the writing assignment, teachers can assign oral reports for these students.
If the names of the organisms or the language on the
cards is too difficult for students, teachers are encouraged
to work with students to make up their own organisms.
The teacher should first make up a template of the ecosystem (as in Figure 1). Teachers can then write a description
for each organism. An easy way to do this is to describe real
animals without using their names. The description for the
made-up Rahpsheraga is based on a lion and the Minedra is
based on a chipmunk. Once the descriptions are in place,
give them to students and let them make up any name they
want to as long as it is appropriate for school.
Conclusion
I like this approach to teaching ecosystems for a number
of reasons. By inventing organisms, I’m able to control the
level of complexity, and the number of organisms can be
modified to meet each student’s level. Because the organisms are made up, the assignment is not complicated by
students’ prior knowledge. Once the unit is finished, the
class can discuss the ecosystem and how it is similar to and
different from real ecosystems.
The biggest advantage that I see with this approach is
its flexibility; I can design the organisms to illustrate any
number of concepts. I use it to illustrate food chains, food
webs, animal adaptation, and niche, but other teachers
will surely find even more ways to use this approach. ■
Acknowledgments
This article first appeared in different form in The Oregon Science
Teacher, 2006, 47 (4): 12–15.
References
Bierer, L.M., and V.F. Lien. 1984. Life science. Lexington, MA:
DC Heath and Company.
Dalton, P. 1992. ProjectWILD. Bethesda, MD: Western Regional Environmental Education Council, Inc.
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