Ecology Module
Keely Davidson-Bennett
NSF STEM Graduate Fellow in K-12 Education, Sugar Creek Watershed Project
Ohio State University – Ohio Agricultural Research and Development Center
December 2010
Module developed with the help of Mrs. Laura Grimm, Dalton Intermediate teacher
Lessons:
1) Deer overpopulation
2) Symbiotic relationships
Deer Overpopulation Activity
Summary:
Students explore the impacts of high deer densities on Ohio forest ecosystem through a
simulation activity.
Ohio Curriculum Alignment:
Grade 7 Standard: Life Science
4: Investigate how overpopulation impacts an ecosystem.
Objective:
Students will be able to identify reductions in plant abundance and plant biodiversity as
consequences of high deer densities.
Context:
Students should begin the activity with some knowledge of population
fluctuations. This could be accomplished by using a food web diagram to have students predict
what will happen to the number of organisms one trophic level below or above a given organism
if that given organism’s population size increases or decreases. Students can also predict
changes in more than one trophic level from the affected organism. Once students have an
understanding of population fluctuations and the ways that populations respond to changes in
other populations’ numbers, the instructor can introduce the idea of overpopulation occurring in
a disturbed system.
Activity
Time: About 15 minutes
Materials: 32 small pieces of blue construction paper
32 small pieces of yellow construction paper
5 crayons
Smartboard or Chalkboard with chalk
Stopwatch, alarm, or clock
Student Instructions:
1) Deer prefer blue plants to yellow plants, so they will chose blue over yellow if blue plants are
available.
2) Deer will browse (eat) for 30 seconds. Deer will represent their bites by drawing an X on the
construction paper. One X = one bite.
3) Deer need to move from table to table after each bite of a plant.
4) After a plant receives 3 bites, it dies. Move it away from the other plants to keep track of live
plants.
Teacher Instructions:
1) The teacher should distribute 8 small pieces of blue construction paper and 8 small pieces of
yellow construction paper around the classroom prior to each round.
2) For the first round, the instructor should designate 2 students as deer by giving them each a
crayon. Let the deer browse for 30 seconds.
3) Draw a chart like this one on the board for students to record their data:
# of Deer # of Yellow Plants # of Blue Plants Total # Plants 2 3 4 5 4) After the first round, have students count the number of yellow and blue plants that are still
alive. Record these numbers in the table.
5) For the second round, introduce a third deer. Allow the deer to browse for 30 seconds, and
record the number of each kind of plant alive at the end of the round in the table.
6) Repeat the process, adding an additional deer each round until you reach 5 deer.
7) Discuss the data with the students. They should see that the number of plants declines as deer
density increases. They should also note that the ratio of blue plants to total plants also decreases
at high deer densities.
Transition back to lecture:
The teacher should make sure that students understand the impact of high deer densities
on plant biodiversity. If students are unfamiliar with the term biodiversity, it should be taught in
conjunction with this activity. The teacher could illustrate the effects of deer overpopulation
using pictures and case studies from Ohio. The accompanying presentation illustrates how this
activity could be included in a lecture on deer overpopulation. "Food Web for a Tundra Community." Science Online. Facts On File, Inc. Web. 1 Dec.2010.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=SciIllus03120&SingleRecord=True>.
What is Overpopulation?
• How do we know if there are too many?
White‐tailed Deer ‐ An Ohio Example
Photo by Stephen J. Krasemann from World Book Advanced Encyclopedia Simulating The Effects of Deer Overpopulation
• Deer prefer blue plants to yellow plants, so they will chose blue over yellow if blue plants are available.
• Deer will browse (eat) for 30 seconds.
• Deer need to move from table to table after each bite of a plant.
• After a plant receives 3 bites, it dies. Move it away from the other plants to keep track of live plants.
# of Deer
# of Yellow Plants
# of Blue Plants
Total # Plants
Effects of High Deer Densities
Picture from Cuyahoga Valley National Park publication Picture from Metroparks Serving Summit County
What are the causes of deer overpopulation?
Other Effects
Areas with high deer impact have:
•lower numbers of under-story trees
•less leaf litter
•drier soils
•fewer small mammals and fewer
invertebrates on which the small
mammals feed.
Assignment
• List 3 ways that high deer densities affect Ohio forest ecosystems. • List 2 reasons why a population might become overpopulated
• Use complete sentences
Symbiotic Relationships Activity
Summary: Students consider depicted symbiotic relationships and attempt to identify them.
Ohio Curriculum Alignment: Life Sciences
2. Investigate how organisms or populations may interact
with one another through symbiotic relationships and how some species have become so adapted
to each other that neither could survive without the other (e.g., predator-prey, parasitism,
mutualism and commensalism).
Objectives:
1) Students will eliminate types of relationships that are not depicted in the picture.
2) Students will be able to give examples for each type of symbiotic relationship.
3) Students will develop good questions they would ask to identify relationships that are unclear
from the pictures.
Context: Prior to beginning this activity, students should understand the definitions for
predator-prey, parasitism, mutualism and commensalism and should have been exposed to some
examples of each type of relationship.
The activity
Materials: 2 sets of pictures
1 set with pictures of a monarch butterfly on a milkweed plant, an Arctic fox with
a least auklet, a horned lark nest containing brown cowbird eggs, and barnacles living on a whale
(# of copies needed = class size/4)
1 set with pictures of ferns living on a tree, a lemur eating fruit, a parasitoid wasp
feeding on a beetle larvae, a clownfish with a sea anemone
(# of copies needed = class size/4)
Worksheets
Questions 1-4 (# of copies needed = class size/4)
Questions 5-8 (# of copies needed = class size/4)
Optional PowerPoint to assist with discussing answers
2. Students work in pairs to determine what they can about pictured relationships with short
captions. A worksheet will guide their discussions and thought processes. Half of the pairs will
work on pictures 1-4 & the other half will work on 5-8. The worksheets contain the following
questions, with species names inserted for organism A and B.
a) How do you think organism A and organism B interact?
b) What do you think organism A obtains from this relationship?
c) What do you think organism B obtains from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
3. As a class, discuss each relationship using the students’ answers to the questions, as well
as providing them with the correct answer.
Each of the following illustrates a symbiotic relationship between 2 organisms. The relationships are one of the following: mutualism, commensalism, parasitism, or predator‐prey. 1) Monarch Butterfly & Milkweed 2) Arctic fox with a Least Auklet 3) Horned Lark Nest with Brown Headed Cowbird Eggs Brown Headed Cowbird Eggs 4) Barnacles Living on a Whale 5) Ferns living on a tree 6) Ring tailed lemur eating fruit 7)Wasp Feeding on a Beetle Larvae 8) Clownfish with Anemone Names____________________________________
Section____________
Use the pictures and captions to answer the following questions.
1. a) How do you think the monarch butterfly and the milkweed interact?
b) What do you think the butterfly obtains from this relationship?
c) What do you think the milkweed obtains from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
2) a) How do you think the Arctic fox and the least auklet interact?
b) What do you think the Arctic fox obtains from this relationship?
c) What do you think the least auklet obtains from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
3. a) How do you think the brown headed cowbird and the horned lark interact?
b) What do you think the horned lark obtains from this relationship?
c) What do you think the brown headed cowbird obtains from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
4. a) How do you think the barnacles and the whales interact?
b) What do you think the whale obtains from this relationship?
c) What do you think the barnacles obtain from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
Names____________________________________
Section____________
Use the pictures and captions to answer the following questions.
5. a) How do you think the ferns and the tree interact?
b) What do you think the tree obtains from this relationship?
c) What do you think the ferns obtain from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
6. a) How do you think the ring tailed lemur and the plant that produced the fruit interact?
b) What do you think the ring tailed lemur obtains from this relationship?
c) What do you think the plant obtain from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f ) What questions would you ask in order to identify this relationship?
7. a) How do you think the wasp and the beetle larvae interact?
b) What do you think the wasp obtains from this relationship?
c) What do you think the beetle larvae obtains from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
8. a) How do you think the clownfish and the anemone interact?
b) What do you think the anemone obtains from this relationship?
c) What do you think the clownfish obtains from this relationship?
d) What kinds of relationships is this not? How can you eliminate those?
e) What kinds of relationships do you think this may be? Why do you think that?
f) What questions would you ask in order to identify this relationship?
Symbiosis Relationship Answer Key
1. Mutualism
The monarch butterfly on the milkweed is designed to be a general example of pollination.
2. Predator-prey
The Arctic fox with the least auklet in its mouth illustrates the predator-prey relationship.
3. Parasitism
The brown cowbird illustrates brood parasitism. This species lays its eggs in other birds’
nests, leaving the other birds to raise its offspring. The host bird’s offspring suffer because the
brown cowbird babies are using their resources.
4. Commensalism
Barnacles live on whales. The barnacles benefit from being transported to food sources
as the whales move. The whales are not affected by this interaction.
5. Commensalism
These ferns are epiphytes. They benefit from having more light from being higher in the
canopy. They also benefit from the organic matter that accumulates in the nooks and crannies of
the trees.
6. Mutualism
Ring tailed lemurs get food from the plant and the plant is benefited by the lemur
dispersing the seeds.
7. Parasitism
The parasitoid wasp feeds on the beetle larvae.
8. Mutualism
The clownfish gains protection from predators by living in an anemone, which stings
most fish. The anemone gains nutrients from the clownfish.