Colorado Agriscience Curriculum
Section
Animal Science
Unit
Unit 7: Animal Behavior and Environment
Lesson Title
Lesson 6: Animal Populations and Environments
Agricultural Education Standards
Standard AGS 11/12.3 The student will demonstrate an understanding of physiological
processes in agriculturally important animals.
Enabler AGS 11/12.3.37 Describe how animals adapt to their environments and
how that affects management practices.
Science Standards
Standard SCI 3.0 Life Sciences: The students know and understand the characteristics
and structure of living things, processes of life and how living things interact with each
other and with their environment.
Competency SCI 3.1 Students know and understand the characteristics of
living things, the diversity of life, and how things interact with each other
and with the environment.
Competency SCI 3.12 Predicting and describing the interactions of
populations and ecosystems.
Competency SCI 3.14 Explaining how changes in an ecosystem can
affect biodiversity and how biodiversity contributes to an ecosystem’s
stability.
Competency SCI 3.15 Analyzing the dynamic equilibrium of ecosystems,
including interactions among living and nonliving components.
Student Learning Objectives (Enablers)
As a result of this lesson, the student will …
1. Students will be able to define carrying capacity and describe how it relates to an
ecosystem and population.
2. Students will describe relationships between species in relation to feeding, energy and
survival
3. Students will create and understand a food web with basic animals.
Time Instruction time for this lesson: 50 minutes.
Unit 7, Lesson 6: Animal Populations and Environments
1
Resources
 http://www.biologycorner.com/worksheets/kaibab.html (Lesson of the Kiabab)
 Biology, the Dynamics of Life Textbook
 http://www.bigelow.org/edhab/fitting_algae.html (Food Chain and Web Info.)
 http://www.harcourtschool.com/activity/food/arctic_activity.html (Food Web Games)
 http://www3.gov.ab.ca/srd/fw/watch/owls_food.html (Owl Food Chain)
Tools, Equipment, and Supplies
 Graph Paper
 Lesson of the Kiabab Worksheets
 Powerpoint Presentation / Equipment for Viewing
 Notes worksheets, Flow of Energy Handouts
Key Terms. The following terms are presented in this lesson and appear in bold italics:
Carrying capacity, Autotrophs, Predator-prey, Heterotrophs, Commensalisms, Omnivores,
Mutualism, Herbivores, Parasitism, Carnivores, Scavengers, Decomposers
Interest Approach
What would happen if the school superintendent required for there to be 100 kids in every
classroom for every period of the day? The classrooms would be overcrowded. What
implications would it have? (Not enough desks, chairs, restrooms, materials to learn)
Would we be successful in learning? (No! We would be beyond our carrying capacity!)
You have just explained to me one the many concepts we’ll learn about today. The
concepts we’ll study are important because they affect us and the environment around us.
Summary of Content and Teaching Strategies
Objective 1. Students will be able to define carrying capacity and describe how it relates
to an ecosystem and population.
If you have posters of wildlife species, this is a good time to display them for your class.
Wildlife Management is one area of agriculture that is rapidly growing. Specialists in this
area spend much of their time managing animal populations to ensure that the ecosystem
they live in is protected. Scientists have discovered, through a series of experiments, that
population size does have a limit. Factors such as food and space determine how many
animals a given ecosystem can support. It’s important that we know this definition:
(Write on the board)
Carrying capacity: The number of organisms of a population that a particular
environment can support over an indefinite period of time.
When populations are under carrying capacity, births exceed deaths until capacity is
reached. If the population overshoots capacity, deaths will temporarily exceed births until
the population is stable again. This seems simple enough, but in reality, there are a lot of
Unit 7, Lesson 6: Animal Populations and Environments
2
factors that complicate this process. In the next twenty minutes, I would like you and a
partner to become wildlife specialists and complete a case study called the Lesson of the
Kiabab. You will need to graph some population data and analyze the situation. You
each need to produce a graph; however, only one worksheet needs to be completed.
You’ll find graph paper in the back of the room. Go investigate!
Objective 2. Students will describe relationships between species in relation to feeding,
energy and survival
Did you know that in some sub-tropical regions of the world, there are acacia trees that
have worked out a great deal with a particular species of ant? The ant protects the tree by
attacking any herbivore that tries to feed on it and cleans vegetation away from the trunk.
The tree provides nectar and a home for the ants. This is what we call mutualism. It’s a
type of relationship we find in nature in which both species benefit. This is just one
example of the relationships we’ll study today. We can’t understand wildlife until we
understand some of the types of relationships they have formed. As we talk about these
relationships, you’ll record them on the Special Relationships Worksheet. After we
record information about each relationship, we’ll brainstorm together about some
common examples of this relationship.
Use Powerpoint Presentation to review this information. Worksheet and worksheet key
follow later in lesson. After each definition, ask the students for an example before
clicking again to make the example come up on the screen. At the end of the
presentation, have the students turn to the person next to them and quiz them on the terms
they recorded on their worksheets.
SLIDE #2
Special Relationships in Wildlife
I.
Many relationships are formed around organisms obtaining energy through
feeding.
a. Autotrophs: Organisms that use energy from the sun or energy stored in
chemical compounds to manufacture food.
i. Plants
ii. Some single cell organisms.
SLIDE #3
b. Heterotrophs: Organisms that depend on autotrophs as their source of
nutrients and energy.
i. Consumers – can’t make their own food.
ii. Herbivores: Feed directly on autotrophs
1. cattle, rabbits, grasshoppers
iii. Carnivores: Eat other Heterotrophs
1. lions
Unit 7, Lesson 6: Animal Populations and Environments
3
SLIDE #4
iv. Scavengers: Some feed on carrion, refuse and dead
1. black vultures, buzzards, ants, beetles
v. Omnivores: Organisms that eat a variety of foods that include both
plant and animals materials.
1. Humans, raccoons, coyotes, bears
vi. Decomposers: break down the complex compounds of dead and
decaying plants and animals.
1. Bacteria, fungi, protozoan
SLIDE #5
II.
Other relationships are formed around organisms for survival
a. Predator-prey: Some animals must kill others for food for survival
i. Lions kill gazelle & wildebeests
SLIDE #6
b. Symbiosis: A close and permanent association between organisms of different
species.
i. Commensalisms: one species benefits and the other species is neither
harmed nor benefited.
1. Spanish moss growing on a tree
ii. Mutualism: Both species benefit.
1. Ants on the acacia tree
iii. Parasitism: One organism derives benefit at the expense on another,
but without killing it.
a. Fleas, ticks, tapeworms, roundworms
Objective 3. Students will create and understand a food web with basic animals.
When you pick an apple from a tree and eat it, you are consuming carbon, nitrogen and other
elements the tree has used to produce the fruit. That apple also contains energy from the sunlight
trapped by the tree’s leaves while the apple was growing and ripening.
This example reminds us that matter and energy are constantly cycling through stable
ecosystems. Ecologists study interactions, such as the ones we just talked about, to trace the flow
of matter and energy through ecosystems. They chart their findings through food chains and food
webs.
On the Flow of Energy handout I gave you, you’ll see an example of a food chain on the left and
a food web on the right. A food chair is a linear depiction of energy flow. A food web shows the
multiple interactions among the different types of organisms. Food webs are generally more
realistic in portraying the energy flow in a system because most organisms eat more than one
type of food and can be eaten by several predators. The examples you have is a typical food
chain and web of a deciduous forest. Grasshoppers eat the grass; mice eat the grasshoppers; and
owls eat the mice. The web is more complicated, and it is even missing many links, for
Unit 7, Lesson 6: Animal Populations and Environments
4
simplicity’s sake. The arrows in these images indicate the direction of energy flow.
(After discussing the handout with the above dialog, students should use a computer for the
following activity.)
In the next 5-10 minutes, you will each visit the website listed on your worksheet to practice
making food webs. Play the three food web games: Meadow Food Web, Artic Food Web, Pond
Food Web. After you have practiced, you will come back and draw your own food web with the
animals listed at the bottom of your page. (Students may need help with this if they are not
familiar with the diets of the animals)
If you have extra time, work on committing the vocabulary from earlier to memory for a short
quiz before we leave today.
Review/Summary.
Use the attached quiz over vocabulary for review by allowing students to complete it with
their notes. Then use version 2 of the quiz for students to complete without their notes for
a grade. The information is the same but the order has been changed and mixed up.
Application
Extended classroom activity:
 Visit this website: www.vtaide.com/png/foodweb.htm so students can create a graphic
image of a food web and print it.
 Have students create a poster that includes an agricultural food web, for example, draw
one with humans, cattle, dogs, cats, grains, grass, etc.
FFA activity:
 Use the food web concept to graph out dependency of officers on each other for
leadership attributes, support and success. Have students draw their own web of
dependency.
Evaluation.
Version 2 of the quiz should be graded for credit. It is a variation of the first version,
using the principle of repetition to learn vocabulary.
Answers to Assessment:
Keys for the worksheets follow them.
Version 1 Quiz Answers
1.
F
2.
J
3.
D
4.
L
Unit 7, Lesson 6: Animal Populations and Environments
5
5.
6.
7.
8.
9.
10.
11.
12.
G
A
B
H
C
I
E
K
Version 2 Quiz Answers
1.
A
2.
E
3.
H
4.
F
5.
D
6.
J
7.
B
8.
L
9.
G
10.
K
11.
I
12.
C
Unit 7, Lesson 6: Animal Populations and Environments
6
Case Study: The Lesson of the Kaibab
Names _____________________________ ______________________________________
The carrying capacity of an ecosystem is the maximum number of organisms that an area can
support on a sustained basis. The density of a population may produce such profound changes in
the environment that the environment becomes unsuitable for the survival of that species. For
instance, overgrazing of land may make the land unable to support the grazing of animals that
lived there.
Background
Before 1905, the deer on the Kaibab Plateau were estimated to number about 4000. The
average carrying capacity of the range was then estimated to be about 30,000 deer. On November
28th, 1906, President Theodore Roosevelt created the Grand Canyon National Game Preserve to
protect the "finest deer herd in America. "Unfortunately, by this time the Kaibab forest area had
already been overgrazed by sheep, cattle, and horses. Most of the tall grasses had been
eliminated. The first step to protect the deer was to ban all hunting. In addition, in 1907, The
Forest Service tried to exterminate the predators of the deer. Between 1907 and 1939, 816
mountain lions, 20 wolves, 7388 coyotes and more than 500 bobcats were
DATA TABLE killed.
Year
1905
1910
1915
1920
1924
1925
1926
1927
1928
1929
1930
1931
1935
1939
Deer
Signs that the deer population was out of control began to appear as early as
Population 1920 - the range was beginning to deteriorate rapidly. The Forest Service
4,000 reduced the number of livestock grazing permits. By 1923, the deer were
reported to be on the verge of starvation and the range conditions were
9,000 described as "deplorable."
25,000
The Kaibab Deer Investigating Committee recommended that all livestock not
65,000
owned by local residents be removed immediately from the range and that the
100,000 number of deer be cut in half as quickly as possible. Hunting was reopened,
60,000 and during the fall of 1924, 675 deer were killed by hunters. However, these
deer represented only one-tenth the number of deer that had been born that
40,000
spring. Over the next two winters, it is estimated that 60,000 deer starved to
37,000 death.
35,000
Today, the Arizona Game Commission carefully manages the Kaibab area with
30,000 regulations geared to specific local needs. Hunting permits are issued to keep
25,000 the deer in balance with their range. Predators are protected to help keep herds
20,000 in balance with food supplies. Tragic winter losses can be checked by keeping
the number of deer near the carrying capacity of the range.
18,000
10,000 DATA
1. Graph the deer population data. Place time on the X axis and "number
Unit 7, Lesson 6: Animal Populations and Environments
7
of deer" on the Y axis
Analysis
1.
During 1906 and 1907, what two methods did the Forest Service use to protect the
Kaibab deer?
2.
Were these methods successful? Use the data from your graph to support your answer.
3.
Why do you suppose the population of deer declined in 1925, although the eliminated of
predators occurred?
4.
Why do you think the deer population size in 1900 was 4,000 when it is estimated that the
plateau has a carrying capacity of 30,000?
5.
Why did the deer population decline after 1924?
6.
Based on these lessons, suggest what YOU would have done in the following years to
manage deer herds.
1915:
1923:
7.
It is a criticism of many population ecologists that the pattern of population increase and
subsequent crash of the deer population would have occurred even if the bounty had not
been placed on the predators. Do you agree or disagree with this statement. Explain your
reasoning.
8.
What future management plans would you suggest for the Kaibab deer herd?
Unit 7, Lesson 6: Animal Populations and Environments
8
Lesson of the Kaibab Key
Analysis
1.
During 1906 and 1907, what two methods did the Forest Service use to protect the
Kaibab deer?
Ban all deer hunting, exterminate predators
2.
Were these methods successful? Use the data from your graph to support your answer.
Yes in the short term. No in the long term because the population got out of control.
3.
Why do you suppose the population of deer declined in 1925, although the eliminated of
predators occurred?
Deer were starving to death.
4.
Why do you think the deer population size in 1900 was 4,000 when it is estimated that the
plateau has a carrying capacity of 30,000?
Because the area had been overgrazed by sheep and cattle.
5.
Why did the deer population decline after 1924?
The population was over carrying capacity.
6.
Based on these lessons, suggest what YOU would have done in the following years to
manage deer herds.
1915: Reinstated some hunting, allow some predators.
1923: Increase hunting and natural predators.
7.
It is a criticism of many population ecologists that the pattern of population increase and
subsequent crash of the deer population would have occurred even if the bounty had not
been placed on the predators. Do you agree or disagree with this statement. Explain your
reasoning.
Student opinion
8.
What future management plans would you suggest for the Kaibab deer herd?
Student opinion
Unit 7, Lesson 6: Animal Populations and Environments
9
Special Relationships in Wildlife Worksheet
Name _______________________________
Type
Autotrophs
Date ________________________
Definition
Examples
Heterotrophs
Herbivores
Carnivores
Scavengers
Omnivores
Decomposers
Predator-prey
relationships
Symbiosis
Commensalisms
Mutualism
Parasitism
Unit 7, Lesson 6: Animal Populations and Environments
10
Special Relationships in Wildlife Key
Name _______________________________
Date ________________________
Type
Autotrophs
Definition
Organisms that use energy from the sun or energy
stored in chemical compounds to manufacture
food.
Examples
Plants
Some single cell
organisms.
Heterotrophs
Humans
Herbivores
Organisms that depend on autotrophs as their
source of nutrients and energy.
Feed directly on autotrophs
Carnivores
Eat other Heterotrophs
lions
Scavengers
Feed on carrion, refuse and dead
Omnivores
Organisms that eat a variety of foods that include
both plant and animals materials.
black vultures,
buzzards, ants,
beetles
Humans, raccoons,
coyotes, bears
Decomposers
Break down the complex compounds of dead and
decaying plants and animals.
Bacteria, fungi,
protozoans
Predator-prey
relationships
Some animals must kill others for food for
survival
Lions kill
wildebeests
Symbiosis
A close and permanent association between
organisms of different species.
Commensalisms
One species benefits and the other species is
neither harmed nor benefited.
Falcons protect
geese during
nesting
Spanish moss
growing on a tree
Mutualism
Both species benefit
Ants on the acacia
tree
Parasitism
One organism derives benefit at the expense on
another, but without killing it.
Fleas, ticks,
tapeworms,
roundworms
Unit 7, Lesson 6: Animal Populations and Environments
cattle, rabbits,
grasshoppers
11
The Flow of Energy Handout
Matter and energy are constantly cycling through stable ecosystems. Ecologists study
interactions to trace the flow of matter and energy through ecosystems. They chart their findings
through food chains and food webs.
This is a typical food chain and web of a deciduous forest. Grasshoppers eat the grass; mice eat
the grasshoppers; and owls eat the mice. The arrows in these images indicate the direction of
energy flow.
Food Chain
A food chair is a linear depiction of
energy flow.
Food Web
A food web shows the multiple interactions
among the different types of organisms.
Food webs are generally more realistic in
portraying the energy flow in a system
Visit this website:
http://www.harcourtschool.com/activity/food/food_menu.html because most organisms eat more than one
type of food and can be eaten by several
Play the three food web games:
predators. The web is more complicated,
Meadow Food Web, Artic Food Web,
and it is even missing many links, for
Pond Food Web.
simplicity’s sake.
They are quick click and drag games that help
students understand the correct order of a food web.
Create your own food web! On the back of this paper, create your own food web with these
organisms: Owl, Weasel, Snowshoe Hare, Mouse, Green Plants, Grouse, Insects, Shrew, Bat
Unit 7, Lesson 6: Animal Populations and Environments
12
Key for create your own food web activity on The Flow of Energy Handout
Unit 7, Lesson 6: Animal Populations and Environments
13
Animal Populations and Environments
Quiz Version 1
Write the letter of the definition that best fits the vocabulary word in the space provided.
Name ____________________________________ Date ____________________________
Answers
Vocabulary Word
Definitions
1.
Autotrophs
A. Organisms that eat a variety of foods that
include both plant and animals materials
2.
Heterotrophs
B. Break down the complex compounds of
dead and decaying plants and animals.
3.
Herbivores
C. A close and permanent association between
organisms of different species.
4.
Carnivores
D. Feed directly on autotrophs
5.
Scavengers
E. Both species benefit
6.
Omnivores
7.
Decomposers
F. Organisms that use energy from the sun or
energy stored in chemical compounds to
manufacture food.
G. Feed on carrion, refuse and dead
8.
Predator-prey relationships
H. Some animals must kill others for food for
survival
9.
Symbiosis
I. One species benefits and the other species is
neither harmed nor benefited.
10.
Commensalisms
J. Organisms that depend on autotrophs as
their source of nutrients and energy.
11.
Mutualism
K. One organism derives benefit at the
expense on another, but without killing it.
12.
Parasitism
L. Eat other Heterotrophs
Unit 7, Lesson 6: Animal Populations and Environments
14
Animal Populations and Environments
Quiz Version 2
Write the letter of the definition that best fits the vocabulary word in the space provided.
Name ____________________________________ Date ____________________________
Answers
Vocabulary Word
Definitions
1.
Autotrophs
A. Organisms that use energy from the sun or
energy stored in chemical compounds to
manufacture food.
2.
Heterotrophs
B. Break down the complex compounds of
dead and decaying plants and animals.
3.
Herbivores
C. One organism derives benefit at the
expense on another, but without killing it.
4.
Carnivores
D. Feed on carrion, refuse and dead
5.
Scavengers
E. Organisms that depend on autotrophs as
their source of nutrients and energy.
6.
Omnivores
F. Eat other Heterotrophs
7.
Decomposers
G. A close and permanent association between
organisms of different species.
8.
Predator-prey relationships
H. Feed directly on autotrophs
9.
Symbiosis
I. Both species benefit
10.
Commensalisms
J. Organisms that eat a variety of foods that
include both plant and animals materials
11.
Mutualism
K. One species benefits and the other species
is neither harmed nor benefited.
12.
Parasitism
L. Some animals must kill others for food for
survival
Unit 7, Lesson 6: Animal Populations and Environments
15