Download Florida 4-H Environmental Education Activities

4H EEX 01
Florida 4-H Environmental Education Activities
GOOBER ETUS
Grade Level
Sunshine State
3-8
Science
SC. G. 1. 2. 1.
SC. F. 2. 3. 3.
Mathematics MA. D. 1. 3. 2.
MA. A. 3. 3. 3.
Major Instructional
Goal
Associated Concepts
Educational/
Instructional
Objectives
To help students understand the relationships that exist between predator
and prey populations which keep them in homeostasis.
A.
B.
C.
D.
Interdependence
Populations
Habitat
Predator-Prey Relationships
E. Adaptation
F. Extinction
G. Homeostasis
Upon completion of this activity, students should be able to:
1.
Name three ways in which prey may be protected.
2.
Explain the advantages to a predator if it preys on more than
one species.
3.
Give two examples of how a population could become ex
tinct.
4.
Construct a graph depicting the change in both predator and
prey population levels over time and give reasons explaining
the shape of the curve for one of the populations.
5.
Define homeostasis and state how the predator-prey popula
tions maintain a dynamic equilibrium. Predation in its
broadest sense can be viewed as one organism consuming
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4H EEX 01
Florida 4-H Environmental Education Activities
another organism as an energy source. The prey is the individual
consumed. Predation represents a direct and often complex
interaction and may help regulate both the predator’s and the
prey’s population levels. For this activity, the use will be limited to
animals hunting other animals.
Background
Information
Given time, a population generally reaches a balance of numbers based
largely on the carrying capacity of the environment, relationships within the
population and outside factors. One factor operating outside the population
may be predation. Usually the population size of the prey is affected by the
population size of the predator in an inverse relationship. Under controlled
laboratory conditions, situations have been observed in which both the
predator and the prey may be eliminated. In natural systems, extinction of
populations caused by predation is much more rare. Extinction of an
organism is complicated by the fact that both predator and prey are part of a
complex food web, immigration/emigration occurs, environmental factors
and behaviors effect interpopulation dynamics.
The long range trend of such predator-prey relationships would be a system
of checks and balances between the two populations. For example, the
numbers of some predators may depend on the abundance of availability of
their prey, and predation may regulate the population of prey. If predators
cannot find and consume a particular prey species due to its scarcity or
another factor, then the predator may shift to other prey species in order to
conserve energy expenditures. This allows the prey population to increase
energy expenditures. This allows the prey population to increase and the
cycle repeats. This dynamic equilibrium in which neither predator nor prey
populations are eliminated is an example of homeostasis.
Extinction may occur but almost always results from new factors impinging
on the existing natural system. Habitat destruction is the most common
cause. Introduction of alien species which outcompete, cause a fatal disease,
or prey on native species, also have decimated many species, especially in
isolated ecosystems. Market hunting and poaching, if not regulated, can
extirpate a species from affected areas. Various types of pollution may also
result in the extinction of certain species.
Both prey and predator species evolve adaptations that allow them to
escape, capture or become more efficient hunters respectively. Camouflage,
increased prowess, or speed adaptive behavior and morphological
characteristics are examples. Predation, as an agent of natural selection, may
help in the development of the many desirable ‘survival’ traits possessed by
animals.
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4H EEX 01
Florida 4-H Environmental Education Activities
Activity
A.
B.
Introduction
1.
Learning Site – any edge community of about 100
square yards containing separate areas of short and
taller vegetation. This area should be free of poisonous plants or other hazards.
2.
Materials – Peanuts in the shell (100 per group of
10-15 students), graph paper, a chalkboard and
chalk to record the date and illustrate the concepts.
3.
Preparation by Instructor – Randomly scatter the
peanuts throughout the edge community before
the participants arrive.
4.
Critical Vocabulary – Predator, Prey, Population,
Protective Coloration, Habitat, Adaptation, Extinction.
5.
References :
a.
Ecology Text
b.
Gilbert, N., (Frazer, S., D. Gutierez, A.P.,
Jones R.E.) Ecological Relationships
c.
Camouflage: A CWES activity
d.
Sticklers : An OBIS activity
Directions for Actual Activity
1.
3
Focus – 10-15 minutes. Introduce the group to the
idea of studying a population which recently
immigrated to the area. Describe the populations as
invertebrates having a beige exoskeleton without
giving the animal away as a peanut. Discuss the
adaptations the ‘Goober Etus’ have in order to help
protect them from predation (camouflage and exoskeleton are two of many possibilities). Describe the
habitat they live in and any other pertinent points to
convince the students the populations is worth
investigating. Briefly explain that the group is to
observe the population in its habitat and record its
behavior. The group can be told that humans can be
predators and ask if anyone would wish to try one
(this will increase the excitement level). Take the
group to the site and demonstrate capturing the
‘Goober Etus’. After it is revealed to be a peanut,
explain that they will play a game in which they will
be the predators.
4H EEX 01
Florida 4-H Environmental Education Activities
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2.
The Activity – 15 min. Introduce the concepts of
predator and prey and explain the rules of the game
as follows: Predators will be given one minute to
hunt. They are to collect as many peanuts as they
can. This one minute time span represents a long
time period such as one or two weeks. If a predator
fails to find any food, he/she will starve to death.
This game will be repeated four times with only
successful predators participating. Data on the
number of predators and prey surviving after each
hunt should be recorded. Plot the data for both
predator and prey populations against time on the
same graph. This way the students will be able to see
the relationship that exists between predator and prey
populations. With younger students, piles of peanuts
or pieces of paper representing predators could be
used in place of graphs.
3.
Synthesizing Strategy – Reinforce the concepts
illustrated through the activity. Discuss why
scientists use graphs in their studies (showing
relationships between two variables, noting changes
in rate, making predictions). Through using the
graph, have the students describe the relationships
between predator and prey in this simulation.
Contrast it to real relationships between predatorprey populations. The following points should be
discussed and illustrated through examples:
population inputs, individuals that fall victim to
predation, predators utilizing more than one food
source, dynamic equilibrium maintained between
predator and prey population, extinction and major
causes. Many relationships or concepts could be a
major topic of focus from this activity. The important
idea is to extend the predator-prey model illustrated
by the game to that negatively. That humans have
impact on this relationship can also be a topic of
discussion/investigation.
a.
Did the color of ‘Goober Etus’ blend with its
environment? If so, how?
b.
Could this color(s) be used as protection from
predators?
c.
As the game proceeds, what happens to the
predator and prey population? What are the
three factors that account for more prey being
caught in the beginning than toward the end?
4H EEX 01
Florida 4-H Environmental Education Activities
d.
e.
f.
4.
(more prey, more predators, and easier to
find) How does this correspond to actual
predator-prey relationships?
If the game continued, do you think that the
‘Goober Etus’ population will become
extinct? Why or why not? Will the predator
population become extinct?
In a real situation, like wolves and deer, why
do both populations continue to coexist? How
does the deer population control the wolf
population and vice versa?
What are two reasons why populations be
come extinct? (habitat destruction, market
hunting by man, introduction of new blight
or disease, and introduction of new species
which will outcompete the original one for its
niche.) What role does man play in extinction?
Suggestions on Time and Problems – The total activity can be completed within one hour. The activity
itself, however, is relatively short. You may want to
make the peanuts harder to find for older students.
The number of time periods is relative depending
upon population sizes and time. However, it would
be best to stop the hunts before either population
level reaches zero.
The study and graph showing the population fluctuations between the hare and the lynx would help show
how a dynamic between predator and prey populations is established and maintained. This may be difficult for younger students to conceptualize.
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