Classroom Activities
Lesson One
Background
This activity will help students identify three essential components of a habitat which are food, water and shelter. They will also describe factors that influence carrying capacity which is the population size that the environment can sustain in the long term, given the food, habitat, water and other necessities available in the environment.
Limiting factors will also be defined as anything that tends to make it more difficult for a species to live and grow, or reproduce in its environment. Students will be able to give examples such as water, climate/weather, competition, predation, environmental pollution and habitat destruction as some of the factors. Students will also understand that ecological systems undergo constant change and that some fluctuations in response to a variety of limiting factors are natural in wildlife populations.
Materials
The materials needed for this activity are a large area, outside on the playground or gym, colored poker chips (red, blue and white) or squares of colored paper, science journals and a chart to record the data.
Activity
Before moving to the large area, explain the activity to the students. Select six students to be the red wolves, two students will be your helpers (later to become the hunters) and the rest of the students are the essential components of the habitat (food, water or shelter/space). The hand motion for shelter is to hold both hands over the head with finger tips touching forming a house shape (shelter) over your head. Shelters chip color is white. The hand motion for water is both hands over your mouth and the color chip is blue. The hand motion for food is both hands on your stomach and red chips represent food. Have students practice each of the hand motions correlated to the color of the poker chips.
Explain the rules of the activity. Students must stay inside of the designated habitat, students must walk, and students must stand with their backs to the opposite line until told to turn around. Explain that the activity will be played a number of times (10-15) depending on time frame and records will be kept in order to make a chart when we return to the room.
Take students to the designated area and line the wolves up on one side and the other students about twenty feet away from them. With the two lines facing away from each other, ask your helpers to pass by each student with the bowl of chips so that they can select what component they would like to be, or in the case of the wolves, to seek out. After each has selected ask the students to make their hand symbol that corresponds to their selected chip.
On the count of three the two lines turn around to face each other. Only the wolves are allowed to move. They walk to the other line and find a person with the same symbol as they have chosen. They touch that person on the shoulder then they both walk back to the line the wolves were on. If a wolf does not find the same symbol then he is no longer a wolf and remains on the component side and will select a component the next round.
During the second and third round the students will see that as the wolf population increases the essential components of their habitat decreases and fewer animals can survive. You can simulate a drought by taking all of the blue chips away from the essential components or a loss of habitat by taking most white chips away. A large snowfall could be shown by reducing the amount of prey (red chips). During the last few rounds let your helpers become hunters who stand in the middle of the two lines and try to touch as many wolves as possible as they walk by. This should lead to very few wolves, if any, that survive.
Upon returning to class have students draw a chart in their journals and log the number of rounds and the number of wolves for each round. For this assignment each round will stand for one year in the life of the wolf pack. Ask students to write in their journals how the information gathered simulates what occurs in the habitat of the wolves by taking the perspective of a wolf who survived most of the changes.
Ask for volunteers to read their stories to the class, listing on the board limiting factors as they come up in the stories. Discuss reasons why the wolves ended up on the endangered species list and what are some actions we can take to help them recover and to keep other animals from being added to the list. Ask the students to summarize some of the concepts they learned from this activity and add this new understanding to their journals. Use the following questions in a think, pair and share discussion. What do animals need to survive? How do these components influence carrying capacity? What are some "limiting factors" that affect the survival of animals? How do factors limiting carrying capacity affect the health, numbers and distribution of animals? Why is good habitat important for animals? Are wildlife populations static, or do they tend to fluctuate as part of an overall "balance" of nature? Is nature ever really in "balance" or are ecological systems involved in a process of constant change?
Lesson Two
Background
In the past humans have contributed to animals becoming endangered by using products that did what they were made to do but were not tested to see the long term effects on the environment. Tragic examples of this is DDT and PCBs (polychlorinated biphenyls) which are two dangerous persistent pollutants that accumulate in the fatty tissues of animals. As each small animal is eaten by an organism higher on the food chain, it accumulates the store of poison from its prey. This is called Biomagnification.
DDT is a pesticide that was sprayed on crops to kill insect pests. It is a manmade (manufactured) chemical that has a long half-life of about 50 years. It is now banned in most of the world, although India is beginning to manufacture and use it again to kill mosquitoes.
PCBs are also manufactured chemicals. They were primarily used in electrical transformers. They made their way into the environment through accidental spillage during manufacture and distribution as well as by illegal dumps of transformers. Although no longer produced, PCBs are extremely persistent in the environment.
Over its lifetime, a predator will eat many smaller food items, thus concentrating more of the poison in its tissues than any single prey item ever contained. As we look at the animals higher up the food chain, we observe higher concentrations of pollutants.
This exercise will simulate the concentration of pollutants through a food chain. Although we will first look at an entire food chain, the simulation will be limited to three steps of the food chain. Students will discover how interrelationships between organisms (including humans) affect each other.
Materials
In preparation of this activity we will need a bag of colored Goldfish crackers. These will represent minnows in the activity. Each student will need a container (brown lunch bag) to place his "minnows" in and a name tag designating them as either an Eagle or a trout. Students will use index cards, whole punch and string to make their identification tags. I will choose two students who have lots of energy to be my Eagles, the rest of the class will be trout. If there is a student who is uncomfortable with the active part of the lesson, I will ask them to be the "Wildlife Agent" and keep track of the information on a chart.
I will also make copies of the Eagles food chain found at http://www.learner.org/jnorth/tm/eagle/FoodChainDrawings.html (one for each team of two) and cut them into cards. I will show the students an example of an energy pyramid using my computer and LCD projector. The web site I will use is http://www.earthforce.org/content/article/detail/1284
Activity
This lesson will take place after students have selected specific animals and have created an individual food chain and collective food web for their animals. To engage the students each pair will work together to place the Eagle food chain cards in the correct order. We will then discuss the food chain. We will discuss key questions such as what would happen if one of the organisms' population was reduced, if the water became contaminated, and how humans affect the food chain.
I will then introduce the concept of an energy pyramid through the use of a poster located on the web. Students will create an energy pyramid in their journals. I will use the visual to point out to the students the large number of individual organisms at the bottom of the pyramid and how the size and energy needs increase toward the top of the pyramid. Biomagnification will also be introduced through the discussion of the energy pyramid.
Following the discussion, students will be ready to participate in the activity. Students will put on their nametags (eagle or trout) and we will go outside to a designated location. I will set the boundaries of the "pond" and the location of the eagles' nests. I will explain the rules of the activity. Only walking is permitted.
Eagles need to catch one trout at a time and bring that trout back to the nest so that they can feed their babies. When caught, the trout must go willingly back to the nest with the eagle where they are "eaten" and can not swim away. The caught trout will stay at the nest until the activity is finished.
When the eagles are at their nests and the trout are in the pond with their containers I will run through the "pond" distributing the minnows (Goldfish) all over the ground. The trout will scramble to pick up as many minnows as they can. After all minnows are scattered, tell the eagles to start hunting. When the eagles have caught all the trout the students will be in two groups holding their bags of minnows. Have students line up according to the number of minnows they caught then record the number of minnows each trout ate, how many trout each eagle ate, and the total about of minnows (through eating the trout) each eagle consumed.
Upon returning to the class explain to the class that each minnow (Goldfish) contained 0.5 ppm (parts per million) of DDT. Although each trout needed to eat the minnows to sustain life the pesticide contained within the minnows could adversely affect the trout since it accumulated in their fat. Then direct the students attention to the eagles and how much they acquired by eating the trout. Also discuss how the off spring of the eagles faired. Remembering that the eaglets are small but consuming DDT from their parents, through the trout.
Lesson Three
Background
In the past forty years the world population has doubled. In the year 2000 the world population reached six billion. Most of the growth takes place in developing countries. Population growth leads to the loss of natural habitat.
The United States has a total resident population of 305 million. It is an urbanized nation, with 81% of the population residing in cities and suburbs. Population and economic growth in urban centers has been increasing pressures on ecosystems. Dense urban settlement is considered to be a lesser burden on the environment than urban and suburban sprawl. Human population growth and the consumption of open space and resources destroy habitat required by wildlife for survival. Human development can disturb whole ecosystems, often irreparably.
Important wildlife habitat is rapidly lost or fragmented in the course of urban development, oil and gas extraction, and the conversion of land to agricultural uses. Some of the damage to wildlife is visibly the result of humans encroaching on wildlife habitat. An example is the loss of habitat for reptiles, rodents, birds, and mammals as they clear cut all the trees to construct a new subdivision. The trees that are cut down also were oxygen producers and CO2 eliminators. With the clear cut subdivision new homes for humans can be built less expensively, but a large cost to the biodiversity of our earth.
Materials
For this activity students will work in pairs to create a habitat. Each group will need a large (12x18) piece of construction paper that will represent their habitat (assortment of colors to represent different habitats. Students will need a wide selection of small plastic animals or they can create their own from construction paper. Blue paper will be needed to represent water. Brown bags or medium size pieces of construction paper will represent the human's use of the habitat. Scissors, glue, and crayons will also be placed on the distribution table to be used as needed by the students.
Activity
Working in pairs the students will agree on a habitat to represent. Using the provided materials the students will create a habitat for several animals keeping, in mind the needs of the animals (food, water, shelter, space.) I will divide the pairs of students into two groups. The first group will take turns visiting and asking questions of the second groups projects, then we will reverse the roles. During writing time students will write in their journals how and why they selected their animals and their habitat.
The next day I will give the students a small size brown bag or a piece of paper and tell them that this represents a new hotel that has just been built on their land. Students will then redesign their habitat to incorporate the new building, roads and support structures to accommodate the hotel on their land. When the pair has finished one student will take the perspective of the hotel owner and the other will take the perspective of one of the animals. They will each write a story and tell what happened to them from their assigned point of view. When they have finished the writing assignment they will share their story with each other. I will then divide the class into hotel owners and animals and we will hold a town meeting (debate) to discuss the benefits and disadvantages of the new hotel.
The next day we will explore ways the hotel could be built in an environmentally friendly way. We will discuss renewable and nonrenewable resources and what part renewable resources could play in the building of the hotel. We will discuss responsible ways to reduce water and air pollution.
As we focus on positive solutions to humans and animals living in close proximity I will guide the discussion to what we as individuals can do to help the endangered animals from becoming extinct. I want my students to feel empowered to make a difference in their world through taking personal responsibility in both small and large ways.
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