Summary

At Hidden Villa students have the opportunity to explore a variety of different mini-ecosystems and observe the body form and behavior of many animals. In the garden, students learn about the 6 plant parts and can use this knowledge in the wilderness to appreciate how plants form the base of the food chain. These nature experiences can provide students the information, inspiration and excitement to fuel a deeper study of ecosystems within the classroom.

Part I: Discovering the Basic Concepts

This first week of activities lays the ground work for students to use what they learn at Hidden Villa in their study of food chains. The Interactive Writing project on the six plant parts will support student understanding of the plant's important role at the beginning of each food chain. Each of the Food Chain lesson steps for this first week is shorter so that you can start or end each science period with the Plant Part IAW project. For more background knowledge about the Interactive Writing teaching strategy, go to "Best Practices" under the introduction to this section on Hidden Villa Classroom Curriculum. Please note: Many of the food chain activities in this unit use photocopied pictures of the different animals and plants that live in the ecosystem(s) at Hidden Villa. You can find a copy of these pictures under "Download Materials."

Lesson 1: Describing plant parts and functions through interactive and independent writing

Lesson 2: Identifying Hidden Villa plants and animals by matching pictures with names

Lesson 3: Recording facts learned about pictured plants and animals

Lesson 4: Plant and animal sort based on chosen characteristics

Lesson 5: Plant an animal sort based on scientific classification (kingdoms)

Lesson 6: Plant and animal sort based on ecological classification (trophic level)

Part II: Links in the Food Chain

This set of lessons offers a more in-depth study of each ecological level in a food chain. Each science lesson begins with a Shared Reading about food chains and includes a time for students to practice reading informational texts through Reciprocal Teaching. There are many texts that you could use for these readings. I have included examples of each in the "Download Materials" for this unit, which can be printed and used directly in your classroom. For more information about Shared Reading (SR) and Reciprocal Teaching (RT) please see "Best Practices" under the introduction to this section on Hidden Villa Classroom Curriculum.

Lesson 1: Shared Reading and Reciprocal Teaching on producers and photosynthesis

Lesson 2: Shared Reading and Reciprocal Teaching on herbivores

Lesson 3: Shared Reading and Reciprocal Teaching on carnivores

Lesson 4: Shared Reading and Reciprocal Teaching on decomposers

Part III: Putting it All Together

Now that students have a good understanding of each link in a food chain, it is time to connect the links and understand the cyclical nature of food chains. The first step includes suggestions on how to guide students to a deeper understanding of food chains. The ideas that follow describe several different ways students could represent their understanding of this concept.

Lesson 1: Creating a food chain with Hidden Villa plants and animals

Lesson 2: Demonstrating energy loss in a food chain with a class activity

Lesson 3: Writing essays about the Hidden Villa food chains

Lesson 4: Representing the Hidden Villa food chain through an art project

Lesson 5: Making a class mobile from the Hidden Villa food chains

Lesson 6: Performing the first act of the Eco Play (Download Materials)

Part IV: A Step Further to Food Pyramids

In this series of lessons, students learn that food chains are not one-to-one relationships. One plant is not enough to sustain one mouse, and one mouse certainly is not enough to sustain one coyote. Sustaining top predators in an ecosystem requires a much larder prey population and an even larger abundance of the prey's food. Food pyramids are powerful visuals to help students easily understand this concept. I have integrated this part of the unit with the California State math standards in algebra, which could be suitable for students in grades 3 through 5 depending on the time in the academic year and your students' math level. Adapt these lessons to your class's math level if needed or implement the ideas without linking them to algebra.

The first lesson is based on two short math stories about animal populations. In the first, Hidden Villa staff discover a pattern in how many mice are living in the garden and the number of sunflower seeds that disappear every day. In the second, Hidden Villa staff discover a pattern in the number of owl pellets (with mice remains) and the number of owls nesting in a nearby tree. I have included these short stories at the very end of this unit and you can print them out for classroom use under "Download Materials." You could also, of course, make up your own.

Lesson 1: Math mystery problem solving as class and in partners

Lesson 2: Making "relational rules" for each link in their Hidden Villa food chain.

Lesson 3: Using algebra to calculate the amount of plants needed in an ecosystem to support the top predator

Lesson 4: Creating a food pyramid using the algebraic relationship from previous lessons

Lesson 5: Food pyramid tag game

Lesson 6: Describing the group food pyramid through a paragraph, essay or quiz

Part V: Increased Complexity

The interactions between animals and plants in an ecosystem are of course more complex than can be represented in a food chain or even in a food pyramid. The following three activities offer ideas on ways to start students thinking about the complex realities of real interactions in an ecosystem. If you want to lead your students further in this study, I am sure you can find more ideas in other environmental education activity books.

Lesson 1: Connecting students who are representing the plants and animals of the Hidden Villa food chain with string to demonstrate a food web

Lesson 2: Creating food chains from lunch ingredients

Lesson 3: Observing and recording mini ecosystems in the school environment

Part I: Discovering the Basic Concepts

During the Hidden Villa field trip students will explore the six plant parts in the garden. This Interactive Writing project is a fun way to put together their knowledge of the function of each plant part. Each day you will guide your students in making a poster of each plant part. At the end of the entire project, you can assemble your huge plant on a bulletin board. Here is a suggested schedule for this IAW project:

1. Introduce the plant part and guide an initial discussion about how they learned about this plant part at Hidden Villa
2. Invite a few students to come up and draw a huge representation of that plant part on chart paper (as each plant part will be on a different piece of paper it is a good idea to measure the width of those parts that will need to connect.
3. Invite one student to come up and write the plant part title.
4. Guide a focused discussion about the function of this plant part. Why is it important to the plant?
5. Help your students construct a sentence or two that summarizes the function of this plant park.
6. Invite different students to come up and write the sentence(s). As they write, you can focus on other writing, grammar, spelling or science teaching points depending on your students' needs and the issues that come up in each individual sentence.
7. Ask students to think of different examples of how humans use this particular plant part and write this list on another place on the poster. For example: stems - celery, rhubarb, wood from pine tree trunks

Lesson 2: Identifying Hidden Villa plants and animals by matching pictures with names

Before: Make sure you have a single-sided photocopied set of Hidden Villa life cards along with the accompanying checklist of animals and plants for each pair of students and a single, larger teacher set for teaching purposes (see Download Options).

Orientation:  Demonstrate how you would like students to perform each of the following steps in their groups:

1. Look at the pictures of plants and animals on your cards.
2. Read through the entire check list.
3. With your partner, match names with pictures.
4. In pencil, write each name under the picture.
5. Be ready to justify your decisions with your class.
6. After your class discussion, check your answers by looking at the class set of cards at the front of the room.

Share: Gather students together to share what they decided were the names of the animals and plants in each photo. When the class has finally come to a "consensus" for each photo, write the corresponding name on the class set of Hidden Villa cards posted on the board. Note: You will probably want to pass out envelopes or bags in which each pair can store their Hidden Villa cards.

Lesson 3: Recording facts learned about pictured plants and animals

Model: Ask your students to think about what they know about each animal or plant on the Hidden Villa cards. Pick 2-3 animals or plants to work on as a class. Write the class information about each on the class set of cards.
Group: Students work in partners to come up with facts that they know for each plant or animal in their deck of Hidden Villa cards. They should have their field trip notes out for assistance. Give groups only about 10 minutes to do this. Let them know that they should work quickly, but that it's okay if they don't know facts for each card. Student Instructions:

1.    Look through your cards to find one you have information about.
2.    Use your notes to come up with as many facts as you can.
3.    With your partner think about the following questions:

• Did you see it at Hidden Villa?
• Where does it live?
• What is special about it?
• What does it need to live?

4.    Write as much as you know on the back of the card in a list.
5.    Repeat this for as many cards as you can.

Share: Have groups share their information lists. Tell your class, "Hidden Villa has given me facts on each of our animals and plants. Let's see how many things we already know about them!" As your students present, check their answers on the back of the teacher set of Hidden Villa cards. If they share with information you are sure is correct that is not listed on your set of cards, you may want to add this information. Celebrate how much they already know as you read any other facts listed on your teacher set of cards that they did not mention. You probably won't have time to finish sharing about each card. You can finish at the beginning of the next lesson.

Lesson 4: Plant and animal sort based on chosen characteristics

 
Orientation: Each group will be working together to sort their Hidden Villa cards in their own way. Most students should be familiar with the concept of sorting based on different characteristics. However, you may still want to review the concept of a "free-sort." Before you begin have each pair take out their Hidden Villa cards and spread them over their desk.

Model: Start by sorting together as a class. Say, "For our first sort, I would like for you to divide your cards into those that can fly and those that can't." Circulate to support partners that may need help. Then ask, "Does anybody else have an idea for how we could sort our cards?" Listen to a few ideas and choose one that seems simple. Have your class sort their cards again in this new way.

Brainstorm: Think-Pair-Share: Have students think of other characteristics they could use to sort their cards with their partners and share these ideas with the class. Remind students that some sorts might have more than just two groups (ie: sorting by color). List their ideas on the board.

Groups: Together partners choose a characteristic to use to sort their cards (a new idea or one from the class brainstorm), separate their cards into appropriate categories and write down their sort in their science notebooks. When groups have finished with one sort, invite them to sort the Hidden Villa cards in a different way.

Share: Invite different groups to share their sorts and explain their reasoning. If the Hidden Villa cards in your class set are easy to manipulate (you could tape magnets to the back), one group member could actually sort the cards on the whiteboard while the other members give the explanation.

Lesson 5: Plant an animal sort based on scientific classification (kingdoms)

The biological classification of organisms is very complex. However, most upper elementary students should be familiar with at least some of the major groupings. This point in the unit provides a great opportunity to introduce the major kingdoms of organisms and the classification system of animals (ie: invertebrates and vertebrates - mammals, birds, reptiles, amphibians, fish etc.). You can find this lesson at the end of this unit section. If you do not wish to delve into this topic at the moment, move directly to Lesson 6.
The biological classification of organisms is very complex. However, most upper elementary students should be familiar with at least some of the major groupings. This point in the unit provides a great opportunity to introduce the major kingdoms of organisms and the classification system of animals (ie: invertebrates and vertebrates - mammals, birds, reptiles, amphibians, fish etc.). You can find this lesson at the end of this unit section. If you do not wish to delve into this topic at the moment, move directly to Lesson 6.

Before: Adapt this lesson to whatever difficulty you think is right for your students. For an extra challenge, you can introduce the Protist Kingdom (bacteria) or further classification of the invertebrate. For this lesson it will be most helpful to have an easy way to move around the class set of Hidden Villa cards such that all students can see. If you have a magnetic board, I highly recommend taping magnets to the back of each card.

Orientation: Review the sorts that each group shared the previous lesson. Explain that classifying things that are similar helps us understand them better. Scientists have many different ways of classifying living organisms to help them understand how they survive, reproduce and interact with its environment. Some students probably touched on at least one of the classification groups in their free sort from the previous lesson - reference this idea now.  

Lesson: "In their free sort yesterday Maria's group used the category 'birds.' This is an example of one of the categories scientists use when they want to classify living organisms by the structure of their bodies. The initial method of sorting living organizations is what scientists call 5 big kingdoms." (At your grade level you should be familiar with 3 of these kingdoms.) "One of these kingdoms is 'Animals.' Can anyone else think of what the other 2 might be?" Write these three headings on the board. Ask students what they think defines each kingdom, what makes them different from each other. Write these ideas under each heading as a short, bulleted list. Then invite students to come up and move the Hidden Villa cards on the board into the 3 categories.

Groups: To get students more involved, you might want to send your students back into their groups, but make sure they can see the board. Give them sticky-notes to stick to their table and instruct them to copy the headings and bulleted list onto each sticky note. Then they should sort their own Hidden Villa cards to match the board.

Orientation: At your grade level, you don't need to be able to sort the plants or fungi further. However, you should know a lot more about the animals. Guide your students to feel their backbone and introduce the headings "vertebrate" and "invertebrate." Write these headings under "Animals." Then invite two more students to sort the animals into these two categories.

Groups: Students return to their groups to quickly repeat this next classification step with their own cards.

Orientation: "We could think of other ways to sort the invertebrates, but we are going to leave them the way they are for today. However, I would like for you to look at the animals left in the vertebrate group. Can you think of ways that you can sort them?" Introduce or review the groups mammals, birds, reptiles, amphibians and review some defining characteristics for each. Write these under each heading as a bulleted list.

Groups: Students copy this next step with their own Hidden Villa cards. Then they work together to figure out how to represent the information they have on their desk into a written diagram in their science notebooks.

Extension: Have students think of other animals they know that belong to each of the final categories.

Lesson 6: Plant and animal sort based on ecological classification (trophic level)

• producer (makes food using energy from the sun)
• herbivore (eats only plants)
• omnivore eats both plants and animals)
• carnivore (eats other animals for its energy)
• decomposers (breaks down dead material into fertile soil).

Support: Students use a sorting chart (Download Materials) or write the 5 categories on sticky-notes to create their own chart on their desks. Sort at least 5 cards together as a class so that there is an example in each category before asking student to sort their cards into each category with their partners. Student Instructions:

1. Read the information you wrote on the back of each Hidden Villa card.
2. Sort your cards onto your category chart.
3. As you sort, justify your decision with your partner.
4. Be ready to share your ideas.
5. After class discussion, record your sort in your notebook.

Share: Facilitate a discussion about the classification of each Hidden Villa card. Ask students to justify their decision based on the characteristics of the ecological category and the information they know about the organism.
Extension: Invite students to think of other animals they know that fit in each category and add it to their lists.

Part II: Links in the Food Chain

Lesson 1: Shared Reading and Reciprocal Teaching on producers and photosynthesis

A. SR: Read entire text. Focus on pronunciation.

Orientation: Teach the process of photosynthesis to your students. At the end you will want your students to understand that plants are the only living organism that can store the energy from the sun in the form of simple sugars. Older students should memorize that the plant uses the energy from the sun to power the process that turns water (H20) from the soil and carbon dioxide (C02) from the air into sugar.

Analogy: It is helpful to make the analogy between the green plant cells and a factory - raw materials enter the factory, the factory uses energy from a source (electricity, petroleum, sun) to break the raw materials up and fuse them back together in a new way, producing a product that exits the factory. As in all factories, there are waste products. In the case of photosynthesis, the waste product is gaseous oxygen we use to breath.

Drawing: Draw a large picture of a leaf with the green chlorophyll taking on the shape of a typical factory to get the idea across. Draw huge "satellite dish" looking things on the top to represent how the plant captures the energy from the sun since most students are familiar with this instrument.

Support: Students read together the several paragraphs about photosynthesis in reciprocal teaching groups, which reinforces and reviews the information you have just taught.

B. This can be a fun, short PE game to get kids moving, while at the same time drilling the basic processes of photosynthesis into their heads. It is based on the simple game "red-light, green-light."

Preparation:  In class, each pair of students gets two pieces of green construction paper. On one paper write: water (H20) On the back of this paper write the first two letter of the word sugar: SU. On the other paper write: Carbon Dioxide (CO2). On the back write the letters: GAR. Draw a sun on yellow paper and a nighttime scene on black paper. Staple these together back-to-back. (If you have an "extra" student s/he can help with this task.)

Orientation: Review the process of photosynthesis. Emphasize that plants need the energy from the sun to drive the process and that both water and carbon dioxide are needed.

Play: In the game, students will pretend to be the chlorophyll on their pieces of paper.

• Linking arms they can advance from the baseline of the basketball court to the other side when you show the "sun" side of the "day."
• As they walk both partners need to repeatedly shout, "photosynthesis!" to represent that the plant is currently using the energy from the sun to drive the process of photosynthesis.
• When the sign is turned around to show "night" partners must stop immediately.
• If they don't, return them to the beginning of the photosynthesis process (the starting line).
• The first pair to reach the end needs to say a summary of the process of photosynthesis to win to job of being the day/night.

Please Note: This game can be adapted for younger students. Instead of writing the equation of photosynthesis on green paper, simply have students write "Leaf" on one side and "Sugar" on the other.

Lesson 2: Shared Reading and Reciprocal Teaching on herbivores

SR: Re-read the first two paragraphs. Focus on vocabulary.

Orientation:  Before students get into their reciprocal teaching groups, tell them that as they read you would like them to begin thinking about different adaptations that would help herbivores survive.

Support:  In reciprocal teaching groups, students read together about herbivores.

Share: Guide a class discussion about different adaptations student would expect many herbivores to have in order to survive. Examples: Flat teeth for grinding (and a long digestive system) because plant cellulose can be tough. Eyes on each side of their heads giving them greater peripheral vision to watch out for predators. Long, strong legs or camouflage coloring to escape from predators.

Individual: Students should write down these ideas in their science notebooks, while you write their ideas about herbivores on a chart.

Lesson 3: Shared Reading and Reciprocal Teaching on carnivores

Orientation: Remind students to be thinking as they read about adaptations they would help carnivores survive.

Support: In reciprocal teaching groups, students read together about carnivores.

Share: Guide a class discussion about different adaptations student would expect many carnivores to have in order to survive. Example: Sharp teeth to rip into meat. Eyes at the front of the head to help carnivores spot and focus in on their prey. Strong muscles for speed and attacking power. Camouflage to sneak up on prey.

Individual:  Students should write down these ideas in their science notebooks, while you write their ideas about carnivores on your class chart.

Lesson 4: Shared Reading and Reciprocal Teaching on decomposers

Part III: Putting it All Together

Lesson 1: Creating a food chain with Hidden Villa plants and animals
 

  Model: Challenge your class to use what they now know about the organisms on the Hidden Villa cards to put together a food chain that has at least four links.

Think-Pair-Share: Decide on one food chain and invite a student up to select the appropriate Hidden Villa cards from the board and arrange them in order. Ask your class which way they think the arrows between the cards should be drawn. Emphasize that the arrows show the movement of energy and nutrients from one organism to another. For example, the stored energy of the plant goes to the rabbit that eats it, and the stored energy in the rabbit goes to the coyote that eats it. Focus on the end of the food chain. What does the decomposer do? Does it recycle energy? No - it recycles nutrients. When you are done with your food chain, guide the class in writing a quick summary of the diagram; use complete sentences.

Support: With partners, students use the information on their own set of Hidden Villa cards to come up with at least 3 different food chains together. They should draw the diagram of these food chains in their notebooks and include a quick summary.

Share: Each group chooses one food chain to explain to the class. (Ex: I am the western rattlesnake and I hunt my prey, the deer mouse. The energy stored in the deer mouse I ate, gives me the energy I need to move and grow.)

Note:

We often tell students that decomposers are the link that moves the food chain around in circles. However, older students (4th and 5th grades) might benefit from a clarification of the concept. When we typically draw food chains, we start with the sun and end with the decomposer. Confusion likes in the fact that decomposers do not recycle dead matter and turn it into the sun, which, in our simplified drawings, supposedly begins the food chain. Explain to students that plants and animals need two things in order to grow: nutrients and energy. At the beginning of the food chain, plants get nutrients from soil and energy from the sun. Energy from the sun provides plant the power they need to carry out all the steps necessary to extract nutrients from the soil and combine them to build new plant material. When a rabbit eats a plant, its digestive system breaks down the plant material and releases the stored energy to power its own movement and growth. We all know that moving takes up a lot of energy. When a rabbit runs it uses up energy (originally from the plant) to power its movement. That energy is spent, lost to the food chain. Energy that is not used for movement is stored in the rabbit's body and used for growth. The plant nutrients that the rabbit cannot break down and use are pushed out of its body as scat and lost from the food chain. When a coyote comes and eats the rabbit, creating another link in the food chain. At the end of the food chain, most of the stored energy originally from the sun has been used up and whatever remains is used by the decomposer to fuel its movement and growth. The decomposer "poops out" the left-over nutrients, which go back into the soil to be used again by plants to grow bigger.

1. Draw a basic food chain on the board. Explain that some details have been left out. "This diagram seems to say that all a plant needs in order to grow is energy from the sun. What else does a plant need? "
2. Show the yellow and blue paper and explain what they represent.
3. Ask for volunteers to role play each organism in the food chain (e.g. plant, rabbit, two carnivores, worm). They should hold their Hidden Villa card and stand in order.
4. As you hand the plant volunteer the yellow and blue pieces of paper ask the class what the plant does with these two things. "Yes, the plant uses the energy from the sun to make sugar. Then the cells in the plant can use the energy of the sugar to suck up the nutrients from the soil and be able to grow bigger."
5. Take out the green piece of paper. Put this piece of paper on top of the others and paper-clip or staple them together to emphasize the sun's energy and nutrients from the soil are now present in the plant as stored energy.
6. The plant volunteer now hands the papers over to the rabbit, representing the rabbit eating the plant.
7. Remind students that the stored energy is made up 2 components that are separated in the digestive system: energy and nutrients.
8. "Some of this energy the rabbit uses up by running around and the movement of her heart and lungs." Cut a strip from the stack of paper about 1/4 of the paper width. Crumple up the green part, reminding students that the rabbit converted the "green" stored energy into its components. Then crumple up the yellow part and put in your pocket to represent the energy being used up.
9. "Some of the nutrients in the stored energy of the plant the rabbit can't break down and it scats this out onto the ground." Take the blue part and drop it on the ground.
10. Now explain that the rest of the energy and nutrients the rabbit stores in its body by growing bigger. (This is the part of the stapled together paper that the rabbit volunteer is still holding.

Repeat this process with the next two carnivores in the food chain. At the end the top carnivore "dies" and is now eaten by the decomposer. The decomposer is able to break down all the nutrients the other animals weren't able to (worm volunteer could have a sock puppet and mime munching up all the blue nutrients left on the ground) and gives them back to the soil, which the plant can now use again. Point out, though, that the plant will need to capture new energy from the sun.

This role play isn't perfect, but in my experience does give students a fun, visual way to think about the complexities of the food chain. At the end you could guide your students in drawing a "reformed" diagram of the food chain with all of the new information included.

 Guide students in writing an essay about the different levels of the food chain, using a chosen Hidden Villa food chain serving as a focal point. If you have already introduced how to organize an informational report, this lesson offers an excellent opportunity to practice these skills because the needed information is already fairly organized.

You could either 1) guide your entire class in a lengthy IAW project or 2) use the information for writing prompt practice for either district or state writing tests. To give students some support, lead a class discussion about what the topic of the 3 body paragraphs could be (producers, consumers, decomposers) and how they might want to introduce the subject of the food chain in their introductory paragraph. Let them use their notes and the information posted around the room from the unit so far. You could give them an essay outline planner (see the unit on "Informational Reports" for more ideas) and then time their writing period as in a testing situation.

Lesson 4: Representing the Hidden Villa food chain through an art project

Students choose a Hidden Villa food chain to represent artistically. Students draw the outline of each organism in their food chain on different colored construction paper. Links in the chain should be drawn in order and in increasing sizes, such that the top predator is the biggest. Students cut the outlines and glue all the levels together, with the sun being the smallest piece inside the plant's outline. This project illustrates the top carnivore's dependence on all the animals in the food chain, and ultimately on the plants and sun, for survival. Note: Emphasize that students need to start BIG by making the outline of the top carnivore take up the entire space of the construction paper.

Lesson 5: Making a class mobile from the Hidden Villa food chains

Lesson 6: Performing the first act of the Eco Play (Download Materials)

Part IV: A Step Further to Food Pyramids 

Lesson 1: Math mystery problem solving as class and in partners

Ask your students to figure out the "rule" (multiply by 3). Write the rule, in words, across the board: the number of mice x 3 = the number of mission sunflower seed rows. Point out that this takes a lot of space. Do they have any ideas how we could represent this rule in a shorter way? Lead students to using letters to represent the amounts (m x 3 = s).

Support: Students follow the same steps in pairs as they read through the second Hidden Villa math mystery:

1. Read the story together
2. Circle the important information
3. Make a table
4. Figure out the rule
5. Write the rule as an algebraic expression.

Share: Have a few students explain how they figured out the mystery and see if all students came up with the same answer. Their answer should be: number of owls x 2 = number of mice eaten.

Lesson 2: Making "relational rules" for each link in their Hidden Villa food chain.

 Model: Demonstrate how to take a food chain and make up the relational rules for each link. On the top of their paper students should draw the diagram of the food chain with arrows ending in the top predator (sun - grass - mouse - snake - hawk). Below that they should make up symbols to represent the quantity of each organism (grass = g, mouse = m, snake = s, hawk = h).

Model how to determine a reasonable amount of food each animal will eat in a week and write "rules" below. (Tell students all rules have to be between 2 and 9.) For example, it is probable that a mouse would eat a lot of grass in a week but unlikely that a hawk would need to eat very many whole snakes.

You could write algebraic expression, e.g. link #1: m x 8 = g; link #2: s x 3 = m; link #3: h x 2 = s. Support: In groups, students follow the same steps. I recommend using a photocopied worksheet to guide them in their work (see Download Materials).

Lesson 3: Using algebra to calculate the amount of plants needed in an ecosystem to support the top predator

Model: Explain that today you are going to use the algebraic expressions for each food chain (Lesson 2) to figure out how many plants need to be present in the ecosystem to support the top predator. For the math mysteries we have two equations, e.g. link#1: m x 3 = s; link#2: o x 2 = m. Ask students for ideas about how to use this information to solve the problem. Guide them to see that they need to input the number of top predators (1), then use the output number of mice (2) as the input number for the next equation to find that s = 6 rows of seeds. Have students help you remember and write up the different steps for finding the answer. Practice the process as a class, this time using the food chain information from the modeled lesson in Lesson 2 above. Release more responsibility to your students this time.

Support:  Groups switch their papers from Lesson 2 and work together to figure out the total amount of plants needed in the ecosystem to support the top predator by following the modeled steps.

Share: Groups share their process and answers.

Lesson 4: Creating a food pyramid using the algebraic relationship from previous lessons

Model: Demonstrate how to turn the information from the algebraic relationships from Lesson 2 into a representational drawing of a food pyramid.

Student Instructions:

1. Draw the top predator at the top of the large piece of paper. Using the example from the Hidden Villa math mysteries, this would be an owl.
2. In the next level down, evenly space a drawing of the prey. In our example this would be two mice.
3.  Draw an arrow from each prey going towards the top predator.
4. In the next level down (at the bottom of the page) evenly space the total number of plants the herbivores eat (the answer from the question in Lesson 3). In our example: this is 6 rows of sunflower seeds.
5. Draw an arrow from each row of sunflower seeds to the nearest mouse such that each mouse has three arrows pointing to it.

Support: Students work together in their groups to draw the food pyramid for the food chain that they were working on in Lesson 3. Point out to your class that if they have 4 animals in their food chain instead of 3 they will need to plan for an extra level in their drawing.

Discussion: Have each group share the drawing of their food pyramid. Then guide a class discussion about what information these drawings give us. What is the relationship between the top predator and the plants in their ecosystem? What would happen to the top predator if half of the plants were suddenly destroyed? Why? - they don't actually eat the plants. (In case of time limitations, guide this discussion at the beginning of the next lesson.)

Orientation:  Student will become mice or owls in this adaptation of tag. Each student assigned to be a mouse will need to "eat" 3 plants by picking up the green object from the ground. Then, those students assigned to be owls will be sent out to hunt the mice. To survive each owl needs to catch 2 mice.

For the first round: Divide the class so that there will be enough mice for all the owls to eat, as well as some surviving mice to keep the mouse population going. 1/4 of the class taking the part of the owl should work. Also, spread out enough "plants" around the court for each mouse to survive. Line the mice up along one line of the basketball court. When you let them loose they should run around to collect their 3 plants. After the "mice" have finished "foraging" release owls to chase after the mice. When an owl has caught a mouse they should link arms and run together.

For the second round: Explain that something has suddenly happened to the plant population. This time scatter only half the number of "plants" around the court. Have the students predict what is going to happen. If a mouse or owl cannot find enough food, it "dies" by sitting on the sidelines. Play as before, but note the differences.

Discussion: What does the game tell us about food pyramids? An interesting thing to note is that many students will predict that the mouse population will decrease by half because the plant population was reduced by half. In reality, though, this rarely happens in this game because many student mice pick up one or two plants. These mice don't survive, but the plants that they ate in their attempts for survival reduced the availability of food for others. Therefore, very few student mice actually find all three plants they need to survive and the mouse population decreases dramatically by more than half. Ask the class, in real ecosystems, what are some things that might change the plant population so drastically?

Note: This same game can be used as a wonderful demonstration of bio-magnification of pesticides (ie: the now classic case of DDT). Put tape or stickers on some of the plants in the game to represent sprayed plants. During the game students can keep track of how many mice get "poisoned" by the pesticide and how much pesticide the poisoned mice ate. Then in the next round they can see how many owls get "poisoned" by eating the mice (the mice pass on all of their green plants to the owl when it gets eaten). Again, look to see what quantity has been passed on to the owl. It can be helpful to explain that these type of pesticides don't kill animals straight away, but get stored away in their body fat and can cause all sorts of problems including reproduction difficulties and cancer.

To finish up this part of the unit you could have students write a short essay or paragraph explaining their group's food pyramid. Or you could develop a short quiz. This could be an individual quiz or be turned into a game-show type activity.

Part V: Increased Complexity

Lesson 1: Connecting students who are representing the plants and animals of the Hidden Villa food chain with string to demonstrate a food web

Activity:  Students stand in a circle, representing the ecosystem. When students receive the ball of string they need to explain what part of the ecosystem their role directly depends on. For example, the owl could pass the string to the mouse or to the rabbit. The rabbit depends on the grass and the grass depends on fertile soil. The two steps that are a little tricky are realizing that the fertile soil depends on the decomposers (any of them) and that the decomposers depend on any dead material and can therefore choose to pass the string to any living organism. Students need to make sure that they hold on securely to the string each time that it gets passed to them.

Teacher Role: As a teacher, you may want to help in the passing of the string to avoid long missed throws across the room. You may also need to guide the activity at some point so that each student is included. You can choose to end the activity at any time after each students has been passed the string at least once.

Conclusion: At the end, the class should have created a complex web. At this point you can have students lean back against their part of the string. If everyone holds on tightly all the students should be able to lean back and be held up by their connection to the other components of the ecosystem. Ask what they think would happen if one animal was taken out - maybe the top predator has lost its habitat due to suburban sprawl, has been over-hunted, or has been affected by pesticide use. Have the student(s) representing this animal let go of their strings. What happens? Repeat with different components of the ecosystem.

Discussion: At the end, you can discuss what happened in the game and have students write about what they learned.

Lesson 2: Creating food chains from lunch ingredients

Lesson 3: Observing and recording mini ecosystems in the school environment

Download Materials

Lesson Materials

Part I

Lesson 1, 2, 3, 4, 5, 6

Single-sided photocopied set of Hidden Villa life cards for each pair of students

Single, larger teacher set of Hidden Villa life cards for teaching purposes

Part II

Lesson 1

Reciprocal Teaching on Producers

Lesson 2

Reciprocal Teaching on Herbivores

Lesson 3

Reciprocal Teaching on Carnivores

Lesson 4

Reciprocal Teaching on Decomposers

Part III

Lesson 1, 5

Single-sided photocopied set of Hidden Villa life cards for each pair of students

Single, larger teacher set of Hidden Villa life cards for teaching purposes

Lesson 6

Eco Play Script Scene 1 (English)

Eco Play Script Act 1 (Spanish)

Part IV

Lesson 1

Math Mystery #1 on an overhead transparency

Math Mystery #2 one for each pair of students

Part V

Lesson 1

Single-sided photocopied set of Hidden Villa life cards for each pair of students

Single, larger teacher set of Hidden Villa life cards for teaching purposes

Student Worksheets

Part I

Lesson 2

Plant and Animal Check List

Lesson 6

Plant and Animal Sorting Chart

Part IV

Lesson 2, 3

Food Pyramid Student Worksheet