Developed by the Wildlife Medical Clinic

University of Illinois College of Veterinary Medicine

Objectives Explain the working arrangements TEACHER’S GUIDE of a food web. Discuss what happens to the food Food Web Activity web when pollution of some kind occurs. Consider options for protecting the environment again such damage.

Introduction This activity is a fun and somewhat complex event that will magnify for students the interconnections among all forms of life and the problems that can arise when one destructive action occurs.

Materials 5 balls of yarn in the following colors: o Yellow – leave long o Red o Green Cut into several o Black 6 foot lengths o Brown Piece of paper with the role each student will play Masking tape

Teacher Instructions 1. Review with the students the definitions of producers, consumers, herbivores, carnivores, omnivores, scavengers, and decomposers. 2. Students should be divided into four groups representing four ecosystems – pond, ocean, meadow, forest. 3. Students should gather in four corners of the room. You will need to move desks so that eventually the groups can be connected. This is a great activity to do outside on a lawn or in a field. Ask students to sit down. 4. Give each student a card with the name of an animal, plant, or insect on it. Pin or tape the name on each student’s shirt. The teacher, or another student, should take the role of the sun. 5. Ask students to consider what they are. For instance, “spartina grass” would be a producer, “blackfly” would be a carnivore, “raccoon” would be both an herbivore and a carnivore called an omnivore. Within each of the four ecosystems students should decide who eats whom.

For more information visit the Wildlife Medical Clinic website at http://vetmed.illinois.edu/wmc/

Developed by the Wildlife Medical Clinic

University of Illinois College of Veterinary Medicine

6. Once students have determine their roles within the ecosystem (the teacher’s guide will help you with any questions that arise), ask all herbivores to raise their hands. Give each one of these students a piece of green yarn about six feet long. Then ask carnivores to raise their hands and give each one a six foot piece of red yarn. If a student is both an herbivore and a carnivore, give red and green yarn. Scavengers receive black yarn; decomposers receive brown yarn. Producers just wait for the sun’s energy. 7. The sun will hold the yellow yarn. When all ecosystems are ready, i.e. all students know their parts and have their yarn, the sun passes the yellow yarn (while retaining hold of one end) to the lowest level in the food web – any one of the plants. That plant passes the yarn on to another plant. (Point out that the sun’s energy comes directly to all plants, but for our purpose, the sun will pass only one strand of yellow). The yellow yarn continues to pass from plant to plant and on to the next ecosystem until the yellow sun’s energy has traveled to all producers. Let the end of the yarn just drop and point out that most of the sun’s energy is not used and leaves the earth, reentering the atmosphere. 8. Now ask the herbivores (green) within each ecosystem to decide whom they will eat. They should hold on to their yarn and may tie each end of it on to at least two plants in their systems. Carnivores (Red) will repeat the same procedure, tying onto two animals. Omnivores have four possibilities as they have red and green yarn. Scavengers and decomposers may tie onto any plant or animal provided they realize their meal has been rotting or dead for some time. 9. Once the connections within an ecosystem are complete (webbed), the complexity of food relationships in one place should be evident. 10. If your students seem ready, begin to ask questions that will stimulate thinking about relationships between ecosystems. For example: Does the deer ever leave the forest and got the meadow? Does the gull leave the ocean fly inland over the meadow? Does the raccoon eat shrimp at the ocean as well as bird eggs near the pond? 11. Once this movement is clear, to show the interconnections between ecosystems give the deer in the forest another piece of long green yarn and ask him to also tie into the wheat grass in the meadow. Give the raccoon another piece of red yarn and ask him to tie to the shrimp at the ocean. Give the herring gull black yarn and ask him to tie to the meadow vole (dead). Many more of these connection can be made, but this is probably adequate to show the complicated arrangement of food in our world.

For more information visit the Wildlife Medical Clinic website at http://vetmed.illinois.edu/wmc/

Developed by the Wildlife Medical Clinic

University of Illinois College of Veterinary Medicine

12. If you wish to carry this out further, introduce a catastrophe at this point. An oil truck delivering heating oil to a farm house near the meadow has an accident resulting in a major oil spill. The oil runs off across the meadow and into the stream that feeds into the nearby pond. Ask all the animals and plants that will be affected by this event to drop their ties – in other words make a break in the food web. If the meadow is coated with oil, most plants and animals will die. The run-off to the steam will affect some of the pond community. If the grass in the meadow dies that will affect the deer in the forest, and so on. Continue this discussion as far as you wish to take it. You could invent another catastrophe like pollution from a landfill also affecting water resources or air pollution from a factory affecting plant growth. Students should come away from this activity with a much clearer picture of food webs.

Food Web Roles

Pond Algae – producer Duckweed – producer Bacteria – decomposer Mayfly nymph – herbivore (eats water plants) Green frog – carnivore Blue-winged teal – primarily herbivore; occasionally carnivore (eats some insects) Raccoon – omnivore Golden shiner (fish) – omnivore (algae/small crustaceans) Painted turtles – young turtles are carnivores; old turtles are herbivores Red-ringed blackbird – herbivore/carnivore (seeds/insects)

Meadow Millipede – herbivore (eats decomposing vegetation) Aphid – herbivore Honeybee – herbivore Wild strawberry – producer Wheat grass – producer Queen Anne’s lace – producer Green snake – carnivore (eats spiders and insects) Meadow vole – primarily herbivore (but eats some insects) Red-tailed hawk – carnivore Earthworm – scavenger

For more information visit the Wildlife Medical Clinic website at http://vetmed.illinois.edu/wmc/

Developed by the Wildlife Medical Clinic

University of Illinois College of Veterinary Medicine

Forest Mushroom – decomposer Earthworm – scavenger Wood thrush – primarily herbivore (but eats some insects) Blackfly – carnivore Ruffed grouse – primarily herbivore (but eats some insects) Red baneberry – producer Oak tree – producer Deer – herbivore Beech tree – producer Gray fox – omnivore

Ocean (Rocky Shore) Herring gull – scavenger Soft-shell clam – omnivore (eats plankton) Periwinkle – herbivore (eats algae) Ribbon worm – carnivore Rockweed – producer Great blue heron – carnivore Beach flea – scavenger Spartina grass – producer Shrimp – herbivore Rock crab – scavenger

Adapted From: Galle, Janet R., Patricia A. Warren, and Arek W. Galle. Ecology Discovery Activities Kit – A Complete Teaching Unit for Grades 4-8. The Center for Applied Research in Education. West Nyack, NY 1999.

For more information visit the Wildlife Medical Clinic website at http://vetmed.illinois.edu/wmc/

Pond

Algae

Pond

Duckweed

Pond

Bacteria

Pond

Mayfly Nymph

Pond

Green Frog

Pond

Blue-Winged Teal

Pond

Raccoon

Pond

Golden Shiner

Pond

Painted Turtle

Pond Red-Winged Blackbird

Meadow

Millipede

Meadow

Aphid

Meadow

Wheat Grass

Meadow

Queen Anne’s Lace

Meadow

Honeybee

Meadow

Wild Strawberry

Meadow\

Green Snake

Meadow

Red-Tailed Hawk

Meadow

Meadow Vole

Meadow

Earthworm

Forest

Mushroom

Forest

Earthworm

Forest

Wood Thrush

Forest

Red Baneberry

Forest

Blackfly

Forest

Oak Tree

Forest

Ruffed Grouse

Forest

Deer

Forest

Beech Tree

Forest

Gray Fox

Ocean

Herring Gull

Ocean

Soft-Shelled Clam

Ocean

Periwinkles

Ocean

Ribbon Worm

Ocean

Rockweed

Ocean

Spartina Grass

Ocean

Beach Flea

Ocean

Great Blue Heron

Ocean

Shrimp

Ocean

Rock Crab