Food Web Game
Here we are using two predators that are likely found near a school yard - a hawk and a cat. You could also include (or substitute) an owl. This "game" could be done afterwards as a poster by the students showing the interdependence of all living organisms. Students may be able to extend the web we have below by adding other species. In the forests there are larger mammals that add to this complex web.
Concepts: Food webs help to illustrate the interdependence of plants and animals in an ecosystem by showing all the possible feeding relationships between the species living in that ecosystem.
Materials:
- large web chart (copied from below) for discussion purpose
- ball of yarn
- species tags (pins or necktags) one for each student
- pair of scissors
Preparations:
Make the species tags of plants and animals by using the names from the web illustrated below.
- Write only one plant or animal name on each large index card.
- Make a loop of yarn, large enough for a necklace, then tape the name tag to the loop. Have the student hang this around his/her neck. Alternatively, have the students cut out pictures of the plants and animals from magazines and paste them to cardboard pieces. Make the neck tags using these picture pieces.
Procedure:
- Draw the students into a circle.
- Distribute the species tags (one per student). There should only be one hawk and one domestic cat in your web. All other species may have multiple tags.
- Discuss with them the meaning of the term, "food web". Describe the many kinds of different plants and animals that make up a food web. Refer to the plants and animals on the species tags.
- The food web games will start with the student who has the hawk tag. Give the end of the ball of yarn to the student who has the hawk tag.
- Ask if anyone has the name tag of a food that the hawk might eat (squirrel, mouse, or bird). When a student suggests an appropriate answer, connect him/her to the hawk with the yarn. Cut the yarn and return the ball to the hawk.
- Ask if anyone else represents an animal that the hawk might eat. Repeat procedure #5. Do this until all the hawk's prey have been identified. (You may have multiple squirrels, mice, etc. so that the students will realize there are multiple meals there for the hawk.)
- Now choose one of the hawk's prey. Ask if anyone is wearing a tag with a name of a food that the animal might eat (acorn, berries, insects, flowers).
- Continue connecting students until they have all been strung together in a symbol of the web of life.
- To recognize
the interconnectedness of all the animals and plants in an ecosystem,
present the following problems:
- Who would be affected if it was a low mast (low seed production) year for trees?
- Who would be affected if the mouse population became infected with a fatal disease?
- Who would be affected if there was no rain during the spring and summer?
- Who would be affected if an aggressive, invasive foreign species of plant begins to choke out your flowers? (Think Purple Loosestrife!) Assist students in determing the answers. Who or what would be affected the most?
- Demonstrate what will happen if a species of plant is threatened by reducing their numbers in the web. Don't take them all out, just a few. Is the remaining plant population enough to keep all of the things that depend on them alive? Demonstrate what happens when one plant becomes extinct.
- Pretend that one animal becomes extinct. Have the students wearing the name tag of the selected animal drop their string. All plants and animals who were connected with the yarn to that animal must also drop their strings. Have the person representing the extinct animal move away from the remaining food web.
- Discuss with the students what they think will happen to the populations of animals and plants in the food web, that were once devoured by the animal, which has now become extinct.
