Bison on the prairie
Larry McAfee, National Park Service photograph
All life needs energy to grow and survive. Plants receive a vital part of their energy from the Sun, while animals receive their energy from eating plants or other animals. The path energy takes through an series of organisms is known as a food chain, while all the paths energy can travel through an ecosystem is known as a food web. Discover how the mixed-grass prairie plants and animals of Badlands National Park are connected to each other through food chains and an overall food web.
Students will be able to trace prairie food chains and illustrate a prairie food web.
A food web shows how energy is transferred in the environment. Energy is transferred from the Sun to plants, then to herbivores (plant eaters), then to carnivores (meat eaters).
The mixed-grass prairie ecosystem of Badlands National Park is home to a variety of plants, herbivores, and carnivores. Herbivores like grasshoppers and rabbits eat grasses like ricegrass and wheatgrass. Meanwhile, birds like the meadowlark and the golden eagle prey upon the herbivores. As is the case in most ecosystems, plants and herbivores can be energy sources for many different animals.
Student worksheets, Prairie Food Web Answer Key, pencils, and classroom whiteboard
Tell the class that a park ranger from Badlands National Park will be visiting the classroom this week. Describe where Badlands National Park is. Show a map or tell the students how long it would take to drive to the Badlands.
Explain that Badlands National Park is a special place. One reason Badlands is special is that it protects one of the largest remaining mixed-grass prairie ecosystems remaining in the United States. What is a prairie? (North American grassland, usually flat to gently rolling and with few trees.) What living things do we find in the prairie habitat in Badlands National Park? (Some of the many possible answers are: bison, mule deer, prairie dogs, coyotes, swift fox, rabbits, eagles, hawks, snakes, lizards, grasses, and wildflowers.)
Discuss how all living things need energy. Where does a person's energy come from? (Food.) What about a plant? Does it eat? Where does its energy come from? Illustrate a simple food chain on the board, drawing arrows to show the direction of energy transfer.
Sun --> Grass --> Cow --> Human
Have students brainstorm one or more examples of a prairie food chain featuring animals that live in the Badlands, illustrating the food chain(s) on the board.
Introduce the idea of food webs. A food chain shows one specific route that energy can take through an ecosystem, like one path you could walk to get from your home to school. A food web is like a map of the neighborhood that shows all the possible ways you could get from home to school: it shows how all the different species in an area can interact with each other to meet their energy needs. Most species don't get their energy by eating just one thing. For example, a coyote may eat many different small mammals, insects, carrion (dead meat), and plant matter.
Hand out the Prairie Food Web worksheet
. Have students draw arrows between different mem- bers of the food web to show where the different members of the prairie food web get their energy. Students may also draw in one or two additional plants or animals that live in the Badlands and fit them into the food web.
Discuss what happens if part of the food web is disturbed. What if there is a bad drought? What if a species goes extinct? Can people have an effect on the food web?
Tell the class that the park ranger who visits the class will talk about historic uses of the bison by Native Americans. People are part of the food web, too!
These resources are available through Badlands National History Association (BNHA), a not-for-profit organization established to support education and research efforts at Badlands National Park.
- America's Prairie and Grasslands by Marianne D. Wallace
- Local Tracks of North America "Quick Guide"
- Golden Guide: Mammals
- Badlands Suite: Land of Stone and Light, From Field to Lab, Multiple Perspectives DVD
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