LibGuides: Yellowstone National Park: Trophic Cascade: Home

Grade Level

3rd Grade

Library Standards

AASL I.A.1. Formulating questions about a personal interest or a curricular topic.

AASL Ill.A.2. Developing new understandings through engagement in a learning group

Core Standards

Reading 2.A.4

Time Frame

30-45 min. Preparation time

30-45 min. with the students

Author/Creator

This lesson was modified for 3rd grade by Kat Pogatshnik, Raymore Elementary School.

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Books on the topic

The Wolves of Yellowstone by Catherine Barr
ISBN: 9781547607983

Publication Date: 2022-04-05

Here is the fascinating true story of the wolves who restored the ecosystem at Yellowstone National Park, written by Catherine Barr and illustrated by award-winner Jenni Desmond. In the 1930s, the last wolves disappeared from Yellowstone National Park. Without them, elk herds overran the plains. Bears starved, rabbit families shrunk, and birds flew away to new homes. Then plants and trees started to die off, too-even the flow of rivers was affected. Could the park be saved . . . by the wolves it had lost? After years of planning, in 1995 a team of experts was ready to find out. They carefully relocated fourteen wolves from the Canadian Rockies to Yellowstone. This is the story of their homecoming. Engaging, informative, and hopeful, The Wolves of Yellowstone shows us that every creature plays a role in sustaining a thriving ecosystem.
Bringing Back the Wolves by Jude Isabella; Kim Smith (Illustrator)
ISBN: 9781771386258

Publication Date: 2020-03-03

An unintended experiment in Yellowstone National Park, in which an ecosystem is devastated and then remarkably rehabilitated, provides crucial lessons about nature's intricate balancing act. In the 1800s, hunters were paid by the American government to eliminate threats to livestock on cattle ranches near Yellowstone National Park. They did such a good job that, by 1926, no gray wolf packs were left in the park. Over the following decades, virtually every other part of the park's ecosystem was affected by the loss of the wolves -- from the animals who were their prey, to the plants that were the food for that prey, to the streams that were sheltered by those plants -- and the landscape was in distress. So, starting in 1995, in an attempt to reverse course, the government reintroduced gray wolves to the park. Over time, animal populations stabilized, waterways were restored and a healthy ecosystem was recreated across the land. It's a striking transformation, and a fascinating tale of life's complicated interdependencies. Jude Isabella's thoroughly researched, expert-reviewed text and Kim Smith's beautiful nature art bring science to life in this captivating story of renewal. Readers will recognize just how complex an ecosystem is and learn about the surprising interconnectedness of its members. Biodiversity, ecosystems, the food chain, habitats, needs of living things and the importance of human stewardship of the environment are all covered through this real-life example, offering direct links to earth and life science curriculums. Food web infographics help reinforce the information. A glossary and index add to the book's usefulness.

Summary

Students will observe what happened to the ecosystem of Yellowstone National Park when we (humans) removed the wolves. Students will then discuss the impact of one species to an ecosystems' balance, if it can be "fixed" and balanced regained, and watch a short video on the effects of re-introducing the wolves into Yellowstone National Park.

Materials

What you need:

Balloons
Yarn
Chairs set up in a circle with the chair backs in the middle of the circle, 1 per student/participant,
Sign that says “Yellowstone National Park Ecosystem”
Printed animal cards (Wolf, Bear, Beaver, Deer, Salmon, Leaf)

Ecosystem Cards
You will need one card per chair used. There are 12 images in this file, 2 of each type.

Learning Outcomes

Students will be able to discuss and see the effects of a Trophic Cascade (taking a top predator out of an ecosystem) using a real-life example.

Instructional Procedures

Students have read the MyView text for "Wolves of Yellowstone" and have discussed both sides of the argument: Keep the wolves in Yellowstone or Take out all of the Wolves in Yellowstone.

Trophic Cascade
Procedure and script for the Trophic Cascade interactive module.
Web Visual
This is what the set up will look like when complete.

Assessment

Discussion questions:

What happened to the ecosystem when the wolves were taken out?

Can this be seen in other areas where we (humans) add or take away species that we don't like? (invasive species)

After the video: How did the wolves change the rivers?

Modifications

If you have a smaller group, have the students make the web by tossing balls of yarn to each other after they tie the end to their chair.