The video is found on the Yellowstone Park website, and it follows the effect of the 1995 reintroduction of wolves. By the end of the 1920s all of the gray wolves in the park had been eliminated. For 70 years the wolf was removed from the food chain, and as a result the elk population exploded. The overpopulation of these grazing herds removed vegetation to the point that erosion became a concern and other animals were affected.

By 1990 Yellowstone biologists began to question the removal of the wolf and began planning to introduce Canadian wolves to the park. In 1995 the first eight wolves were released, and by 2015 there were 10 packs, a total of 99 wolves.

As a result of the reintroduction of the wolf, vegetation was reestablished, the beaver population began to flourish, the number of songbirds increased, and the rivers changed. Yes, you heard that correctly! The behavior of the rivers changed! Watch the video for yourself.

Trophic levels, carrying capacity, trophic cascades, predator-prey relationships, the relationship between biotic and abiotic factors, and ecosystems are just a few of the topics you can discuss with your students.

What are some other discussions you might have after viewing this video? How would you use this as an opportunity to teach NGSS, TEKS, or other state standards? Leave me a note below!

Subscribe to our blog to receive more teaching tips and free downloads.

Check out the Science Sidekicks (grades 3-5), the Science Starters (grades 6-8), Biology Starters or Chemistry Starters with a Free Trial!

Science Sidekick Demo Lesson (grades 3-5)

Science Starter Demo Lesson (grades 6-8)

Biology Demo Lesson

Chemistry Demo Lesson

Request a Quote