Video: Wolves in Yellowstone Park I Reach Out Reporter

Feature

03/10/2022

In 1995, gray wolves were released into Yellowstone National Park in the USA. Watch this video to find out what happened next!

Transcript

Yellowstone National Park, USA

These elk are hungry. They like to eat, and eat, and eat.

A few decades ago, that was causing a big problem at Yellowstone National Park in the USA.

Their enormous appetite for leaves and bark was damaging the trees and the forests were starting to die.

It was a problem that had started with the decline of the elk’s top predator – the wolf.

Back then wolves were seen as dangerous so they were hunted and killed.

With fewer wolves left to hunt the elk – their numbers soared.

The solution?

Bring back the wolves.

If there were more wolves they would hunt the elk and reduce their numbers. That would allow the trees to grow back.

But would the plan work?

In 1995, 14 wolves were reintroduced to Yellowstone National Park.

The wolves attacked the elk and the number of elk started to drop.

The wolves didn’t attack all the elk in Yellowstone though. They only hunted the weakest elk, the ones that were easiest to catch.

So the wolves actually made the elk population healthier, as now only the strongest elk survived.

And on top of that, the trees also began to grow back.

Dr Doug Smith, Yellowstone National Park – "All of these willows, all of these stems that you see here were eaten by elk. But since wolves have been reintroduced we saw it come back before our eyes."

Then something slightly unexpected happened.

Other animals started to benefit too – like the beaver.

With more trees, beavers had something to eat and could use the branches to build dams to live in.

So how did one animal change an entire national park?

The wolves preyed on the elk, which allowed the trees and grasses to grow back.

And with more vegetation, other animals, like the beaver, started to come back too – making the whole ecosystem in Yellowstone National Park a lot healthier.

ecosystem

So it looks as though the big bad wolf might not be all that bad after all.

Reintroducing wolves helped the ecosystem of Yellowstone

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Wolves of Yellowstone

Teaching overview

Learning points

Predators are animals that catch and eat other animals.
Prey are animals that are attacked by other animals that intend to kill and eat them.
A change to the population of one species in an ecosystem can have an affect on every other species.
Reintroducing wolves helped restore balance to the ecosystem of Yellowstone National Park.

Curriculum keywords

Food chains
Food webs
Ecosystems
Habitats

Spark a discussion

What do living things need to survive?
How do living things interact with their environments?
What do you think the word “ecosystem” means? What sort of things would you find in an ecosystem?
How are animals dependent on each other?
How can humans affect the balance of an ecosystem? Are human impacts always negative?
What are predators? Can you name some examples?
What are herbivores, carnivores and omnivores? Can you name some examples?
What do wolves eat? Do any animals eat wolves?
What happened to the trees in Yellowstone when wolves were reintroduced? Why?
What happened to the elk and beaver populations when wolves were reintroduced? Why?
How might the beaver population be affected if the number of wolves was to drop again?
What other living things might benefit from the reintroduction of wolves to Yellowstone?
What other impacts can animals have on their environment?
Why is it important to look after national parks?

Multimedia toolbox

Habitats

Show this visual before the video. Ask the students to suggest what living things you might find in each habitat, and how they might interact.

Elk and wolf

Show this visual before the video to spark a discussion about where these animals live, what they eat, and ways that they might interact.

Predator and prey video loop

Play this video loop before the main video to spark a discussion about predator/prey relationships. Ask the children to suggest other examples.

Food web

Show this visual before or after the video and challenge the students to complete the food web by adding arrows.

Ecosystem

A community of living organisms and their environment.

Ecosystem

Show this visual after the video to reinforce key scientific language.

Activities

Rainforest food webs

CREATE food chains and food webs using plants and animals from the rainforest ecosystem.

Open detailed instructions

Other activity ideas

WRITE a report about the importance of keeping an ecosystem like Yellowstone National Park in balance.
RESEARCH other examples of reintroduction projects, and discuss which animals the class would most like to see introduced to their local area.
OBSERVE the local ecosystem (e.g. the schoolyard or a nearby wood or park). Take photographs if possible, and create a poster showing the balance of wildlife in the local area.
INVESTIGATE the role of decomposers in a food chain, by observing what happens to rotten fruit over time.

Print this sheet

Rainforest food webs

Duration: 60 minutes

Resources:

Rainforest food web images (found in the Multimedia toolbox)
Large sheet of paper
Pens
Ruler
Scissors (optional)
Glue (optional)

Key Learning:

This activity supports the students’ understanding of interdependence in ecosystems, by asking them to draw their own rainforest food webs.

Activity preparation: You may want to print the Rainforest food web images (1 per group) and cut into sets of 16 images. Keep each set together. Alternatively, the students can draw pictures of the animals and plants themselves.

Activity instructions:

Write the following keywords on the whiteboard, and ask the students to discuss their meaning in groups:

Predator (An animal that catches and eats other animals.)
Prey (An animal that is killed and eaten by a predator.)
Producer (Plants and other organisms that can make their own food.)
Consumer (An organism that gets its energy from eating other organisms.)
Primary consumer (An animal that eats producers like plants.)
Secondary consumer (An animal that eats primary consumers.)

Ask volunteers to share their group’s definitions with the rest of the class. Make sure everyone is comfortable with the keywords before proceeding.
Display the Rainforest food web images on the whiteboard, and/or give each group a set of 16 images. Go back through the list of keywords, and challenge the students to identify examples of each – for example, jaguars and boa constrictors are predators, tapirs and sloths are their prey, plants are producers, and so on. Note: It doesn’t matter if the students aren’t familiar with every example. Educated guesswork is perfectly acceptable!
Give each group a large sheet of paper. Ask them to work together to create a food chain, using examples from the Rainforest food web images. The groups can either draw pictures or use glue to stick the printed images in order. Ask them to complete the food chain by drawing arrows between each of the levels.
Discuss their food chains as a class, noting any similarities or differences, and picking up on any misconceptions.
Ask the groups to look at the images they didn’t use in their food chain. How could these be added to their sheets of paper to create a food web? Challenge them to incorporate as many of the different plants and animals as possible. They could even introduce other examples not featured in the visual.
Display the students’ completed food webs in the classroom. Ask the groups to discuss what would happen if one part of the food web was removed. Encourage them to reflect on how the disappearance (and later reintroduction) of wolves affected Yellowstone National Park.
Conclude the lesson by reiterating that all the organisms in an environment are interconnected, and a change to one part of a food web can affect the balance of the entire ecosystem.

Optional extra

Ask the students to think about the possible impact of changes to things like climate or soil quality. How might these nonliving parts of an ecosystem affect the balance of living things?

Background information

An ecosystem is a living community of organisms interacting with their physical environment. Ecosystems can be any size, from a tiny pool to a vast forest. In a stable ecosystem, everything coexists in a sustainable way.
Animals gain energy by consuming plants and/or animals that eat plants. This flow of energy from one organism to the next can be represented in a diagram called a food chain.
Organisms can belong to more than one food chain. The relationships between multiple food chains can be expressed in a diagram called a food web.
Removing, reducing or increasing one type of organism in a food web can significantly affect every other organism in that web. This is called interdependence.
Animals that hunt and kill other animals for food are called predators. Animals that are hunted are called prey.

Glossary

Ecosystem: A community of living organisms and their environment.
Predator: An animal that catches and eats other animals (its prey). Some predators actively hunt prey while others wait for their prey to approach.
Food chain: A means of describing the ways animals gain energy and food from other organisms. All food chains begin with a producer, which produce their own food through photosynthesis.
Food web: A number of interrelated food chains in a habitat. If one part of a food web disappears, it affects the survival of all the other species contained within it.
Interdependence: A relationship by which organisms or systems rely on each other for survival or proper function.

Wolves of Yellowstone

Transcript

Teaching overview

Learning points

Curriculum keywords

Spark a discussion

Multimedia toolbox

Habitats

Elk and wolf

Predator and prey video loop

Food web

Ecosystem

Activities

Rainforest food webs

Other activity ideas

Rainforest food webs

Resources:

Key Learning:

Activity instructions:

Optional extra

Background information

Glossary

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