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

Multicoloured coral reef on the seabed.

Habitats

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

Elk and wolf

Show this visual before the film 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 film to spark a discussion about predator/prey relationships. Ask the children to suggest other examples.

Food web

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

Ecosystem
A community of living organisms and their environment.
A community of living organisms and their environment.

Ecosystem

Show this visual after the film 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 school playground or a nearby wood or hedgerow). 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:

  1. 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.)
  2. Ask volunteers to share their group’s definitions with the rest of the class. Make sure everyone is comfortable with the keywords before proceeding.
  3. Display the Rainforest food web images (found in the Multimedia toolbox) 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!
  4. 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.
  5. Discuss their food chains as a class, noting any similarities or differences, and picking up on any misconceptions.
  6. 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.
  7. 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.
  8. Conclude the activity 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 non-living 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 whilst 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.

Explore our resources

Complete your lesson with teaching resources on food webs from Tigtag.

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Discover free online CPD for primary science from Reach Out CPD.

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