07. Eat or be eaten (or maybe both)
Outcomes:
organise information in a food web
apply knowledge to a new situation
create a food web based on researched information
AtL
Organisation skills: Use appropriate strategies for organising complex information.
Scientists use many different ways to organise and make sense of what they observe, investigate and understand. For example, scientists identify and organise patterns in which organisms interact in different ecosystems.
One of the tools that scientists use to categorise and organise the interactions between organisms in an ecosystem is a food web. A food web refers to the network or connections between what organisms eat in an ecosystem. In a food-web diagram, the producers (plants) and consumers (animals)are drawn or written in, with arrow to connect the organisms that are eaten with the organisms that are eating. Depending on the diversity of the ecosystem, a food web can be very simple with few connections, or very complicated with many connections.
To practice making a food web, use the facts about some of the organisms living in Yellowstone (below) and the food-web template to create a food web for the Yellowstone ecosystem. A portion of the food web has been done for you as an example, Follow the example to help you fill in the remainder of the food web. Remember, use arrows to connect the organism to the organism that is eating (organism eaten → organism eating).
Note that in this food web there may be some different ways to fill in the template as you move left to right on each level, but not as you move up and down between levels. Also, you can choose simply to write in the names of the organisms to fill in the food-web template, or use your computer to put pictures of the organisms in the food web.
Elk eat quaking aspen.
Mayflies and trout eat green algae.
Bison, deer mice and bighorn sheep eat grey willow.
Trout eat mayflies.
Red-tailed hawks, coyotes and grizzly bears eat deer mice.
Grizzly bears, grey wolves and coyotes eat elk.
Coyotes and grey wolves eat bison.
Grey wolves eat bighorn sheep.
Grizzly bears and osprey eat trout.
Bald eagles eat osprey.
Grey wolves eat bald eagles.
When you have finished your food web and compared it with those of your classmates, make a list of the general patterns between organisms in the food web, using the heading "Something I noticed about the interactions between organisms in a food web'.
In this activity we have used the food web as an model to explore and make generalisations about a complex system and to understand the interactions between organisms in an ecosystem.
EXTENSION
AtL
Creative-thinking skills: Apply existing knowledge to generate new ideas.
Can you construct a food web for another ecosystem? to begin, think of an ecosystem you are either familiar with or interested in. It could be a large ecosystem, such as a rainforest, or a small ecosystem, such as a pond or tide pool.
The do an Internet search for the producers, primary consumers, secondary consumers, and maybe tertiary and quaternary consumers in the ecosystem of your choice. For example, you could type rainforest producers or rainforest primary consumers in your search bar. Arrange the organisms you learn about from your search into the levels as we did for the Yellowstone ecosystem, and draw in arrows to show what is eaten and what is eating.
Alternatively, you can search for an already constructed food web for your ecosystem of choice simply by typing the ecosystem followed by the words food web. For instance, to find the food web of the rainforest, you can type rainforest food web in the search bar.
What do you notice about the interactions between organisms in the ecosystem you researched and the Yellowstone ecosystem? In what ways are they similar? How do they differ?