Food Web Activity Instructions

Food Web Activity - Instructions

GOALS: The activity is designed to illustrate the complexity of food webs as well as showing the widespread effects of any alterations or introductions into the web. It can also be used to illustrate both the natural / human induced changes and their consequences.

TASK: The activity uses labels (see Food Web Activity - Labels) with various pictures of animals from a food web. Each student is given a label which they stick on themselves, they then use lengths of string to join themselves to members they eat or are eaten by. Therefore feeding relationships are formed. Students then pull the string to see how many organisms they affect in the food web.

LEARNING: To facilitate the task ask two students to organise the food web, the animals and where the string should go to / from. Then draw the classes food web on the whiteboard, with assistance from the other students.

Pre cut the string so that the food web can be constructed faster. This will eliminate the fact that some students had to stand around waiting for string. Ask students to copy the classes food web from the whiteboard and complete the following questions.

QUESTIONS:

1) List and label the type of producer and consumer. 2) List and label the animals in the second trophic order.

CHALLENGE: Question 3 looks at changes to the food web, such as a natural disease which can eliminate one species. Students are able to visualize how one change could affect the whole food web. Students need to describe the change, prey switching and pressures on the species remaining in the food web.

3) Describe the changes that would occur to the food chain if the following populations declined; a) Grasshopper - pesticide poisoning b) Snake - natural disease c) Eagle - human hunting

Completed Question 3 individually and then as a class discussion.

This higher order question may create a fantastic opportunity for constructive debate within the classroom.

Source: Project for Enhancing Effective Learning (www.peelweb.org)