Overview & Lesson Sequence

Focus on Standards & Assessment

Materials Needed, Preparation & Planning, Management Strategies

Background Info

Intro Activity
Why Study Predator - Prey interactions?

Activity 1
Observation of a predator-prey interaction

Activity 2
What makes a predator successful?

Research Project
Designing a predator - prey experiment

Optional Activity
Biological Control vs. Pesticides

Case Study
Rabbits in Australia

References

Glossary

Suppliers

Resource Sheets

Enforcers Home

CISEO Home

Intro Activity: Why study Predator-Prey Interaction?

Start a general discussion about predator and prey populations using a photograph or graphical display of an ecosystem, food web or food pyramid. Use the following prompts to assess students' prior knowledge:

• In the picture, which are the predators and which are the prey?
• What are some challenges predators must meet? (Finding, catching prey.)
• What makes a predator "successful"?
• What are some common predator adaptations? (Raptors - hooked beak, talons, spiders -fangs). What are some common prey adaptations? (protective coloration, hiding behaviors)
• Can herbivores be predators? (Possibly in the strictest sense of the term since they prey on grains and other vegetation, but they do not have the predator "lifestyle" in which they must hunt and capture their prey.)
• What challenges do carnivores have that herbivores do not? (They must find and capture prey, whereas herbivores just graze.)
• Are parasites predators? (Yes in the sense they prey on the host; no in the sense that they do not usually kill the host outright.)
• What variables affect the number of predators and prey in a population? (Relative numbers of predators and prey; carrying capacity of the environment for both predator and prey.)
• How can predators be used to control a prey population? Why would you want to do that? (The prey may be a pest that can be controlled by the introduction of a predator. For example praying mantids in gardens can reduce the numbers in a pest population.)
• What can studying a predator-prey relationship tell you about other predator-prey relationships? (There are models and principles applicable to predator-prey relationships in general. For example, host-parasite interactions have been used to predict the dynamics of HIV in humans.)

Note the extent of student understanding and any misconceptions they may have. You may want to adjust the lesson or adjust lab groups based on their answers. It is not important at this point if students can answer the questions correctly. They will be discovering many of these aspects as they complete the activities.

Finally, ask students:
What questions do you have about predator and prey populations and their interactions? (post questions on a flip chart or other piece of paper and review answers at regular intervals throughout the lesson; add any that may arise from whole group discussions.)