Competition and Predation

Active learning helps students grasp competition and predation because these concepts are dynamic and relational. When students move, analyze data, and discuss scenarios, they experience firsthand how populations interact and respond to change. This kinesthetic and collaborative approach builds intuition that static images or lectures alone cannot.

• 6th Grade
• Science
• 3 activities
• 20 min–40 min

Learning Objectives

1. Compare and contrast intraspecific and interspecific competition for resources like food, water, and shelter.
2. Analyze the impact of predator-prey relationships on population dynamics, using examples like the snowshoe hare and lynx.
3. Predict the cascading effects on an ecosystem when a predator or prey population significantly increases or decreases.
4. Explain how predation can maintain biodiversity by preventing any single herbivore species from dominating an area.

Simulation Game

⏱ 40 min·Whole Class

Simulation Game: Predator-Prey Tag

In an open space, designate most students as rabbits and a few as foxes. Rabbits must collect resource tokens (paper clips on the ground) to survive each round. Foxes tag rabbits to 'eat' them. After each round, adjust populations based on the rules (starved rabbits removed, well-fed rabbits reproduce, foxes that ate enough reproduce). Track population sizes per round and graph the oscillation.

Prepare & details

Explain in what ways different species compete for or share limited resources.

Facilitation Tip: During Predator-Prey Tag, position yourself as a roaming predator to model visibility challenges in tracking prey.

Setup: Flexible space for group stations

Materials: Role cards with goals/resources, Game currency or tokens, Round tracker

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Role Play

⏱ 35 min·Small Groups

Collaborative Analysis: Lynx and Snowshoe Hare

Provide groups with the historical Hudson's Bay Company population data for lynx and snowshoe hare spanning 90 years. Groups graph the data, identify the oscillating cycles, and develop an explanation for the pattern using cause-and-effect reasoning. Groups then predict what would happen if lynx were removed from the ecosystem.

Prepare & details

Analyze the role of predation in maintaining population balance within an ecosystem.

Facilitation Tip: When analyzing lynx and snowshoe hare data, provide blank population graphs so students can sketch predicted trends before comparing them to historical records.

Setup: Open space or rearranged desks for scenario staging

Materials: Character cards with backstory and goals, Scenario briefing sheet

• Apply
• Analyze
• Evaluate
• Social Awareness
• Self-Awareness

Think-Pair-Share

⏱ 20 min·Pairs

Think-Pair-Share: What Is Competition Really About?

Give students two scenarios: two species of sparrow competing for nest sites in the same territory, and two wolves within a pack competing for access to food. Pairs identify the type of competition in each case and discuss what resource is actually limited. Class discussion surfaces the distinction between intraspecific and interspecific competition and explores when competition leads to niche partitioning rather than exclusion.

Prepare & details

Predict how an increase in a predator population might affect its prey.

Facilitation Tip: In the Think-Pair-Share on competition, give students 30 seconds of private think time before pairing to ensure all voices are heard, especially from quieter students.

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Teaching This Topic

Teaching competition and predation works best when students confront misconceptions directly through simulation and real data. Avoid over-simplifying predator-prey relationships as 'good vs. bad,' and instead focus on interdependence. Research shows that students grasp these concepts more deeply when they manipulate variables and see immediate feedback on their predictions, so simulations and real-world datasets are essential tools.

What to Expect

Students should leave this hub able to distinguish between intraspecific and interspecific competition, explain why predator-prey cycles oscillate, and provide evidence-based reasoning for how these interactions shape ecosystems. Look for clear examples, accurate cause-and-effect language, and thoughtful predictions in their work.

Watch Out for These Misconceptions

Common Misconception

During the Collaborative Analysis of lynx and snowshoe hare data, watch for students who assume the lynx will always drive hares to extinction.

What to Teach Instead

Direct students to examine the cyclical nature of the data and ask them to brainstorm mechanisms like habitat use or seasonal diet shifts that allow both species to coexist. Ask: 'What might happen to the lynx population if hares disappeared completely?'

Common Misconception

During the Predator-Prey Tag simulation, watch for students who treat predators as separate from the ecosystem, suggesting ecosystems would be healthier without them.

What to Teach Instead

After the simulation, have students discuss the immediate and long-term effects of removing predators using the Yellowstone wolf case as a reference point. Ask them to record changes in the 'ecosystem' during the tag game when predators were absent.

Common Misconception

During the Think-Pair-Share on competition, watch for students who believe predator and prey populations change independently.

What to Teach Instead

Use the lynx-hare data from Collaborative Analysis to show how prey numbers spike first, followed by a delayed predator increase. Ask students to sketch this lag on their graphs during the pair discussion.

Assessment Ideas

Quick Check

After the Think-Pair-Share, provide students with a scenario of a grassland with zebras, lions, and acacia trees. Ask them to identify one example of competition and one example of predation, and explain how each interaction might affect population sizes.

Discussion Prompt

During the Collaborative Analysis of lynx and snowshoe hare data, pose the question: 'Can predators be beneficial to an ecosystem?' Facilitate a class discussion where students use evidence from their data analysis to support their arguments, referencing predator-prey examples from their work.

Exit Ticket

After the Predator-Prey Tag simulation, ask students to draw a simple food web with at least three organisms. Then, have them write two sentences explaining how competition between two of the organisms might occur and one sentence describing the predator-prey relationship between two others.

Extensions & Scaffolding

• Challenge students who finish early to research and present a case of apparent competition, such as pheasants and grouse sharing a common parasite, and how it affects community structure.
• For students who struggle, provide sentence stems like 'Competition happens when...' and 'Predators affect prey populations by...' to scaffold their explanations during the Think-Pair-Share.
• Deeper exploration: Have students design a controlled experiment to test how resource availability (e.g., food type or space) affects competition intensity among isopods or mealworms.

Key Vocabulary

competition	The struggle between organisms for limited resources such as food, water, shelter, or mates. This can occur within the same species (intraspecific) or between different species (interspecific).
predation	An interaction where one organism, the predator, hunts and kills another organism, the prey, for food. This is a key factor in regulating population sizes.
niche	The specific role an organism plays in its ecosystem, including its habitat, food sources, and interactions with other species. Competition often arises when species share overlapping niches.
population dynamics	The study of how and why populations of organisms change in size and composition over time, influenced by factors like birth rates, death rates, immigration, and emigration.
carrying capacity	The maximum population size of a biological species that can be sustained by that specific environment, considering available resources and environmental conditions.