Lesson Topic: Exploring Population Ecology Target Grade Level: Sixth Grade Though written to target sixth grade learners, you may find that this lesson is applicable to both older and younger grade levels with modification. Overview In this two‐part lesson, students will learn about population ecology and the interactions between species and the ecosystems in which they live. They will focus on how some ecosystems, such as islands, pose special survival challenges for the species that call them home. Students will participate in a modeling activity to learn more about factors that impact populations and explore how small change in isolated or fragile ecosystems can have wide impact. They will also learn the individual conservation story of the Catalina Island fox. Catalina Ecological Principle #1: What “every student should know” to be an ecologically literate world citizen Catalina Ecological Principle #3: The dominant processes of the southern California landscape Catalina Ecological Principle #4: Where things come from (water, energy, food) and where they go (waste, pollution, climate change) Catalina Ecological Principle #5: What it means to be a conservation organization on Catalina and an environmental steward worldwide Next Generation Science Standards (NGSS) Connections: Performance Expectations MS‐LS2‐4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations. Science and Engineering Practices Engaging in argument from evidence in 6‐8 builds on K‐5 experiences and progresses to constructing a convincing argument that supports or refutes claims for either explanations or solutions about the natural and designed world(s). i. Construct an oral or written argument supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon or a solution to a problem (MS‐LS2‐4). Science Knowledge is Based on Empirical Evidence i. Science disciplines share common rules of obtaining and evaluating empirical evidence (MS‐LS2‐4). Disciplinary Core Ideas LS2.C: Ecosystem Dynamics, Functioning, and Resilience i. Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations (MS‐LS2‐4). Crosscutting Concepts Stability and Change i. Small changes in one part of a system might cause large changes in another part (MS‐ LS2‐4). Lesson Objectives Students will define the term population ecology. Students will explore factors that limit species populations in an ecosystem such as: ‐ Resource availability ‐ Physical habitat ‐ Other species Students will learn about the unique attributes of island ecology. Students will play a game that models species survival with limited resources. Students will discuss survival pressures faced by the Catalina Island fox. Vocabulary Abiotic: a non‐living item such as a rock; a system or area without life Biodiversity: the variety of life within an ecosystem Biotic: a living item such as a plant; a system or area with life Carrying capacity: species population an area can support with existing resources Crepuscular: an animal that is active during dawn and dusk Endemic: a species that is found only in a single geographic area Population ecology: the study of interactions between a species population and its ecosystem Materials Part 1: Population Ecology Presentation Preparation (Provided) Fox Skull Images: Grey Fox and Catalina Island Fox (Provided) If you have access to scientific specimens of fox skulls, also called biomaterials, these can be used as engaging learning tools. We have provided photos so you the activity can be conducted without biomaterials. Lamination of photos is suggested. Fox Images: Grey Fox and Catalina Island Fox (Provided) Catalina Island Fox Lesson Review (Provided) Graph of Channel Island Fox Populations (Provided) Map of Catalina Island (Provided) Dry Erase Markers Roll of bulletin board or butcher paper Four Cones (to mark game boundaries) Blank Graph Paper (Laminated) Pencils Clipboards Educator Preparation To prepare for this lesson: Print and laminate the provided photos of foxes and fox skulls. You may also choose to use a combination of photos and specimens if you have access skulls or skull replicas. Print enough copies so there is one photo of each for every two students. Create two strips of paper corresponding to the size of both a gray fox and a Catalina Island fox. Students will use these strips to compare size. The strips should have a mark where the body ends and the tail begins for each fox. Make enough strips for each type of fox so there is one set for every two students. Do not label the strips. o A gray fox can grow up to 44” in length. This is the largest they can be, though some may be smaller. Of that length, 17” is tail. o A Catalina Island fox can grow up to 19½”. This is the largest they can be, though some may be smaller. Of that length, 11½” is tail. Read through the full lesson to familiarize yourself at what points to share content information from the Population Ecology Presentation Preparation in order to promote critical thinking by students. Make photocopies of Catalina Island Fox Review Sheet for each student. Prepare the clipboards and pencils. Procedure Part 1: Learning about Catalina Island 1. Inform students that today they will learn about ecosystems and the interaction of species within an ecosystem. Explain they’ll be learning about how ecosystems can support a certain number of individuals of each plant and animal species based on available resources. This is the study of population ecology. The carrying capacity is how many individuals of a species can ecosystem can support. 2. Start the lesson by reviewing the vocabulary above. Explain that Catalina Island is a unique ecosystem. Using the Population Ecology Presentation Preparation review some of the elements that make Catalina and other islands a unique place for plants and animals. 3. Give each pair of students a copy of each fox photo, the photo of the two fox skulls side by side, and a set of paper fox size strips. Ask them to recall the class discussion on island dwarfism and to look at the photos of the two species of fox. Then have them decide which paper strip matches each species. Circulate among students to help them with their decision. Ask students to report out on their discoveries and justify their selection. Lead a visual review of the photos as a class. The photos show the Catalina Island fox has a shorter snout and thinner build in addition to the body length differences observed during the paper strip activity. 4. Students will next discuss preferred food of the Catalina Island fox. Pass out the photo of the Catalina Island fox skull. Have students work with the partners to brainstorm what this fox might eat. After working in pairs, have students share their observations with the class. Use information from the Population Ecology Presentation Preparation to guide the discussion and provide students with accurate information. 5. Lastly, review with students the information about the threatened status of the Catalina Island fox. Have them discuss at their table or in groups of four what types of factors might have contributed to the decline of Catalina Island fox populations. Once the class has successfully identified disease as a threat, share the story of the Catalina Island fox’s decline and later conservation efforts that saved the species. 6. Tell students you’re going to conduct a class vote. Ask students if they think it is more likely for the Catalina Island fox to become extinct or the mainland gray fox to become extinct. Have students discuss this with their partner. When it is time to vote, have students raise the photo of the fox they think is more vulnerable to extinction. The answer is the Catalina Island fox due to the fragile nature of its ecosystem and isolation of its population. Have students share their thoughts on why they selected the fox species they did. Correct any misunderstandings while validating alternative points of view that are based in evidence or sound critical thinking. Evaluation: Part 1 Students can be evaluated using the following rubric, which focuses on participation in the different discussion topics. Activity 1 2 3 Participation in Student watches while Student attempts to Student actively matching fox species to partner participates. participate in parts of participates by paper strip of correct the exercise. collaborating with length his/her partner to match fox species to paper strip of correct length. Participation in Student watches and Student attempts to Student actively discussion about listens to others. participate in parts of participates by Catalina Island fox diet the exercise. suggesting a food source and/or demonstrates active listening while others share. Part 2: Survive like a Fox! 1. Inform students that to learn more about population ecology, they will participate in a modeling activity by playing a game. 2. Use content from the Population Ecology Presentation Preparation to review the important elements of an ecosystem (biotic and abiotic) as well as the basic elements animals need to survive (food, water, shelter). Refer to examples using animals students are familiar with in their own community. Explain that this game will focus on the survival of the Catalina Island fox. 3. Locate a space outside to play the game with space for active movement. Set up the activity area with the use of four cones or other markers. Use the cones to mark the ends of two parallel lines about three yards long. These two lines should be 15 yards away from each other. 15 yards Habitat Foxes Essentials 4. Separate class so that ¼ of the students are a student fox and ¾ are habitat essentials.