This activity is part of the Extinction Stinks! unit. 
 

• Ask students what they think the term “biodiversity” means. 
• Break down the word into its two parts: “bio,” meaning life, and “diversity,” meaning variety and difference.
• Define biodiversity for students: “all the different kinds of living organisms within a certain area.”
• Show the Penguins of Patagonia video (4:31) as an example of biodiversity in coastal Argentina. 
• In the video, Explorer Pablo Borboroglu defines biodiversity and uses it as one measurement of ecosystem resilience—how well the ecosystem can persist through disturbances. Have students listen for specific benefits of biodiversity that are identified in the video.
• After watching the video, lead a discussion with students about the benefits of biodiversity they heard. List them on the board for future reference.

• Review the definition of the term ecosystem from the SOS—Saving Our Species activity.
• Explain that within an ecosystem, organisms are categorized based on how they gain the energy they need.
• Producers create their own food, often using energy from the sun. All plants, as well as some microorganisms like cyanobacteria, are producers.
• Consumers eat producers or other consumers. Consumers are usually categorized by their typical diet: herbivores eat primarily plants, carnivores eat primarily meat, and omnivores eat a combination of plants, meat, and fungi.
• Decomposers gain their energy from dead and decaying organisms. 
• Display the Who’s in My Backyard? food web infographic. 
• Ask students to predict what they think the arrows in the diagram represent.
• Explain that arrows show how energy moves between species—the arrow points in the direction of energy flow from one organism to another.
• Explain to students that they will model a food web using organisms that live in the Sumatran rhino’s ecosystem. Each student will receive a role for the activity of one organism or other factor that is a part of the food web.
• Display the Vanishing Populations Map used in The Roots of Extinction activity. Point out Way Kambas National Park, the ecosystem that is home to the organisms used in this model ecosystem. This is also the place where the Sumatran Rhino Rescue site is located.
• Distribute the Way Kambas Food Web Cards (one card to each student) with an organism typically found in Way Kambas National Park.     
• Have students organize themselves in a few ways to have some fun and get oriented with who is in the ecosystem. Some ideas include:
• Line up by size (have them make their best guess!).
• Organize into groups by producers, consumers, decomposers, and anything else.
• Organize so every organism is standing next to another organism that it has a direct energy relationship with—either giving or receiving energy to each other.
• Then prompt students to follow the steps below to build a model of the relationships between species. 
• Distribute the pieces of yarn so that each student has at least three or four pieces.
• Have students stand in a circle with their cards facing outwards. 
• Students should take several pieces of yarn and use them to connect to others in the circle from whom they receive energy. For some, this will be just one source and for others this can be many different sources.
• Producers will all connect to the sun. 
• Consumers will connect to several examples of the organisms they eat as food.
• Decomposers should connect to several organisms they might eat.
• Once everyone has connected to the species they are related to, point out to students that there are many relationships within the ecosystem that overlap with each other. 

• Distribute the Way Kambas Food Web Model handout to students. 
• Prompt students to complete Part A by creating a food web model using a subset of the organisms from Way Kambas National Park.

• Have students retake their positions in the yarn-based model of the relationships between species, then use each of the Way Kambas Food Web Disruption Cards to introduce four different scenarios to the ecosystem. When each disruption happens, pause and prompt students to reflect on how that change would affect different species within the ecosystem using the questions printed on the card.
• After disruptions #1 and #2, reset the food web before continuing with the next scenario.
• After disruption #3, do not reset the ecosystem. Ask students to predict how an additional disruption might affect the ecosystem differently after already experiencing the impacts of this challenge. Then, complete disruption #4 with a reduced population of organisms in the ecosystem.
• After the disruptions are over, ask students to complete Part B of the Way Kambas Food Web Model handout and then consider how biodiversity affects the survival of the Sumatran rhino. Their ideas may include:
• More species in an ecosystem allow for different sources of energy.
• When species' numbers are depleted, the lower number of ecological relationships decreases an ecosystem’s resilience after a disruptive event.
• Biodiversity allows increased numbers of relationships between species, strengthening the resilience of the ecosystem.

• Distribute the class Know & Need to Know chart from the Saving Our Species—SOS activity.
• Direct students to add new information they have learned about biodiversity through this activity. Examples may include:
• Biodiversity is one measure of the health of an ecosystem supporting an endangered species.
• Decreases in biodiversity might increase the risk of a species going endangered or extinct.
• Species in an ecosystem affect each other even when they are not directly connected through an energy transfer.
• Students can also add new questions or ideas they have related to conserving endangered species while also protecting the needs of humans and other species.