- 8½” x 11” square piece of white cardstock paper
- Colored pencils
- Transparent tape
- Masking tape
- Books about the plants and animals of a tropical rainforest
- Push pins
- Corrugated cardboard
Whew! The tropical rainforest is a hot topic. Tropical rainforests can be found around the world near the equator, an imaginary line around the middle part of the earth. Areas closer to the equator tend to be warmer. Warmth and moisture combine to make the world’s tropical rainforests home to nearly half of the species of plants and animals on earth.
One of our planet’s tropical rainforests is located in Central America, and has many gorgeous species of butterflies. The Blue Morpho Butterfly eats plant leaves of legumes when it is in its larval state. When it becomes an adult, it drinks nectar from plants using its proboscis, an appendage that acts like a drinking straw.
Tropical birds like to eat butterflies and other insects. Jacamars are medium-sized birds with long beaks, and they like to eat all sorts of insects, including butterflies, moths, and wasps.
The jaguarondi is a small wild cat that lives in Central American forests. It looks a little bit like an otter. It’s very fast and can easily catch fish and birds. It will even jump up to knock birds out of the air!
Can you think of other plants and animals that live in a tropical rainforest? Look up one of your favorite large animals and see if you can find out what it eats.
Food chains, food webs, and food pyramids: what’s the difference? In this activity, you’ll build all three.
Creating a Food Chain
A food chain is a simple line demonstrating which organisms eat which. In a food chain, you begin with a plant. In the tropical rainforest, this might be a legume that the blue morpho caterpillar likes to munch on. Along comes a bird called a jacamar, which catches and eats the morpho. Just as the bird is flying away, the jaguarondi that was hiding in the bushes leaps out and catches the jacamar.
- To create a food chain, place a foot-long piece of string on the cardboard. Pin it at either end.
- Create labels that say “legume plant,” “blue morpho,” “jacamar,” and “jaguarondi” and add these labels to push pins.
- Place the legume plant pin at one end of the string, followed by the blue morpho, the jacamar, and the jaguarondi.
- You’ve created a food chain—a simple line that shows how plants feed butterflies, which feed birds, which feed larger predators like the jaguarondi.
Creating a Food Web
So do wild cats like the jaguarondi only eat birds? Of course not! Animals often eat a wide variety of other plants and animals—far more than you could fit into a food chain. This is where a food web comes in handy.
- Create two more labeled push pins that say “marmoset” and “flower”. Use your string to attach the jaguarondi to the marmoset and the butterfly to the flower.
- This pattern is starting to look more like a web than a chain! Can you think of other animals that might be part of this food web? What else does a Jacamar like to eat, for example? Add your findings to push pins and continue building your web.
Creating a Food Pyramid
A food pyramid is different from a food chain or web. How is it different? Well, think about your blue morpho. How many legume plants does it need to eat to grow into a butterfly, and how many flowers does it visit once it’s an adult? Quite a few! On the other hand, a jacamar eats fewer butterflies than a butterfly visits flowers, and a jaguarondi eats even fewer jacamars.
Think about it this way: as you move up the food chain, each level can support fewer animals than the last. These levels are called trophic levels, and they stand for the position an organism occupies in a food chain. A single jaguarondi (ultimate consumer) can eat many birds or marmosets (secondary consumers), and a single bird can eat even more butterflies (primary consumer). Each butterfly drinks from many, many flowers, which are called producers because they produce food from the sun. Therefore, thousands of flowers indirectly fill the belly of the jaguarondi. A food pyramid can help demonstrate this by showing the different numbers of organisms that are necessary at each level of the food chain (that’s why it’s thicker at the bottom). At the bottom of your food chain, you might draw many different plants, but there will be only one jaguarondi in the small triangle at the top.
- Let’s build your pyramid! Print out this template on cardstock paper, and we can get started.
- Use your scissors to cut out the template from the cardstock paper.
- From bottom to top, label the four parts of one triangle with the following names: producer, primary consumer, secondary consumer, ultimate consumer.
- From bottom to top, label the four parts of the second triangle with the names of the plants and animals on your food chain. You’ll begin with the plants at the bottom and put the name of the top predator at the top. Remember: The legume plants are the producers, the blue morpho butterflies are the primary consumers, the jacamar is the secondary consumer, and the jaguarondi is the ultimate consumer.
- On a third triangle, draw a picture of each plant or animal.
- To complete your ocean food pyramid, tape the tab on your first triangle to the underside of your third triangle. You’ve made a food pyramid!