Biology Activity: Food Web Puzzle & Energy Pyramids
Name:____________________________________
Sonoran desert: Close to the equator and at low elevation, the Sonoran desert of California and Arizona is one of the hottest
driest deserts in North America. For much of the year, the desert appears desolate of life. However, the spring rains bring
life to the desert, carpeting the terrain with a beautiful array of desert blossoms. The desert is indeed teaming with life,
hundreds of lizards, frogs, snakes, owls, bats, tortoises and rodents.
Desert tortoises: I enjoy eating cacti, although my favorite food is the desert blooming annual flowers.
Gila monsters: I love to eat eggs, ground nesting birds and other lizards. I use my hemotoxin to subdue my prey.
Kangaroo rats: I love to hop along eating grasses and seeds.
Collared Peccary: I love to feast on roots, fruit, seeds and cacti but also relish insects and juicy little worms.
Coyote: Eat small mammals, insects, reptiles, and fruit & carrion.
Kit Foxes: rodents, insects, birds, lizards, amphibians, and fish.
Bobcats: Rabbits, rats and squirrels.
Chuckwalla: Fruits, leaves, buds, and flowers.
Prickly Pear Fruit: This is a fruit that is made by the cactus, before it is a fruit it is a flower
Woodpecker: insects, prickly pear fruit,
Your group needs to work together to form a food web of the animals you were given.
Procedure
1) Draw a BIG sun in the middle of your paper.
2) Cut out the pictures. Cut around the name of each organism so they are easy to identify.
3) Paste the pictures onto your paper around the initial source of energy (the sun).
4) Decide and label whether each plant or animal is a producer, herbivore, carnivore or omnivore from the descriptions.
Write the label on each picture.
5) Make connections between the animals and plants that are likely connected in the Sonoran Desert food web. Draw
arrows to indicate energy flow. BE CAREFUL – make sure your arrows are pointing the correct direction.
6) Find TWO food chains within the food web created. Label each organism in the TWO food chain with the
appropriate trophic level. You should have at least one food chain with FOUR trophic levels.
7) Obtain teacher approval.
8) Answer the analysis questions.
Analysis
1. Using the food chain with FOUR trophic levels, place the organisms within the energy pyramid below.
Don’t forget labels.
2. On the bottom level of the energy pyramid created, write “9,000 kcal” . This is the amount of available
energy that level possesses. Label how much energy is transferred to each of the other three levels.
3. What happens to the amount of energy as you go up the energy pyramid? Be specific as possible.
4. Why doesn’t each trophic level receive ALL of the energy from the trophic level below it?
5. How is an energy pyramid different than a food chain or food web?
6. Why is it very unlikely for a food chain to be more than 10 “links” long? Think about your answer to #3.
7. Where could decomposers or scavengers fit into the food web that you created?
Desert Tortoise
Cactus
Kangaroo Rat
Gila Monster
Collard Peccary
Coyote
Kit Fox
Rabbit
Bobcat
Chuckwalla
Woodpecker
Prickly Pear
Grasses
Flowers