Carnivores, Herbivores, Omnivores?
- Grade Level:
- Sixth Grade-Eighth Grade
- Biology: Animals, Biology: Plants, Conservation, Ecology, Environment, Wildlife Biology
- 45 minutes
- Group Size:
- Up to 24 (4-8 breakout groups)
- National/State Standards:
- Standard 6: Students assess the interrelated cycles and forces that shape Earth’s surface, including human interaction with Earth. (ASDOE Elementary Science Standards: Grade 6-8, pp. 56-73)
OverviewMost animals can be grouped by what and how many kinds of foods they eat. Animals that eat many different things are called generalists, while those that eat only one or a few foods are called specialists. True specialization is often a two-way dependency: an animal depends on a plant for food, and the plant depends on that animal to help it disperse its seeds. On remote islands like American Samoa, there are limited food supplies, and cyclones can cause serious shortages of food.
Students will be able to:
1. Define the vocabulary terms carnivore, herbivore, and omnivore.
2. Identify two examples for each of the vocabulary terms in American Samoa's ecosystem.3. Describe how our actions can threaten the health of our ecosystems
The technical word for the generalist—omnivore—literally means “eats everything.” Humans probably have the broadest diet of any animal—we happily eat meat, vegetables, seeds, and fruit. Animals that are most likely to survive in new environments, like when they first arrived on Tutuila, are often omnivores. A good example is the rat (isumu), which can eat fruit, eggs, crabs, fungi, and probably many other things.
Carnivores are those species that eat almost exclusively other animals. We usually think of carnivores as fierce hunters, like wolves or lions, but actually any animal that eats other animals are carnivores. The Barn Owl, or lulu, is the only Samoan animal that hunts other birds and mammals, but there are lots of other carnivores, including fish-eating birds and multiple animals that eat insects.
Herbivores describe animals that eat only plants. This is a very general term, so it is better to specify what part of a plant is eaten, whether leaves, fruits, or nectar. Each kind of animal usually is good at eating only one, or at most two, of these parts of a plant, because they are so different. For example, to rely on leaves, you need strong teeth to grind up the tough fibers and a big stomach to process all that material. Cows and horses are well equipped for the job. At the other extreme, to rely on nectar (the sweet liquid inside of flowers), you need to be able to zip between lots of flowers and reach inside to suck up the small amount of juice in each one. Nectar-feeders tend to be small and energetic, with long beaks or tongues to reach inside flowers. Finally, to eat fruit, you need to be able to travel long distances, since trees with fruit are often hard to find.
There are no native Samoan animals that are specialists in eating leaves (except insects and snails). However, leaves are regular parts of the diet of fruit bats (pe'a) and the Pacific Pigeon (lupe). Perhaps the leaves contain a nutrient that can't be found in fruit, or maybe they help to fill up a hungry animal when there is little other food available.
2. Flash cards
3. Hole puncher
4. String and/or plastic ribbon
5. Pencils and/or pens
Introduce Inquiry Question?
What are carnivores, herbivores, and omnivores?
Ask: Can you name any animals that you may have come in contact with on a daily, weekly, or monthly basis? Where and when did you encounter these animals? Have you ever heard the term carnivore? If yes, what and how did you hear about it? If not, what do you think it means? Wait for a response from students that may include tigers, sharks, lions, etc. Explain that carnivore refers to living things that eat almost exclusively other animals. Tell students that an ecosystem with carnivores reflects a balance between them and other living things in that area. Introduce students to two carnivores found in American Samoa by distributing the “Wildlife” handout and asking them to point out which animals are carnivores.
Ask: Have you ever heard the term herbivore? If yes, what and how did you hear about it? If not, what do you think it means? Wait for a response from students that may include birds, fruit bats, etc. Explain that herbivore refers to living things that eat only plants. Tell students that an ecosystem with herbivores reflects a balance between them and other living things in that area. Introduce students to two herbivores found in American Samoa by distributing the “Wildlife” handout and asking them to point out which animals are herbivores.
Ask: Have you ever heard the term omnivore? If yes, what and how did you hear about it? If not, what do you think it means? Wait for a response from students which may include birds, humans, dogs, etc. Explain that omnivore refers to living things that eats anything. Tell students that an ecosystem with omnivores reflects a balance between them and other living things in that area. Introduce students to two omnivores found in American Samoa by distributing the “Wildlife” handout and asking them to point out which animals are omnivores.
Ask: Have you ever heard the term conservation? If yes, what and how did you hear about it? If not, what do you think it means? Explain that conservation means “to protect something important from being destroyed or overused.”
Activity 1: Carnivore, Herbivore, and Omnivore Pocketbook (CHOP)
1. Introduce students to six animals found in American Samoa by referring to the “Wildlife” handout. They will see what these animals look like and learn about their type of diet.
2. Distribute flash cards, string, glue, and scissors. Have students use the scissors to cut out the photos of the different animals from the “Wildlife” handout. Use glue to attach these photos to the flash cards. Use a marker to write the name of each animal above the photo on the flashcard, and on the back, have students use pencils and/or pens to write a brief description of what that particular animal likes for breakfast, lunch, and dinner. Caution students to be careful when handling the glue and scissors.
3. Take the hole puncher and create two holes at the top ends of the flash cards with the pest photo facing towards the student. After creating the two holes at the top ends, cut two pieces of string and/or plastic ribbon and insert into the two holes and then tie them into a knot.
4. Ask students to use markers to design their flash cards. They can write key words that describe the animal on each flashcard to make it more personal (i.e. Vegan, Meat lover, Combo delight, etc.).
5. Gather students as a group and review what they have learned about the different animals by having them share to the class their personalized “CHOP.” Make sure that students understand that they can carry these pocketbooks around with them so that they can easily identify carnivores, herbivores, and omnivores in and around their community. Make sure students understand that they can add more animals to their “CHOP.”
Activity 2: Carnivore, Herbivore, and Omnivore Discussion
Have a class discussion about how we might negatively affect our ecosystems in terms of conservation. Ask the following questions:
1. What are some factors that contribute to the loss of a species? What happens when there’s an over or under abundance of one particular carnivore, herbivore, or omnivore?
2. What can we do to protect the balance in our natural ecosystem?
Conclusion with Inquiry Question
What are carnivores, herbivores, and omnivores?
Encourage your family and friends to conserve, preserve, and protect our wildlife by not disturbing them in their natural habitat.