Lesson 4: Amphibians and Reptiles

• Students will develop an understanding of amphibians and reptiles.
• Students will understand the concepts of warm-blooded vs. cold-blooded.
• Students will understand what metamorphosis is.
• Students will understand adaptations of amphibians and reptiles.

Most amphibians and reptiles start life from eggs. Amphibians lay their eggs in water without a hard shell. Most reptiles bury their eggs underground. Their eggs have a hard shell to conserve valuable water. Reptiles hatch as small copies of adults, just like mammals and birds. Amphibians hatch in water and have to grow up there before moving to land. They have a complex life cycle with different body shapes that enable them to adapt to two different habitats:

1. The female frog lays clusters of eggs in or near the water.

2. Tiny tadpoles hatch out of the eggs. Tadpoles swim, have a tail, and breathe with gills.

3. As they grow, tadpoles develop legs.

4. Tadpoles become froglets; they have four legs, breathe with lungs, and lose their tail.

5. An adult frog lives on land, breathes with lungs, has four legs and no tail. This transformation from tadpole to adult is called metamorphosis.

• Metamorphosis: the rapid transformation of a larva into an adult that occurs in some animals
• Adaptations: a genetically determined characteristic that enhances the ability of an organism to cope with its environment, such as the shape of a bird’s beak

• Notebooks and pencils
• Unlined index cards

1. Ask students to name some reptiles. Then ask them to name some amphibians. (Several reptiles and amphibians live in Laikipia. There are: cobras, leopard tortoises, Nile monitor lizards, and puff adders).

2. Ask students to list characteristics of reptiles, then of amphibians. Make a list on the board. Add any the students did not think of. Have the students compare and contrast reptiles and amphibians.

3. How do reptiles and amphibians communicate? Watch the movements of lizards, and listen to the croaking of frogs. Can you tell what they mean?

4. Discuss coloration in frogs, toads, snakes, and lizards.

5. How and what do reptiles and amphibians eat? Lizards and frogs eat insects. Snakes eat bird eggs and small rodents.

6. Explain the life cycle of a frog, an amphibian they may be familiar with. Have students illustrate it and/or act it out.

7. Take the students outside to look for lizards, snakes, and frogs.

8. Have students draw pictures of amphibians and reptiles on cards. Add these to the collection.

9. To understand cold-blooded vs. warm-blooded, have students touch each other on the forehead or wrist. Then put a frog or lizard in the shade and touch it. Place the frog or lizard in the sun and touch it again after a few minutes.

1.Collecting Frog Eggs

If possible, collect some frog eggs, and bring them into the classroom in a container of water. Watch them turn into tadpoles and finally adults. Put a rock in the water so the froglets can climb; otherwise they can drown. Release the adults where the eggs were taken.

2. Feel the Vibrations

Snakes and elephants can feel sound. What would it be like if we could feel sound? Tie a string to a metal fork. Tie the other end of the string to a hole in the bottom of a paper cup. Put the cup over the student’s ear as you tap the dangling fork. Can you feel the sound? Explain why this is useful in the animal kingdom (to locate a predator, food source, etc.).

(Watch a video about elephant research at the Mpala Research Centre in Laikipia.)