Four hours. (It will take five hours if you show students the video.)
Part I. Physical Geography of the Islands
Write the words "land" and "life" on the board. For older students, you might write "geology" next to "land" and "biology" next to "life." Explain that they will learn about some of the special land features of the Galapagos, including how the islands were created and what they are made of. They will also learn about some of the animal life on the islands.
Ask a student volunteer to locate South America on a world map and to point out its location to the rest of the class.
Help students locate Ecuador by explaining that Ecuador means "equator" in Spanish. Ask them to first find the equator and to then find the country of Ecuador. They can then look along the equator to the west of Ecuador to locate the Galapagos Islands. As an option, you may have students find the Galapagos Islands on the National Geographic MapMachine.
Ask students to use the map scale to estimate how far the Galapagos Islands are from the coast of Ecuador. They should discover that the islands are approximately 600 miles (965.6 kilometers) west of the coast.
Ask students what they think the climate is like along the equator. They have probably learned that the equator receives the most constant and direct sunlight of any place in the world. It is therefore generally hot throughout the year.
Give each student or pair of students a copy of the Galapagos Islands map. Ask students to identify the volcanoes on this map. How many can they find?
Explain that the Galapagos Islands are really the tips of huge underwater volcanoes. If the ocean were sucked dry, students would see that the "islands" are actually enormous volcanoes. Most of the volcanic rock is underwater, and only the upper parts of some of the tallest volcanoes can be seen.
(Option) To illustrate how volcanic islands are formed, have students go to the National Geographic Xpedition Hall and link to Standard 7 (at the top of the screen, click the number "7" above "Physical Systems"). Click on the "pool." On the next screen, click the "volcano sketch" in the foreground. Students will see an illustration of how magma rises from below Earth’s crust and forms a mountainous island. Explain that the rock on the island is lava that has come out of the volcano and cooled.
Part II. Biogeography
Now that students know the Galapagos Islands were created by volcanoes, ask them to think about how animals and plants that were not brought to the islands by humans could have arrived on the islands. Remind them that the Galapagos Islands are 600 miles (965.6 kilometers) from the South American coast. In a brief class discussion, allow students to brainstorm how animals (fish, birds, mammals, reptiles, insects) and plants could have reached the islands. All of the following are ways in which animals and plants arrived on the Galapagos:
- Birds flew.
- Fish and other marine animals swam.
- Some land animals floated on vegetation that washed out to sea during flash floods on the mainland.
- Some plants and seeds floated on the currents. Seeds could also be carried on floating debris and on the bodies of birds and possibly land animals. Some seeds and plant parts may have been carried by the wind.
Discuss the challenges animals might have faced upon first arriving on the islands. What might an animal that was the first of its kind in the Galapagos have needed to find (e.g. food, fresh water sources, shelter)? What if only one animal of a species made it to the Galapagos? Could that species have survived on the islands? (The animal would have had to have been pregnant or carrying fertilized eggs, or would have needed to mate with another member of its species that arrived at a later time).
Tell students that the Galapagos Islands are home to some unusual animals. In the next part of the lesson, they will learn about some of these animals.
Ask students to imagine that they are the first explorers who visit the Galapagos Islands. They come across several interesting animal species that they have never heard of, and they want to keep a journal about the things they observe. They may work individually or in pairs.
Give each student copies of the Galapagos Animals (PDF) handout and the Galapagos Journal (PDF) handout. Explain that the Galapagos Animals handout provides information about some of the islands' animal species. (You may wish to have students take turns reading the Galapagos Animals handout out loud to the class.)
To see photographs of each animal, have students visit the National Geographic Channel’s Galapagos micro-site.
In the Galapagos Journal, students should draw pictures and write about each of the animal species in the Galapagos Animal handout.
If you plan to show the first hour of the Galapagos DVD from National Geographic Channel, this would be a good time to do it. Ask students to pay close attention to the animals and their unique behaviors. You may wish to pause the program after each animal is featured and discuss what makes this animal interesting and why it behaves or appears the way it does.
After students have completed their Galapagos Journal, discuss as a class how each animal's unique physical features reflect its adaptations to its environment. How is each animal especially suited to its island habitat? How do these adaptations help the animal survive?
Ask students to compare and contrast the Galapagos animals they’ve studied with animals commonly found in their local area. How are these animals different and similar in appearance, behavior, and adaptation?
Which animal species did students find the most interesting? Why? If they could visit the Galapagos Islands, which of these animals would they most like to see?
Part III. Conservation
Ask students to name some environmental problems they have heard about. They might mention pollution, loss of habitat, or endangered species. Explain that even though the Galapagos Islands are beautiful and have many interesting animals, they, too, face environmental problems.
Distribute copies of the Galapagos Conservation (PDF) handout. Review the questions with the class. Working in pairs or small groups, ask students to brainstorm ideas and write their answers on the Galapagos Conservation handout. The goal is for students to think about why each of the activities mentioned on the worksheet might pose a problem to the animals and ecosystems of the Galapagos Islands.
After students have had a chance to brainstorm, write their answers on the board. Hold a class discussion emphasizing the following points:
- Animals that are not native to the Galapagos, such as goats and wild pigs, eat much of the plant food that native island species such as tortoises and iguanas usually eat. (The earliest human settlers in the 19th century brought non-native species, such as goats and pigs, to the islands. These animals have bred, and their populations have multiplied. People continue to introduce non-native species, even though we’re now aware of the threats they pose to native species).
- Non-native species introduced to the islands disrupt the food web by eating native island species. Dogs and cats eat baby iguanas and birds, and pigs eat tortoise and bird eggs.
- In places where people live and visit, it's important to collect garbage and not pollute the environment. Galapagos officials try to reduce human impact by limiting the number of people allowed to visit every year.
- Illegal poaching has greatly reduced the islands’ number of giant tortoises. Only 11 types of giant tortoises remain, down from 15 when Darwin arrived. The tortoises are now listed as endangered and are being protected by the Ecuadorian government. For more information about giant tortoises visit the National Geographic: Galapagos Tortoise page.
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