National Geographic “Strange Days on Planet Earth: Predators”
Video Discussion & Reflection Questions
Recall & Summary Questions:
A. Lake Guri, Venezuela
1. What was the cause of fragmentation to the Caroni Valley in Venezuela resulting in the
formation of Lake Guri and all of the islands?
2. What happened as a result of the fragmentation?
3. How did the lack of predators change the landscape of the islands? Provide specific
examples.
4. How did the lack of predators affect the behavior of Howler monkeys?
5. Summarize the evidence found for the loss of predators causing these landscape changes.
B. Yellowstone NP, WY
1. What primary predator population was decimated and then reintroduced at Yellowstone?
2. What other large carnivores were also present 150 years ago?
3. What changes occurred to the Lamar River due to the loss of predators?
4. What changes to the landscape of Yellowstone occurred by the 1990’s?
5. How did scientists determine that changes in the Lamar River and landscape of Yellowstone
were due to loss of top predators and not climate change or fire?
6. What were the numbers of wolves in Yellowstone when they were at their peak? When
were the last wolves of Yellowstone killed?
7. When were the wolves listed as endangered species? When were the wolves reintroduced?
8. Describe the result of the reintroduction and the role of wolves in shaping the landscape of
Yellowstone.
9. Why was the wolf reintroduction controversial?
C. Discovery Bay, Jamaica & St. Lucia
1. Why are the coral reefs dying?
2. Summarize the core sample research and results.
3. Why don’t the women in the fish markets in Jamaica believe there is a problem with global
fisheries?
4. What is occurring with the sea urchin population? Why is this a problem?
5. What are marine reserves? Why did St. Lucia set one up? Was it successful? Provide
evidence from the video.
Further Reflection and Connection Questions:
1. Explain what is meant by the following statement: “Changes in the characteristcs of the Lamar
River are due to the activity of wolves through Elk through vegetation.
2. Compare and contrast changes in the Caroni valley, Venezuela to those in Jamaica and the
surrounding Islands.
3. Compare and contrast changes in ecosystems from eutrophication and over-fishing.
4. Summarize the “Isle Royal Challenge”.
5. Compare and contrast the issues at Isle Royal NP with Yellowstone NP.