National Geographic Video
Strange Days on Planet Earth
Name _______________________
Date __________ Pd ___ pg#____
Episode 3: PREDATORS!
These are some things to think about while you watch the movie – jot down some notes/answers
to these questions, and you may use this sheet to help you when you are asked to do a writing
assignment next class!
Lake Guri, Venezuela
1. What are the biologists in the motor boats in Venezuela doing in the first part of the video?
What caused this flood?
2. What is going on a few miles north at Lake Guri, Venezuela?
3. What is happening with the animals on Iguana Island? (Think of the iguanas and howler
monkeys…)
4. What do the scientists propose as a theory for all of these changes that are taking place on
these and other similar islands?
5. How does this same idea affect areas like the one in which we live?
6. Why can’t we just put the predators back?
Yellowstone
1. What is wrong with the river? How is it different from pictures that we have of these stream
banks from the past?
2. What kinds of organisms used to be in Yellowstone (or used to be there in far greater
numbers)?
3. In trying to figure out why the aspen trees are disappearing so rapidly, what factors did the
scientists originally suspect to be the cause of this ecological disaster? Why did they reject
these ideas?
4. What did the scientists find when they took core samples of the trees and counted up the
growth rings?
5. How does the proposed explanation for these changes tie into something that we studied
earlier this year?
6. What are some positive effects that the wolves have on the ecosystem?
7. What are some negative effects or repercussions of the reintroduction of the wolves?
Coral Reefs – Discovery Bay, Jamaica
1. What kinds of organisms are the top predators in the sea, surrounding many coral reefs?
(Back before they disappeared in some ecosystems…)
2. How do they “look at the fossil record” of a coral reef? What did they discover?
3. What clues does the fish market provide to help explain the destruction of the coral reefs? ‘
a. What does “fishing down the food web” mean?
4. What happened when large predators were taken out of the system, and how did this affect
the coral? (There are several steps in the “chain” that contributed to this topple of the coral
reef ecosystems…what are they?)
5. How has this impacted St. Lucia and the economics and cultural traditions there?
6. How have the Caribbean Islands attempted to “solve” the problems of overfishing and coral
reef decimation, and has it made a difference?