What We Know About a Giant: teacher key

Black Caimans, grade 6 edition, written for 6th grade. A giant caiman lives in the rivers of the Amazon. See what it eats, how it nests and how much scientists still have to learn.

Read the book. Print this page for the key.

Questions and answers

1. How long can the biggest old males be?
   • Longer than 5 metres (answer)
   • About 1 metre
   • About 20 metres
2. Where does a black caiman hunt mostly?
   • In caves
   • In the water (answer)
   • In treetops
3. What can large predators like the black caiman do?
   • Stop the rain
   • Make the river dry
   • Shape the community of animals around them (answer)
4. What did hunting do to black caimans in the 20th century?
   • It raised their number
   • It made no change
   • It cut their number by about 99 percent, as an estimate (answer)
5. Scientists knew little about black caimans until the 1980s. What does that suggest?
   • Few good studies of their habits have been made (answer)
   • They never live in water
   • They are tiny

Words

• predators: animal hunters
• capybara: big rodent
• mound: pile of earth
• estimate: careful guess
• captivity: human care