Counting Caimans in a Drought: teacher key

Black Caimans, grade 10 edition, written for 10th grade. In 2023 a drought reduced the water habitat of a reserve. Read how scientists count caimans by boat and what the numbers did and did not show.

Read the book. Print this page for the key.

Questions and answers

1. From which years did the Mamirauá surveys run?
   • 1908 to 1923
   • 2008 to 2023 (answer)
   • 2018 to 2023
2. How did the scientists count the caimans?
   • From planes
   • By boat at night with flashlights (answer)
   • By digging up mud
3. What was the 2023 drought count per kilometre?
   • 44
   • 240 (answer)
   • 4,412
4. What do the authors say their methods cannot show?
   • That the caiman population grew (answer)
   • That caimans live in water
   • That the drought happened
5. The 2023 rate per kilometre was much higher, yet the total counted was close to average. Why?
   • The survey covered much less distance (answer)
   • The boat went faster
   • Flashlights were not used

Words

• abundance: how many
• drought: long dry spell
• hectare: large land area