A Poison, a Ban and a Comeback: teacher key

Bald Eagles, grade 10 edition, written for 10th grade. The story of DDT and the bald eagle, the counts that follow its recovery, how eagles nest, travel and hunt, and what they need to thrive.

Read the book. Print this page for the key.

Questions and answers

1. What does DDT do as it passes up the food chain?
   • It breaks down quickly
   • It builds up, because it dissolves in fat (answer)
   • It turns into water
2. What happened to bald eagle numbers in Washington State from 1981 to 2005?
   • They grew by about 700 percent (answer)
   • They fell by half
   • They stayed the same
3. What three things do bald eagles need?
   • Snow, tall mountains and trees
   • Rivers, desert and wind
   • Food, nest sites near the food, and freedom from disturbance while nesting (answer)
4. Why did DDT put top predators such as bald eagles at great risk?
   • It builds up as it passes up the food chain (answer)
   • It made rivers freeze
   • It took away their nests
5. What can lower how much eagles feed?
   • Warm weather
   • People being active nearby, by as much as 35 percent (answer)
   • A new nest
6. What does the word fledglings mean?
   • Young flyers (answer)
   • Old nests
   • Fish hooks

Words

• insecticide: bug poison
• contiguous: touching, joined
• fledglings: young flyers
• roosts: resting places
• crop: a food pouch