What the Evidence Can and Cannot Say: teacher key

Great Horned Owls, grade 11 edition, written for 11th grade. Some numbers about a great horned owl come from methods with limits, such as pellets and banding. See what each can show.

Read the book. Print this page for the key.

Questions and answers

1. What did the authors of the 2005 pellet study write about pellet studies using only bones?
   • That a pellet finding shows an important bias that challenges their reliability (answer)
   • That bones are the only fair test
   • That pellets are too large to study
2. Why can banding-based longevity records only go up?
   • Nobody counts them
   • More birds are banded and found over time (answer)
   • Owls grow older each year
3. How did published incubation times for great horned owl eggs compare?
   • They were all the same
   • They were not published
   • They differ from one account to another (answer)
4. What does the American Bird Conservancy say about larger birds like the great horned owl, as of November 2026?
   • They can live to be nearly 30 (answer)
   • They live about 2 years
   • They never live past 13
5. The oldest banded owl in the 1995 review was 13 years old, yet the record is 28. Which idea from the pages fits?
   • Banding stopped in 1995
   • Longevity records based on banding can only go up as more birds are banded and found (answer)
   • Owls cannot live past 13
6. What do banded great horned owls usually do, according to banding studies?
   • Disappear
   • Travel far from where they were banded
   • Stay within 48 miles (80 km) of where they were banded (answer)

Words

• regurgitated: coughed up
• incubation: egg-sitting time
• banding: tagging with rings
• longevity: length of life
• cervical: of the neck
• vertebrae: spine bones