Two Ways to Hunt in the Sea: teacher key

Orcas, grade 10 edition, written for 10th grade. An orca group hunts the way its parents taught it. Read how noisy salmon hunters differ from silent seal hunters, how grandmothers help and why boats matter.

Read the book. Print this page for the key.

Questions and answers

1. Why are Resident orcas probably so vocal?
   • Salmon hear poorly, so sound is unlikely to frighten them off (answer)
   • They cannot see underwater
   • Their prey listens for silence
2. How do Bigg's orcas behave while hunting?
   • They call loudly to their pod
   • They keep a low profile and stalk in silence (answer)
   • They travel in groups of a thousand
3. What did the 2019 study find about grandmothers?
   • They lead the hunt
   • They leave the pod after menopause
   • Grandmothers past menopause boost their grandcalves' survival (answer)
4. Why might Bigg's orcas hunt quietly?
   • Their prey also uses sound (answer)
   • Echoes cannot travel in cold water
   • Calves are sleeping
5. In this book, what does "stalk" mean?
   • To dive very deep
   • To call to the pod
   • To follow food quietly (answer)

Words

• ecotype: habit group
• echolocation: sensing by echoes
• vocal: noisy, calling often
• stalk: follow quietly
• menopause: end of calves