• Winter light on the Fairweather Range

    Glacier Bay

    National Park & Preserve Alaska

Activity #2: The Sea Otter Diet

Student Worksheet: Calories to Burn

Student Worksheet: Calories to Burn

Procedure

1. Complete Student Worksheet: Calories to Burn
Ask students to keep a tally of the food they eat for one day using the Food Diary on the Student Worksheet: Calories to Burn.

Note: You may wish to have students keep the diary for an entire week and average their daily caloric intake.

 
What can I eat

Student Worksheet: What Can I Eat?

2. Keep Student Activity Diary in Student Worksheet: What Can I Eat.

Then, have students use the resources on Student Worksheet: What Can I Eat to list their vital statistics – weight, height, age and average daily caloric intake; compute the total number of calories they eat each day and determine their level of physical activity.

Answer: Answers will vary.

 
Student Worksheet: You do the math

Student Worksheet: You do the math

3. Read Student Resource: An Otter's Life and Complete Student Worksheet: You Do the Math

Have students read the Student Resource: An Otter's Life. Then, using the Student Worksheet: You Do the Math, ask them to figure the approximate number of calories an adult male otter must eat each day to maintain his weight. Then, they can use information from the Student Resource: An Otter's Life to answer the following questions:

  • What foods does an average-sized male otter probably eat each day if he lives in Glacier Bay?
    Answer: Clams, mussels, Dungeness crabs, sea urchins, snails, scallops and octopus.
  • For each kilogram, how many calories must he eat each day to maintain his weight?
    Answer: 253 calories/kilogram of weight
  • How many total calories must an average male otter eat/day to maintain his weight?
    Answer: 10,626 calories/kilogram of weight
 
Student Resource: an otter's life

Student Resource: An Otter's Life

4. Compare the caloric value of the food eaten by sea otters and humans.

Next, using the Student Resource: an Otter's Life and/or other resources listed below, have students draw up an imaginary diary of an otter's day. Discuss with students how the sea otter lifestyle, its environment and his daily activities, requires the animal to burn so many calories to survive.

Write the calories per kilogram of weight that a male otter eats each day on the chalkboard. (253 calories/kg). Then help students figure out how many calories they eat per kilogram of body weight. Briefly discuss the comparison between themselves and the otter. Does the otter eat a lot more than the human? Why do students think this might be so?

Answer: Yes. The otter does eat more calories/kilogram of body weight. He does so because he needs to keep his metabolism running high to stay warm and to fuel the almost constant activity of hunting, guarding, playing, etc. in which he engages each day.

 

5. "If I Ate Like a Sea Otter" Activity
Based on their research into their own and otters' nutritional requirements and exercise activities, challenge students to write and illustrate a diary entry of at least one page entitled, "If I ate like an otter."

Extension:
Explore other adaptations of the sea otters in Glacier Bay that allow them to live in this harsh, yet rich, environment.

Resources:

Sea Otter adaptations

Return of the Sea Otter
http://oceanlink.island.net/ONews/OceanNewsReader/ON2.pdf
pages 6-8

Otternet: Species Profile, Sea Otter
http://www.otternet.com/species/seaotter.htm

 

Activity #3
Sea Otter Census

Did You Know?