Humpback Whale Migration

Got Milk?
Daily Food Requirements of a Humpback Calf

Background

Photo Courtesy of Leslie Rapp

Every day, a mother humpback whale must produce between 100 and 130 gallons of rich, caloric milk for her calf. She must do this throughout the first eight to twelve months of the calf's life. Nourished with this nutritional diet, the calf grows up to a foot per month in its first year. Although during the calf's first summer with its mother in the colder, food-rich waters of the north, some small fish may be ingested, the mother's milk is the primary source of food for the calf. This quantity is so enormous it is difficult to imagine. Likewise, it is difficult for us to visualize a comparison between the size of a newborn humpback calf and the size of a human.

In this activity students collect and display one-gallon milk jugs to represent the daily quantity of milk that is consumed by a humpback calf, create a life-sized painting of a humpback calf, and teach others what they learned.

In Your Classroom
Part I
Humpback calves need a lot of milk to grow. Just how much milk is 130 gallons? Can anyone imagine?

How much milk do you suppose the students in our class drink every day? On the board, tally the number of 8 oz. glasses of milk students estimate they consume each day. Then calculate the number of gallons.
How long do you think it would take the families of all of our students in our class to drink 130 gallons of milk? (Ask students how they could estimate this answer, based on the above estimate.)
Let's find out! Every day, have students bring milk containers to school until you have 130 gallons. (Print this take home letter for students to share their "Got Milk" exploration with their families.)

Compare the nutritional qualities of whale milk with cow's milk.
Did you know--?

whales' milk has less water than the milk of other mammals (40-50% versus 80-90%)
whales'milk has much more fat (40-50% as compared with 2-17%)
whales' milk has about twice the concentration of protein as milk of other mammals

What facts can you find out about cow's milk? Use nutritional labels to learn about milk. Where else could you look for information?

Part II
Look at a picture of a humpback whale. Use the picture to create a painting of a 12-foot humpback calf (a calf looks similar to an adult, just smaller).

Part III
Create a poster to teach others about the humpback whale calf and its food requirements. Compare this to your own classroom's milk consumption. Share information you learned about the differences between whales' milk and cows, milk. Make a display! Use your poster, the life-sized humpback calf painting and your classroom collection of milk jugs to teach other classes what you learned.

How do you manage that many milk jugs?

tie the milk jugs together in a line and hang them from the ceiling
string them around the room, or along the hallway (Be sure to get permission!)