Monarch migration can be invisible to us when we watch from the ground. There is a large gap overhead where monarchs can travel and we can't see them. Journey North tracks migration based on visual observations, so questions about the height of flight are important:
Driving Question: How high do monarchs fly - and how high can we see them?
For use with Photo Gallery: How High Do Monarchs Fly?
Pre-Reading
1. Begin With a Question
Hold up a life-size paper monarch and ask:
- At what distance are monarchs no longer visible to the naked eye?
Have students share ideas about how they could answer this question. Ask them to predict the distance at which they would no longer be able to see the paper butterfly.
2. Brainstorm Experiment Ideas
How could you design and experiment to test the distance at which monarchs disappear from view? If possible, go outside to conduct experiments.
3. Explore Sample Experiments
Compare your ideas with the experiments shown in pictures Experiment #1 and Experiment #2. In these samples, monarchs were no longer visible to the naked eye at about 300 feet, and about 500 feet with binoculars. Ask questions to help students translate their distance measurements to height.
- What tall objects can we use as reference points?
- How do our measurements compare to the height of our school building, tallest tree, tallest building in town, etc.
Read and View
As you read the photo gallery text together, encourage students to take notes or mark up the text-only version or booklet —underlining key words and ideas and jotting down their thoughts in the margins.
After Reading
1. Consider the Significance
Show students this graphic and discuss:
- We can't see monarchs when they fly more than about 300 feet high.
- There is a gap overhead two miles high where monarchs can travel and we can't see them.
2. Make Connections
Remind students that Journey North collects visual observations. Discuss these questions:
- Do the data provide a complete picture of monarch migration? Why or why not?
- If monarchs disappear from view at 300 feet high, how might monarch migration data, maps, and conclusions be affected?
- When analyzing migration, why is it important to say, "according to observers"?
Extend Learning
1. Skyscraper Math
Discuss skyscraper photo:
- How high were the monarchs flying? (Assume each floor is about 10 feet high.)
- Do you think a person on the ground would be able to see them?
2. Scale Model
How high can migrating butterflies fly? Higher than skyscrapers, mountains, jets, and hot air balloons? Look at the flight height chart and brainstorm how to make a model to scale.
Image: Monarch Gap Overhead
