How Many Miles Per Day Does the Migration Travel?
Keeping Track Through the Season

 Photo: James Down
Migrating animals travel at very different average rates. A bog turtle might travel just 56 feet in a day, but a monarch butterfly might fly 40 to 100 miles a day! How fast and far do hummingbirds travel? Try to figure this out yourselves:
1. As you receive records from Journey North, put a sticker on the location in each state or province where a hummingbird was sighted. Record the date on the face of the sticker.

2. After you've received the first 10 or so records from each state/province, calculate an "average first arrival date" for that place.

3. As the season progresses, find places that have the same "average first arrival date." Draw lines on your map to connect these places. Each of the wavy lines you draw is known as an "isopleth". ("Isopleth: A line on a map connecting points at which a given variable has a specified, constant value".)

4. Finally, at the end of the season, measure the distances between the waves and determine out how you would complete this sentence:

"The ruby-throated hummingbird migration advances at the average rate of _____ miles per day."

Discussion and Journaling Questions

• How many miles per week did the migration move across the continent?
• What types of factors do you think influence how far the migration moves on a given day or week?
• Did the hummingbirds move directly north?
• If not, how would you describe the progression?
• Why do you think the migration moved that way?

Digging Deeper