How
Many Miles Per Day Does the Migration Travel?
Keeping
Track Through the Season
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:
- 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.
- After
you've received the first 10 or so records from each state/province,
calculate an "average first arrival date" for that place.
- 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".)
- 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
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