Monarch
Butterfly Migration Update: September 2, 2005
Today’s
Update Includes
Highlights
From the Migration Trail
A year ago at this time, most everyone was talking about how few monarch
butterflies there were. At best, only a handful of monarchs were being
seen at nectar sites or flying overhead, and not a single large roost
had been reported. What a welcome change this year! Already, southbound
butterflies have been seen at points across the map and people in the
north have found 27 large roosts. This year, everybody seems to be talking
about how many monarch butterflies there are. During the last week for
example:
- Thousands
of monarchs in our fields today. Largest numbers at my location in many
years!
- More
monarchs in my yard tonight than I had for the whole season last year.
- We're
seeing monarchs again after several years of no sightings.
Comments
like these are signs that monarchs have rebounded during the summer breeding
season. Yet how many monarchs there actually are, and what causes their
numbers to rise and fall, are questions that baffle scientists.
Monarchs
resting in Watertown, South Dakota
...1,835 miles from to their winter home in Mexico
Photos
Courtesy of Connie Johnson
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The monarchs were discovered in this row of trees called a "shelterbelt."
Trees are planted in South Dakota this way to protect against the
strong prairie winds. |
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Why
Do Monarchs Form Roosts? Clues from the Field
Migrating monarchs rest at overnight roosts at the end of the day. Imagine
finding a roost in your hometown, with hundreds or thousands of butterflies!
How might roosting help monarchs survive the migration? Read this week's
collection of observations and look for clues. Then answer Challenge Question
#1:
Estimating
the Number of Monarchs in a Roost: Let's Practice
People are dazzled by the beauty of fall "butterfly trees."
It's rare to see more monarch butterflies than a person can count. Maybe
this is why people always try to count them! If
you were to discover a monarch roost, how would you count the butterflies?
Scientists often use photographs to estimate numbers, whether they are counting
whales or caribou, bats or butterflies. How many monarchs are in the roosts
in these pictures?
Why
Do Nightly Monarch Counts Go Up and Down?
At any overnight roost, the number of visiting monarchs tends
to rise and fall from one night to the next. Monarchs roost every
year in Mr. Paul Viger’s yard in Campbell, Minnesota. What do
their resting patterns tell us about monarch migration patterns? Take
a look at Mr. Viger's data and see what you can find: |
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Fly
Like a Butterfly All the Way to Mexico
Try Google's new interactive satellite maps and you'll feel like
you're flying! Follow the step-by-step instructions at the link
above. We'll show you how to find the monarch's winter home in Mexico
and your own hometown. Then zoom-out and fly like a butterfly all
the way to Mexico!
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Ultralight
Plane Traveling with the Migration
Painted like a monarch, an ultralight plane is flying along the
migration trail this fall with the monarchs. The crew began the
journey in Quebec, Canada and is about to cross the U.S. border,
over Niagra Falls, into New York state. The pilots are sharing the
view as they look down on the earth below. You can see pictures
and read tales about their journey.
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Habitat
and Survival: What do Monarchs Need During
Fall Migration?
Monarchs
must find habitat all along their route to Mexico. As you travel
with the monarchs, find examples of their habitat needs. Look for
specific ways they find food, water, shelter, and space. Record
the many challenges to survival they face this fall, and in the
full year ahead.
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Habitat
The place and conditions where all of an organism’s needs for
life are met. Food, water, shelter and space are key components of
an organism’s habitat. |
How
to Report Your Observations
Put your monarch news on the map! Please send reports of monarchs feeding,
flying, and resting.
The
Next Monarch Migration Update Will Be Posted on September 9, 2005.
Copyright
2005 Journey North. All Rights Reserved.
Please send all questions, comments, and suggestions to jn-help@learner.org
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