Monarch
Butterfly Migration Update: September 5, 2003
Today’s
Update Includes:
Highlights
From the Migration Trail
|
Click Map to Read Highlights
Along the Migration Trail |
The strongest
migration of the season to date was reported last week across Minnesota.
Neighbors in Iowa are now noticing the influx as monarchs move southward.
Monarchs were also on the move in Michigan, Wisconsin, Illinois, Missouri
and other Midwest states. Migrating monarchs were even on the runway at
the Detroit airport, beside jumbo jets heading for their own international
destinations. In the Northeast, butterflies were flying south across the
St. Lawrence River in New York, alongside raptors in Ontario, and touched
down at Butler Elementary's butterfly garden in Mystic, Connecticut. For
several weeks, scattered sightings have also been reported all the way to
Texas. Tracking
the fall migration is tricky. It's impossible to know the FIRST migrating
monarch when we see it, as we can in the spring. Thus, the sightings selected
for the migration map are simply "migration highlights." Some
are roost sites, some signify peak migration, and others are noteworthy
observations made during the monarch's remarkable journey.
Monarch
Off the Map: How Can a Monarch Land in England?
|
The
Prince of Wales visiting the monarch sanctuaries in Mexico |
A surprising
report arrived on Monday from across the ocean! A monarch was spotted in
Penzance, England (50.15 N, 5.50 W), near the tip of the Land's End peninsula
in Cornwall. Milkweed doesn't grow in the United Kingdom so it couldn't
have been a local monarch. The nearest breeding populations of monarchs
are found in southern Spain and North Africa, but those are non-migratory
populations. So
where did the monarch come from? Scientists there have considered 4 main
hypotheses. Next week we'll provide an article that summarizes them. Meanwhile,
pull out a map and consider the question yourself:
Challenge
Question #2
"Where do you think the monarch that was sighted in Cornwall, England
came from? Describe how you think it got there."
(To
respond to this question, please follow the instructions below.)
Don't
Compare Apples and Oranges:
Calculate the Migration Rate
As you monitor the migration this fall, quantify your sightings the way
good scientists do. Tell us how many monarchs you see AND how long you were
watching. Then calculate the migration rate. (For standard units, use monarchs
per minute and/or monarch per hour). By calculating the migrate rate, you
can compare one observation to the next.
Who
Saw The Most Monarchs? Challenge Question #3
Here are some examples that people reported this week. Who saw the most
monarchs?
- Observer
#1) I'm reporting the first sighting of several butterflies from my
22nd floor residence on Chicago's north side on the lakefront. I witnessed
around two dozen an hour.
- Observer
#2) During my 5:30 p.m. to 5:45 p.m. observation time, I saw eight Monarch
Butterflies flying overhead.
- Observer
#3) The students reported seeing two Monarch Butterflies on the playground
between 2:00 p.m. and 2:15 p.m. today.
- Observer
#4) During a three-hour morning visit to Neal Smith National Wildlife
refuge in Iowa, 246 monarchs were observed.
- Observer
#5) I counted 86 monarchs in 5 minutes.
Challenge
Question #3:
"Who saw the most monarchs? Arrange the observations in order,
from the observer who saw the most to the fewest monarchs. In your
answer, use standard units to compare the number of monarchs (monarchs/hour
or monarchs/minute)."
(To
respond to this question, please follow the instructions below.)
Migration
Viewing Tip: Binoculars Needed During Strong North
Wind
By Elizabeth Howard I
saw an impressive migration last Friday in Minnesota, but I almost missed
it entirely. The wind was blowing from the north and I wasn't seeing many
monarchs. Then I remembered Bill Calvert's tip for watching monarch migration
during a north wind:
"Use
binoculars and look beneath the clouds. The butterflies travel way up
high and are easier to see against a white backdrop."
Sure enough!
Monarchs were flooding southward on the strong north wind, blowing some
20+ mph. It took a minute or two to train my eye, then suddenly I saw
them, zipping by as fast as the wind. I counted 86 monarchs in 5 minutes!
Discussion
of Challenge Question #1
We asked, Even though they don't have the words to say it, what do monarchs
instinctively know about time and direction?
Mrs. Lodge's
science class from RHAM Middle School in Hebron, CT discussed the first
challenge question and came through with shining colors. They say monarchs
know that, "The sun appears to move across the southern part of
the sky from east to west at a rate of 15 degrees/hour."
How
to Respond to Today's Challenge Question
1. Address an e-mail message to: jn-challenge-monarch@learner.org
2. In the Subject Line of the message write: Challenge Question #2 (or #3)
3. In the body of the message, answer the question above.
The Next Monarch Migration Update Will Be Posted on September
12, 2003.
Copyright
2003 Journey North. All Rights Reserved.
Please send all questions, comments, and suggestions to our feedback form
|