Monarch Migration Update: September 8, 1998
Today's Report Includes:
Highlights From the Migration Trail
The monarch migration takes place without a single sound--all the way to Mexico--but it creates a great stir of
excitement in the hearts and voices of people who witness it. Over the next weeks, we'll forward highlights of
this fall's migration, as reported from people along the monarchs' path. Please send your own observations (see
suggestions below) and help track the monarch's trip to Mexico.
Students in the over-wintering region near Angangueo, Michoacan are already watching for the monarchs. Massachusetts
teacher Lauren Ockene recently visited and equipped the teachers with data sheets, so they can carefully record
the big event. How long do you think it will take the monarchs to travel to Mexico?
Challenge Question #1
"When do you predict students in Angangueo, Michoacan, Mexico (19N, -100W) will report the first big wave
of monarchs arriving at the over-wintering sites? (Give the exact date you think we'll receive their report and
tell us how you calculated your answer.)"
To respond to this Challenge Question, please follow
the instructions below.
Cold Front Pushes Monarchs Southward
All day yesterday, reports arrived in the wake of the cold front that moved southward from Canada during the past
3 days. Look at these weather maps for September 5-7 and read the observers' comments below. After the front passed,
what happened to the wind direction? To the cloud cover? How do you think these weather changes might have affected
(Maps produced by Purdue University Weather
These maps track a weather system over 3 days. (Click on face of maps to enlarge.) The blue line indicates a cold
front. The barbs on the arrows show wind direction and the head of the arrow indicates cloud cover.
September 7 Ontario
Don Davis reported a major monarch migration east of Toronto on the north shore of Lake Ontario: "Gordon Vogg
at Darlington Provincial Park (44N, -78W) east of Toronto, reports that hundreds of monarchs concentrated in the
park just after sunset Monday. He found 2 poplar trees with roosts in them. The roosts were about 30 - 40 feet
high. He estimated about 300+ monarchs covering an area of perhaps 20 square feet. They pulled themselves together
from over a 1 km distance into these relatively small patches during the last half hour before sunset. A major
movement of raptors was also in progress, including 500 + kestrels, 50+ sharp-shinned hawks, 10+ Cooper's hawks,
as well as harriers, merlins, osprey and broad winged hawks."
Don Davis, Toronto, ON
September 7 Ontario
"We have just started to notice single monarchs floating west through the fields on our farm.... a rough total
of a dozen or so. We have a 3 acre field to the west of the house that we have allowed to lay fallow for the last
three years so that it is now full of goldenrod and milkweed. A monarch's delight! Perhaps we will experience a
roosting in the spruce trees around the field again this year."
Penny Wearne, Dorchester, Ontario
September 7 Iowa
"The migrating monarchs are here! Since the first of August we had around 20 monarchs roosting in our trees,
but tonight was the first night I noticed the butterflies in clusters. Tonight it's cool, as a cold front came
through. Yesterday was beastly hot and today was cooler, 80s instead of 95 and humid."
Kathy Reed, Malvern, Iowa
September 7 Nebraska
"We had a break in our terribly hot weather and a cold front moved through during the night. We noticed this
afternoon the movement of several monarchs (12 to 15 visible at once) through the neighborhood, more than usual.
This isn't a large movement but certainly a change from what we've been seeing lately."
Gayle Kloewer, York Middle School, York, NE
September 6 Nebraska
"This past week we have spotted at least 50-75 Monarchs traveling through our playground area. We caught two,
very carefully, to examine them and then sent them on their way south. 'The butterflies all seem to be going toward
Omaha (south of Ft.Calhoun) so we know they are on their way south,' observed the first graders. The children are
very excited about spotting the Monarchs and learning about their trip to Mexico."
Marti Leishman, Fort Calhoun, NE
September 8 Wisconsin
"After a summer of nearly no monarch sightings, we now have quite a little 'flock' in our Racine, WI backyard.
As many as five at one time were feeding on the Buddleia bush. They were feeding vigorously!"
Dawn Sutherland, Racine, Wisconsin
Monarchs Scarce This Season
You're not alone if you saw fewer monarchs this summer than last. In fact, many people didn't report their "FIRST"
monarch of the season until July--or even August. In Oakville, Ontario, Rod Murray compared his observations this
fall to last year's:
"Today we were in Toronto for the Toronto Air Show. We usually count 20-30 Monarchs per hour as we sit on
the waterfront, on a point where goldenrod and other nectar flowers grow. Today we saw only 3 in over 2 hours.
And while at one of my Oakville, Ontario hotspots several days ago, I noticed only ONE Monarch where last year
at this time, I saw 3 groups of 100-200 on three adjacent trees." (firstname.lastname@example.org)
In late August, Dr. Lincoln Brower estimated the population could be down by nearly 90% from last year. Use the
numbers provided by Rod Murray (above) and in Dr. Brower's report (below), and make a graph to depict the apparent
drop in population size from last year.
Dr. Brower's Notes About August Population Size
"C. J. Meitner has just reported her preliminary data comparing the number of monarchs she has seen in the
Upper Penninsula of Michigan in August 1997 and 1998. Between 15-23 August she counted 1038 monarchs in 1997 compared
to 99 in 1998 for the same period. This Michigan ratio = 0.095.
Linda Fink and Lincoln Brower have been censusing monarch adults in a Buddleia garden at Sweet Briar College, on
the eastern edge of the Blue Ridge Mountains in Virginia, over the past two years. Counts for the same number of
days between 16 and 27 August were 184 monarchs in 1997 and 21 in 1998. This Virginia ratio is 0.114%.
Brower attributes this precipitous drop to the deterioration of the overwintering habitat in Mexico caused by excessive
thinning and illegal logging of the Oyamel Forests in the states of Michoacan and Mexico. Time will tell. Let's
hope I am wrong and that apparent decline of the the eastern population of the monarch butterfly in North America
is only natural variation."
Lincoln Brower and Linda Fink
Sweet Briar College, Sweet Briar, VA.
How to Monitor the Fall Migration
Next spring, tracking the migration will be easy. You'll be asked to report the FIRST monarch you see and together
we'll map the wave of the FIRST monarchs as they move northward. But reporting the LAST fall monarch isn't as meaningful.
It's extremely difficult to keep track of the LAST time you see something, and the results wouldn't show the pace
of the migration. Therefore, we hope the following guidelines will help you report "migration highlights"
from your region. (You may want to make a map to show where these migration highlights occur during the fall season.)
1) Count Monarch Numbers
Keep track of the numbers of monarchs you are seeing. Watch the clock and count how many you see per hour (or minute).
Try to make your observations on a regular basis, at the same time each day, if possible. Some people count monarchs
when driving the same stretch of road each day. Others record monarchs visiting their butterfly gardens, or roosting
on trees for the evening.
When you submit your report, try to compare monarch sightings from day to day, to indicate the pace of the migration
through your area. For example, "We didn't see any monarchs yesterday but today we saw 15." or "These
are the 1st monarchs we've seen in 15 days."
Remember: It's equally important to keep track of monarchs you are NOT seeing! (Even though not much fun.)
2) Describe the Monarchs' Activity
Tell us what the monarchs were doing when you observed them. Were they nectaring at flowers in your butterfly garden,
on a farmer's field or roadside? Were they in flight? (If so, estimate height and direction traveling.)
3) Watch the Weather
Try to describe the weather conditions, especially on days you see changes in the pace of the migration. Include
notes about: Wind direction, wind speed, the daily high/low temperatures, cloud cover, etc. For the big picture,
look at a weather map so you can describe the major weather patterns moving through your region. Here are WWW maps
produced by Purdue University:
4) How to Report Your Sightings
Simply press the Owl Button on any WWW page and a field data form will appear (or send e-mail to email@example.com)
When you see something exciting, let us know right away! Or, collect sightings for several days and summarize your
observations, as described above.
Special Butterflies Heading for Mexico
Monarchs have recently joined the migration, after being raised and released by:
Pittston Elementary, Gardiner, ME
North Hall Middle School, Gainesville, GA
Holly Hedge School, Wolfeboro, NH
Be sure to let us know when your monarchs are on their way!
Symbolic Migration Deadline
All migrating symbolic monarchs must be on their way no later than October 9th.
Don't forget this postmark deadline. (For more information)
Teacher Trip to Mexican Monarch Sanctuaries
Greet the monarchs as they arrive in Mexico! Join Dr. Bill Calvert this November 14-20. Contact Dr. Calvert (firstname.lastname@example.org) with questions or to express interest. (For
How to Respond to Today's Challenge Question
- Address an e-mail message to: email@example.com
- In the Subject Line of your message write: Challenge Question # 1
- In the body of the message, answer the question above.
The Next Monarch Migration Update Will be Posted on September 15, 1998.
Copyright 1998 Journey North. All Rights Reserved.