Monarch
Butterfly Migration Update: September 24, 2004
Today’s
Update Includes
Highlights
From the Migration Trail
At
last! The season’s first big wave of migration has finally occurred!
A sudden rash of reports arrived as large numbers of monarchs apparently
moved through southern Iowa, and on into Nebraska, Missouri and Kansas.
09/20/04
Sergeant Bluff, IA
“There were hundreds of Monarchs roosting in the understory of
the grove on the north side of the house. The monarchs have been arriving
for the last 3 days.”
09/17/104 Creston, IA
“Finally!! Over 50 monarchs in our hackberry tree tonight. I've
seen a few arriving late afternoons for about a week, but not enough
to even find where they were roosting. They are a welcome sight.”
09/19/04 York, NE
“They're here! Where the alfalfa fields are blooming, there are
butterflies! We haven't seen any roosting sites yet but the fields are
showing Monarchs nectaring. We had a cold front move through last week
but the last two days have been hot and windy with winds from the south
over 20 miles an hour. The Monarchs are holding onto their flowers tightly!
9/20/04 Kansas City, MO
“While outside at Noon at Washington Park, Crown Center area in
Kansas City, MO, I observed 10 Monarchs flying to the Southwest, within
a 30 minute time frame.”
Interactive
Maps: Read All Reports on the "MapServer"
All monarch sightings that have been reported are displayed on our MapServer.
You can “click” to read each observer’s comments.
Migration
Rate Math: Who Saw the Most Monarchs?
|
Dr. Calvert counts monarchs
as they arrive at the sanctuaries in Mexico. |
The observer
in Kansas City watched her watch while she watched the monarchs. Thanks
to her, we know butterflies were streaming by at a rate of 20 per hour.
By calculating the migrate rate, we can compare one observation to the next.
When you watch for monarchs, follow her example. Record the number of monarchs
you see AND the number of minutes you watched for monarchs. Then calculate
the migration rate. For units, use monarchs per minute (or monarch per hour).
For practice, here’s a worksheet with examples from previous years.
Who saw the most monarchs?
- Migration
Rate Math
Challenge Question #7
"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.)
Not
All Go to Mexico: Utah Students Study “Western” Monarchs
|
Which
monarchs go to Mexico?
Dots suggest areas of uncertainty. |
Do monarchs
east of the Rocky Mountains mix with those that over-winter on the California
Coast? Are the Rocky Mountains truly a barrier monarchs between the two
populations? If so, does the Continental Divide mark the line between the
two populations?
For years, those questions have been debated. This week, we received a message
from a Utah teacher whose students helped uncover some answers. Mr. Ron
Hellstern of Byrum, Utah, wrote:
“My
classes initiated the Intermountain Monarch Butterfly Project. We are
associated with the Monarch Program of San Diego, and have helped them
determine the winter migration destinations of Intermountain Monarchs.
“When we started this project back in 1994 there was little, if
any, knowledge about the migration routes or roosts of the Intermountain
Western population. My students helped to establish the baseline data,
and recruit other schools along the western slope of the Rocky Mountains
to assist in collecting this information.
"Thanks to some of our tags, our Monarchs have been spotted in
Santa Cruz, California, which means these beautiful and delicate creatures
cross the Great Basin Desert and the Sierra. Amazing!!! Our monarchs
may not be going to Mexico, but we feel just as attached to them."
|
Which
direction did the Utah monarch fly? |
Try
This!
- Trace
the course the Utah students’ monarch might have flown from Byrum,
Utah, to Santa Cruz, California.
- Can you
find the Great Basin Desert? The Sierras?
- How many
kilometers did this monarch fly? How many miles?
- Which
direction did the monarch travel?
- Find
the Rocky Mountains on a physical map.
- Can
you also find the Continental Divide?
- At
various points in the Rocky Mountain region, predict where a monarch
from this region might over-winter. Would it fly southward to Mexico
or westward to the California Coast? Explain the reasoning behind your
prediction.
Chasing
Monarchs on Both Sides of the Continental Divide
|
"The
'Berlin Wall' model of monarch migration was based on assumption
and repetition rather than fact," says Pyle. |
Naturalist Robert
Pyle traveled extensively on both sides of the Continental Divide one year
during fall migration, watching for migratory monarchs. Whenever he found
a monarch, he watched the direction it flew. Then he chased its invisible
path until he found another monarch. All along the way, he interviewed the
people he met and asked them when and where monarchs had been seen. His
book, "Chasing Monarchs" chronicles his journey.
“By
physically traveling with the monarchs, day by day, north to south,
I hoped to shed a few lumens of light on several mysteries of the monarchs,”
he said.
Do the Rocky Mountains truly form a barrier
between the eastern and western monarch populations?
A basic assumption of North American natural
history was based on thin evidence, concluded Pyle. The eastern and western
monarch populations are not the distinct entities scientists have long
assumed. Read his book and see his article in Orion magazine:
Watching
and Waiting at the Over-wintering Sanctuaries in Mexico
Estela Romero and German Medina live beside the monarch sanctuaries in the
mountain town of Angangueo, Michoacan, Mexico.
They have promised to report to us weekly as they watch for the first monarchs
to arrive. No monarchs have been seen yet!
The Romeros have a small grocery store near the center of town. It’s
fun to spend time in the store and watch members of this mountain community
come and go. People visit all day long, buying everything from chile peppers
to soap and fertilizer. The Romeros have everybody in the valley helping
to watch for monarchs.
- “Hola
a todos los interesados una vez mas en la migracion de la Mariposa Monarca
para el ciclo 2004-2005,” begins Estela Romero. (Spanish
version)
- “Hello
to all people involved in the Migration of the Monarch Butterfly over
the 2004-2005 season,” begins Estela Romero. (English
version)
Reminder:
Symbolic Migration Deadline Oct 15
Only 21 more butterfly-making days before the Symbolic Migration deadline.
Don't be late! Butterflies received after the postmarked deadline cannot
migrate.
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 #7
3. In the body of the message, answer the question above.
The Next Monarch Migration Update Will Be Posted on October 1,
2004.
Copyright
2004 Journey North. All Rights Reserved. Please send all questions, comments,
and suggestions to jn-help@learner.org
|