Journey North: Monarch Butterfly Fall, 2002

Monarch Migration Update: November 22, 2002

Today's Report Includes:

Field Notes from the Monarch Sanctuary Region in Mexico
Like Finding a Needle in a Haystack? Discussion of CQ #16
The Importance of the Intact Oyamel Forest Ecosystem
Geography and Migration: Mexico's Role in Preserving Biodiversity
Catch the Globe: Water or Land?/¿Agua o Tierra?
See You Next February When Journey North Begins!

Field Notes from the Monarch Sanctuary Region in Mexico
Here is the final fall monitoring report from German Medina:

Dear Students,

German Medina writes from Angangueo

Monarchs spent more time in the "El Cerrito" and "Los Cedros" staging areas this year than usual. At this time last year, they had all gathered up in the sanctuaries.

From November 14-17, about 14 trees with 3,000 Monarchs (on average) were observed. On November 18, 14 trees were covered, but with many fewer butterflies (only about 1,000 on each tree). And on November 20, only 5 trees with 1,000 butterflies were remaining. It seems as though they will all be up in the sanctuaries by the weekend.

For us people who drive tourists up to the sanctuaries, it's better that the monarchs spent more time in these places, since it's easier to get there. Foreign tourists have started to visit us, but they are very few still.

The weather here started to freeze approximately two weeks ago and, of course, it's turning colder every day. Weather continues to be very cold in the mornings, beautifully sunny during the day, and drops down again at night. Sometimes days are a bit windy. One day it was so cloudy and freezy that, for a while, it seemed it would snow!

Regards,
German Medina

Journaling Question
Were you surprised to hear about the cold weather in the sanctuary region? How does the weather compare to your expectations? (We'll come back to this topic when Journey North begins in February.)

Like Finding a Needle in a Haystack? Discussion of CQ #16
In our last update, we compared the size of the overwintering region to the size of the area monarchs migrate across. We said, "Finding the Mexican sanctuaries in the North American continent is like finding a _____ on a football field. (Fill in the blank with something to scale. That is, name an object that is 11,000 times smaller than a football field.)"

Third grade teacher Mrs. West at Poth Elementary in Texas wrote,

"My students found the area of the football field to be 6,399 square yards. We divided that by 11,000 and found that we would be looking for something that would be about 1/2 of a yard long or 18 inches. My students decided that would be about the size of a kindergarten chair."

The Importance of the Intact Oyamel Forest Ecosystem
Great job, third graders! The sanctuary region is indeed small. It is outlined in green on the map to the right.

Amazingly, the monarchs form their colonies in this region only where the "oyamel" fir forest grows. Like "vegetational islands," the oyamel forest ecosystem is found only at high elevations, between 2,400 and 3,600 meters. So, if the sanctuary area were the size of the seat of a kindergarten chair, the sanctuaries themselves would be little dots on that chair. The map shows each of the known sites as a red triangle.

Imagine: Monarchs from across eastern North America will be concentrated all winter long in this tiny area! And, as Dr. Lincoln Brower points out, "The densely aggregating butterflies are, in effect, the seed crop which must survive the winter to be able to recolonize the eastern North American breeding range when spring and summer conditions return."

The Importance of the Intact Oyamel Forest Ecosystem

Geography and Migration
Mexico's Role in Preserving Biodiversity
Monarch butterflies are not the only species that migrates to Mexico to escape the cold, northern winters. In fact, Mexico is important to the survival of hundreds of North America's migratory species. For example, more than half of all bird species that breed in Canada and the United States spend the winter south of the U.S. border.

When delivering Symbolic Monarchs to the sanctuary area schools last winter, we played a game of "catch the globe" with the students. By way of this game, students compared the land mass of Mexico to that of the rest of North America.

Look at a globe and take note: Mexico is almost 10 times smaller than the U.S. and Canada. This means that millions and millions of animals must share limited space during the winter months. They are compressed into an area during the winter that is much smaller than the breeding area. Importantly, when habitat in the overwintering region is destroyed, the impact can be many times greater because so many individuals are sharing the land.

Here are photos of students at Esceula Benito Juarez as they played. You can see the Sierra Chincua Monarch Sanctuary in the background.

**Visiting Escuela Benito Juarez**
**With the Sierra Chincua Monarch Sanctuary in the Background**

Catch the Globe: Water or Land?/¿Agua o Tierra?
Here is the lesson conducted at Esceula Benito Juarez, in both English and Spanish:

See You Next February When Journey North Begins!
Each year at this time, we head to Mexico and join up with the butterflies. The camera and recorder are packed, ready to record sights and sounds of the monarchs' mountain refuge. Although you won't hear from us during the weeks ahead, we'll be busy arranging ways to "take you along" when Journey North begins in 2003. Watch for the first update, from the monarch sanctuaries, on Friday, February 7, 2003.

Thanks to everyone for helping to track the monarch migration this fall. We hope you'll be back next spring to track the northward migration, as you welcome the monarch's return to your home town.

Elizabeth Howard
Program Director, Journey North

This is the FINAL Fall Monarch Butterfly Migration Update. See you in February!