Monarch Migration Update: November 22, 2002 Today's Report Includes:
Field Notes from the Monarch Sanctuary Region in Mexico Here is the final fall monitoring report from German Medina: Dear Students,
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,
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,
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." Geography and Migration 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. Catch the Globe: Water or
Land?/¿Agua o Tierra? 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 This is the FINAL Fall Monarch Butterfly Migration
Update. See you in February!
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