Monarch Migration Update: September 6, 2002
Today's Report Includes:
Highlights Along the Migration Trail
Almost 100 people reporting migration sightings during the last week, but people described the migration so far as lackluster and are hoping it’s just late. This poetic comment from northern Minnesota describes its slow pace best: “Fat, fresh, monarchs lazily floating southward in onesies, twosies, threesies. No large roostings or mass flights.”
The first strong cold front of the season did push through on Monday, and several people noted their first nighttime roosts in the north. In states across the south, first monarchs are now appearing, after being absent in most places all summer. Scientists think these monarchs produce a final, fall generation there. This is something learned recently, thanks to volunteer observers compiling their observations.
Southbound With the Butterflies:
Orioles Take Off for the Tropics
How Iowa Students are Monitoring the Migration
Thanks to students at Sheandoah Middle School in Sheandoah, IA, for their great example of how you can watch and document monarch migration where you live:
“We live in the southwest corner of the state of Iowa. Every morning at 9:40 AM we walk outside our school building down by a ditch that has some milkweed in it. We stand outside for four minutes. We started our log on August 29th and didn't see any monarchs. September 4th we saw four monarchs and captured one monarch caterpillar. Today, September 5th we saw ten monarchs. We will keep you posted.” Alex, Ben and Hanna
Discussion of Challenge Question #1
In last week’s story, monarch tagger Tom Murphy noticed monarchs gathering on the same side of his tent whenever caught inside. Challenge Question #1 asked, "On which side of the tent do you think the monarchs gather? Why?"
It was fun to receive your answers all week and see the good reasoning taking place. On which side of the tent did the students think the monarchs gathered, and why?
Thanks to students in these schools for contributing their answers!
At the Murphy’s, the monarchs gathered on the south side, ready to head to Mexico! Amazingly, the doors on the cold frame are on the east and west ends, but the butterflies don’t fly out the open doors to escape. During fall migration, people often see monarchs so intent on flying southward that they’ll nearly hit a building in their path. They fly straight up and over, rather than around, the building at the last second. Monarchs are serious about heading straight south!
You’re the Scientist: Thinking Through Research Design
As a class, discuss how you might investigate these questions and/or answer them in your science journal. Better yet, organize your colleagues and conduct your own research!
How Do They Know Which Way to
Here’s what the biologists did: They collected monarchs, divided them into three groups, and put them in their lab under artificial light. The control group received light during normal daylight hours (for 12 hours, from 7 am to 7 pm). But the two test groups were “clock-shifted,” meaning they were exposed to 12 hours of light but not during normal daylight hours. One group was “clock-shifted” 6 hours early (receiving light from 1 am to 1 pm). The other group was “clock-shifted” 6 hours late (receiving light from 1 pm to 1 am).
Before reading further, think what would happen if your biological clock were shifted by 6 hours:
Try This! Follow The Sun
(Just think, monarchs know all of this by instinct! So even if you find this complicated, you’ll appreciate the challenges monarchs face when using the sun as a clock and compass! )
Link to: Follow the Sun
Reminder: Symbolic Migration Deadline--October 11
Only 36 more butterfly-making days before the deadline. Don't be late! Butterflies received after the postmarked deadline cannot migrate!
Please Report Your Sightings!
We can't track migration without your help. Please come to the web and share your observations.
How to Respond to Today's Challenge Question
1. Address an e-mail message to: email@example.com
The Next Monarch Migration Update Will Be Posted on September 13, 2002.
Copyright 2002 Journey
North. All Rights Reserved.