Monarch Butterfly Migration Update: February 14, 2001
Today's Report Includes:
Brrrrrr...It's Cold in Mexico!
At 10,000 feet in elevation, the over-wintering sites are often cold indeed, especially at night. In fact, if you visited the sanctuaries in the evening--as the temperatures were dropping--you'd see the forest floor fluttering with shivering monarch butterflies. These are butterflies that have fallen from the trees, often forced down by strong wind, rain, hail or even snow. If it's below 5C, it's too cold for them to fly or even crawl. Once the temperature reaches about 5C they can begin to shiver and warm themselves enough to move.
Video Clip of a Shivering Monarch
Play the video clip above and see how hard the monarch is working to warm up its muscles. Notice that it never leaves the twig, but keeps moving its wings vigorously. If you stayed to watch, a monarch might shiver this way for many hours, with rests in between. So far, this butterfly has made it off the ground by climbing to the top of this stick in the forest under-story.
Try This! Shivering Simulation
Find a volunteer who's willing to shiver. Ask him to sit on the edge of his chair and shiver all the muscles in his body at once--feet, legs, arms and hands. How many seconds does it take until he can feel his body warming? How long until he can feel himself getting tired? How long until he begins to perspire?
Survival of the Fattest
As you can see, shivering uses energy. Now remember, these butterflies need to conserve the lipids stored in their bodies so they'll have the energy to fly back north in the spring. So why do you think butterflies shiver so hard--and spend so much energy--to get off of the ground?
Then do your own research about warm and cold-blooded animals so you can answer this week's Challenge Questions:
Try This: My Day as a Cold-blooded Creature
How would your life be different if YOU were cold-blooded? Write a short story about the day your warm-blooded body went cold, and you had to plan your activities around the day's temperature changes. Describe how this affected your plans, and what warm-blooded people had to do to help you!
This Week's Field Notes from Eligio Garcia
Here are this week's observations from the Sierra Chincua sanctuary. What changes do you notice from last week?
My First Job
Esmeralda Cruz Guzman and the Symbolic Monarchs
"To me, the Monarch butterfly is a very amazing little animal. The most incredible aspect about it is that every year around the same date, it arrives to this same place to spend the winter. And, since I live right outside the sanctuary, I've always seen them come here. When they first come and when they leave again in the spring, they fly by my house."
Symbolic Migration News: Watch Your Mailbox!
Over 1,500 letters will soon flood north across the Mexican border from children in the sanctuary area schools. When we gave them your Symbolic Butterflies we included addressed envelopes so they could send a "winter welcome" to their friends in the north. Later this month we'll have other news from Mexico about the Symbolic Migration. In the meantime, watch your mailbox!
Teacher Tip: Learn About Mexican-U.S. Relations This Week
Here are some suggested Web links to begin:
How to Respond to Today's Challenge Questions
1. Address an e-mail message to: email@example.com
2. In the Subject Line of your message write: Challenge Question #2 (#3 or #4).
3. In the body of the your message, answer the question above.
The Next Monarch Migration Update Will Be Posted on February 21, 2001.