Monarch Butterfly Migration Update: March 7, 2001
Today's Report Includes:
Field Notes from Mexico
Snow Hits the Monarch Region
On this week's visit to Sierra Chincua, Eligio Garcia observed winds gusts up to 77 km/h (47 mph). He did not count number of trees filled with monarchs this week, and says many butterflies had been grounded by the storm.
Dr. Calvert Reports: How Does Snow Affect Butterflies?
March 4, 2001
Snow in all parts! The climb up the Nevada de Toluca from the city of Toluca was painfully slow due very heavy traffic. Everybody and his brother was out for an adventure in the snow. Snow is infrequent here in Central Mexico. The day was crystal clear and the snow was melting fast so everyone had to hurry before it disappeared. As we climbed toward the pass we saw snowmen of every variety on the hoods, tops and trucks of cars. The favorites were dogs, or I should say "snowdogs" if there is such a word. Dogs wore sunglasses, kerchiefs around their necks, and often times hats of different styles.
Along the road there was much evidence of remaining snow and especially plant carnage. The weight of wet snow and strong winds had broken tens of thousands of limbs. It had snapped off and uprooted trees. At the Herrada colony the trail we normally take to view the butterflies drinking water was almost impassable due to downed trees and branches. There were no butterflies to be seen. We can only speculate what happened in the butterfly colonies. Tomorrow we will know, when we visit Chincua and El Rosario.
After a snowstorm, I'd expect that most butterflies would survive, even many of those stuck in the snow. Miraculously, once the snow melts, I've seen them warm up and finally move off. They might even be buried for up to a week!
However, the year of the devastating snow storm (1981) we were monitoring mortality in the Chincua colony and documented tremendous mortality. Review the data we collected (see link below). Then compare the safety of the monarchs that were on the ground to those that were clustered on a tree bough.
Until next week,
Where Would You Rather Be?
Based on Dr. Calvert's data above, what could you conclude about the safety of the two positions within the colony during a snow storm?
Monarch's Forest Like an Umbrella and a Blanket
Dr. Lincoln Brower has studied the monarchs in their wintering sanctuaries for over 20 years. Whenever he describes the monarchs' winter habitat, he uses this analogy:
"The forest serves as an umbrella
Read about the oyamel forest habitat in the two articles below. Since you're already familiar with blankets and umbrellas, you can apply your knowledge to a question about monarch habitat.
You may be surprised how helpful analogies can be when answering any challenging question. Try this one!
How is a Hot Dog Like a Shoe? Thinking by Analogy
The world of science and invention is filled with examples of analogous thinking. Here's a fun activity you can do to practice thinking by analogy:
Two Geographic Clues Led Brower and Calvert to the Monarchs
Life in the Sanctuary Region
What's in a Family Name?
What would your name be if you lived in Mexico? Karina Romero de Avila walks you through the steps to find out:
Important: Please Report Winter Monarch Sightings Now
We need your help before the monarchs arrive from Mexico. In order to track the migration accurately, we need to know where monarchs may have remained all winter.
People assume the spring migratory monarchs are all coming up from Mexico but we really don't know the importance
of the Gulf Coast over-wintering population.
How to Respond to Today's Monarch Challenge Questions:
1. Address an e-mail message to: firstname.lastname@example.org