Field
Notes from Mexico
by Dr. Bill Calvert
February
17, 2005
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"What
had been a drab display of cryptic camouflage was now color and
movement."
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"Our
lesson was plain and simple: butterfly activity—and butterfly
motion—was powered by the sun." |
Day
1: The Herrada Colony
On Sunday, February 13th a group of teachers from Georgia, Minnesota, and
Texas, and myself traveled from Mexico City to the butterfly colony “Herrada."
(See
map.) Although they didn’t know what to expect, I was full of
anxiety. The day was cloudy and the mountain obscured by haze. Just as I
had worried, there were no butterflies, neither streaming down the road
nor in the arroyo where there is water for them to drink.
This was
the first part of what was to become a dramatic lesson that illustrated
the power of the sun to affect butterfly behavior.
Day
2: The Rosario Colony
The following day we ascended to the Rosario Colony and trudged up the
781 feet to parking lot to the colony. Again the day was cloudy and cool.
The dormant, clustered butterflies presented themselves as a Japanese
tapestry, showing no color. Moans of disappointment were audible from
the onlookers.
Day
3: The Chincua Colony
We visited Chinua the following day and found an intermediate situation.
The morning had begun crystal clear but rapidly clouded over. We trekked
the 2 kilometers to the colony on horseback arriving early afternoon.
The sky was mainly cloudy, but had breaks among the clouds, allowing the
ambient [temperature] to heat up a bit. Butterflies were flying about,
but not in great numbers.
Then the
sun burst through for a 15-minute period and the scene changed dramatically.
Millions more butterflies opened their wings, and millions took to the
air. What had been a drab display of cryptic camouflage the day before
at Rosario was now color and movement. The clouds came back and millions
of baskers took to the air.
Day
4: The Pelon Colony
The next day was Wednesday. We ascended 2,500 feet to the Pelon colony
again by horseback (the poor horses) to find a cloudless sky and butterflies
flying everywhere. They were on all the flowers, and they basked on vegetation
as far as a mile from the colony. The clusters that had been closed and
inactive at Rosario were now full of color and action. The spectacle was
simply dazzling. We descended the mountain exhausted but much elated.
(The horses breathed a sign of relief.)
Our lesson
was plain and simple: butterfly activity, and butterfly motion, was powered
by the sun.
Map
of the monarch colonies in Mexico.
(Click map to enlarge.)
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