To: Journey North
From: Dr. Lincoln Brower, University of Florida
I was in Mexico in the middle of March at the Sierra Chincua overwintering site. We now know that the early January, 1996 estimates of the severity of the storm damage were mistaken. Eneida Montesinos Patino and Eduardo Rendon Salinas, our Mexican student researchers, have hard numbers: Only 6 to 7% of the butterflies were killed by the late December, 1995 snowstorm.
The error was generated from assuming that all the butterflies that were knocked down by wind on top of the snow had been killed. However, most were not. When it cleared, they gradually opened their wings and absorbed the warmth from the sun until they could fly back up into the clusters.
Nevertheless, the thousands of butterflies knocked out of the trees by this storm WAS a bad omen: Thinning and deforestation is increasing the exposure of the overwintering butterflies. This makes them more vulnerable to the frost, snow and rain that accompanies these heavy winter storms.
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