Fly away
Feb 13, 2010
Monarch butterflies know how to enjoy winter; they fly south, leaving the eastern United States and heading for the mountains around Tlalpujahua, in the state of Michoacan, Mexico. Winter nights can get chilly up there in the mountains, and the butterflies huddle together in the trees. But the days are warm and sunny, and every morning as the temperature approaches 70 degrees, the Monarchs take to the air, flocking skyward all at once.
No single Monarch lives long enough to migrate to Mexico in the fall and back to the States in the spring. But somehow, the young butterflies born in Mexico each winter know to start flying north in March, and even know to head for particular ancestral summer homes, which they've never seen before. There, they mate and produce a new generation, which is born not only with the magic power to change from caterpillars into pupae into butterflies but also with the knowledge of when to head south in the fall and how to find the Mexican mountaintop where their ancestors always liked to spend the winter.
