Monarch Butterflies at their winter home in Mexico.
Estimates put the number of monarchs at 4 million per acre in some of the butterfly reserves. Can you imagine?“I have on many occasions seen Spaniards, Italians, Americans, Canadians, and Mexicans come into the butterfly colonies and literally weep,” said Lincoln Brower, a monarch expert at the University of Florida. “It’s such an overwhelming emotional experience to realize that you’re actually looking at these tens of millions of monarch butterflies that have come into this tiny, little area of Mexico.”
The eastern monarchs are the butterflies that winter in Mexico (the western monarchs stay in California) and they come to the exact same mountains every year. But the ones that arrive in the fall are not the ones that leave in the spring. After mating in Mexico (in March) and finding milkweed for their caterpillars, the females only live a few more weeks. It’s the next generation that migrates home. It can take up to four generations of butterflies to travel all the way back to New England, Canada, and the Great Lakes. In the fall, the robust autumn monarchs gain extra weight and live 12 times longer than the summer monarchs so they can survive the journey to their winter paradise.
