(NY Times Op-Ed, Friday, Jan. 26, 1966)
As many as 30 million monarch butterflies died after a snowstorm hit their sanctuaries in central Mexico on Dec. 30. But storms are not the real threat to the monarchs. The real danger is the destruction of the Oyamel fir forests. About 90 percent of the world's monarchs live east of the Rocky Mountains. Each fall, they migrate 2,000 miles from as far away as southern Canada to their winter quarters in the Oyamel forests.
By early April, the butterflies migrate 800 miles back to the southern U.S., where each female lays about 400 eggs on milkweeds. The eggs turn into caterpillars, the caterpillars into jade-colored chrysalids. When they hatch, this spring generation travels north to Canada. Over the summer, two or three more generations are produced, and the great-grandchildren of those that flew north go back to Mexico to repeat the cycle.
But the monarch's existence is threatened by the cutting of the Oyamel forests. When intact, a forest serves as an umbrella, protecting the butterflies from freezing rains. Logging creates gaps that allow rain and snow to fall through the forest canopy and onto the butterfly clusters. As the weather clears, the heat radiated from the butterflies' bodies leaks out through these holes and the monarchs freeze to death.
The Government continues to permit logging. Illegal commercial cutting is rampant. Local peasants harvest trees for fuel and building materials, and cattle trample and eat the fir seedlings.
It is not too late to undo the damage. The Government and international conservation groups together should buy or lease the forests from the local peasant communities. The local people could benefit if they had help to create ecotourism ventures. To plan and pay for such projects, Mexico and private environmental groups and foundations need help from the U.S. and Canada. Can trilateral cooperation save the Oyamel sanctuaries? Or will North America let the forests fall and the butterflies disappear?
Homero Aridjis is president of the Group of 100, a Mexican environmental organization. Lincoln P. Brower is professor of zoology at the University of Florida.