Back in l999, I wrote a piece about the race to find the wintering grounds of the monarch butterflies, which was as heated as the race to discover the source of the Nile in the nineteenth century. http://www.dispatchesfromthevanishingworld.com/pastdispatches/monarch/monarch1.html
At that point there were two threats to the survival of the monarchs and their epic migration : the local campesinos were not allowed to cut the oyamel fir trees in which the butterflies nest, but they were allowed to cut an oyamel if it was dead, so they were girdling the trees on the lower edge of their forests on the volcano tops of Michoacan, and waiting for them to die, and the oyamel forests was also being threatened by global warming, which is pushing them higher up the volcanos and eventually, if the warming continues, there will be no oyamels left there, so where will the monarchs nest. There is no forest, only desert, for 400 miles north, until you get to the Ponderosa pine forests of the Sierra Madre. Will the monarchs be able to make this huge adaptation, to a different species of tree in a different mountain range ? Their future may depend on it.
This morning’s Montreal Gazette has an article about how this years’ migration is threatened by the drought in Texas. Many monarchs will die because there isn’t enough milkweed on their drought-stricken route. Central Texas is one of their chief fueling and fattening grounds so they have shifted their route west, but there isn’t much milkweed there either. New Mexico had terrible wild fires this summer. Also, the cold summer in the Great Lakes Region slowed down their breeding cycle, plus in the Midwest, genetically engineered pesticide-resistant corn is wiping out the milkweed there.
here’s the story : http://www.montrealgazette.com/technology/Texas+drought+take+toll+butterfly+migration/5736504/story.html