Sierra Madre Butterfly Swarms

Central Mexico’s Michoacán region is famous as the Land of the Fishermen. But every year, on the first of November, a natural miracle occurs. A pulsing, palpitating orange cloud flows over forests, rivers and deserts to descend upon the forests of the Sierra Madres. It is not a scene from a Science Fiction movie, but one of natures most spectacular events, the migration of Danaus plexippus, the Monarch Butterfly.Every year, billions of these long-distance commuters leave their homes in Canada and the Northern US, and fly non-stop to this area of Mexico to hibernate through the winter. Many fly a distances of over 3000 miles. This is the equivalent of a human making two round trips to the sun, under his/her own power. Upon arriving in their southern resort, the butterflies form up into a dozen or so colonies and roost in the oyamel trees. Each colony may have as many as 20 million individuals, with enough combined weight to actually break some of the branches. They cluster in the trees with their wings folded for the night, huddled densely to conserve heat. The undersides of their wings are a charcoal grey, so they can’t be seen very good at night. But when the sun comes up in the mornings, Read more…