SMART NEWS

Beautiful Monarch Butterflies Basically Aren’t Migrating Anymore

Over the past two years, the migration has shrunk by nearly 60 percent, the latest in a long-term plummet

March 14, 2013

Enjoy, for a moment, the soothing tones and the sound of beating wings in National Geographic‘s quirky mashup of indie rockers Temper Trap and some beautiful footage of one of the world’s greatest mass animal voyages, the annual migration of the monarch butterfly. Each year, says the World Wildlife Fund, monarch butterflies “embark on a marvelous migratory phenomenon.”

They travel between 1,200 and 2,800 miles or more from the United States and Canada to central Mexican forests. There the butterflies hibernate in the mountain forests, where a less extreme climate provides them a better chance to survive.

Relaxed and enthralled with the brilliance of the natural world? Good. Try to hold on that feeling as long as you can, because as the New York Times reports, the spectacle of the monarch migration is crashing: “The number of monarch butterflies that completed an annual migration to their winter home in a Mexican forest sank this year to its lowest level in at least two decades.” In just the past two years, the area of Mexican forest taken up by the monarchs shrank from 7.14 acres to 2.94 acres, both down from an earlier peak of 50 acres. The Associated Press:

It was the third straight year of declines for the orange-and-black butterflies that migrate from the United States and Canada to spend the winter sheltering in mountaintop fir forests in central Mexico. Six of the last seven years have shown drops, and there are now only one-fifteenth as many butterflies as there were in 1997.

The decline in the Monarch population now marks a statistical long-term trend and can no longer be seen as a combination of yearly or seasonal events, the experts said.

The blame for the drop, says the AP and the Times, is being spread around everything from logging to pesticides to habitat destruction to changes in climate. The Times:

Mr. Taylor said a further decline could cross a tipping point at which the insects will be unusually vulnerable to outside events like a Mexican cold snap or more extreme heat that could put them in peril.

“Normally, there’s a surplus of butterflies and even if they take a big hit, they recover,” he said. But if their current 2.94-acre wintering ground drops below 2.5 acres, bouncing back could be difficult.

“This is one of the world’s great migrations,” he said. “It would be a shame to lose it.”