Accessibility links

Breaking News

The Migration of the Monarch Butterflies


Naturalists are beginning a transcontinental flight -- following the path of the longest insect migration in the world: the Monarch butterfly’s flight each autumn from Canada, through the United States, to Mexico.

Like all butterflies, the Monarch begins as a caterpillar, inching along on tiny legs, feasting on leaves. Then comes the slow transformation inside the chrysalis: from worm-like creature into a thing of wings -- and beauty.

Monarch butterflies, instantly recognizable for their gold and black markings, are found in many places around the world. But only those east of the Rocky Mountains in North America make the longest annual insect migration. From their summer habitats in the north, every autumn 300 million butterflies fly south – more than 5,000 kilometers -- to a few small forests in Mexico.

And that’s the path that this unusual ultra-light aircraft will follow this year – piloted by a crew of documentary filmmakers, including lead pilot Francisco Gutierrez.

At a stop in Washington, D.C., Mr. Gutierrez said he’d designed the plane’s Monarch-like wing markings himself. The purpose of the flight, he said, is to raise public consciousness about the environment. “Basically, the idea is to make people aware that we have to take care of our world,” he said. “And I found in this incredible insect, the Monarch butterfly, a very magic and amazing phenomenon.”

Pilots from all three countries will take turns flying the motorized glider from Canada through the United States to Mexico. The butterflies will determine the flight schedule.

“If the Monarchs fly, it’s because we have good weather,” Mr. Gutierrez said. “If they don’t fly, it’s not good, so I’m just trying to follow their rules. So, if I fly with them, I will be ready.” Reporter: So they take a break if the weather is bad? “Yes, when they have a thunderstorm, they stay somewhere, I don’t know where. And when the weather is good again, they fly.”

“To me, the Monarch is a symbol of the interrelatedness of all animals and plants,” says Sweet Briar College professor Lincoln Brower. Now a fellow at the World Wildlife Fund, Professor Brower has studied Monarch butterflies for 52 years. He says that large-scale agriculture’s herbicides and gene-engineered crops are killing off everything else, including the plants that butterflies eat -- with disastrous consequences for biological diversity. In Mexico, meanwhile, illegal logging is also destroying the high-altitude forests that the Monarch butterflies shelter in over the winter.

“The Monarchs depend on the trees to get through the winter,” Professor Brower says. “If they lose that over-wintering habitat in Mexico, at some point the straw will break the camel’s back and we’ll lose the whole migratory phenomenon.”

While the Monarch species itself isn’t endangered, Dr. Brower says that the butterflies’ migration is both a beautiful natural resource, and a well of scientific knowledge. “For example, right now there’s a current controversy as to whether the Monarch is capable of detecting magnetic lines of force,” he says. “The fact that these little guys can fly from Toronto to a pinpoint on the map in Mexico, nearly 2,000 miles, how do they do it? What clues are they using? How is their brain processing this information? I mean, the brain of a Monarch is about the size of a small steel pinhead, and yet within it is the capacity of navigation comparable to the highest humans have, or even higher, for that matter.”

The pilots of Papalotzin, as the motorized glider is called -– the word means “little butterfly” in the ancient Aztec language -– must depend on cruder navigational tools as they track the clouds of butterflies south. The flight began in August in Canada, and will end in November in Central Mexico.