• Image about Mexico

The butterfly-migration season roughly follows the annual growth cycle of the milkweed plant, a favorite food of the monarchs.

opens a gate on a wooden fence and takes us off the trail. We walk a bit further, deeper into the forest, and then Alfredo stops and points. Giant podlike clumps dangle from trees, pulsating slightly with movement. They look like grayish alien larvae from a horror film, but in fact they are thousands and thousands of monarchs, all slumbering together, weighing down the branches, which look as though they are about to snap off. This is the mother lode, the starting point of one of nature’s most mysterious migrations.

The gray color comes from the undersides of the wings and blends in easily with the shades of the forest. Alfredo whispers that throughout the winter, they will rotate sleeping positions so that the ones on the outside don’t freeze to death.

Monarchs prefer pine and oyamel trees as their winter hotels, and for some reason, they extend their colonies out in a straight line through the forest. Each year, the location moves slightly, Alfredo says, maybe 100 meters or so, because of the dust that humans kick up.

The longer we stand there, the more alive the sky becomes with butterflies responding to the late-morning sun. As they wake up, they fall to the ground and start flapping their wings to warm up. We now have to watch where we step because the ground is carpeted with groggy butterflies. Once they’re fully alert, they will start mating furiously.

I step into a pocket of bright sunlight, and the sensation is that of wandering into the midst of a locust attack. Butterflies attach themselves to my head, pant legs, shoes, shoulders, back -- at one point, I count more than 20 monarchs perched on my body, curiously checking me out. I hear Alfredo say, “Look,” and I turn around. One is affixed to his lips.

Perhaps it’s the 10,000-foot altitude that’s making me light-headed, but being blanketed in butterflies, I’m beginning to feel as if I’m a part of some spectacular Disney movie in which everything is going to be okay. At any moment, Miley Cyrus is going to step out from behind a tree and start singing “Zip-a-Dee-Doo-Dah.” There’s no noise save for the whoosh of tiny wings. It’s a soothing, dreamlike celebration of insect life -- a combination hotel, breeding ground, and cemetery.

I suddenly find myself feeling badly for McClusky, back in Texas. Of the three men responsible for discovering and verifying this amazing migration, he’s the only one still alive. And he’s never actually been here to see it himself.

Alfredo and I head back down the trail, and as we go, we come upon a group of butterflies clustered on the ground at a spring-fed rivulet. “They’re drinking water,” he whispers. Indeed, the monarchs are guzzling like thirsty horses on a trail ride.

As we watch, Alfredo tells me about the day he found a monarch drowning in a water puddle. He gently picked it up and saw that it was a female. She was weak and freezing. He held her in his hand to warm her up and fed her by squeezing nectar from a flower into her mouth.

“She could smell it,” he recalls. The butterfly drank the contents of four flowers and then regained her strength and flitted away. Alfredo smiles. “I never thought I was going to be able to do that.”

Butterfly festivals occur in North America throughout the migration season, according to location. In Michoacán, sightings are best during the spring season, when the region hosts a monthlong Monarch Festival, and during late October and early November, when the butterflies are arriving and preparing for hibernation. Visitor information is available at www.michoacan-travel.com (English), www.michoacan.gob.mx (Spanish), and www.learner.org.