Running the Gauntlet

by Sue Halpern
Spring 2002

The butterfly ambling around the yard was orange and black, and there was no mistaking it for anything but a monarch. My daughter saw it first, and followed its course from the stand of milkweed at the edge of our driveway as it tacked over the gravel, east to west to east again, and headed straight for me. "He likes you," my daughter said, though she is eight, and knows better than to assign human emotions to a bug.

Still, the monarch was circling my shoulders in ever smaller arcs, like a plane about to land, until it finally glided to a stop on the top of my sneaker, which was blue. The monarch unfurled its proboscis and poked around futilely. "He thinks it's water," my daughter said, "or a flower."

Both were good guesses. It was August in the mountains of upstate New York and that monarch would soon be embarking on an improbable journey. It would fly 3,000 miles, to the flank of a steep, 50-acre oyamel fir forest high in the mountains of Mexico where it would wait out the winter. Water and fuel and wind would get it there, and more than a little luck avoiding the long reach of avian predators and storms and cars and disease and the deadly pollen of genetically modified corn on monarch larvae.

The corn pollen threat was new. A few years ago, corn that had been genetically engineered to kill an agricultural pest called the European corn borer was found by chance – after it had been approved by the EPA and was already in production – to be lethal to monarch caterpillars as well. Though it appears that the current strain of GM corn may be significantly less toxic to monarchs, it is unclear what its "sublethal" effects are, or will be, or when we will know. In the meantime, millions of monarchs manage to find their way to Mexico each year.

While that would be remarkable enough – an insect that weighs less than a gram flying thousands of miles to the smallest of spots on the map – what's even more so is that it takes four or five generations to complete the round-trip. That means that no monarch that migrates to Mexico has ever been there before. And nobody, not even the scientists who have devoted their professional lives to this insect, knows how they do it. Not one has been able to prove how monarchs orient and navigate and cross the borders of three countries to end up in a forest so full of monarch butterflies that the beat of their wings is as loud as surf cresting rocks, and the tree branches bow to the ground from their weight, and the sky darkens as they edge out the sun. And though this is the age of the human genome map and the unifying theory of physics, the monarch presents a scientific conundrum that may never be solved.

Certain things are known, however: That in the autumn, monarchs born across much of North America travel 40, 50, 70 miles a day in an effort to outrun winter. They need to do this not because they are like birds, who follow their food as it recedes southward, but for the same thermal reason the flowers and grasses die off then: it's cold outside. Monarchs are, genetically speaking, a tropical species. Their long-distance migration – a migration the likes of which occurs nowhere else in the butterfly world – is an evolutionary adaptation that lets them take advantage of the abundance of milkweed and nectar in the eastern part of North America all spring and summer while avoiding the reliably harsh and punishing winter.

And it is known that they gather in the Mexican mountains because the forests there have the right microclimate. Neither too warm nor too cold, the forest canopy protects the monarch from wind and ice and snow and cold. Until now. Logging, most of it illegal, is punching holes in the protective canopy and the weather is falling through. The monarchs are vulnerable in a way they have never been vulnerable before..

"What are butterflies for?" a man on a call-in radio show asked me not long ago. It was a question for which I was totally unprepared.

"Pollination," I said, and even though the answer was accurate, it was also disingenuous. Monarchs, red admirals, white admirals, skippers, purple hairstreaks, mourning cloaks, spangled frittilaries, tiger swallowtails, painted ladies, viceroys, queens: that is just the short list. It is our biological destiny as well as our biological inheritance to live in the long list. Call that list biodiversity, call it creation, it is our great good fortune either way. Just as we are nothing and we are everything, so, too, are butterflies.

The monarch poking at my foot took off and headed due south for a while before settling into some grass. Here was the most mysterious creature of the visible world just hanging around my yard as if it were nothing special. Then, suddenly, off it went again. Its next stop might be a highway median strip, and after that the cornfields of the Midwest, and finally the shrinking oyamel fir forests of Mexico. I wished it well, this small insect, beating a path through the gauntlet of civilization.

About the Author

Sue Halpern is the author of Four Wings and a Prayer: Caught In the Mystery of the Monarch Butterfly, and Migrations to Solitude, both published by Vintage books. She divides her time between the Adirondack Mountains of New York State, and the Green Mountains of Vermont.