Butterflies on Thin Ice
by Robert Michael Pyle
In the morning, the Mexican alpine sun hit hard and bright and the snow melted fast. We walked down into the center of the colony, where a foot or more of frozen monarchs lay in sheets and windrows, a gray-and-ochre sediment on the forest floor. It was a disaster scene: pathetic, when you thought of all those long, improbable journeys wasted, yet magnificent in its sheer magnitude. Once I got over the shock of walking on butterflies (“They’re just like dead leaves,” I told myself), they beckoned me into their serried, fallen number. Hacking, hurting, eyes burning from the reflected brilliance of the snow and the wings, I lay down in a soft blanket of perished migrants.
This was the first time I’d ever visited the winter-massed monarchs in Mexico; also the first time the scientists studying the phenomenon had experienced a heavy blizzard on the ten-thousand-foot Sierra Chincua. Unprepared, their camp in disarray, they struggled to keep fires alight and stay warm.
My luggage hadn’t made it to the mountains with me, but a wicked bronchitis had, thanks to the mustard-colored air of Mexico City. I bunked in a spare tent with Tom Lovejoy, chief scientist for World Wildlife Fund-U.S. A borrowed sleeping bag and Tom’s long underwear, which I have never returned, saved my life.
Now I was cocooned in that pile of soft orange wings. I felt received, at the same time thinking all that way, just for this…I think I slept. And when I opened my eyes, the ice-blue sky was filled with bright spinners and floaters and gliders, like doubloons falling in and out of focus through seawater. Sun-warming monarchs launched and rose, even more, it seemed, than all the ones struck to the ground by the now-forgotten storm. Behind me, the shaded trunks rose into their own treetops, thickly furred in fox-colored clingers, and the canopy of the oyamel firs themselves spread an immense tent of solid gold filigree overhead. I lay there, millions of monarchs above and below, and I was healed.
We think of animals migrating from cold places to warmer ones for the winter, not from a temperate site to a potentially arctic one. The reasons for migration usually have more to do with food supply than they do with temperature, though for cold-blooded monarchs, both factors count. Still, who would have guessed that the winter hideaway of the wanderers would confront them with lethal blizzards? As if they hadn’t enough to deal with already. Local farmers literally grazed their cattle on living monarchs in those days, and nearby, logs lay stacked in the snow, awaiting transport to mills below. Oyamel fir: Abies religiosa, holy incense of the Toltec, warmth and shelter for the Tarascan Indians, the canopy of Sierra Chincua—and the winter sanctum of Las Monarcas.
When Lincoln Brower’s field expedition awoke to snow on the mountain, the precise location of the eastern monarchs’ wintering grounds had only been known for a few years. Not that the migration had gone unnoticed: even when Georgia naturalist John Abbott published the first known color portrait of the monarch in 1797, he knew that this was no stationary species. Over the years, people spied fresh butterflies southing in the fall and tatty ones northing come spring. By 1878, the versatile government entomologist C. V. Riley proposed a north-south migration to account for the insect’s here today, gone tomorrow reputation. In the late 1930s, Fred Urquhart first graced monarchs with sticky, numbered tags, an enterprise that occupied the Ontario naturalist, his wife Norah, and thousands of volunteers for the next half-century. Now and then a tagged monarch was recovered en route, allowing lines to be drawn on a map.
By the 1970s, many assumed that the eastern monarchs went to Mexico, but no one knew where. Finally, in the first days of 1975, Urquhart collaborators Kenneth and Kathy Brugger found the eye-popping masses on Sierra Pelon and Sierra Chincua, deep in the Transverse Neovolcanic Belt in the state of Michoacán. The “discovery” really meant revelation to the outside world, since the local Indians had always known the orange butterflies that arrived around the Day of the Dead, bringing back the souls of the departed children. But how could they know that these butterflies they call Las Palomas—the doves—were utterly unique in the world, or that they would soon bring the eyes of the world into their shared home?
Urquhart reported the find—one of the greatest in modern natural history—in National Geographic, but tried to keep the location secret. Monarch researchers William Calvert and Lincoln Brower found it on their own within the year. At the time, I chaired the Lepidoptera Specialist Group of IUCN (the World Conservation Union), which met in Washington, D.C. in June 1976. The air was electric with the news from Michoacán. By acclamation, we designated the migratory monarch our top priority in world butterfly conservation. Brower and I had arrived at the same notion: the migratory monarchs were an endangered phenomenon. I included the Mexican and California winter colonies in IUCN’s Invertebrate Red Data Book as Threatened Phenomena, a new category in the listing of species in jeopardy. Brower’s field research aimed at understanding and conserving that phenomenon was five years underway when serious winter and I visited for the first time.
THE MONARCH, DANAUS PLEXIPPUS, is far from endangered as a species. It was the first butterfly I saw upon deplaning in Papua New Guinea, Costa Rica, and Hawaii, and it is common in Australia and New Zealand, but native only to the American tropics. Monarchs belong to the butterfly subfamily Danaiinae, called milkweed butterflies because they feed on members of the plant family Asclepiadaceae as caterpillars. Lacking a winter hibernation in any stage, danaiines are truly tropical. The availability of abundant milkweed in the North, together with the need to avoid prolonged frost, drove the evolution of the monarch migration. Once milkweeds reached places like Hawaii monarchs soon followed, whether as off-course migrants or human introductions. Now the monarch, like the painted lady, is one of the most widespread butterflies in the world. Their alternate names, after all, are respectively the wanderer and the cosmopolitan butterfly.
So it is not the species, a wonderfully adaptable generalist in its nonmigratory mode, that is jeopardized. It is the grandest butterfly spectacle on the planet that stands at risk, and one of the most dramatic and elegantly evolved animal migrations of all. And that doesn’t mean just the Mexican winterers, for monarchs also concentrate on the California coast. The Butterfly Trees of Pacific Grove, “Butterfly Town, U.S.A.,” were known and visited well before Lucia Shepardson began to popularize them in 1898. Variable colonies are now known from Mendocino to Baja, with the largest clusters forming in Santa Cruz and Santa Barbara.
Celebrated by artists from John Steinbeck to the Beach Boys, and visited by millions, the California monarchs arguably make up one of the most cherished elements of the state’s natural heritage. Likewise, the eastern monarchs enjoy enormous popularity and affection from all sorts of people. In recent years, the Entomological Society of America and other groups lobbied hard to have the monarch named National Butterfly by Congress, and nearly succeeded. It seems incredible that our most familiar butterfly could drop out altogether. But if the migration fails, it will, for the abundant monarchs of our American summer depend upon their winter refuges for replenishment. To ensure their future we need a clear understanding of how migration works. And one of the biggest questions is this: how do monarchs in the East and the West actually divvy up the North American continent?
I remember a day in western Colorado, motoring to a noted habitat with my graduate advisor, Charles Remington. A lone monarch perched among a throng of Charlotte’s fritillaries, fiery orange males, chocolatey females, nectaring on big purple bull thistles. I asked my professor where he thought that monarch would end up. The reigning idea was that all of the fall monarchs born west of the Continental Divide wintered on the California coast. We were on the western slope, all right, if by less than a hundred miles; but it was a long, hot, arid way due west to California, across the Great Basin. Could it not be just as likely that a monarch in the intermountain West might follow the major drainages southward—the Green, the Colorado—and wind up in Mexico? Besides, as a former kid collector who’d haunted the Colorado high country whenever possible, I had seen monarchs crossing the Rockies crest in both directions, and doubted its effectiveness as an ultimate barrier.
Remington, a Yale biologist who had founded the Lepidopterists’ Society in the year I was born, knew as much about North American butterflies as anyone. He suggested that the number of monarchs breeding in the Basin and Range region might be insignificantly small. But neither of us knew where this one was really bound when it sailed off on the wind.
Twenty years later, I decided to look into this question. I found that the “Berlin Wall” model of monarch migration was based on assumption and repetition rather than fact. Most of the monarchs tagged, recovered, and mapped in the West had actually been caught in California or Ontario and shipped elsewhere prior to release. These transfer exercises proved nothing about the paths or destinations of wild monarchs, yet they ruled the popular concept of western migration for decades. To find out what was really going on, I thought, one could do no better than migrate with the monarchs. So I followed the western migration, chasing monarchs, throughout the autumn of 1996.
I began at the northwesternmost breeding grounds, in the Okanagan Valley of British Columbia. My plan was to locate monarchs at their nectar sources and overnight roosts, then follow them as far as I was able on foot. I’d catch and tag them when I could. And when they rose and flew away, as they always would, I’d take their vanishing bearings—the direction in which they disappeared—as my running orders. I’d follow in the same direction, as much as the topography allowed, until I found more habitat, more monarchs…and then do it all again, as far as I could. In this manner I believed I could follow the general trend of the migration, wherever it took me.
The monarchs I found in the early autumn sprang from the milkweed fields of the borderlands. Their mothers had laid pale green goosebumps of eggs on the fleshy, furry foliage. Tiny caterpillars ate their eggshells, then tender leaves. They grazed and molted four times as they grew into two-inch cream, yellow, and black banded caterpillars dangling black filaments fore and aft, likely to intimidate predators. Roaming the milkweeds at will, the larvae gained further protection from educated birds by advertising their vile taste—a gift of the milkweeds and their poison-laced latex.
One more skin change, and what came out was an inchoate pre-pupa that soon crystallized, as it were, into one of the loveliest of butterfly chrysalides: clear pale jade, studded with the uncanny molten gold that gave butterfly pupae their Greek name, chrysalis: gold box. Inside, the melted tissues of the wormlike, chewing larva reassembled into the workings of a flying, sucking butterfly. One morning in early September, the wadded creature emerged, pumped blood, spread soft, silky wings, hung, hardened, and flew. Then I would follow, until my unbreakable contract with gravity compelled me to fall behind.
Most butterflies, fresh from the chrysalis, quickly mate. But the autumn-emergent monarchs still make juvenile hormones that keep them sexless. Instead, their whole energy and purpose go in service of an irresistible urge to propel themselves to somewhere else. These very individuals will complete the entire journey deep into Mexico or out to coastal California. Again and again I saw them rise on warm air and circle, raptorlike; float higher and circle again, then disappear from vision into great heights from which they would glide and glide. Not that they can’t flap far and fast: these are strong butterflies. But it would take way too much energy to go so far under their own steam.
Instead, the migrants descended frequently to drink nectar, not just to refuel for the next leg, but also storing up, constantly converting sugars to fats, building lipid reserves to get them through the long winter. And this is where I found them: sneaking up on a bank of color—asters, sunflowers, milkweeds, rabbitbrush—I always tingled in hopes of seeing great orange vanes unfolding over the flowers. Refreshed, they took off again. Before night fell, the wanderers sank through the cooling air in search of shelter. I watched them seek out the lee side, the morning-sun side, of a Russian olive, a locust, a willow; and I bedded down too.
Sometimes in the early morning, the air too cool for butterfly flight, I scanned the leaves still heavy with night and shadows, looking for my leaders. That long, pale, apricot wedge of the sleeping butterfly’s underside—sometimes I could make it out, more often it blended into the leaves as it was meant to do. And then a magic degree would arrive and the wings would spread, first a cinnamon smudge, becoming ripe persimmon, finally straight-out citrus as warmth struck, and…it was gone! As lepidopterist-writer Jo Brewer described them in her wonderful book Wings in the Meadow, like “wings of flame, rising to the sun.” If I was lucky, I saw where, and I too was away.
Following rivers, a built-in sun compass, and likely the earth’s magnetic field, the emigrants press on, making anywhere from a few to a hundred miles a day depending on winds and weather. My own route was more tortured; no one can follow the wind in a straight line. No one can do what these ones do. Icarus tried but flew too high, and look what it got him—a serious dunking, and a blue butterfly in his name. As his father Daedalus made it to Sicily on his waxen wings, so do most of the milkweed butterflies reach their forest resorts, where they hunker all winter long. Only with spring (about Valentine’s Day in California, the equinox in Mexico) will they finally mature and mate, with the fervor and abruptitude of an orgy. And then they are gone, the mountain fastnesses and coastal groves shedding their tawny mantles as quickly as they grew them in fall. Now monarchs drift and skip back into the milkweeds’ range, laying eggs as they go, and dying along the way. Their offspring carry on, and theirs. Thus the continent fills again, until by high summer the entire range has been retaken.
BUT I’VE GOTTEN AHEAD OF MYSELF—where did these go, the monarchs I followed for more than nine thousand miles before I got home again for Halloween? As it turned out, most of the western monarchs I tracked bore away southeasterly rather than toward the southwest as the old maps said they should. They took me down the Columbia, up the Snake, and out into the Great Basin, where a big male materialized over the Bonneville Salt Flats: a living flame streaking across a world of ashen white. Down the Colorado, across Arizona, through the Chiricahuas, out over the saguaro-lands. Ultimately, on a rainy October day, I watched monarchs shooting the border, well west of the Continental Divide. One year later to the day, a monarch I tagged on the Columbia River turned up in Santa Cruz. So some western monarchs enter Mexico, while others populate the foggy coast, and the eastern and western populations are not after all monolithic quantities unto themselves that never shall meet. Heading back north along the coast, I felt I was beginning to catch a clue as to how this continental dance is choreographed.
One more puzzle piece soon fell into place. The California monarch population crashed to nothingness in 1994, then bounced back the next year. Lincoln Brower connected this remarkable recovery with a striking westward shift of returning warblers in the spring of 1995, and proposed that remigrating monarchs may have bent westward also, repopulating California. He theorized that West Coast monarchs may be subject to periodic extinction with drought and climate shifts, and depend upon refreshment from Mexico. This synched nicely with my findings, showing that the Californian and Mexican populations are intertwined, and their conservation must go hand in hand.
When the monarchs reach their respective destinations, they face radically different challenges, both biological and political, though their basic needs are the same. In order to make it through the winter, preserving their genes from one season to another, the wanderers require a narrow set of circumstances—theirs is truly a knife-edge ecology. Too cold, and they freeze in numbers greater than the population can withstand; too warm, and they fly too much, burning up fat they’ll need to fuel the winter and the return flight, however far they get. Brower and Calvert found that this balance may be upset by any factor that opens the protective forest canopy to the harsher influences of wind, rain, snow, and cold by night, to intense sunshine, desiccation, and overheating by day.
In Mexico, even the selective, tidy forestry as practiced in former years may cause these effects; the much more intensive industrial logging seen in Michoacán today has even more baleful consequences. But there lies the conundrum of the wanderer: one person’s butterfly tree is another person’s job, meal, lodging, or gain.
I thought, back at the time of that first visit, that I had seen few more poignant sights than monarchs glazed with ice, frozen on the ground beneath the trees, having failed to reach the safety of the cluster the previous sundown. And I thought I’d seen the worst that intensive commercial logging can do, in the Pacific Northwest rainforest. But the vision of a clear-cut where once stood a temple of trees cloaked in the richest raiment imaginable, seemingly woven of golden threads but actually spun from base weeds far, far away—this transcends poignancy. It says, what kind of a world is this, where the greatest gifts of evolution fall away, not in their own time through natural selection, but as innocent witnesses to the unholy marriage of poverty and profit?
While Michoacán has too few resources for too many people, a common situation for the exploited poor everywhere, California presents the odd spectacle of too many people with too many resources. Pacific Grove, Santa Cruz, and Santa Barbara, hot spots for the West Coast monarchs, are three of the most affluent communities in the world. The challenge in Michoacán is maintaining a decent livelihood for the ejidatarios while sustaining the essential needs of the monarchs. In California, it is a matter of mediating between the esthetics of those who want mansions and those who prefer parks, between native plants advocates who insist on removing eucalypts and others who know that monarchs depend upon eucalyptus roosts since their native coastal groves were cut.
You could say that for one group, this is a life-and-death issue; for the other, a luxury. For the monarchs, caught in the middle, survival is the only issue. Yet, viewed as a common denominator, they could help plot common cause—if not reconciling grossly mismatched economies, at least providing a focus for those who care about both people and the rest of nature in both cultures. It wouldn’t be the first time mere butterflies have shown the way to higher ground.
DURING THE 1980’S, BROWER AND I CO-CHAIRED the Xerces Society‘s Monarch Project. Again and again, we wandered the maze of Mexican bureaucracy in search of a plan to protect the monarchs while ensuring the livelihood of the local people. After the frustration, intensity, and wretched air of the capital, we retreated to the cool high forests and the balm of the monarchs, never failing to be renewed in spirit and commitment by the cause of all the commotion: the butterflies themselves. I couldn’t wait to hike into the Arroyo Barranca Honda, a colony then known as “Julia.” As we dropped through the scent of yerba buena floating over the blue lupines and scarlet salvias, and the sun came over the far sierra, we stopped before a sky-high scrim of gilt sequins—a cool forest fire of living, moving cinders arrived on the wind like sparks from a far blaze—and then we stepped inside. For the next several hours, we were never out of sight and sound of millions of fluttering, gliding, whispering wings.
Some worried that if many people came, the forests would suffer from the threat of real fire, the soils from trampling, the monarchs from disturbance. But inevitably, people would come. After all, tourists have flocked to the much smaller California sites for more than one hundred years, creating a substantial tourist trade on the Monterey Peninsula and in Pismo Beach. So it was natural that ecotourism would be promoted as a source of alternative income for the locals deprived of subsistence by forest set-asides. I have led a number of tours to the sanctuary, and the effect has seemed generally positive. I shall never forget standing on the high Llano des los Conejos amid a warren of astonished naturalists as dark stuffed “bags” of butterflies burst into fireworks that fluttered down all around us, alighting on hats and hands and faces with their streaming eyes. Time and again I have witnessed the magical power of Las Monarcas to transcend daily cares, refresh a blunted sense of wonder, or arouse a deeper love for life.
Coming down the trail at El Rosario with a group of thrilled norteamericanos, sharing cold Cerveza Victoria and quesadillas hot off a vendor’s grill, life seemed good. But I have begun to wonder. The muchachas who sell Chiclets and postcards to the visitors seem to have lost the shy and giggling demeanor of their sisters who did the same in earlier years. Their pitch has become more urgent, their faces hardened like the children who sell Chiclets and notions on the median strips of Guadalajara expressways. Over at the Sierra Chincua site, expert caballeros delight in riding up and down the mountain hawking horseback rides to foot-weary pilgrims. But the thick dust their ponies kick up can’t be good for these boys, and it certainly isn’t good for the suffocating monarchs or the pulverized vegetation. At El Rosario, local men jockey cattle trucks full of sightseers up steep, rocky roads from the towns of Ocampo and Angangueo. Guides are eager to hurry visitors around the trails, and when they find dead tagged monarchs, they no longer present them to the scientists as gifts: they know that each tag is now worth fifty pesos—a lot of money where there are few other means of making a living. Ecotourism is indeed helping to some extent. Vendors’ stalls serve the many visitors while providing an outlet for monarch-related arts and handicrafts, and guides earn a decent day’s wage. But sometimes I wonder whether an impoverished farm economy has simply given way to a poor tourist economy.
On one of my most recent visits to El Rosario, I sat back in a branchwork bench beside a well-watered lawn put in by an entrepreneurial resident of the village. The monarchs must come down daily for water, a scarce quantity; by providing this wet green expanse, the villager had created an oasis both for thirsty monarchs and winded visitors who, for one peso, can step off the steep high trail, sit down, and watch thousands of monarchs sipping and swirling. Basking in this mental massage of monarchs, I was taken back to another time and place of bliss among the butterflies. It was some fifteen years ago. Butterfly scientists and conservationists had gathered at the Esalen Institute on the central Californian shore, hopeful of coming up with a plan to protect West Coast monarchs. After an intensive work session, we’d retired to the hot soaking pools perched between the wild coast and wilder mountains of Big Sur. Sea otters crunched abalones a few yards away, and monarchs from Esalen’s own colony floated overhead like paper umbrellas in a mai tai sky. Recalling that other idyll, I realized that the sheer delight monarchs bring us is much the same everywhere; but we return the favor with a gauntlet of challenges that changes face, if not severity, as soon as the travelers pass the invisible borders we scrawl across their flight plans.
Now when I return to Sierra Chincua or Santa Cruz and watch the monarchs bundled in the foliage like hanks of golden fleece; to the country ditch in Colorado where as a boy I saw what Nabokov described in Pnin: “their incompletely retracted black legs hanging rather low beneath their polka-dotted bodies”; or to a special spot in the Columbia Gorge where I almost never fail to find monarchs in season, gliding among two species of milkweeds sheltered by pioneer locusts and Russian olives, I ask myself—what are monarchs, really, to inspire all this fuss?
For a start, monarchs are certainly our best known, best beloved butterflies, recalled by generations as a bright memory in the classrooms and the fields of home. Lately, some treat them as mere geegaws. Butterfly profiteers rear monarchs for indiscriminate release at weddings and other events, smearing our picture of their natural movements, so critical for conservation. When our de facto national butterfly becomes nothing more than a living bauble, its power is sucked away like the color of dead wings left to bleach in the sun. But for others, this insect is still the very heart of the land: the bringer of spring from the south, the essence of a summer meadow, as much a part of the autumn sky as drifting milkweed floss, the promise of flight to spite the winter. And it is always the Monarch of the Americas: the best catalyst since migratory waterfowl for real cooperation between Canada, the United States and Mexico in service to conservation.
Beyond all these roles, the monarch serves as a powerful metaphor. To different eyes, it represents the meeting place of desire and need, of property and poverty, of power and helplessness. And the fact that we could actually lose it from our fauna gives this one butterfly an emblematic significance that no species could ever want: the monarch stands for every fine and delicate thing that philistine force and greed would gladly eradicate from this bruised and beautiful world.
Finally, the wanderers are the most wondrous emanation of life I know. To transnavigate a continent, borne aloft on a bit of flimsy tissue, directed through all the valleys and ranges, over all waters and winds, by a poppyseed of instinct and sense. To find the small, special places that lend them safety, twenty million strong at rest in a snowy mountain forest. Then in spring to climb, two by two in their nuptial flight, on their “wings of flame, rising to the sun.” And to carry on, and on, all over again. Even in their frozen death the monarchs healed me, and I know I will fight for them as long as I live.