Environment : RETURN OF THE MONARCHS : For eons, millions have migrated each year to Mexico. But now, logging threatens to relegate them to the history books.

You who go through the day/ Liked a winged tiger/ burning yourself in flight/ tell me what supernatural life/ is painted in your wings/ so that after this life/ I can see you in my night. --Homero Aridjis, 1982.

They have returned anew, as they have for millenia, speckled clouds of orange-and-black gossamer spiraling toward the highland firs of central Mexico, hundreds of millions of wings reverberating in mountaintop forests.

Here the fabled monarch butterflies of eastern North America take winter refuge, roosting in the cool stands of swaying oyamel, waiting out the northern frosts before departing next spring on return voyages of 2,000 miles or more to the United States--and, later, as far as Canada.

In the north, this bountiful species (Danaus plexippus L.) will deposit their eggs on milkweed shrubs and die, the secret of their voyage mysteriously transmitted to future generations.

That a delicate creature like the monarch annually undertakes such a hazardous pilgrimage over mountain, desert and water is indisputably one of nature’s most spectacular migratory phenomena. Lepidopterists (butterfly scientists) documented the exodus only in the past 20 years or so.

However, naturalists warn that this singular migration, eons old, could soon go the way of the storied peregrinations of the North American bison and passenger pigeon, now relegated to historical accounts.

“I’m really concerned that if something isn’t done, the monarch’s eastern migration is going to go down the drain in my lifetime,” lamented Lincoln P. Brower, a 62-year-old zoologist at the University of Florida, Gainesville, who has spent four decades studying the elegant creature.

This year, a convocation of scientists from Mexico, the United States and Canada warned that the wintering practice--possibly dating back to the last ice age more 10,000 years ago--may “collapse” within a mere 15 years.

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The imminent danger: Logging, both legal and illicit, has decimated the isolated butterfly havens west of Mexico City, depriving the insects of habitat and leaving them more vulnerable to the high-altitude chill. Last year, an unusual snap of cold and wet weather killed as many as 70% of the butterflies, their corpses covering the forest floor like a macabre carpet.

Ironically, naturalists are sounding alarm bells about this unique international symbol at a time when the three nations are tearing down trade barriers and cooperating more than ever on environmental protection.

“What could be a more poignant symbol of North American unity?” asks Homero Aridjis, poet and president of the Group of 100, a Mexican environmental confederation.

Conservationists are calling on the Mexican government to heighten vigilance, completely outlaw logging in butterfly zones and expand protected sanctuaries. Five preserves already exist, but lumber depredations have left two badly deforested and others damaged. Ideally, naturalists would like to see Mexico City--perhaps in a joint program with the United States and Canada--purchase the dozen or so known wintering sites in the states of Mexico and Michoacan, destination of perhaps a billion butterflies each winter.

“The whole thing is going to unravel at some point if the cutting isn’t stopped,” said Brower, who noted that the trees provide roosting branches and serve as a thermal blanket, insulating the semi-dormant insects from cold and wind at elevations of 8,500-12,000 feet. “I think the ultimate solution is to form protected national parks, similar to those in the United States.”

But preservationist forces face formidable barriers.

Mexican authorities say they have neither the funding nor the right to acquire the wintering sites, most of which are situated on rural ejidos --a form of post-revolutionary communal land. Impoverished ejidatarios , as residents are known, are disinclined to relinquish their rugged massifs. Lumber has provided their families with a hardscrabble living for generations in a cool climate where only corn and a few other crops can survive.

“What good do las mariposas (butterflies) do for us?” asks Diego Gonzalez Vidal, a 32-year-old father of seven whose community of Cerro Prieto seeks permission to cut wood in the nearby Sierra Chincua sanctuary. “We believe in preserving the forest, in saving the monarch, but we must live.”

Large families are the rule here; most natives must migrate to Mexico City and other urban areas--or to the United States--in order to earn their livings.

In a sense, the dilemma is a Mexican variation of the logging-versus-nature dispute at the heart of the Pacific Northwest’s spotted owl controversy.

For conservationists and policy-makers alike, the delicate balancing act between preserving the monarch habitat and providing for the welfare of area campesinos is illustrative of a global struggle. As populations grow, pressures on sensitive ecosystems from South American rain forests to East African savannas mount, creating clashes that have no easy resolutions.

“I think the case of the monarch butterfly is almost a laboratory for all the world,” says Exequiel Ezcurra, a British-trained ecologist who oversees environmental issues for Mexico’s Social Development Ministry. “If you have barbed wire, and people on the other side are starving, they’re eventually going to cut the wire and enter.”

Conservationists call the government position hypocritical. For years, they argue, corrupt officials have made riches off the lumber trade. Area peasants, they note, barely earned enough to survive.

“I want to help the poor of this area,” says Aridjis, a native of Michoacan state whose youthful memories include winter outings to a butterfly crater known as Cerro Altamirano. “But when the trees and butterflies are all gone, the unfortunate fact is that all of these people will be poorer than ever.”

Under current law, cutting is proscribed in the approximately 11,000 acres of “core” zones in the five federal sanctuaries. However, controlled cutting is permitted in the much broader area--about 28,000 acres--of sanctuary “buffer zones.” And clandestine logging continues at a rapid pace, often with the connivance of bribe-soliciting local authorities, critics say. Underground sawmills proliferate.

“What the government is allowing to happen,” argues Aridjis, whose group seeks a complete ban on cutting in the sanctuary zones, “is the destruction of one of the great marvels of nature.”

Both sides can agree on one thing: the pressing need for alternative development schemes in the central Mexican countryside--often called Mexico profundo, or “deep Mexico.” All acknowledge the role of improved education, access to birth control and other strategies that may enable residents to earn a living without cutting down trees.

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A limited alternative has unfolded here at El Rosario, an ejido that is home to 8,000. Its territory includes the mountaintop sanctuary of El Campanario, the only preserve open to the public. Here, ecological tourism is well established. Some see El Rosario as a potential model for preserving the insect haunts, particularly as more sanctuaries are open to the public.

“At least this way I earn a few cents,” says Maria Guadalupe Cruz, a 73-year-old resident who sells cotton place mats knit with a butterfly pattern to tourists.

During the four-month visitor season that starts in November, thousands of tourists flock to El Rosario, about a 4 1/2-hour drive from Mexico City. Wooden stands leading up to the sanctuary sell food and all kinds of kitschy, butterfly-motif keepsakes, from T-shirts to coffee cups, napkin holders to carvings.

“What else do we have to live on here?” asks Rosa Esquivel, a logger’s daughter who works in a roadside cafe. Three of her children immigrated to Southern California.

While scientists discovered the winter butterfly habitat only in the 1970s, thus resolving a longtime mystery, residents here were long aware of the phenomenon. According to legend, some indigenous peoples regarded the insects as the returning souls of the dead. Indeed, the butterflies begin arriving about Nov. 2, celebrated as the Day of the Dead in Mexico.

In El Rosario, the old-timers recall celebrating the return of las palomitas-- “the little doves.”

To experience the Sierra Campanario on a sunny morning as the butterflies awaken from their torpor is to be transported to the magical fairyland familiar to readers of Gabriel Garcia Marquez. In the early chill, the insects cling to branches in dense pods, like fall leaves incongruously lumped on evergreen branches. Gradually, the sunshine warms them up, bringing gyrating life to the assembled colonies.

Soon, a steady whir of flapping echoes in the Christmas tree forest and great curtains of diaphanous wings drape the horizon--”like dancing incandescent embers silhouetted against the azure sky,” as Brower, the Florida zoologist, has written. The insects sip nectar from abundant wildflowers, gather en masse at streams to drink water, and swarm, like sun-dappled confetti, by tourists, farmers, cattle and everything else in their path.

“This is the butterfly’s house,” says Juan Garcia Martinez, a 39-year-old father of nine who is one of a score of guides at the site. “We can’t destroy their home.”

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Natural toxins from milkweed, their larval-stage food, deter predators. However, mice and two species of birds--the black-headed grosbeak and the black-backed oriole--have learned to gorge on the butterflies, largely without ill effects.

At the foot of the sanctuary, dozens of men work in a government-assisted nursery that is dedicated to reforestation, a tortuous process. (A fir can take half a century to reach a full height of 40 to 50 feet.) Nearby, somewhat paradoxically, a community sawmill processes lumber taken from the woods.

“We want jobs here; we want the opportunity to work,” says Abel Castro Posadas, the 50-year-old nursery boss.

While committed to replanting, Castro sympathizes with the plight of neighbors eager to cut the forest. After all, he notes, two full-grown oyamel trees can net a campesino more than $1,000 on the black market--enough to stock a year’s worth of corn.

“If a man faces a choice between cutting down a tree and not feeding his family, what will he do?” Castro asks sagely as he surveys the baby firs, pines and cedars destined for replanting. “Of course, he will cut the trees. I would do the same. So would any man.”