Fears Mount in Mexico That Butterflies Are Losing Ground

The reality was bad enough: Millions of monarch butterflies had died at their wintering sanctuaries in the mountain forests west of Mexico City.

But the worst fears were nightmarish. Some people suspected that the monarchs had been intentionally slaughtered--sprayed with insecticides to clear the way for loggers to cut down the trees where the butterflies nestle each winter night.

Mexico’s environmental prosecutor’s office reported last month that an investigation it conducted showed the monarchs had died because of a sharp cold front in December, not through any human malice. That conclusion suggested that the die-off was part of a natural process and that millions more butterflies at other reserves were fine.

Still, some butterfly advocates remain skeptical and angry. And they say that whatever happened, the deaths underline the need to step up protection on the steep slopes that provide the stage for one of nature’s most spectacular annual performances.

Each November, the monarchs make their way south from the United States and Canada to the same dozen sites in the states of Mexico and Michoacan. There they spend the winter, clustering together at night in what look like huge beehives hanging from the tall pine branches. The orange-and-black monarchs awaken each morning in a spectacular flourish of motion and then flutter down into nearby valleys to feed.

Homero Aridjis, a prominent Mexican poet and environmental activist, first spread the word of villagers’ reports that loggers had sprayed at least one reserve, atop the 11,000-foot Cerro San Andres in Michoacan near the town of Maravatio.

Town officials went up and found the hill blanketed with dead butterflies, Aridjis said. He quoted one villager, who requested anonymity because of death threats, as saying that police had told him the whole area smelled of insecticide.

But two biologists from the environmental prosecutor’s office said they found no evidence of insecticide in dead butterflies collected from San Andres.

Aridjis, president of the Group of 100 activist organization, answers that the butterflies were found dead in early February, not December.

“One thing is evident: The systematic deforestation of the sanctuary of San Andres and the other sanctuaries in the Monarch Butterfly Reserve, where sawmills are proliferating like mushrooms in number and size, is gravely damaging the migration of the monarch butterflies,” Aridjis said.

The thinner tree cover, he said, makes the monarchs more vulnerable to frosts and other weather changes.

The loggers insist that they are cutting only in authorized areas, but environmentalists argue that there is little control of them and much corruption.

Meanwhile, David Marriott, a butterfly expert in San Diego, says he has information about mass butterfly deaths at a second sanctuary, El Cerro Pelon (Bald Hill)--where people told him that spraying also occurred. The Pelon sanctuary is about 60 miles southeast of San Andres, in the state of Mexico.

“We can’t say too much because we don’t have direct scientific proof,” he said by telephone. “But there is a problem, and we need to seek a tri-national solution because these butterflies represent three countries.”

Marriott says his main concerns are to ensure adequate protection of the habitat and better education of the villagers who live in the area, to help them value the unique nature of the butterfly migration.

Aridjis notes that in November, then-President Ernesto Zedillo enlarged the 15-year-old reserve from 39,767 acres to 138,960 acres. Villagers have been aided by a program paying them “rent” for their trees to protect the reserve.

But the expansion of the reserve directly affects the loggers’ interests. And Aridjis suspects that the loggers were trying to challenge the expansion of the reserve by spraying.

The monarchs left their Mexican sanctuaries for the springtime flight north in late March.

For the poet Aridjis, “the butterfly is an image of peace, of flying, angelic beauty. It’s an illumination, a beautiful presence, it’s completely inoffensive.

“This is the first time--if it is true--that the butterflies suffered direct aggression,” he added. “Before, we had incidental deaths because of logging, destruction of habitat, natural predators, too much tourism, cold weather. But if this is true, it will be the first time that somebody killed the butterflies directly. . . . To kill a butterfly really would be shocking.”