Sister Sophie
23-Feb-2005, 01:43 AM
Feb. 18, 2005
Fewer monarchs make winter flight to Mexico
Experts point fingers north and south on why there are few butterflies
Houston Chronicle
Associated Press
Mexico reports 75 percent fewer monarch butterflies in 2004.
MEXICO CITY - The number of monarch butterflies wintering in Mexico has declined by 75 percent this year, and some researchers warned Thursday that conditions in this country as well as in the United States and Canada threaten the survival of one of nature's great wonders.
"We're getting to what we see as a really dangerous situation for the future of the monarch," said Lincoln Brower, a biologist at Sweet Briar College in Virginia and a leading butterfly expert.
Each year, millions of monarchs make a remarkable journey of up to 2,500 miles from Canada and the United States to a remote, mountainous area in the central Mexican state of Michoacan where they spend the winter. The butterflies attract thousands of tourists.
Mexico's Environment Ministry issued a statement this week that blamed the population decline on unseasonably cold weather last spring and summer in North America and on increased use of genetically modified crops and herbicides there.
But a report, put out Thursday by Brower and other leading monarch researchers, said the U.S. and Canadian factors merely exacerbated the menace posed by continuing deforestation in the Michoacan mountains.
A leading Mexican environmentalist, Homero Aridjis, accused Mexico's government of trying to pin blame on other countries while ignoring illegal logging in the butterflies' winter refuge.
'Our back yard'
Clandestine loggers often operate with impunity despite the government's creation of a butterfly reserve, said Aridjis, a poet and novelist who founded one of Mexico's oldest environmental groups.
"The real problem is in our back yard," Aridjis said. "Local police and officials are paid off, and the federal government stands back and does nothing."
Brower said the Mexican government seemed to be downplaying the effect of deforestation on the monarchs.
"To minimize the effect of logging is madness," he said. "What has happened out there in the past decade has been simply devastating."
But Ernesto Enkerlin, who oversees ecologically protected areas at the Environment Ministry, insisted that logging near the butterflies' nesting areas was halted last August.
The monarchs' summer breeding areas in the United States and Canada, he said, are more important to the species' survival than their wintering areas in Mexico.
Mona Lisa and Mozart
"We are not trying to blame the United States for this problem," Enkerlin said. "It's an important cross-border issue we have to work together to solve."
Wherever the preponderance of blame falls, Brower suggested, the beautiful yet fragile monarchs find themselves as a species caught in a two-fisted grip from which they might not escape.
The butterflies' fate might not concern most people in a world beset by environmental disaster. But it certainly should, Brower said.
"Why do we care about the Mona Lisa? Why do we care about Mozart's music?" Brower asked. "In the end we're really diminished by losing these things."
But some experts are not as pessimistic about the fate of the monarchs.
Jeffrey Glassberg, the president of the North American Butterfly Association, pointed out that insect populations can rise and fall by 50 percent or more from year to year. One bad year does not necessarily make for a species-threatening trend, he said.
"Monarchs are not in any threat of extinction," Glassberg said. "With a one-time event like this, without more information, one can only speculate what the cause might be."
The monarchs' migration from the northern United States and Canada each fall and back again in the spring constitutes one of the most dramatic journeys of its kind in nature.
Leaving their summer grounds at the end of August, the insects fly as many as 2,500 miles and arrive by early November in Mexico at a five-acre patch of pine-covered mountainside. The monarchs spend the winter clustered by the thousands in pods hanging from tree branches.
They head north again in early March. By the time they reach their summer grounds, where they breed and die, some of them will have traveled more than 5,000 miles in all.
Scientists remain uncertain about how the monarchs navigate to the same mountainside year after year but suspect some form of genetic imprinting that utilizes light, prevailing winds and other factors.
Other dangers
Freezes and deforestation in the mountain highlands where the monarchs winter have taken their toll. But so have the widespread destruction of North American plants and habitat upon which the butterflies depend in the summertime.
Millions of monarchs died in a freeze in Mexico in the winter of 2001-2002. The monarch population rebounded during the summer, experts said, with as many as 500 million butterflies returning to Mexico that fall.
That apparently hasn't happened this year.
Brower and others warned that the population decline may point to long-term doom for the monarchs.
They cited as particularly worrisome genetically altered crops and the rapid conversion of U.S. farms and woodlands into suburbs.
Modified crops blamed
Studies suggesting that pollen from genetically modified corn was lethal to monarch larvae were later rejected by the U.S. Environmental Protection Agency.
But those studies looked at pesticide resistant crops.
Brower and other monarch experts argue that the widespread use of herbicide resistant crops — which allow for wider and longer use of weed-killing chemicals — may have destroyed a significant amount of the milkweed plants on which the monarchs feed.
"If we don't see a recovery in a few more years, we might start looking at that a little closer," said Mike Quinn, an entomologist with Texas Parks and Wildlife who also works with Texas Monarch Watch, a volunteer organization that tracks the insects migration.
Fewer monarchs make winter flight to Mexico
Experts point fingers north and south on why there are few butterflies
Houston Chronicle
Associated Press
Mexico reports 75 percent fewer monarch butterflies in 2004.
MEXICO CITY - The number of monarch butterflies wintering in Mexico has declined by 75 percent this year, and some researchers warned Thursday that conditions in this country as well as in the United States and Canada threaten the survival of one of nature's great wonders.
"We're getting to what we see as a really dangerous situation for the future of the monarch," said Lincoln Brower, a biologist at Sweet Briar College in Virginia and a leading butterfly expert.
Each year, millions of monarchs make a remarkable journey of up to 2,500 miles from Canada and the United States to a remote, mountainous area in the central Mexican state of Michoacan where they spend the winter. The butterflies attract thousands of tourists.
Mexico's Environment Ministry issued a statement this week that blamed the population decline on unseasonably cold weather last spring and summer in North America and on increased use of genetically modified crops and herbicides there.
But a report, put out Thursday by Brower and other leading monarch researchers, said the U.S. and Canadian factors merely exacerbated the menace posed by continuing deforestation in the Michoacan mountains.
A leading Mexican environmentalist, Homero Aridjis, accused Mexico's government of trying to pin blame on other countries while ignoring illegal logging in the butterflies' winter refuge.
'Our back yard'
Clandestine loggers often operate with impunity despite the government's creation of a butterfly reserve, said Aridjis, a poet and novelist who founded one of Mexico's oldest environmental groups.
"The real problem is in our back yard," Aridjis said. "Local police and officials are paid off, and the federal government stands back and does nothing."
Brower said the Mexican government seemed to be downplaying the effect of deforestation on the monarchs.
"To minimize the effect of logging is madness," he said. "What has happened out there in the past decade has been simply devastating."
But Ernesto Enkerlin, who oversees ecologically protected areas at the Environment Ministry, insisted that logging near the butterflies' nesting areas was halted last August.
The monarchs' summer breeding areas in the United States and Canada, he said, are more important to the species' survival than their wintering areas in Mexico.
Mona Lisa and Mozart
"We are not trying to blame the United States for this problem," Enkerlin said. "It's an important cross-border issue we have to work together to solve."
Wherever the preponderance of blame falls, Brower suggested, the beautiful yet fragile monarchs find themselves as a species caught in a two-fisted grip from which they might not escape.
The butterflies' fate might not concern most people in a world beset by environmental disaster. But it certainly should, Brower said.
"Why do we care about the Mona Lisa? Why do we care about Mozart's music?" Brower asked. "In the end we're really diminished by losing these things."
But some experts are not as pessimistic about the fate of the monarchs.
Jeffrey Glassberg, the president of the North American Butterfly Association, pointed out that insect populations can rise and fall by 50 percent or more from year to year. One bad year does not necessarily make for a species-threatening trend, he said.
"Monarchs are not in any threat of extinction," Glassberg said. "With a one-time event like this, without more information, one can only speculate what the cause might be."
The monarchs' migration from the northern United States and Canada each fall and back again in the spring constitutes one of the most dramatic journeys of its kind in nature.
Leaving their summer grounds at the end of August, the insects fly as many as 2,500 miles and arrive by early November in Mexico at a five-acre patch of pine-covered mountainside. The monarchs spend the winter clustered by the thousands in pods hanging from tree branches.
They head north again in early March. By the time they reach their summer grounds, where they breed and die, some of them will have traveled more than 5,000 miles in all.
Scientists remain uncertain about how the monarchs navigate to the same mountainside year after year but suspect some form of genetic imprinting that utilizes light, prevailing winds and other factors.
Other dangers
Freezes and deforestation in the mountain highlands where the monarchs winter have taken their toll. But so have the widespread destruction of North American plants and habitat upon which the butterflies depend in the summertime.
Millions of monarchs died in a freeze in Mexico in the winter of 2001-2002. The monarch population rebounded during the summer, experts said, with as many as 500 million butterflies returning to Mexico that fall.
That apparently hasn't happened this year.
Brower and others warned that the population decline may point to long-term doom for the monarchs.
They cited as particularly worrisome genetically altered crops and the rapid conversion of U.S. farms and woodlands into suburbs.
Modified crops blamed
Studies suggesting that pollen from genetically modified corn was lethal to monarch larvae were later rejected by the U.S. Environmental Protection Agency.
But those studies looked at pesticide resistant crops.
Brower and other monarch experts argue that the widespread use of herbicide resistant crops — which allow for wider and longer use of weed-killing chemicals — may have destroyed a significant amount of the milkweed plants on which the monarchs feed.
"If we don't see a recovery in a few more years, we might start looking at that a little closer," said Mike Quinn, an entomologist with Texas Parks and Wildlife who also works with Texas Monarch Watch, a volunteer organization that tracks the insects migration.