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 Editorials | Environmental | April 2005 
Monarchs Come to the End of Another Losing Season
 Talli Nauman - The Herald Mexico
| | More studies and citizen pressure are needed to convince industry and government to stop the use of the genetically modified crops and their broad-spectrum herbicides from damaging the butterfly population. |
As the monarch butterfly’s November-March migration season in Mexico draws to the close of another cycle, this year’s evaluation of threats to its delicate balance is once again worrisome.
Mexican butterfly enthusiasts’ hero Lincoln Brower has revealed that the monarchs numbered fewer this winter than in any of the last 12 years since researchers have been monitoring them in their southernmost sanctuaries.
With an estimated 75 percent fewer monarchs migrating to Mexico from the United States and Canada than in previous seasons, the biologist who specializes in these black and orange lepidopteron is blaming human activities for much of the decline.
Symbolic of a variety of things in different societies, monarchs are, for one, the icon of the North American Commission for Environmental Cooperation, embodying the concept of citizens’ motivation to participate in tri-national collaboration for shared ecosystem protection.
Humans rejoice over the presence of butterflies, even when we don’t stop to think that these winged creatures are an essential part of the food chain and of the biodiversity inherent in a healthy, stable environment. Tourists thrill to the sight of monarch colonies blanketing soaring evergreens in Mexico’s high mountains. The disappearance of these colonies over acres and acres in 2004-2005 is warning to mend our ways.
Due to the dwindling of the butterfly populations observed as far back as 1970 in Mexico, governments and foundations have put up millions of dollars in recent years to support grassroots and scientific efforts protecting the insects on their twice-a-year, 2,000-mile migrations. And yet we face this bleak panorama.
Where are we going wrong?
The easiest answer is the obvious: tree cutting. Illegal logging and inexplicably permitted timbering in or near the monarchs’ wintering grounds in central Mexico are destroying the habitat these miniature migrants must have for their reproduction. Besides destroying the trees where they would attach themselves, the cutting causes changes in micro-climates, such as an unusual cold spell in the 2001-2002 winter that produced a mass die-off.
Climatic changes in the United States and Canada also can have a deleterious effect on the migration pattern necessary to monarch survival, according to a recent report by a team Brower led. Human activities, including lumbering and air pollution, are part of the reason for major weather shifts.
To make matters worse, the increasing use of potent weed killers designed for genetically modified crops that are resistant to these chemicals are wiping out plants in the United States and Canada on which the butterflies depend as they travel on their long, purposeful journeys. Brower’s team discovered these herbicides have knocked out thousands of acres of the broad-leaved milkweed, which is where the monarchs lay their eggs. The eggs are destroyed along with the milkweed.
Another set of studies, which were recently released in England, corroborated the findings about the devastating impact of these herbicides on the harmless butterfly. A four-year series of experiments that consisted of farm-scale trials of genetically modified crops was conducted to evaluate their environmental impact.
In a central part of the research that conjures up stereotypical images of butterfly catchers with nets and safari hats, scientists contrasted the effects of conventional oilseed crops with those of genetically modified oilseed crops in adjacent plots at 65 sites across Britain. The researchers made 7,000 field trips to monitor wild flowers, grasses, seeds, bees, butterflies and other invertebrates. Over the course of three years, they counted a million weeds and 2 million insects. They found broad-leaved weeds, bees and butterflies were far fewer in the plots using genetically modified seed and its associated weed killer than in the plots of conventional oilseed crop.
More studies and citizen pressure are needed to convince industry and government to stop the use of the genetically modified crops and their broad-spectrum herbicides from damaging the butterfly population.
Also needed are more and better programs to provide locally controlled income alternatives to woodcutters and their families. These should be combined with targeting resources for enforcement of timbering bans in the monarch reserves.
Awareness and action must increase exponentially to make prospects better for future monarch butterfly migrations.
Talli Nauman is a founder and co-director of Journalism to Raise Environmental Awareness, a project initiated with support from the MacArthur Foundation. She is a program associate at the Americas Program of the International Relations Center. (talli@direcway.com) |
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