They fly through the Louisville area each year on their way from Canada to Mexico — an iconic flutter of orange and black that has taught generations of Americans about the biology of life cycles and metamorphosis, but now may be at risk of vanishing.
Monarch butterfly populations have plummeted so much that the U.S. Fish and Wildlife Service now believes there might be reason to protect them under the Endangered Species Act.
Responding to a petition from butterfly advocates, the agency last week opened a “status review,” the first step in deciding whether monarchs should fall under the umbrella of one of the nation’s most powerful environmental laws.
“Everyone has been aware of how small the population is,” said Tierra Curry, a senior scientist at the Arizona-based Center for Biological Diversity, one of three groups that petitioned for the review. “A couple of bad storms could really send the population into an irreversible decline.”
Any eventual listing could bring more conservation of the butterfly’s habitat, putting a pinch on farmers and St. Louis-based company Monsanto, whose Roundup herbicide and genetically engineered crops such as corn and soybeans were cited in the petition as a leading cause in the butterfly’s decline.
Herbicide tolerant varieties comprise 94 percent of soybeans and 89 percent of all corn grown in the United States, and the herbicides used on them have been wiping out milkweed, the monarch caterpillar’s sole food source, according to the petition.
In a written statement, Monsanto acknowledged the declining availability of milkweed was “certainly a contributing factor.
“This challenge is complicated since monarchs need milkweed to survive, but farmers consider the plant a weed which competes with their crops for water, soil and nutrients.”
The statement said the company was working with farm groups and the government “to be a part of the solution.”
Several years ago when corn prices soared, many farmers were planting “fence row to fence row, not leaving any of that habitat,” said said Gary Palmer, assistant director for agriculture and natural resources with the University of Kentucky Cooperative Extension Service. “With corn prices down, maybe that will change,” he added.
Until recently, logging in Mexico was the species’ biggest threat, Curry said. But those threats have been lessened with government protections, she said.
With a surge in biofuels produced with corn, butterflies may have lost 65 percent of their milkweed in the Midwest, the groups assert. Between agriculture losses and other developments, they estimate a potential Texas-sized loss in monarch habitat since the mid-1990s.
The population fell from about 1 billion butterflies in the mid-1990s to only 35 million butterflies last winter, the lowest number ever recorded, the groups said, adding that climate change may also put monarchs in jeopardy.
In a Dec. 31 request for scientific and commercial information, Fish and Wildlife acknowledged a significant fall in monarch numbers. Their migration journey, the agency said, “has become more perilous. Threats include habitat loss … and mortality resulting from pesticide use.”
In addition to the Center for Biological Diversity, the petition was submitted by the Center for Food Safety, the Xerces Society and Lincoln Brower, a researcher who has authored more than 200 scientific papers on the butterfly.
The soonest the government could make a decision on a listing would be two years, but in the past, decisions have taken many years or even decades, Curry said.
Reference: USA Today