by Sue Halpern
By all accounts, the 21st century has not been kind to monarch butterflies in North America. The orange-and-black creatures, who make a remarkable 3500 mile migration from Canada, through the United States, to the Transvolcanic Mountains of Mexico where they spend the winter, have seen a 90 percent decline in population. There are many causes, but all of them have to do in some way or other with habitat loss, both here and in Mexico. A particularly virulent culprit is the herbicide Roundup, which farmers spray on their fields to curtail weeds, and which has had the unintended consequence of wiping out the milkweed monarch need to survive. As Chris Clark explains it:
With the advent of genetically modified corn and soybeans designed to resist the effects of the broad-spectrum herbicide glyphosate, trade-named Roundup, use of the herbicide has increased dramatically over the last two decades. That increased use of Roundup is also spurred by federal energy policy, as we reported here in February: subsidies to encourage growing corn for ethanol have encouraged a huge increase in acreage devoted to growing corn: about 30,000 square miles more than in 2007.
The monarch’s population decline is so precipitous–from about a billion in 1990 down to about 33 million overwintering in Mexico last year–that yesterday a petition was filed by three environmental groups asking the U.S. Fish and Wildlife Service that the monarch butterfly be designated an endangered species.
In the words of perhaps the world’s leading monarch researcher, the zoologist Lincoln Brower, who was also a signatory to the petition, “Monarchs are in a deadly free fall and the threats they face are now so large in scale that Endangered Species Act protection is needed sooner rather than later, while there is still time to reverse the severe decline in the heart of their range.”
But time may not be on the monarch’s side. The Fish and Wildlife Service has 90 days to decide if it it will consider the request, and after that, as Clark reports, “the soonest the butterfly could win ESA protection is two years from the petition date.”