Researchers at the Center for Biological Diversity in Arizona report a 90 percent decrease in the monarch butterfly population in the past 20 years and have just petitioned the U.S. Fish and Wildlife service to protect them under the Endangered Species Act. These researchers blame the decline on genetically modified seed and loss of habitat, but I think it could just be artist Damian Hirst’s penchant for making huge collages from thousands of butterfly wings:
Of course, that’s absurd. Hirst doesn’t discriminate against monarchs—he kills all sorts of species to make his lepidopteristic masterpieces.
But think about it—how many monarchs have you seen this summer, compared to previous summers? My backyard butterfly bush died in the last barbaric Michigan winter, so I didn’t see any monarchs this year. However, I can’t say that 20 years ago I saw 90 percent more than none. But my evidence is anecdotal, not scientific, and if respected scientists say there are 90 percent fewer monarchs, I believe them. You should too.
But let’s get back to the two main reasons for the monarch decline:
- A decrease in the milkweed plant that serves as the monarch’s breeding ground and food source. This is linked to increased herbicide use, which itself is linked to the rise of genetically modified (GM) corn. GM corn is modified to withstand harsh herbicides, so it can be sprayed liberally and still grow vigorously. Meanwhile, the surrounding weeds die. Milkweed is—you guessed it—a weed, in farmers’ eyes. The herbicide kills the milkweed, and the monarchs have nothing to eat and nowhere to call home. Starvation ensues; generations fail to reproduce. Before you know it, the end is nigh. For those that do survive the hatching of their eggs, their growth into caterpillars, their transformation into monarchs, and their migration to Mexico, a second disaster awaits them.
- Extreme habitat destruction in the monarch’s Mexican winter hideaway, which has altered the ecosystem to be inhospitable to the butterfly. The great monarch migration is a wonder of the biological world. Each year millions of butterflies born late in the season travel thousands of miles from their homes in North America to warmer climates, kind of like retired people. Monarchs in the western United States find secluded spots in California. East of the Rocky Mountains, most land near Angangueo, Michoacán, Mexico. In 2003 the Mexican colony covered roughly 22 acres; by 2013 the colony covered only 2.9 acres. Most of this decrease was caused by illegal logging, which stripped the region of the oyamel fir trees the insects prefer. Without the protective forest, they are more exposed to the elements. Take a look at this:
This photo was taken after a severe winter storm in January 2002 killed 75 percent of the monarchs that overwinter in Mexico. The loss of the oyamel fir trees changed the ecosystem, making the storm worse and leaving the butterflies unprotected. In some places the dead butterflies were up to 18 inches deep; many on the bottom layer survived initially because they were kept warm by those on top. How many were able to escape from the morass is unclear.
Back in North America, the loss of milkweed is proving to be just as serious as the loss of the oyamel fir. According to Karen Oberhauser, a researcher at the University of Minnesota, the amount of milkweed in the Midwest has fallen by more than 80 percent in the past decade or so. This is due to the popularity of GM corn and soybeans and the fact that a million acres of grassland, formerly a friendly environment for the monarch, have been converted to corn and soybean cropland as the market for products derived from these crops expands. Milkweed that used to grow on the fringes of these fields is now eliminated by the liberal use of herbicides that protect the crops.
Does this mean that big, bad Monsanto, the maker of the most popular brand of GM corn (Round-Up Ready), is to blame? The issue isn’t that simple, says Monsanto. In a statement published in the Vancouver Columbian, a Monsanto spokesperson said that
“Scientists think a number of inter-related factors are contributing to the decline and year-to-year variation of monarch butterfly populations. While weather events (snowfall and frost) at mountaintop overwintering sites and logging in Mexico continue to be factors, experts are also focusing on agricultural practices and land use changes that have reduced milkweeds along the migration path in central regions of North America.”
This sounds as noncommittal as those who claim that there is no evidence for anthropogenic climate change. They can proclaim that the jury is still out simply by virtue of the fact that their own dissenting opinion prevents a unanimous consensus on the issue.
Nevertheless, coming and going, the monarchs are screwed. Various conservation groups (and even Monsanto) have called upon farmers and others to voluntarily plant milkweed in an effort to revive the monarch species. Sounds like a great idea. Milkweed comes in all sorts of shapes, sizes, and colors, and no doubt you can find one that’s right for your growth zone. You can even get free milkweed seeds online from LiveMonarch.com.
Lincoln Brower is one of the scientists leading the fight for the monarch, the species to which he has devoted his career, and is the principal researcher that called for the petition to save the monarch. According to Brower, the monarch is “the canary in the cornfield” because its decline may be foreshadowing other problems, such as colony collapse disorder with bees, which may ultimately imperil our food supply.
As Tom Philpott, writing in Mother Jones, so succinctly says:
“the story here is about more than the decline of a butterfly species. It’s also about the unintended consequences of subjecting millions of acres of our best farmland to a single chemical-dependent technology, one literally designed to wipe out plant biodiversity in farm fields. We know about the plight of the monarch only because it’s a fascinating, beloved creature that attracts scrutiny from researchers.”
The monarch is worth saving. Even if you’re not a butterfly fan (although, really, why wouldn’t you be?), how can you look at this little guy and not fall in love?
Kathy Wilson Peacock is a writer, editor, nature lover, and flaneur of the zeitgeist. She favors science over superstition and believes that knowledge is the best super power. Favorite secret weapon: A library card.