Apologies for lack of posting at this site! More to come… Thanks for stopping by! – Cathryn, B-girl Guide
Five or so years ago, I saw seven Monarch Butterflies in one month, two crossing the crazily hectic Brooklyn-Queens Expressway (a migration path?) but typically in greener settings. I always feel hopeful when I see a butterfly. If I am a little bit down, I invariably take it as a good sign. But we need their numbers to rebound for many reasons other than that they are so magical.
An article appeared this week in the New York Times about the great and alarming reduction in their numbers which has widely publicized (thankfully) but with no resolution as yet. And while there are a few contributing factors, it seems all roads often lead to Monsanto.
From the New York Times, For the Monarch Butterfly a Long Road Back
Less than 20 years ago, a billion butterflies from east of the Rocky Mountains reached the oyamel firs, and more than a million western monarchs migrated to the California coast to winter among its firs and eucalypts. Since then, the numbers have dropped by more than 90 percent, hitting a record low in Mexico last year after a three-year tailspin.
Source: New York Times
Preliminary counts of migrants this fall are encouraging. “But we’re definitely not out of the woods,” said Ms. [Dara] Satterfield [from Odum School of Ecology at the University of Georgia], who studies human effects on migratory behavior. “One good year doesn’t mean we’ve recovered the migration.”
To make matters worse, she and her graduate adviser, Sonia Altizer, a disease ecologist at Georgia, fear that well-meaning efforts by butterfly lovers may be contributing to the monarch’s plight.
In recent years amateur conservationists have sought to replenish drastic declines in milkweed, the only plant female monarchs lay eggs on. But the most widely available milkweed for planting, the scientists say, is an exotic species called tropical milkweed — not the native species with which the butterflies evolved. That may lead to unseasonal breeding, putting monarchs at higher risk of disease and reproductive failure.
Unlike most migrating species, monarch butterflies employ an improbable strategy that splits their round-trip migration between generations. So their life cycles must be intricately synchronized with those of the milkweed on which they lay their eggs.
Monarchs returning from Mexico reach the Southeast soon after native milkweeds appear in spring, producing the first of up to three generations that breed on new milkweed through summer. When the perennials start dying back in the fall, a final generation of butterflies typically emerges in a sexually immature state. Rather than reproduce when food is scarce and caterpillars might freeze, they fly to Mexico, to wait out the winter.
“The tiny creatures that engage in this big, beautiful migration have never seen the sites in Mexico before and somehow know where to go,” Ms. Satterfield said. “It’s incredible.”
But in the Midwest, which produces half of Mexico’s wintering monarchs, the scores of wild milkweed species among grasslands and farms are fast disappearing. Nearly 60 percent of native Midwestern milkweeds vanished between 1999 and 2009, the biologists Karen Oberhauser and John Pleasants reported in 2012 in the journal Insect Conservation and Diversity. The loss coincided with increased applications of the weedkiller Roundup on expanded plantings of corn and soybeans genetically altered to tolerate the herbicide. Meanwhile, monarch reproduction in the Midwest dropped more than 80 percent, as did populations in Mexico.
With the loss of native milkweeds that die in the fall, monarchs are encountering tropical milkweeds that are still thriving.
“There’s this huge groundswell of people planting tropical milkweed, and we don’t know what it’s doing to the butterflies,” said Francis X. Villablanca, a biology professor at California Polytechnic University. “We’re all in a rush to figure it out.”
Dr. Altizer fears that when monarchs encounter lush foliage in the fall, they may become confused, start breeding and stop migrating.
“It’s sad, because people think planting milkweed will help,” she said. “But when milkweed is available during the winter, it changes the butterfly’s behavior.”
Butterfly enthusiasts shouldn’t feel bad for planting tropical milkweed, monarch researchers say. But they should cut the plants back in fall and winter. Or even better, replace them with natives. There are native plant societies across the country that can offer advice.
I had no idea there was a movement of sorts planting milkweed! Let’s get back the billion butterflies!!
From my other blog, Washington Square Park Blog: March Against Monsanto, Washington Square May 30, 2013
And speaking of Monsanto, join Reverend Billy Talen on Thanksgiving at the corporation’s St. Louis headquarters (Thursday, November 27)for Organic Thanksgiving at Monsanto.
Top Photo: Don Sutherland
Bottom Photo: Cathryn