Demand for corn threatening milkweed, and thus the monarch butterfly, which lives off the plant

Scientists and conservationists in the Great Plains are leading a crusade to save milkweed, and in turn, the monarch butterfly, which lives solely on the plant, Michael Wines reports for The New York Times. While there are many theories for the demise of the two, the main concern is that a rising demand for corn is destroying the land where milkweed thrives. (Pentagraph photo by Steve Smedley: Monarch feeds on milkweed)

In the summer of 2010, the University of Northern Iowa counted 176 monarchs in its 100 acres of prairie grass and flowers, but this year, counted only 11, Wines writes: "The decline has no single cause. Drought and bad weather have decimated the monarch during some recent migrations. Illegal logging of its winter home in Mexico has been a constant threat. Some studies conclude that pesticides and fungicides contribute not just to the monarchs’ woes, but to population declines among bees, other butterflies and pollinators in general."

The greatest threat, though, "is its dwindling habitat in the Midwest and the Great Plains, the vast expanse over which monarchs fly, breed new generations and die during migrations every spring and autumn," Wines writes. And this is due in large part to a rising demand in corn. "Since 2007, farmers nationwide have taken more than 17,500 square miles of land out of federal conservation reserves," a federal program that pays growers to leave land fallow for wildlife and soil conservation. "Iowa has lost a quarter of its reserve land; Kansas, nearly 30 percent; South Dakota, half."

"A study published in February in the Proceedings of the National Academy of Sciences analyzed land use in five states — Iowa, Minnesota, the Dakotas and Nebraska — in the broad arc of farmland where corn and soybeans are intensively planted," Wines writes. "Over the five years from 2006 to 2011, the study concluded, 5 percent to 30 percent of the grasslands were converted to corn and soybean fields, a rate it said was 'comparable to deforestation rates in Brazil, Malaysia and Indonesia.'”

Some groups are pushing for federal legislation to save monarch habitats, Wines writes. Others want to education or encourage businesses to work safely around the butterflies, or provide habitats for them. But Laura Jackson, a University of Northern Iowa biologist and director of its Tallgrass Prairie Center, worries that people will forget about the butterflies. She told Wines, “Monarchs are just like other iconic species. Once people stop being accustomed to seeing them, they stop caring and they forget. Support drops like a ratchet.” (Read more)