Monarch Butterflies Will Be Considered for Endangered Species List

Two monarch butterflies at the insects’ wintering grounds in Mexico. Andrew Winning / REUTERS

There was a time, not long ago, when monarch butterflies were widespread enough that it would've been crazy to think about listing them as endangered. In 1996, for example, 1 billion of these regal orange-and-black insects were estimated to have arrived at their wintering grounds in Mexico. Last year that number reached a record low of 33 million.

Due to this precipitous decline, several conservation groups petitioned the U.S. Fish and Wildlife Service in August to list the monarch butterfly as threatened under the Endangered Species Act. And on Monday the federal agency announced that it would indeed look into whether the monarch should be listed, saying in a release that the petition "presents substantial information indicating that listing may be warranted."

The formal process will begin with a two-month public information period during which the agency will gather information from scientists and citizens about the health of the butterfly, including details of its biology, current population levels and more. The entire process will take a year to complete.

"This is huge," says Tierra Curry, a scientist at the Center for Biological Diversity, one of the groups that signed the petition. In a release, she noted that "the Endangered Species Act is the most powerful tool available to save North America's monarchs, so I'm really happy that these amazing butterflies are a step closer to the protection they so desperately need."

Researchers have blamed the monarch's decline on loss of habitat and a decline in the abundance of milkweed, the only plant on which it feeds and lays its eggs. This has been exacerbated by the introduction of genetically modified crops like Monsanto's Roundup-ready corn and soybeans, which are resistant to traditional herbicides.

After the introduction of these crops in 1996 (also the year of the most recent peak in butterfly numbers), farmers began to spray more and more Roundup—the Monsanto-made chemical—over wider and wider areas. Roundup readily kills milkweed, bad news for the butterflies. One million new acres of land have been cultivated in the past few years, driven by higher corn and soybean prices and leading to less fallow land and more Roundup application—all of which has taken a further toll on milkweed abundance.

If the monarch were listed as endangered, the agency would take several steps to defend the species. For example, it would become illegal to kill the butterflies, Curry tells Newsweek, except in certain circumstances. The Fish and Wildlife Service would also likely issue guidelines for protecting them, encouraging (or perhaps offering benefits to) farmers to set aside land for milkweed, she adds.

Beginning December 31, if you are so inclined, you can submit a letter yourself to the Fish and Wildlife Service about the proposed listing.