Monarch Butterfly May Gain Threatened Status

Monarch butterflies have declined by more than 90 percent since 1990, and conservationists fear that they could disappear from North America altogether if more isn't done to protect their habitats.

In a legal petition filed Tuesday, conservation groups asked the Obama administration to deem the monarchs as "threatened" under the Endangered Species Act.

"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," Lincoln Brower, a conservationist who has studied monarchs since 1954 and who joined the petition, said in a press release.

These brilliant orange and black butterflies can be found throughout the United States, and make a spectacular migration each year from Canada to Mexico. But where they are getting hit hardest is in the Midwest.

Where there were once one billion of these butterflies in the mid-1990s, there are now only 35 million - the lowest their population has ever been.

According to the Center for Biological Diversity, who led the petition, widespread use of herbicides on genetically engineered crops is killing their only food supply - milkweed. Since the 1990s, American farmers have increasingly planted seeds that are genetically modified to resist herbicides like Monsanto's Roundup weed killer, a practice that in turn destroys milkweed.

And herbicides aren't the only factor threatening monarchs and their habitats. Climate change, drought, heat waves, and logging on their Mexican wintering grounds are also putting these insects at risk.

"We need to take immediate action to protect the monarch so that it doesn't become another tragic example of a widespread species being erased because we falsely assumed it was too common to become extinct," said Sarina Jepsen, endangered species director at the Xerces Society.

Monarchs have lost more than 165 million acres of habitat -- an area about the size of Texas - in the past two decades, a swath that includes nearly a third of their summer breeding grounds, the conservation groups said in their petition. A similar threat is facing other types of "pollinators," including honeybees, birds and bats, which have all seen their populations decline in recent decades.