The once ubiquitous monarch butterfly may soon be placed on the endangered species list because its population has declined so dramatically in the past two decades.
The U.S. Fish and Wildlife Service announced Monday it will begin a year-long review to determine whether the monarch should be placed under federal protection as an endangered or threatened species.
The number of monarchs has dropped 90 percent – from a high of about 1 billion butterflies in the mid-1990s to only 35 million butterflies last year, which is the lowest number on record.
Monarch butterflies are found throughout the U.S, but most of them are born in the Midwest. They migrate up to 3,000 miles to central Mexico each year to spend the winter.
Several environmental groups had urged the FWS to take the action, including the Center for Biological Diversity, which says the butterflies are in danger because of the dramatic growth in the use of genetically engineered crops in the Midwest.
Those crops are made to be resistant to herbicides which kill milkweed, which is the only food source for monarch caterpillars. Milkweed plants have been virtually wiped out in areas where corn and soybeans are heavily planted, according to the group.
They estimate that over the past 20 years, monarchs have lost about 165 million acres of habitat, an area about the size of Texas.
Another factor in the population decline is ongoing illegal logging in their winter home in central Mexico.
“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,” said Tierra Curry, a senior scientist at the center.
The Fish and Wildlife Service will accept public comments regarding the review for two months, until March 2, 2015. To read the notice and submit a comment, visit www.regulations.gov and search of docket number FWS-R3-ES-2014-0056.
There is a bit of a bright spot to report this year, however. Observers say it appears more monarchs made it to their winter grounds in Mexico this time around compared to the previous year, according to the Star Tribune.
The exact number won't be available until next month, and it's far too soon to know whether it's the beginning of a positive trend.
If you want to know more about the monarch butterfly and how it completes its epic journey to Mexico each year, the movie "Flight of the Butterflies" is being shown at the Science Museum of Minnesota's Omnitheater through Jan. 8. Here's the movie's trailer.