After months of debate, monarch butterflies are one step closer to gaining protections and may make the endangered species list, after populations declined a whopping 90 percent in the past 20 years, the US Fish and Wildlife Service (FWS) said Monday.

"We are extremely pleased that the federal agency in charge of protecting our nation's wildlife has recognized the dire situation of the monarch," Sarina Jepsen, the Xerces Society's endangered species director, said in a news release. "Protection as a threatened species will enable extensive monarch habitat recovery on both public and private lands."

Two decades ago it would have seemed highly unlikely that North America's monarchs would be endangered, given that one billion of these butterflies were flittering across the country in the mid-1990s. But as of last winter there are only 35 million left, the lowest their population has ever been.

That's mostly thanks to the use of herbicides, which are chemicals sprayed on genetically modified crops such as corn and soybeans that kill milkweed plants, monarchs' only source of food. In the last 20 years, these orange and black butterflies have lost more than 165 million acres of vital habitat once overflowing with milkweed plants - an area about the size of Texas.

The monarch butterfly is also threatened by drought, heat waves, climate change and logging.

Concerned over their dwindling numbers, the Xerces Society, along with the Center for Biological Diversity and scientist Lincoln Brower, who specializes in monarchs, filed a petition asking that the butterflies be given federal protections.

The FWS said Monday that the dire situation of the monarch may warrant protection, and it will conduct a one-year status review to determine if the species should be included under the Endangered Species Act.

"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," added Tierra Curry, a senior scientist at the Center for Biological Diversity.

Should the monarch make the cut, protective measures would make the killing of these butterflies illegal (with certain exceptions), guidelines would be instilled to protect the insects, and farmers would be encouraged - and possibly compensated - for allotting land for milkweed to help monarchs flourish once more.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).