The U.S. Fish and Wildlife Service has proposed listing monarch butterflies as a threatened species, blaming its decline in the U.S. on habitat loss, pesticides and climate change.

USFWS planned Dec. 12 to open a 90-day comment period on the proposal. A final decision on giving the butterfly the protection of the Endangered Species Act will be left to the incoming Trump administration.

Farm groups reacted with cautious statements. The American Farm Bureau noted USFWS proposed listing the butterfly under a provision of the ESA that allows the Interior Secretary to loosen restrictions.

“This opens the door for an important dialogue about farmers as caretakers and cultivators of the land,” Farm Bureau President Zippy Duvall said in a statement.

Environmental groups petitioned USFWS a decade ago to list monarchs as a threatened species. USFWS said in a statement to be printed in the Federal Register that monarch butteries are on a path toward extinction.

Monarch butterflies are grouped into Western and Eastern migratory populations. Oregon, Washington, Idaho, California, Arizona, Nevada and Utah form the core of the Western range. The few monarch butterflies in Washington are east of the Cascades, according to the Washington Department of Fish and Wildlife.

Western monarchs migrate to coastal California for the winter. Monarchs wintering in California 2023 numbered a little over 200,000, compared to about 1.2 million in 1997. Eastern monarchs have suffered nearly as sharp a decline, according to USFWS.

The USFWS proposed designating 4,395 acres in Alameda, Marin, Monterey, San Luis Obispo, Santa Barbara, Santa Cruz and Ventura counties in California as critical habitat. The designation could limit use of private property if the landowner needs federal approval or funding for a project.

Monarchs lay eggs on milkweed. The USFWS said it hoped to mobilize the public to plant small and large patches. The USFWS cited a study that concluded the Midwest lost almost 40% of its milkweed between 1999 and 2014.

“A majority of the past milkweed loss has occurred on agricultural lands, where intensive herbicide usage for weed control has resulted in widespread milkweed eradication,” USFWS stated.

Many farmers already maintain plots of habitat for wildlife and pollinators, American Soybean Association board member Brandon Wipf, a South Dakota soybean grower, said in a statement.

“Farmers need to continue doing what they have been doing: being good, proactive stewards of our natural resources, including maintaining conservation practices that help protect monarch butterflies,” he said.

Texas Agriculture Commissioner Sid Miller said listing monarch butterflies will hurt farmers and called the proposal a “parting shot from the Biden administration.”

“This is not a balanced approach to conservation. It’s a roadblock to growth, jobs and prosperity, all in the name of feel good policies,” he said in a statement.

The Center for Biological Diversity was one of the groups that petitioned USFWS in 2014 to list monarch butterflies and sued to prod the agency into making a decision.

“What’s bad for monarchs is bad for humans, so we have to stop pretending that our health is somehow separate from that of the wildlife our activities are decimating,” Tierra Curry, a center senior scientist, said.