The orange-and-black monarch butterfly, known for its 3,000-mile migration across North America and its plunging population, meets the criteria for listing as a threatened or endangered species, said the Interior Department on Tuesday. But it will be listed only as a candidate for federal protection because “we must focus resources on our higher-priority listing actions,” said Fish and Wildlife Service director Aurelia Skipwith.
At 60 million in 2019, the monarch population is less than one-sixth of its size in 1996. The government has studied the butterfly since environmental groups filed a petition in 2014 to list it as a threatened species. The monarch suffers from loss of habitat, expanded use of insecticides and climate change.
“Protection for monarchs is needed — and warranted — now,” said George Kimbrell of the Center for Food Safety, one of the groups that filed the petition. “The Trump administration has placed Monsanto profits above monarchs. The Biden administration must follow the law and science and protect them.” Some activists blame weedkillers for loss of milkweed, the sole food source of the monarch caterpillar. Now owned by Bayer, Monsanto produced the most widely used herbicide in the world.
In its decision, the Fish and Wildlife Service said listing the monarch was warranted but precluded because other species have higher priority. As a candidate species, the monarch’s status will be reviewed each year. Some 161 species of plants, insects, birds, shellfish, fish and mammals out-rank the monarch on the agency’s National Listing Workplan.
In the interim, conservationists and the Interior Department said they would pursue voluntary action to preserve the monarch and its habitat. “There is a role for everyone,” said Wendy Caldwell, executive director of Monarch Joint Venture, a conservation initiative.
Monarch butterflies only lay their eggs on milkweed and the plant is the food source for the monarch caterpillar, which becomes the butterfly. Because of the importance of milkweed, many conservation plans for the butterfly encourage stands of milkweed.
More than half a million acres are set aside for bee and butterfly habitat, said the American Farm Bureau Federation. “The warranted but precluded decision will give stakeholders time to continue conservation and research efforts,” said AFBF president Zippy Duvall.
Ninety percent of the world’s monarch butterflies are in North America. The brightly patterned butterfly spends the winter in Mexico and California and migrates northward as far as Canada during the summer.
The Interior Department home page for the monarch butterfly is available here.