Kristian Hernandez / Stateline.org (TNS)

Each spring, millions of monarch butterflies leave their wintering grounds in the Sierra Madre mountains of central Mexico and begin their annual migration north across the United States.

The exodus and return of the iconic orange and black butterfly is one of the most awe-inspiring sights in the natural world. But that sight is becoming increasingly rare as the monarch’s population has declined nearly 90% in the past two decades, according to federal scientists.

The monarch faces many threats, including the loss of milkweed and other flowering plants across its range, the degradation and loss of overwintering thickets on the California and Mexican coast, and the widespread use of herbicides and pesticides. Many of these stressors are compounded by climate change, advocates say.

Over the past two years, some state departments of transportation, local governments, and energy companies in 23 states have pledged to preserve monarch habitat in hopes of protecting the species and preventing its further development. be added to the federal endangered species list.

Nearly three dozen organizations have agreed to preserve some 815,000 acres of monarch habitat along energy and road corridors since the initiative was launched.

The unusual conservation effort grew out of a 2020 agreement between the U.S. Fish and Wildlife Service and the Energy Resources Center at the University of Illinois at Chicago, which led a group of experts in developing a butterfly protection plan.

Under the so-called Monarch Candidate Conservation Agreement with Assurances, or CCAA, public and private landowners voluntarily agree to certain conservation measures, including pest and vegetation management to protect the monarch butterfly and its habitat. The agreement also requires companies to reduce or eliminate threats to butterfly survival. In return, the federal government guarantees that landowners will not be required to implement additional conservation measures even if the species is listed.

“The effort is unprecedented in terms of cross-sector participation and geographic scope,” said Iris Caldwell, sustainable landscapes program manager for the Energy Resources Center. “This is not just the first CCAA for the monarch butterfly. This is the first nationwide CCAA for all species.

The group’s goal is to conserve 2.3 million acres across the continental United States.

“The Monarch is such an iconic species that it provides us with a rallying point that brings people together. This is important because we are looking at large-scale pollinator conservation,” Caldwell said. “If we can create and maintain monarch habitats, it will benefit so many other species.”

But some conservationists are wary of the deal. Jeffrey Glassberg, president and founder of the North American Butterfly Association, an advocacy group, said while conservation agreements can be effective tools to advance environmental goals, the most important way to save these butterflies is to deploy intensive, large-scale efforts to recreate grasslands in the northern plains that will sustain their populations.

“The main factors affecting monarch populations appear to be the degradation of overwintering sites in Mexico, climate change, and the continued and increasing use of neonicotinoids. [insecticides]“, Glassberg wrote in an email. “This project will not solve any of these problems.”

The eastern monarch population, which winters in Mexico and moves east of the Rocky Mountains, has fallen by about 88% from 1996 to 2020, from about 383 million to just under 45 million, according to the Fish and Wildlife Service. The western population, which winters in California, has fallen more than 99% since the 1980s, from 4.5 million monarchs to less than 2,000, the agency said.

In 2014, conservationists petitioned the Fish and Wildlife Service to place the butterfly on the endangered species list. In December 2020, the agency ruled that monarch butterflies deserve federal protections, but that it must first prioritize the other species on hold on the list.

The petition alone has sparked major conservation interest across the country, in part because a monarch listing would lead to regulations on agriculture and other activities. According to Stateline research, natural resources departments in Arkansas, Indiana, Iowa, Kentucky, Missouri, Nebraska, New Jersey, North Dakota, Texas, and Wisconsin have adopted monarch preservation plans for the past six years.

Most of these plans expand or establish efforts to increase pollinator plant habitats in state parks, state natural areas, and wildlife management areas.

The federal agreement expands another previous effort to protect monarchs: the creation of a monarch highway across the states to establish and maintain roadside habitats for the monarch.

In 2016, the state departments of transportation in Iowa, Kansas, Minnesota, Missouri, Oklahoma, and Texas created the Monarch Highway. It begins at the US-Mexico border in Laredo, Texas, and follows the monarch’s migratory path along the Interstate 35 corridor north to Duluth, Minnesota.

In Texas, the state Department of Transportation has been promoting pollinator habitats for nearly a century, according to Samuel Glinsky, a vegetation specialist at the department.

He said the state established a guideline in the 1930s to mow most roadsides only twice a year to allow wildflowers to sow. The department oversees more than 1 million acres of land across the state.

“It’s important that we provide this suitable habitat on this land just because of the size of it,” Glinsky said. “Pollinators such as the monarch butterfly pollinate a very large percentage of our food crops, so they are a very important resource to protect as their extinction could have a huge economic impact.”

Texas signed the LACC agreement, as did the departments of transportation in Georgia, Minnesota, Ohio, Oklahoma, Vermont and Virginia. The Texas department hasn’t had to change its operation as a result, except for some monitoring and gathering evidence that shows the habitats it maintains are suitable for monarchs, Glinsky said.

Roadside habitats alone aren’t the answer to saving the monarch, said Marianna Treviño-Wright, director of the National Butterfly Center in South Texas.

“It forces the butterflies to run a gauntlet,” Treviño-Wright said. “Why would you want to create a habitat next to a highway with speeding cars?”

A 2020 study by Texas A&M, sponsored by the Texas Department of Transportation, found that 2% to 4% of the total population of migratory monarchs heading south toward Mexico die on Texas roads.

For the past five years, researchers at the University of Minnesota have studied the viability of habitats along roads across the state. Roadsides offer potential opportunities as monarch habitat, but they also come with risks, said Emilie Snell-Rood, associate professor of ecology, evolution and behavior at the University of Minnesota, during a webinar last month hosted by the Monarch Joint Venture, an advocacy group.

Researchers found a slight increase in the death rate of caterpillars that ingest zinc, but for the most part the monarchs appeared unscathed from the heavy metals, salt and other chemicals found at elevated levels by roadways, according to Snell. -Rood. Still, she said more studies need to be done to ensure that roadside habitats are suitable for monarch preservation.

Caldwell of the Energy Resources Center said roadsides are an important part of the federal agreement’s conservation efforts, but officials are trying to incorporate other rights-of-way that could provide less risky habitats. Using a GIS mapping tool, the group identified some 21 million acres of electrical transmission corridors and pipelines that could serve as travel corridors for the butterflies, she said.

Northern Natural Gas has a 14,500-mile pipeline that stretches from Texas to Minnesota through the middle of the eastern monarch flyway. The company has pledged to conserve some 112,000 acres of monarch habitat along the pipeline, according to spokesman Mike Loeffler. He said the company was very interested in becoming part of the CCAA because listing the monarch as an endangered species could affect operations.

While at least 45 entities have expressed interest in the CCAA agreement in 2020, only 33 have applied to join. As of March 25, 19 applications had been approved and 14 were pending, according to Caldwell.

Caldwell said several organizations chose not to list or delayed listing in part because of the Fish and Wildlife Service’s decision not to immediately protect the species.

“I think they saw the Fish and Wildlife Service’s decision as giving them a bit of extra time and kind of relieved some of the pressure on them to feel like they had to sign up right away.” , Caldwell said.

“But it’s in that time before a list is finalized that we really have the opportunity to demonstrate the value of the voluntary conservation that’s happening,” she added, “and hopefully to help inform or perhaps avoid this list”.