The U.S. Fish and Wildlife Service has proposed to list the monarch butterfly as a threatened species under the U.S. Endangered Species Act, as announced today in the advance Federal Register. Here's why and what this means for people and monarchs.
 

Why were monarchs considered for Endangered Species Act protection?

Monarchs aren’t doing well. By counting their populations while they overwinter in California and Mexico, we know the population in western North America has declined by more than 95% since the 1980s, and the eastern population has declined by more than 80% since the 1990s. The overwintering area occupied by eastern monarchs in Mexico’s oyamel forests dropped to just 2.2 acres last winter, down from 44.9 acres in the late 1990s. Early monitoring this fall by the Xerces Society at western monarch groves in California suggests it is the second lowest overwintering population since the late 1990s.

Research supports that monarchs fit the Endangered Species Act (ESA) classification of threatened (“likely to become endangered in the foreseeable future throughout a significant portion of its range”), and not yet endangered (“in danger of extinction throughout all or a significant portion of its range”). Monarchs need conservation action now, before they are at the brink of extinction.
 

Why would it be a big deal for monarchs to be listed as threatened under the Endangered Species Act?

Monarch butterflies would be one of the widest-ranging species ever to be listed under the ESA, occurring in nearly every state. Successful conservation requires a consistent response across the entire country and will involve working with many different people and sectors. Their listing could influence how we approach wide-scale conservation.
 

What are the threats to monarch butterflies?

The primary threats to monarchs are habitat loss, pesticides and climate change. The main food source for monarch caterpillars, milkweed plants, have largely disappeared from crop lands in the Midwest and elsewhere since the mid-1990s due to the introduction of herbicide-resistant crops (Hartzler, 2010; Pleasants & Oberhauser, 2013). Neonicotinoid insecticides, often used on seed coatings, have also been linked to declines (Van Deynze et al. 2024). Coastal development in California and pesticides have been linked to the western population’s decline (Crone et al. 2019). 
 

How will protection under the Endangered Species Act help monarchs?

The Endangered Species Act is one of the best tools we have for preventing extinction. The ESA is credited with preventing extinction for 99% of listed species, including bald eagles, condors, and Fender’s blue butterfly. Listing the monarch as threatened could help monarchs by:

• Protecting monarch overwintering habitat in coastal California
• Building more monarch habitat nationwide
• Better monitoring of monarch populations and more effective recovery efforts 
• Increasing research on how to address the problems monarchs face
• Allowing federal agencies to consider monarchs when making decisions, such as whether or when to use pesticides on federal lands
• Creating financial incentives for agriculture and private landowners to engage in conservation, such as by planting habitat
   

How will monarchs being listed as threatened impact people like farmers, gardeners, and researchers? 

The ESA gives the U.S. Fish and Wildlife Service flexibility to create regulations that work for the public, agriculture, landowners, and monarchs. They can create incentives for private conservation and make exemptions for activities like land development if they are balanced with conservation actions. Due to something called a 4(d) rule, which can carve out exemptions from regulation, people should likely still be able to farm, ranch, garden, etc. without major disruptions. We anticipate that the Service will also still allow people to handle, research, and rear monarchs on a small scale, as before.
 

Have voluntary efforts helped monarchs at all?

Yes! Voluntary efforts like pollinator gardens and restoring habitat are probably the reason monarch populations aren’t in worse shape. However, they are not enough. To help monarchs actually recover, we need to work at a larger scale and address widespread issues like pesticide contamination and climate change that are beyond what voluntary efforts have been able to achieve.
 

Why care about monarch butterflies?

Monarch butterflies play an important ecological role in the food web, and their habitat supports many other wildlife species such as native bees and sage grouse. Their migration is one of the great natural wonders of the world, and they are symbolically important to many cultures. As one of the most visible and well-studied insects in North America, they are ambassadors for the larger insect biodiversity crisis and can inspire people to take action for all pollinators.
 

What can I do to help monarch butterflies?

• Keep up your habitat efforts. Monarchs need more milkweed for caterpillars, native nectar plants for adults, and habitat protected from pesticides. Californians can join the western monarch call-to-action.
• Contribute to community science. Join a project to report your monarch and milkweed sightings.
• Become an advocate. Teach others about monarch conservation. Support local, state, or national conservation organizations. Advocate for strong environmental policies.
• Be a conscious consumer. Think about the impact of the food and products you purchase on pesticide, water and land use, and do what you can to mitigate climate change.
• Voice your support for a strong listing decision. Following the proposed rule, there will be a  public comment period where you can voice your support for strong protections. Subscribe to Xerces Society news to keep abreast of this and other opportunities.
   

What is the Xerces Society doing to help conserve monarchs?

The Xerces Society has a long history of working toward the conservation of monarch butterflies. We work with partners from the U.S., Canada and Mexico to identify conservation strategies. We work with researchers to understand how pesticides impact this migratory species. We manage the long running Western Monarch Count, which engages community scientists in monitoring the western monarch population at overwintering sites, and the Western Monarch Milkweed Mapper, which identifies key breeding areas. Using the best science, we work across the U.S. to provide technical assistance, direct support and plant materials for restoration projects at overwintering sites and within breeding habitat on farms, pasture and rangelands, urban farms and community gardens, roadsides and rights-of-way, natural areas, and home gardens. We advocate for policies that protect habitat and curb pesticide use over millions of acres, including coauthoring the 2014 petition that led to this listing of the monarch as a threatened species under the U.S. Endangered Species Act. You can support this important work by becoming a Xerces Society member today.