Monarch butterflies (Danaus plexippus) are perhaps the most well-known and beloved butterflies in North America. Seen in gardens, prairies, and natural areas from coast to coast, their arrival in northern states and Canadian provinces is viewed by many as a welcome sign of the change in seasons from spring to summer. Renowned for their long-distance seasonal migration and spectacular winter gatherings in Mexico and California, the monarch butterfly population has recently declined to dangerously low levels.
In the 1990s, millions of monarchs made the epic flight each fall from the northern plains of the U.S. and Canada to sites in the oyamel fir forests in central Mexico, and more than a million monarchs overwintered in forested groves on the California coast. Now, researchers and community scientists estimate that only a fraction of the population remains—a decline of more than 80% has been seen in central Mexico and a decline of more than 95% has been seen in California.
The International Union for the Conservation of Nature (IUCN) classifies monarchs as vulnerable as of December 2023, although this status does not confer legal protection. Monarchs have varied legal status depending on the country.
- In the United States, the U.S. Fish and Wildlife Service proposed in December 2024 to list monarchs as threatened under the U.S. Endangered Species Act (ESA). Public comments will be accepted on the proposal until March 12, 2025. The Service will then evaluate the comments and any additional information on the species and determine whether to list the monarch butterfly.
- In Canada, monarchs were listed as endangered under the Species at Risk Act (SARA) in 2023, which grants legal protection for monarchs and their habitats in the country.
- In Mexico, monarchs are recognized as a species of special protection and are legally protected in the Monarch Butterfly Biosphere Reserve, a UNESCO World Heritage Site.
The Xerces Society and our partners are working across the U.S. to protect and restore habitat for monarch butterflies, provide education on monarch conservation, and contribute to research—including through our community science projects like the Western Monarch Count and the Western Monarch Milkweed Mapper.
Eastern Monarch Conservation
Conservation of eastern monarchs—which breed east of the Rocky Mountains and overwinter in central Mexico—is an important part of Xerces' work across the Midwest, Southern Great Plains, Northeast, and Southeast. Learn more about their needs and what we're doing to help.
Western Monarch Conservation
A significant focus of our monarch conservation efforts focuses on western monarchs, which breed west of the Rocky Mountains and generally overwinter in coastal California. Western monarchs are less well-studied—yet they are at a greater risk of extinction than their eastern counterparts.
Western Monarch Call to Action
These rapid-response conservation actions, if applied immediately, can help western monarchs. This plan outlines actions that can be implemented in the short-term to avoid a total collapse of the western monarch migration and set the stage for long-term efforts.
Gardens, Towns, & Cities
Simple changes to how we manage home landscapes, parks, and greenspaces can make a big difference for monarchs.
Natural Areas
Find resources for identifying and protecting habitat, and learn about management practices to support monarchs.
Working Lands
Resources for managing farms, rangelands, and other working lands for monarchs.
Roadsides & Rights-of-Way
Roadsides and other rights-of-way present opportunities to provide vital monarch habitat.
Western Monarch Count
Volunteer to help document the overwintering population along the California coast.
Western Monarch Milkweed Mapper
Help us gather data across the West to further scientific understanding of monarch and milkweed distribution.
Other Community Science Opportunities
The Xerces Society and partners offer a wide array of community science projects. Check out our full listings to find the right fit for you!
Native Milkweeds
Learn how to establish milkweed from seed, find region-specific plant lists, or search local vendors listed in our Milkweed Finder.
Monarch Nectar Plant Guides
Science-based, region-specific lists of plants known to support adult monarchs.
Managing Habitat for Pollinators
Gain insight into best practices for supporting monarchs and other important pollinators.
Western Monarch Overwintering Site Resources
Learn how to manage these vital landscapes.
Working Lands for Wildlife
Farmers and ranchers can support monarch butterfly recovery on their lands through this NRCS program.
Pollinator Conservation Resource Center
Region-specific plant lists, guides, and other tools to support monarchs and other key pollinators.
