Monarch Butterfly Conservation

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 determined in 2020 that monarchs warrant protection under the U.S. Endangered Species Act (ESA), but adding them was precluded by higher-priority species listings. An updated decision is anticipated in December of 2024.
• 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.