In July 2022, the monarch butterfly was reclassified from “declining” to “endangered” on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. The IUCN Red List is a widely used and highly regarded global resource that highlights imminent threats to the survival of various species. It is not, however, a legal classification, and the monarch butterfly is not listed under either the Federal Endangered Species Act (ESA) of 1973 or the California Endangered Species Act (CESA).
Advocates call on federal government to protect monarch
Monarch Butterflies by Ann Hobbie
Monarchs Overwintering in Mexico Down 53%
Monarch butterfly declining; endangered status decision nears
After Record Low, Monarch Butterflies Return to California - Bloomberg
WSU butterfly researcher: monarchs need legal protection
Monarch Butterfly Population Moves Closer to Extinction – NBC 7
Endangered-species decision expected on beloved butterfly
U.S. agency sidesteps listing monarch butterflies as endangered
The Monarch Butterfly's Path to Federal Protection