In July 2022, the International Union for Conservation of Nature (IUCN) re-classified the migratory monarch butterfly as endangered on its “red list.” It had previously been classified as declining. IUCN’s action will help draw attention to the causes of the monarch’s decline, including habitat loss, climate change and pesticide exposure. The decrease has been steeper in the western population that overwinters in California than in the eastern population that overwinters in Mexico.  

However, the IUCN classification does not translate to legal or regulatory protections for the species. The U.S. Fish and Wildlife Service has concluded that listing monarchs under the Federal Endangered Species Act would be warranted but is precluded due to other high priority species. Currently, the monarch is scheduled to be federally listed in 2024. Monarchs are not listed as threatened or endangered under the California Endangered Species Act (CESA). The process for CESA listing can be found at 

In early 2022, new data showed that overwintering numbers for western monarch butterflies increased to almost 250,000. While these numbers are encouraging, this one-year trend does not represent a full recovery given that historically monarchs numbered in the millions along the California coast.  

Nevertheless, the California Department of Fish and Wildlife (CDFW) remains cautiously optimistic and inspired to build on the past year’s success. We are focused on improving management of CDFW-owned overwintering sites, increasing the availability of early-season native milkweed to support first generation monarchs, and enhancing collaboration with state and federal partners to catalyze monarch conservation throughout California.  

For more information visit CDFW’s monarch butterfly webpage which includes a section on frequently asked questions.

Submitted by Ken Paglia