The Western Monarch Count is a community science effort to collect data on western monarchs and their habitat during their overwintering season, managed by the Xerces Society and count co-founder, Mia Monroe. Participants follow a standard protocol to survey over 250 overwintering habitat sites and estimate the number of butterflies in coastal California as well as northern Baja, Mexico, the Saline Valley of California, and the greater Phoenix, Arizona area. January’s fires in Los Angeles County burned tree groves where monarchs overwinter, including a site in Lower Topanga Canyon.

The western monarch population is geographically distinct from eastern monarchs that overwinter in central Mexico each year, separated by the Rocky Mountains. Like their eastern counterparts, the western monarch migration takes place over multiple generations of butterflies. The western population’s final generation primarily overwinters in clusters sheltered in tree groves along coastal California and northern Baja, Mexico. Surveys of the wintering eastern monarchs in Mexico continue through early March.

In December, the U.S. Fish and Wildlife Service proposed to list the monarch butterfly as a threatened species under the U.S. Endangered Species Act. When finalized, the decision is expected to provide support for the species including improved protection for overwintering habitat in California, greater focus by federal agencies on the species, and more incentives for breeding habitat restoration. A public comment period on the listing is open until March 12.