Monitoring Monarch Butterfly Overwintering and Roosting Sites in Baja California

Through funding provided as part of the 2027 Deconstructed El Niño Expeditions, Monarca Baja California Monarch will conduct the most extensive and ambitious monarch butterfly monitoring effort ever documented in the state. This project will strengthen scientific knowledge of the species’ migratory routes and roosting sites, as well as habitat conditions in northern Baja California, generating critical data for its conservation in the face of global climate change.

The project’s objectives include:

• Mapping and documenting activity at known feeding and overwintering sites in the municipalities of northern Baja California, strengthening the monitoring of local monarch sanctuaries.
• Identifying and documenting new overwintering sites along the northern coastline of the state through field surveys and the observation of suitable microclimates.
• Assessing the impact of 2026–2027 climate conditions on documented overwintering sites—including El Sauzal, Villas Hotel California, La Misión, and Real del Mar—as well as on newly identified sites.
• Training local communities in citizen science to strengthen the continuous monitoring of the western monarch butterfly population in coordination with regional and international networks.
• Producing a technical report with public policy recommendations aimed at securing legal protection and restoring critical habitat within the identified biological corridors.