Southern California residents have a new call to action as part of California Biodiversity Day, which runs from Saturday through September 13. The California State Parks Foundation is asking anyone who spots a western monarch butterfly or its caterpillars to take a clear photo and upload the observation using the free iNaturalist app. By crowdsourcing these sightings, scientists hope to build a more accurate picture of where the beloved insects are at different times of the year.
Why monarchs matter
Western monarchs once numbered in the millions as they migrated along the coast each fall and returned each spring. Their dramatic decline over recent decades has been linked to climate change, loss of native habitat, pesticide use, and disease. The most recent Western Monarch Count recorded a peak of just 12,260 butterflies, the third‑lowest overwintering total since the count began in 1997.
How the data will be used
Each observation entered into iNaturalist will be added to a growing database that scientists use to map monarch movements and identify critical breeding and overwintering sites. The information will feed directly into the upcoming 30th annual Western Monarch Count, a key benchmark for conservation agencies and nonprofit groups working to protect the species.
Key overwintering sites in Southern California
The foundation notes several state parks that host western monarch overwintering groves, including Point Mugu, Leo Carrillo, Doheny State Beach, San Clemente State Park, and Torrey Pines State Natural Reserve. Historically, state parks have supported at least 20 % of the western monarch population during the winter months, with some years seeing more than half of the butterflies congregating in these protected areas.
What you can do
Randy Widera, director of programs for the California State Parks Foundation, emphasizes that ordinary Californians can make a real difference. “The western monarch butterfly is among the most beloved species in our state,” he said. “Californians can play a critical role in preserving our western monarch butterfly population by advocating for the protection of butterfly habitats and helping scientists track butterfly locations.”
To participate, download the iNaturalist app, create a free account, and follow the simple steps to upload a photo with the location and date. Even a single sighting can help fill gaps in the data, especially in urban and suburban areas where monarchs are increasingly rare.
Supporting broader conservation efforts
Beyond citizen science, the foundation encourages residents to support habitat restoration projects, plant native milkweed and nectar‑rich flowers, and reduce pesticide use in gardens. These grassroots actions complement the data‑driven approach of the monarch count, creating a two‑pronged strategy to halt and reverse the species’ decline.
By turning a simple walk in the park into a scientific contribution, Southern Californians can help ensure that future generations continue to enjoy the sight of monarchs fluttering across the sky during the annual migration.
Original reporting: NBC4 Los Angeles — read the source article.
