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California Overwintering Sites
Nov. – Jan.

The Western Monarch Count is a volunteer-powered community science effort to track the status of overwintering western monarchs & their habitat. Join us!

The Western Monarch Count is an annual effort of volunteers to collect data on the status of monarch populations along the California coast during the overwintering season, which occurs from approximately October through March. The height of this volunteer effort occurs during the Thanksgiving Count, which runs for three weeks surrounding the Thanksgiving holiday. Thanks to the extraordinary effort of a cadre of volunteers, we now have over 20 years of data demonstrating that monarchs have undergone a dramatic decline estimated more than 95% in the western U.S. since the 1980s (Schultz et al. 2017). This effort has been coordinated by Mia Monroe, Shawna Stevens, and Dennis Frey in the past, and is now coordinated by Mia and The Xerces Society for Invertebrate Conservation.

In January 2017, The Xerces Society and Western Monarch Count volunteers expanded their efforts to monitor western monarchs for a second period each winter. This New Year’s Count serves as a follow-up to the annual Thanksgiving Count to help scientists better understand how the western monarch population changes throughout the overwintering season.  

Visit the Western Monarch Count website to get involved!