Western Monarch Count

The Western Monarch Count (WMC) is an annual effort of volunteer community scientists to collect data on the status of the western monarch population during the overwintering season, which occurs from approximately October through March. This initiative occurs each Fall/Winter during three official monitoring periods: (1) the early-season count runs for two weeks spanning late October to early November; (2) the mid-season count spans three weeks from mid November through early December; and (3) the late-season count runs for two weeks from late December through early January. Dates for this year’s monitoring periods can be found here: https://westernmonarchcount.org/

Thanks to the extraordinary effort of a cadre of volunteers and conservation partners, we now have decades of data demonstrating that migratory monarchs have undergone a dramatic decline estimated more than 95% in the western U.S. since the 1980s. The project is currently managed by the Xerces Society for Invertebrate Conservation and Mia Monroe, one of the count co-founders.