The Vanishing Butterfly Groves of California
Action is urgently needed to address the challenges facing monarch butterfly overwintering sites.
With the number of western monarchs overwintering in California at less than 1% of historic levels for the second year in a row, it is obvious that monarchs are vanishing from the state. What’s less obvious, but vitally important to understand, is that the forested groves that the western monarchs call home each winter are also disappearing.
The latest research suggests that the damage and loss of overwintering habitat is one of the primary drivers of the decline of western monarchs. Yet the dominant story of monarch conservation in the United States so far has focused on planting milkweed and other nectar plants; reducing pesticides; and, to a lesser extent, acknowledging the roles of climate change and disease.
When overwintering habitat issues are mentioned, it’s nearly always in regards to the eastern monarchs’ overwintering grounds in central Mexico, where illegal logging continues to be a threat to the butterfly and, sometimes even human rights—as evidenced most recently by the disturbing disappearance of El Rosario’s manager, Homero Gómez González. Here at Xerces, we hope for his safe recovery and are keeping his family and his community in our thoughts.
We of course need to continue to work to meaningfully support overwintering protections in Mexico. It is also time for the U.S. monarch conservation efforts to bring their energy to bear on the problems facing the California overwintering sites, which still have no meaningful protection from damage or destruction.