Monarchs on the Brink

Written By: Isis Howard, Gold Ridge RCD Project Coordinator
Published: December 2, 2020

SPECIES BACKGROUND: The monarch butterfly is one of the most iconic species of wildlife in all of America. These incredible butterflies undertake one of the world’s most remarkable and fascinating migrations, traveling thousands of miles over many generations from Mexico, across the United States, to Canada. During winter months, monarchs find seasonal refuge in carefully selected forested groves along the Pacific Coast and the mountains of central Mexico–these special refuges are called overwintering sites.
Overwintering sites provide a very specific microclimate to help monarchs conserve their energy and protect them from winter storms and freezing temperatures. Astonishingly, monarchs tend to return to the same sites–even the same trees–each fall! Favorite trees of the western monarch include:
● nonnative blue gum eucalyptus (Eucalyptus globulus)
● native Monterey cypress (Cupressus macrocarpa)
● native Monterey pine (Pinus radiata)

Western monarch overwintering sites along the Sonoma Coast once supported thousands of butterflies. However, like most other sites throughout the state, they have shown cataclysmic population declines in the past two decades. Despite the essential nature of monarch overwintering habitat, known sites remain largely unprotected in California, legally and in practice. Based on annual surveys, less than 1% of historic western monarch populations survive today; the largest impacts are the result of habitat loss, pesticide use, and climate change.
The probability that monarchs persist through the next decade is just 30%, and experts agree that this iconic species will likely go extinct within the next fifty years without widespread, immediate efforts to restore the ecological features upon which they depend.

RCD CONSERVATION EFFORTS: The team at Gold Ridge RCD is grateful to have an opportunity to address monarch conservation strategies in the Sonoma Coast Monarch Overwintering Site Protection and Enhancement Project, funded by the Wildlife Conservation Board (WCB). We are working in partnership with coastal landowners as well as federal, state, and local partners, including Creekside Science and The Xerces Society for Invertebrate Conservation to develop monarch habitat conservation plans for several known overwintering sites in Sonoma County, including known sites on private land, State Parks, County Regional Parks, and a WCB monarch reserve.
Researchers have determined that the most effective strategies to bolster the western monarch population include:
● Protecting and restoring overwintering sites
● Providing nectar resources along the migratory flyway
● Increasing the availability of early-season native milkweed

The next several years will be a critical time to bring the butterflies back from near-extinction, and we hope you are as excited as we are to protect and enhance monarch habitat on our local public and working lands!

GET INVOLVED: If you would like to take action to support western monarchs, there are many fantastic ways to get involved. One way is to participate in annual overwintering monarch surveys! Mia Monroe, North bay resident and decades-long advocate for western monarchs, says: “My volunteer work as a community scientist is so rewarding, and this is an invaluable way for others to help document sightings, breeding success and more.”
This year the Western Monarch Thanksgiving Count runs from Saturday, November 14 to Sunday, December 6. The New Year’s Count runs from Saturday, December 26 to Sunday, January 10. You can find instructions and training videos on how to become a volunteer at: If you decide to volunteer, you might meet Mia Monroe; she helps coordinate many of these events in the north bay!
To learn more about the biology and status of the western monarch, we recommend you follow The Xerces Society, Western Monarch Milkweed Mapper, and Monarch Joint Venture online or on social media. You might also search for “Monarch Nectar Plant Guides” if you feel inspired to spruce up your gardens to create vital nectar resources and breeding habitat for migrating monarchs.

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