By Jessica Garces, SPAWN Habitat Restoration Intern
Historically in West Marin, “monarch butterflies have been noted in huge beautiful numbers at “butterfly trees” in Bolinas and Stinson Beach since the turn of the last century and not too long after that in Muir Beach. We don’t know (yet) what happened before the coastal forests were gone but many speculate that they’d pause, sometimes for days to weeks, in the coastal groves of bishop pine and redwood trees as they traveled towards and down the coast to their favored place to tuck for the winter: the cypress and pine forests of the Santa Cruz and Monterey peninsulas to Cambria (the range of the Monterey Pine). This pause could have been to nectar, to be in a cool place during a heat wave or smoky period. In the early 1980s an inventory was done through a WWF grant to the Xerces Society to do a thorough inventory of overwintering sites. This became the base for the CA Natural Diversity Data Base, and eventually grew into a community science effort to continue regular monitoring. Thus, the decline of the overwintering population, loss of sites and other changes have been documented since.”- Mia Monroe, co-founder of the Marin Monarch Working Group and Western Monarch Count at the Xerces Society.
Western monarchs breed during the spring and summer as they fly north along the western U.S and southern Canada in search of milkweed plants to lay their eggs. As fall approaches, the migratory population will travel south to find appropriate habitat for them to overwinter along the California coast, Baja and Arizona. This migratory generation lives 6-9 months, compared to the 2-5 weeks of earlier generations, and will go through a hibernation-like period called diapause. During diapause, the butterflies’ reproductive organs do not fully develop until after winter and their activities are restricted to sunning, rehydrating, and feeding on nectar. Overwintering habitat sites provide a microclimate suitable for the diapause stage of their life cycle, and are a crucial element to the survival of the western monarch. In recent years, the population of the western monarch butterfly has declined significantly. According to the Center for Biological Diversity, the western migratory population is down more than 95% since the 1980s, and less than 12,260 butterflies were counted this winter, the third lowest count on record. The causes of this drastic population decline are thought to be driven by a combination of pesticide use, habitat loss, and climate change.
But there is hope! AB 2254 is a bill that seeks to strengthen protections for coastal monarch butterfly overwintering sites in California, and is soon to be presented to the California Assembly. If passed, AB 2254 would require the Department of Fish and Wildlife, in coordination with the California Coastal Commission, to identify western monarch butterfly overwintering habitat sites in coastal zones, provide guidance to local governments on model policies to protect monarch overwintering habitat (including habitat restoration and enhancement), and mandate that sites with confirmed overwintering habitat develop and implement enforceable monarch butterfly overwintering habitat site protection. Please join us in supporting this bill by reaching out to your California Assembly Member today and urge them to vote AYE on AB 2254 via https://win.newmode.net/ab2254-monarch-ca.
The Xerces Society served as a primary advocate for this bill, and has spearheaded many projects to protect the monarch butterfly, including the Western Monarch Count, an intensive community science project to monitor western monarch populations across California. They have done incredible science-based conservation work, and SPAWN is proud to have donated plants grown at our California Native nursery.
Here in Marin County, the Marin Monarch Working Group (MMWG) hosts training and monitoring opportunities for the general public and completes habitat restoration projects to restore western monarch habitats in private and public spaces. We have also donated milkweed to support their restoration efforts, and are grateful for our partnership. They are an excellent resource for local folks looking to get involved in monarch conservation- check out their upcoming events on their website at https://www.marinmonarch.com. SPAWN is grateful to be a part of such an important cause, and contribute to environmental conservation in West Marin!
Sources for further learning:
- Virtual interview with Mia Monroe, co-founder of the Marin Monarch Working Group and Western Monarch Count at the Xerces Society.
- Monarch Joint Venture – Migration article
- Western Monarch Trail
- California State Parks Foundation – Ideal Home for Western Monarch Butterflies article
- Smithsonian Magazine – Butterflies are in Dramatic Decline Across North America article
