Western Monarch Call to Action

This western monarch call to action, led by the Xerces Society for Invertebrate Conservation, provides a set of rapid-response conservation actions that, if applied immediately, can help the western monarch population bounce back from its critically low numbers. We recognize and support longer-term recovery efforts in place for western monarchs such as the Western Association of Fish & Wildlife Agencies (WAFWA) plan and Monarch Joint Venture (MJV) implementation plan. The goal of this call to action, however, is to identify actions that can be implemented in the short-term to avoid a total collapse of the western monarch migration and set the stage for longer-term efforts.

The five key steps to recovering the western monarch population in the short term are:

1. Protect and manage California overwintering sites.
2. Restore breeding and migratory habitat in California.
3. Protect monarchs and their habitat from pesticides.
4. Protect, manage, and restore summer breeding and fall migration monarch habitat outside of California.
5. Answer key research questions about how to best aid western monarch recovery.

Saving western monarchs depends upon getting a lot of people involved, quickly.  Share this resource with your local officials, park managers, gardeners, plant nurseries, and friends and family.

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Last updated November 2024.

Each year, overwintering sites—even some which are legally protected—are destroyed or damaged by human actions like development or inappropriate tree trimming, sometimes leading to total abandonment of a site by the butterflies.Take action by:

• Find your local overwintering sites and become an advocate for the sites’ protection and active management.
• Contact your elected officials at the local, regional and state levels to ask that monarch overwintering sites in your area be protected.
• Create and implement an overwintering site management plan. 

The primary focus for habitat restoration should be the Coast Range, Central Valley, and the foothills of the Sierra Nevada—areas critical to producing the first generation of monarchs in the spring.

• Plant flowers which are attractive to monarchs and other butterflies, with an emphasis on the best monarch nectar plants for your region.
  • Prioritize planting species which bloom early in the spring (February–April), and also the fall (September–October). If you live near the coast, winter blooming (November–January) species are also valuable for overwintering monarchs to nectar on.
• Plant native milkweed, especially species which emerge earliest and are already at the seedling or transplant stage. Find milkweed seed and plant vendors.
  • Early emerging species native to California include woollypod (Asclepias eriocarpa), California (A. californica), and heartleaf (A. cordifolia) milkweeds. Later-emerging native species with more seed availability include narrowleaf (A. fascicularis) and showy (A. speciosa) milkweeds. In the desert southwest of California, plant rush (A. subulata) and desert (A. erosa) milkweeds. In all cases, plant milkweed species native to California, and ideally, to your area. 
  • Plant milkweed greater than 5 miles inland from the coast if you live north of Santa Barbara. Milkweed doesn’t naturally grow close to the coast north of Santa Barbara and can interrupt natural monarch overwintering behavior. 
• Help increase the supply of native milkweed and nectar plant seeds and transplants available. 
  • Ask your local nursery to start supplying native milkweed.
  • Organize a group to collect milkweed seed and propagate it.
  • Seed companies, plant nurseries, and land management entities are encouraged to work together to ramp up production and ensure a diverse supply of native milkweeds and nectar plants that are insecticide free.
• Remove tropical milkweed to replace it with native milkweed and nectar plants.
  • Avoid planting tropical milkweed, a nonnative species which stays evergreen and does not die back in areas with mild winters. Tropical milkweed interrupts the monarchs’ natural migratory cycle, leading to disease build-up and winter breeding which are both associated with poorer outcomes for monarchs.
  • If you already have tropical milkweed in your garden, it is very important to cut it back to the ground in the fall (October/November) and repeatedly throughout the winter to mimic native milkweed and break the disease cycle. Ideally, tropical milkweed should be removed entirely and replaced with native milkweed and/or nectar species. 

• Avoid using pesticides and seek out non-chemical options to prevent and manage pests in your garden and landscaping.
• Support policies and plant retailers that keep neonicotinoids out of the commercial production of milkweed plants.
• Reduce herbicide and insecticide use in and around overwintering sites and key breeding regions.
  • Avoid herbicide applications on milkweed and flowering plants in monarch habitat.
  • When herbicides must be used, they should be targeted and limited, with precautions to limit off-site movement. 
  • Avoid use of neonicotinoid insecticides at all times in monarch habitat due to their persistence, systemic nature, and toxicity.

Garden plants are frequently treated with insecticides to prevent unsightly holes rather than to promote healthy plants. Such cosmetic use should be banned as the chemicals can harm flower-visiting insects. (Photo: Xerces Society / Matthew Shepherd)

• Identify existing monarch habitat near you so you can work to protect it.
• Learn to manage monarch habitat in a way that minimizes harm.
• Restore monarch habitat, particularly in areas highly suitable for monarchs and where habitat has been lost such as the Columbia Plateau, Snake River Plain, and riparian areas. This is the highest priority activity for areas outside of California.
  • Practice climate-smart restoration.
  • Choose monarch nectar plants native to your region. 

• Join an existing western monarch research project.
• Western Monarch Count. Volunteer community scientists help count monarchs during their overwintering season at sites in California and Arizona. This project has provided several decades of population data, revealing that monarchs have undergone a dramatic decline (Pelton et al 2019).
• Western Monarch Milkweed Mapper. Volunteer community scientists report their monarch adult, caterpillar, egg, nectaring, and milkweed sightings throughout the western states. Your observations will improve our understanding of the distribution and phenology of monarchs and milkweeds, identify important breeding areas, and help us better understand monarch conservation needs. Observations are especially needed in New Mexico, Colorado, Utah, Wyoming, and Montana. We also need Californians and Arizonans to collect observations in the early spring (February–April), the period when we know the least about monarch locations, behavior, and milkweed availability.
• Start your own western monarch research project to answer a priority research question, such as:
  • When are monarchs leaving overwintering sites in late winter/early spring?
  • Where are monarchs facing high levels of pesticide contamination and how can we minimize negative impacts of pesticides on monarchs?
  • What are the causes of high overwintering mortality and how can we lower mortality risk at overwintering sites?

Contact [email protected] for more information on research collaborations and accessing existing data.

• Western Monarchs Are in Trouble: This Is How You Can Help (updated January 2021)
• Western Monarch Call to Action (updated January 2021)

Thank you to the western monarch researchers and partners with whom conversations about the most effective actions we need to take helped form the basis of this call to action, including Wendy Caldwell, coordinator of the Monarch Joint Venture; Abi Convery, planning biologist for Ventura County; Elizabeth Crone, professor at Tufts University; Matt Forister, professor at University of Nevada–Reno; Jessica Griffiths, Charis van der Heide, and Dan Meade, overwintering site biologists in California; David James, associate professor at Washington State University; Karen Miner, biologist with California Department of Fish and Wildlife; Mia Monroe, cofounder of the Western Monarch Count; Gail Morris, coordinator of the nonprofit Southwest Monarch Study; Ann Potter, biologist for Washington Department of Fish and Wildlife; Robert M. Pyle, founder of the Xerces Society; Cheryl Schultz, associate professor at Washington State University; Francis Villablanca, professor at Cal Poly; Beth Waterbury, retired biologist for Idaho Department of Fish and Game; Louie Yang, associate professor at University of California–Davis; and others.

Thank you to all the Western Monarch Count volunteers and regional coordinators whose dedication makes understanding the population’s status possible.

Thank you, too, to all the individuals and groups already doing good work on behalf of monarch conservation. Your work is critical—keep it up!

Espeset, A. E., J. G. Harrison, A. M. Shapiro, C. C. Nice, J. H. Thorne, D. P. Waetjen, J. A. Fordyce, and M. L.Forister. 2016. Understanding a migratory species in a changing world: climatic effects and demographic declines in the western monarch revealed by four decades of intensive monitoring. Oecologia 181:819–830.

Pyle, R. M., and M. Monroe. 2004. Conservation of Western Monarchs. Wings 27(1):13–17.

Schultz, C. B., L. M. Brown, E. Pelton, and E. E. Crone. 2017. Citizen science monitoring demonstrates dramatic declines of monarch butterflies in western North America. Biological Conservation 214:343–346.