Monarch Butterfly - MultiAgency Collaborative Working Group

four photos of the monarch life stages: caterpillar, adult on a yellow flower, chrysalis, and clustered overwintering adults

New Report: Conservation Priorities for Western Monarchs in California

butterflies

The California Multi-Agency Monarch and Pollinator Collaborative, a working group comprised of 13 state and federal partner agencies, has published a new report highlighting actions that can support monarch butterflies in California. To develop the report, partners reviewed the Western Association of Fish and Wildlife Agencies’ 50-year monarch conservation plan (see the recently published update) and the Western Monarch Summit Priorities. The ‘Conservation Priorities for Western Monarchs in California’ report can be used by agencies, researchers, land managers, and other interested parties as a roadmap for monarch conservation in the state. Read the full report here.

Collaborative Mission and Members

The California Multi-Agency Monarch and Pollinator Collaborative was created to inform and promote integrated science, natural resource management, and policy to increase the pace and scale of monarch and pollinator conservation throughout California. Current members include: California Department of Fish and Wildlife, California Coastal Commission, California Department of Food and Agriculture, California Department of Parks and Recreation, California Department of Pesticide Regulation, California Department of Transportation, Wildlife Conservation Board, Bureau of Land Management, U.S. Department of Defense, U.S. Fish and Wildlife Service, U.S. Forest Service, U.S. Geological Survey, U.S. National Park Service, and U.S. Natural Resources Conservation Service.

Monarch Butterfly Decline

Historically, millions of monarchs gathered in reproductive diapause in groves of trees along the west coast spanning from Mendocino County, California, to Baja California, Mexico. Western migratory monarch butterfly overwintering counts have declined precipitously in recent decades, with counts in three of the past five years reaching record lows (for more information see the Xerces Society’s Western Monarch Count website).

In December 2024, the U.S. Fish and Wildlife Service proposed listing monarchs as a threatened species with designated critical habitat in California’s overwintering grounds. Recognizing the precarious state of their population, western migratory monarchs are also on CDFW’s Terrestrial and Vernal Pool Invertebrates of Conservation Priority List and recognized as a Species of Greatest Conservation Need in the California State Wildlife Action Plan.

Importance of Monarch Butterflies

Healthy monarch populations enhance ecosystems by providing pollination services, providing food for birds and small animals, and contributing to California’s biodiversity. Monarchs are also cultural icons and educational ambassadors, helping children learn about natural phenomena including long-distance migration, mimicry, chemical protection, and metamorphosis.  As a widespread, formerly abundant species, monarchs are emblematic of the decline of a wide array of pollinator species. Increasing resources for monarchs can support other pollinators, ecosystems, and wildlife. For more information on monarchs and pollinators, see the CDFW monarch and pollinator pages.

Resources

Collaborative partners compiled monarch-focused resources (see below). If you’d like to recommend a resource to add to this collection, email wildlifemgt@wildlife.ca.gov.

Breeding and Migratory Habitat

Overwintering Habitat

Community Science

Educational Materials

Working Groups

Partners participate in several topical or regional working groups aimed at advancing monarch and pollinator conservation:

Pesticides

Although pesticides like herbicides and insecticides target pest insects, they can negatively also impact pollinators including monarchs. These resources can help reduce the pesticide exposure in pollinator habitat:

  • PRESCRIBE database - CDPR’s tool for pesticide applicators to look up California Endangered Species Act-listed species that occur where applications are planned and recommended mitigations to reduce exposure to these species.
  • EPA ECOTOX database - Provides toxicity data for single chemical stressors to aquatic and terrestrial species.
  • Bee Precaution UC IPM database - Look up toxicity classification of various pesticides to pollinators.
  • SF Environmental Reduced Risk Pesticide List - List of pesticides approved for use in San Francisco, including pesticide risk classifications and use limitations.
  • BeeWhere - Beekeepers, pesticide advisors, and pesticide applicators can look up where hives are being kept as well as where sprays are planned.
  • CA Animal Health and Food Lab at UCD - Carcasses of vertebrates that died to suspected pesticide poisoning can be tested at this lab.
  • CDFW Wildlife Incident Reporting Database - Deaths of any wildlife due to suspected pesticide poisoning (or other causes) can be reported here.
  • WCB Herbicide Questionnaire (PDF) - Set of questions to help rationale methods for invasive plant control.
  • Pesticide Use Reporting (PUR) - Statewide pesticide use reporting provides information such as location (county), date, and amount of pesticide applications in California. This reporting is required for nearly all types of agricultural pesticide use and certain nonagricultural pesticide uses.

Funding Sources

MOG Resources

Partners

California Coastal Commission logo California Department of Food and Agriculture logo California Department of Fish and Wildlife logo California Department of Pesticide Regulation logo Caltrans logo California State Parks logo Bureau of Land Management logo National Park Service logo Natural Resources Conservation Service logoUnited States Geological Survey logo United States Forest Service logo United States Fish and Wildlife Service logo 300px_WCB-logo_new_2024

 

Wildlife Branch — Wildlife Diversity Program
1010 Riverside Parkway, West Sacramento, CA 95605
wildlifemgt@wildlife.ca.gov