Monarch butterflies (Danaus plexippus) of North America are renowned for their long-distance seasonal migration and spectacular winter gatherings in Mexico and California. The monarch butterfly population has recently declined to dangerously low levels. In the 1990s, estimates of up to one billion monarchs made the epic flight each fall from the northern plains of the U.S. and Canada to sites in the oyamel fir forests north of Mexico City, and more than one million monarchs overwintered in forested groves on the California Coast. Now, researchers and citizen scientists estimate the only a fraction of the population remains, a decline of more than 80% has been seen in central Mexico and a decline of 74% has been seen in coastal California.
To conserve this animal and its habitat, Xerces works with multiple partners across North America. We believe that by working broadly with multiple stakeholders, we are well-positioned to truly recover these butterflies. See The Xerces Society’s Partnerships for Monarchs for a summary of our recent efforts and ongoing partnerships.
Nationally, Xerces is working to restore monarch breeding habitat through Project Milkweed. Our partnership with the USDA NRCS, has resulted in planting more than 120,000 acres of habitat for monarchs and other pollinators, including tens of thousands of diverse wildflower plantings that include milkweed. We are also working to increase the availability of native seed and to make it less expensive to use in restoration activities.
In the western U.S., Xerces is working to identify, understand, and protect monarch overwintering and breeding habitat. In partnership with the Monarch Joint Venture, we have monitored more than 140 California overwintering sites, trained volunteers to monitor many more as part of the Western Monarch Thanksgiving Count, and created a database of all California overwintering sites that allows us to better understand the status of western monarchs and how pending development projects will affect them. Working with land managers and herbaria, we created a database of more than 25,000 milkweed and monarch breeding locations in eleven western states, to work toward identifying and conserving important monarch breeding areas.
North American Monarch Migration Map
- Plant native milkweed and nectar plants. Find sources of local, native milkweed seed in your state using our Milkweed Seed Finder.
- Learn more about growing milkweeds on our Project Milkweed page.
- Avoid using insecticides and herbicides.
- Support agriculture that is organic or free of Genetically Modified ingredients.
- Become a citizen scientist and contribute to research efforts to track the monarch population in its breeding and overwintering range.
- Support the Xerces Society’s monarch conservation efforts.
- North American Monarch Conservation Plan
- Project Milkweed fact sheet
- Xerces Society Policy on Butterfly Releases
- SE Monarchs, Milkweeds, & Hostplants Brochure
- April 14, 2014 letter to President Obama and Secretaries Vilsack and Jewell; press release
- The Xerces Society’s Partnerships for Monarchs
- Conservation Status and Ecology of the Monarch Butterfly in the United States
- July 2016 Monarch Update: Helping Monarch Conservation Take Flight
- California Pollinator Plants: Native Milkweeds
- Western Monarchs in Peril – Xerces Society Fact Sheet
- Protecting Monarch Groves
- The Legal Status of Monarchs in California
- Xerces Society Conservation and Management Guidelines (1993)
- The Monarch Habitat Handbook: A California Landowner’s Guide to Managing Monarch Butterfly Overwintering habitat
- State of the Monarch Butterfly Overwintering Sites in California