Western Monarchs Rebound So Many Butterflies

Western monarchs recover nearly 250,000 butterflies

PORTLAND, Ore. – For decades, the count of the Western monarch has catalogued the rapid decline of one of the most enigmatic butterflies in North America. In a surprising and remarkable way, I have made a final record of 247,237 monarch butterflies observed in the West, an increase of 100 times compared to the previous year for a total of less than 2,000 monarchs and the highest total since 2016.

“We are delighted with the results and hope that this trend will continue,” says Emma Pelton, head of the Western monarch at the Xerces Society. “There are so many environmental factors at play throughout its range that there is no definitive cause or answer for this year’s recovery, but I hope it means that we still have time to protect this species.”

Wintering areas inclined to the south

Santa Barbara County recorded the largest number of monarchs this year, with more than 95,000, including the largest isolated site where more than 25,000 privately owned butterflies were recorded. San Luis Obispo County ranked second with more than 90,000 butterflies reported in wintering areas, including the Pismo Beach Butterfly Sanctuary, managed by the California State Park, which recorded the second largest number of Wintering Areas this season with 20,871 butterflies.

As a rule, the central coast of California is home to the majority of monarchs, as well as a significant number in the San Francisco Bay Area. However, there were few or no monarchs in the Bay area that year, with fewer than 600 butterflies recorded in wintering areas from Mendocino to San Mateo County.

Other monarchs have been found near Santa Cruz, with more than 1,000 in Natural Bridges State Park and Lake Moran. And in Monterey County, the city of Pacific Grove celebrated the return of about 14,000 monarchs to its sanctuary. In Ventura and Los Angeles Counties, monarchs have been found in numbers not seen since the early 2000s – almost 19,500 butterflies and more than 4,000 butterflies.

Thanks to public advice, five new beds have been discovered this season in San Luis Obispo and Los Angeles Counties, totaling more than 7,000 butterflies.

These totals were observed thanks to a record performance of volunteers in the study of 283 wintering sites. Supported by regional coordinators, the volunteers search for and record groups of monarchs who gather for the winter heat.

“I actually had more volunteers this year than I have in the last 10 years because so many people care about monarchs and want to help,” says Jessica Griffiths, San Luis Obispo County regional volunteer coordinator. “They were outside in the cold at dawn, scanning the trees with binoculars. Some of the new volunteers saw groups of monarchs on their pages for the first time this year, which was really exciting.”

Rebound offers a glimmer of hope to ward off extinction

While the 2021 figures deserve to be celebrated, the Western monarchs have experienced a significant decline since the 1980s, losing more than 95% of their population.

“This year’s total is a step in the right direction, but still indicates a sharp decline in the Population,” says Isis Howard, biologist for the protection of endangered species at the Xerces Society. “Maintenance more than ever, we have the opportunity to double our conservation efforts. Acting quickly to take advantage of the momentum of this recovery is our best chance to prevent Western monarchs and other endangered butterflies from being lost forever.”

The main measures taken to support the recovery of Western monarchs include the protection of their habitat and their wintering areas, the reduction of the use of pesticides and the restoration of new habitats by planting nectarines and native milkweeds in the appropriate places of their range, as indicated in the call for action of Western monarchs launched by the European Commission

“Insects can be incredibly resistant if we give them a chance,” says Scott Hoffman Black, director of Xerces. “Everyone has a role to play, whether it’s adding pollinators and avoiding pesticides in your garden or advocating a Pro-monarch policy in our neighborhood, public lands, nurseries and agricultural suppliers.”

The following organizations support the protection of Western monarchs by the Xerces Society:

Bureau of Land Management, California Department of Fish and Wildlife, California State Parks Foundation, California Conservation Office, Chantecaille, Google.org , Forest Service International Program, Marion R. Weber Family Fund, National Fish and Wildlife Foundation, Conservation Service, San Diego Zoo Wildlife Alliance, Taggart saxon National Fund, US Fish and Wildlife Service and members of the Xerces Society.


The Western Monarch count is an annual effort by volunteer community scientists to collect data on the state of the western monarch Population — its wintering period, which takes place from about October to March. The sightings extend along the Pacific coast from Mendocino, California, north to Baja, Mexico, as well as to some inland sites in California and Arizona. The culmination of this volunteer effort takes place during the Western Monarch’s Thanksgiving Count, which takes place three weeks around Thanksgiving. It started in 1997 as a concerted action by Mia Monroe, Dennis Frey and David Marriott. Today, the census is coordinated by the Xerces Society for Invertebrate Conservation and Mia Monroe.

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