In a glimmer of good news for the declining western monarch butterfly population, volunteers in California have recorded record-breaking numbers during this year’s migration, giving hope for the future of these beautiful insects.
In the weeks before heavy rains battered the California coast, volunteers grabbed their binoculars and headed out in an annual pilgrimage for a beloved animal. This year, their efforts for the 26th Western Monarch Count paid off with good news: a final tally of 335,479 butterflies during the study’s Thanksgiving counting period.
“We can all celebrate this tally,” says Emma Pelton, a conservation biologist at the Xerces Society and western monarch lead. “A second year in a row of relatively good numbers gives us hope that there is still time to act to save the western migration. That said, we know we still have a long way to go to reach population recovery, and the storms that hit right afterward mean we’ll start the spring with far, far less than this total.”
The results are a welcome reprieve from a total of fewer than 2,000 individuals counted in 2020 and nearly 250,000 in 2021. Yet the butterflies remain far from the low millions seen in the 1980s, and their recovery remains vulnerable to pressures like habitat loss, pesticide use and climate change.
Today the Xerces Society announced that 335,479 monarch butterflies were counted in the Western Monarch Thanksgiving Count last fall. What does it mean? Here is the abridged version. pic.twitter.com/SRD8hZjudX— The Xerces Society (@xercessociety) January 31, 2023
Central Coast hosts majority of western monarchs
More than 250 people participated in this year’s Western Monarch Count, surveying a total of 272 sites across coastal California and a few sites in interior California and Arizona between November 12 and December 4, 2022. Volunteers count clusters of monarchs as they huddle together to overwinter in groves of trees, often non-native eucalyptus.
California’s Central Coast continued to host a majority of the largest sites and overwintering western monarchs, with over 130,000 butterflies reported in both Santa Barbara and San Luis Obispo counties. The Bay Area witnessed a comeback from low numbers last year, with more than 8,000 butterflies reported in surrounding counties such as Alameda, Marin and Solano.
The largest count was 34,180 butterflies at an overwintering site in Santa Barbara County owned by The Nature Conservancy, followed by 25,710 butterflies at a private residential site in Santa Barbara County. Pismo State Beach Monarch Butterfly Grove had the third largest monarch count and is open for public viewing, with 24,128 butterflies reported at their peak.
Vulnerable to extreme weather
Shortly after the Thanksgiving count period ended, back-to-back atmospheric rivers drenched most of the California coast, battering overwintering sites. Observers reported flooding, downed tree limbs and even entire trees uprooted. While some sites fared well, volunteers at others reported more monarchs on the ground, blown from their clusters and vulnerable to the cold, wet conditions and predation.
“Small populations are particularly vulnerable to being snuffed out by extreme weather, so we are lucky these storms occurred in a relatively good year,” said Pelton. “We don’t want to count on luck alone to ensure the survival of the western monarch migration.”
That calls for not only restoring more monarch butterfly habitat throughout their range, but doubling down on making sure overwintering sites are protected and resilient to climate change. Site managers and landowners can take steps to replace dead and dying trees, landscape sites to prevent or mitigate flooding, and plant native nectar sources.
Need for more legal protections
“Unfortunately, there continues to be very little meaningful protection for the species or its habitat. Overwintering sites in particular continue to be destroyed and damaged each year,” says Isis Howard, a conservation biologist with The Xerces Society and coordinator of the count.
While migratory monarch butterflies were declared endangered on the IUCN Red List of Threatened SpeciesTM last summer, they are not yet listed under U.S. or state Endangered Species Acts, which would afford the species legal protections. A federal listing by the U.S. Fish and Wildlife Service is anticipated in fiscal year 2024.
“The plain fact is that if we lose overwintering sites in California, we could lose migratory western monarchs. Development, eucalyptus removal, and tree trimming all need to be managed thoughtfully if we are to leave space for these animals to survive,” says Howard.
How you can help
Once western monarchs depart from their overwintering sites, they rely on finding high-quality habitat and safe breeding grounds across several western states. Everyday gardeners, park managers, schools, and others can make simple but meaningful changes to help the western monarch population recover:
- Plant native milkweed.
- Plant a diversity of nectar plants, ideally native to your area.
- Stop using pesticides, or minimize risk associated with pesticide use.
- Call on legislators to support policies such as Recovering America’s Wildlife Act and the Monarch Action, Recovery, and Conservation of Habitat Act.
- Contribute to community science projects that track monarchs, such as the Western Monarch Milkweed Mapper, Western Monarch Mystery Challenge, and nationwide Integrated Monarch Monitoring Program.