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California's Monarch Butterflies May Be In Extinction Spiral

A monarch butterfly sits on a flower at Butterfly Farms in Encinitas on May 24, 2019
Erik Anderson
A monarch butterfly sits on a flower at Butterfly Farms in Encinitas on May 24, 2019

California monarchs are in trouble and federal officials have demurred when it comes to providing help.

A new survey of the Western population of the orange, black and white butterflies shows that the migrating population is crashing.

California’s Monarch Butterflies May Be In Extinction Spiral
Listen to this story by Erik Anderson.

A Thanksgiving holiday survey of the butterfly’s traditional West Coast wintering sites recorded only 2,000 of the iconic butterflies.


Hundreds of volunteers helped scour known sites along the Pacific coast.

“We have monarch sites as far north as Mendocino County down to Baja Mexico,” said Emma Pelton, a senior conservation biologist with the Xerces Society for Invertebrate Conservation. So no single person could possibly count all those sites at once.”

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Pelton is alarmed by the latest findings.

“The last two years we were at all-time lows, just below 30,000 butterflies,” Pelton said. “So we knew they were in trouble. But we didn’t expect the decrease to just about 2,000 monarchs so we’ve had another order of magnitude decline.”


Meanwhile, the U.S. Fish and Wildlife Service finally ruled on a petition to grant both the Eastern and Western monarchs endangered species protection.

The federal agency determined the monarch's quality for federal protection, but the agency has other priorities that will keep that from happening. The butterfly’s status will be reviewed once a year.

That may not be enough to protect the butterfly's Western population.

VIDEO: California's Monarch Butterflies May Be In Extinction Spiral

“I think this is a warning to the greater population,” said Paige Howorth, the director of invertebrate care and conservation at San Diego Zoo Global. “This petition for listing was submitted in 2014 and here we are in 2020 with less than 2,000 butterflies that figured out how to get to overwintering sites.”

There were 200,000 migrating Monarchs just three years ago, and in the 1980s the butterflies numbered in the millions.

There are local populations that do not migrate, but they may not be here in large enough numbers to keep the Western population viable.

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Since 2014, when environmental groups petitioned to list the monarch, school groups, garden clubs, government agencies and others around the nation have restored about 5.6 million acres (nearly 2.3 million hectares) of milkweed plants on which monarchs depend, said Charlie Wooley, head of the USFWS Great Lakes office. They lay eggs on the leaves, which caterpillars eat, while adults gather nectar from the flowers.

The volunteer effort “has been phenomenal to see,” he said. “It has made a difference in the long-term survival of monarchs and helped other pollinators that are potentially in trouble.”

But advocacy groups say it has compensated for only a small fraction of the estimated 165 million acres of monarch habitat — an area the size of Texas — lost in the past 20 years to development or herbicide applications in cropland.

“Monarchs are too important for us to just plant flowers on roadsides and hope for the best,” said Tierra Curry, a senior scientist at the Center for Biological Diversity. “They need the comprehensive protection that comes only from the Endangered Species Act, which would save them and so many other beleaguered pollinators that share their habitat.”

The pandemic has worsened burnout and stress on caregivers for disabled veterans. Meanwhile, San Diego’s Rady Children’s hospital received their first round of COVID-19 vaccines for their frontline emergency nurses. Also, the population of California’s Monarch Butterfly is crashing.

Corrected: December 11, 2023 at 11:01 AM PST
The Associated Press contributed to this story