The number of western monarch butterflies counted at a Pismo Beach grove this fall has more than tripled in the past three weeks, according to preliminary counts by California State Parks employees.
Across California, the number has quintupled — “Which is awesome,” said Emma Pelton, a senior conservation biologist with the nonprofit organization Xerces Society for Invertebrate Conservation. “It’s kind of amazing,”
About 22,400 monarchs were counted in the Pismo State Beach Monarch Butterfly Grove off Highway 1 on Nov. 10, according to State Parks.
Another 30,000 monarchs were counted in other overwintering groves around California on the same day, including about 13,000 at the Pacific Grove Monarch Butterfly Sanctuary and 10,000 at a site in Big Sur, Pelton said.
Pelton said there are likely more than 50,000 monarchs overwintering in California this year. “Actually, that’s probably a low, low estimate,” she noted.
During the annual Thanksgiving western monarch count organized by the Xerces Society and conducted by about 400 volunteers, scientists and researchers will gather a more accurate and complete count of how many butterflies are overwintering in the state this year.
The count began on Saturday and ends on Dec. 5.
Despite her enthusiasm about the high numbers of monarchs counted so far, Pelton was quick to temper her optimism.
“It’s also not recovery,” she said. “So it’s really great and we should celebrate this — yes, these are the best numbers we’ve seen in four years — but four years ago this would have been nothing.”
In 2017, more than 192,000 monarchs were counted in California, according to data from the Xerces Society.
The number of monarchs counted at the Pismo Beach grove is likely the best in six years, however.
In 2015, more than 28,000 butterflies were counted at the grove in southern San Luis Obispo County, the Xerces Society’s data show.
What is causing monarch butterfly population increase?
Several theories are floating around as to why or how the monarch population is seemingly bouncing back this fall, Pelton said.
One is that the warmer, drier summer and mild fall could have aided the butterflies’ reproductive rates and spurred their migration — what Pelton called the right combination of “good weather, good conditions and good luck.”
Most likely, however, is that the population jump is due to many factors.
Pelton, professor Elizabeth Crone of Tufts University and professor Cheryl Schultz of Washington State University co-authored a blog in which they note the monarch butterfly population, like other insects, is naturally “bouncy,” or can “fluctuate from year to year in response to the temperature, rainfall, the availability of food and other factors.”
“Hence, seeing 50,000 in early reports is certainly a hopeful sign and evidence that the migration is definitely not gone, as some feared after last year,” the blog reads.
Experts urge strong conservation measures
In the continual effort to help the monarch population grow to its historic numbers, the Xerces Society and many other organizations around the nation continue to push for less pesticide and insecticide use on farms and in gardens, as well as the restoration of monarch and pollinator habitats.
And there’s some legislation to keep an eye on.
The Monarch Pollinator and Highway Act — reintroduced in the U.S. House of Representatives by U.S. Rep. Salud Carbajal (D-Santa Barbara), Rep. Jimmy Panetta (D-Carmel Valley) and Sen. Jeff Merkley (D-Oregon) in March — would establish a federal grant program available to Native American tribes, federal land management agency and state departments of transportation to carry out pollinator-friendly practices on roadways and highway rights-of-way.
The bill has since been added to the $1 trillion Infrastructure Investment and Jobs Act that President Joe is expected to sign into law on Monday.
Originally, the bill proposed providing $5 million per fiscal year from 2022 to 2028, but the language in the infrastructure package decreased that to $2 million per fiscal year.
Another bill reintroduced by the same politicians, the Monarch Action, Recovery and Conservation of Habitat (MONARCH) Act, is still being considered in the House.
As it was proposed, the MONARCH Act would set aside $62.5 million to implement a massive western monarch butterfly conservation plan prepared by the Western Association of Fish and Wildlife Agencies in January 2019, and another $62.5 million for any eligible entities that implement a monarch conservation project.
Pelton advocated for the passage of those bills, partly because they stand as some of the only federally-supported protection and restoration measures for the species.
Monarch butterflies were denied federal protection under the Endangered Species Act in 2020, despite the U.S. Fish and Wildlife Service acknowledging the species’ population could collapse in the next 50 years.
What’s the best time to spot monarch butterflies in Pismo Beach?
Danielle Bronson, an interpreter with State Parks, said there are certain times when monarch butterfly viewing at the Pismo State Beach grove is at its best.
If you want to see the butterflies clustering on the tree branches, “it’s better when it’s cooler,” Bronson said.
Because monarchs are cold-blooded insects, they hang tight on the branches close to each other for warmth, she said.
Then, she added, when it gets warmer the monarchs will fly around more.
If you’re lucky, you may see what Bronson called a “sunburst,” or when a big group of the monarchs suddenly leave their perch and burst into the air.
To witness that, Bronson advised visitors to get to the grove mid-morning — when it’s still cool from the night but the sun is beginning to warm up the day. For the Pismo Beach grove, that’s around 9:30 to 10 a.m., she said.
Bronson shared an additional tip for would-be butterfly watchers: “Bring binoculars!”