A few visitors shielded their eyes from the sun on a warm December day as they peered into the eucalyptus trees at Pismo State Beach Monarch Butterfly Grove trying to spot a cluster of orange and black wings.
But the trees and sky were fairly empty.
Two monarchs fluttered around at about eye level by the small white trailer near the grove where visitors can get more information about the insect or purchase a souvenir.
“That’s not normal,” said Valerie Glahn, who has volunteered at the grove for eight years. “I don’t think they realize it’s winter.”
According to the U.S. Fish and Wildlife Service (FWS), more than 4.5 million Western monarch butterflies once flocked to the California coast in the 1980s to overwinter—Natural Bridges State Park and Pismo Beach being two of the largest overwintering grounds on the West Coast. Huddled close together, the insects form clusters in eucalyptus, pine, and oak trees for warmth and protection from November through February.
Amid decades of lost habitat for breeding and overwintering, pesticides, and climate change, the vital pollinator’s numbers have declined by 95 percent, leaving the Western monarch species with a 99 percent chance of extinction by 2080, according to the FWS.
To combat the butterfly’s looming disappearance, on Dec. 12 the FWS proposed to protect the insect by placing it as “threatened” under the Endangered Species Act. This listing would designate approximately 4,395 acres of critical habitat for the monarchs in San Luis Obispo, Santa Barbara, Monterey, Santa Cruz, and Ventura counties.
California State Parks Information Officer Jo Biswas said via email that Pismo’s butterfly grove has experienced the decline since State Parks started surveying butterfly numbers in 1997—a time when they were reported to be at 100,000.
This November, the survey reported roughly 400.
FWS Media Officer Joanna Gilkeson said that it can be hard to imagine why the monarch needs to be placed on the endangered species list, especially when they can seem so common in everyday life. But the FWS has seen the insect’s numbers consistently declining over the past 10 to 15 years.
“In the mid ’90s, there were really large amounts of butterflies counted, both on the West Coast in the Pismo Beach area, and along the coast,” she said. “But there’s been a pretty steep decline, and fewer and fewer monarchs counted at their historic overwintering grounds in those area.”
When counting the monarchs, Gilkeson said they use the clusters.
“That’s how they’re counted, right? It is when they’re congregating in the overwintering clusters because it’s the only time when they’re all sort of in the same place, and we’re able to get a handle on what their population is,” she said.
With fewer and smaller clusters throughout the years, Gilkeson said the service is attributing the decline to land conversion as humans build on critical habitat that naturally grows milkweed—what monarchs eat and lay their eggs on.
“Humans changing the land has affected their food supply and basically their ability to reproduce,” she said. “They require the milkweed plant to lay their eggs, and that’s the only food that they eat. So, the less milkweed available, the less they’re able to reproduce and survive. And so it’s just kind of like a vicious cycle.”
Pismo Butterfly Grove volunteer Glahn said this winter is the second lowest season there, after seeing its lowest numbers at about 200 in 2020.
But Glahn said that this year is more unusual than that. On Thanksgiving, the grove saw more than 400 butterflies, but she said by the end of December it had maybe 200.
“Usually when they cluster, they stay,” she explained.
The clustered butterflies had scattered within a month when usually they would stay together until February.
“This year they never got into their normal overwintering clusters,” she said. “This season they are flying around.”
Typically, monarchs start breeding in January and February when the cold season passes, Glahn said, but this year they had already started to breed in December. She equated this behavioral change to the warmer weather and pointed to a visitor wearing shorts and a T-shirt.
“The cues are telling them it’s fall,” she said.
With the butterflies laying eggs too early in a habitat that’s already lacking milkweed, Glahn said she worried this year could even be the last migration.
“Usually when I volunteer it’s happy, but this season has been doom and gloom,” she said.
Listing the monarch as a threatened species could be a years-long process, but the first step was proving that there’s a reason to even propose it, FWS Media Officer Gilkeson said.
“How that works is our biologists have done a big analysis over a period of time, looking at all the information that’s available out there about monarchs, determining that, yes, they do meet the definition of a threatened species,” she explained.
The FWS’s submitted threatened species proposal opened a 90-day public comment period, which will close on March 12, 2025.
“We encourage people with information and comments to submit them to us, and our biologists will go and look at all of those comments and determine and incorporate them as necessary,” she said.
Based on the biologists’ review and comments from the public, Gilkeson said, the monarch will either be listed as threatened or the rule could be withdrawn.
“It could even go endangered if the population were to quickly decline,” she added. “It usually doesn’t happen, but it could be endangered.”
According to Gilkeson, the official decision to place the monarch on the threatened species list will be made in late 2025, possibly early 2026.
“We try to aim for a year out from the initial proposal. I think that will get a lot of comments on this one, so it’ll be interesting to see how long it takes all of our biologists to go through those comments, because they do read them all … and use that to build the final rule,” she said.
In the meantime, FWS and California State Parks encourage the public to learn more about the monarch and suggested ways to help with its conservation.
“The unique thing about monarchs is that there are lots of things that anybody could do to help, right?” Gilkeson said. This includes planting native milkweed and flowering plants.
“You want some blooming in spring and summer and fall—so there’s an ongoing source of food for monarchs,” she said.
Gilkeson also said that residents can dim their outdoor lights at night or place them on timers, as to not distract or confuse the monarchs.
“You know how moths are drawn to light?” she said. “There are studies coming out talking about how it distracts [monarchs] from being able to pollinate and to gather nectar at night. So, it’s actually impacting their ability to do their jobs, and their ability to gather the energy resources—the food that they need.”
State Parks Information Officer Biswas said that State Parks plans to continue working with the FWS and other partners to help the monarch and continue educating the public about the history and conservation status of the species.
“Similar to other ‘charismatic’ species like giant sequoias, humpback whales, grizzly bears, and bighorn sheep,” Biswas said, “monarchs help crystallize public attention on the need to preserve California’s biodiversity for future generations.” Δ
Reach Staff Writer Libbey Hanson at lhanson@newtimesslo.com.
This article appears in Jan 2-12, 2025.