Borrego Sun - Since 1949

Butterfly Invasion


Last updated 4/22/2019 at 4:49pm

Shawn C. Baker

In what experts say is the biggest butterfly migration since 2005, and we're talking millions then and at least a billion now, according to reports, Painted Ladies are starting to come out in force throughout Southern California, from the Mexican border up thru San Diego County and into Los Angeles.

The migration itself is nothing new. Painted Ladies set off from their wintering grounds in the Mojave and Colorado deserts of southeastern California as winter gives way to spring. They travel roughly the same path every year, flying northwest to Sacramento en route to Oregon, Washington and beyond. (They've been spotted as far north as Alaska.)

Here in Borrego, the Painted Ladies have already arrived in concert with our own expected 2019 Super Bloom, only just beginning.

Light but frequent rains the past few months are raising the likelihood of a Super Bloom, both in Borrego and elsewhere around the southland. As but one example, the average yearly rainfall in Coachella Valley is 3", but this year they had 3½" on Valentine's Day alone.

Following a season bringing almost two inches of rain above Borrego's historical average of about six inches, and with temperatures currently on the rise after a cool period, the wildflowers are starting to bloom and are ready for pollination. The Painted Ladies are here to oblige.

Like Monarchs, Painted Ladies are a bit smaller, about the size of a silver dollar, and they are spotted with dabs of black, white and brown. And they come in swarms, sometimes in large clouds overhead, as was the case back in 2001.

The Painted Lady explosion is a welcome exception to California's current butterfly crisis. The number of butterflies in the state has been in decline for decades, reaching historic lows in 2018, according to research conducted by Art Shapiro, an ecologist at UC Davis who has been tracking butterflies in the state for nearly 50 years.

"It was a terrible – perhaps even catastrophic – butterfly year at all elevations and no, we don't know why," Shapiro wrote in a report.

A monarch count led by the Xerces Society for Invertebrate Conservation in November found only 28,429 of the iconic orange-and-black insects wintering along the California coast, an 85% drop from the previous year and a 99.4% plunge compared to 40 years ago.

Other butterfly populations have been hit even worse. At least 20 species are disappearing faster than the monarch, said Matt Forister, ecologist at the University of Nevada, Reno.

Painted Lady swarms have been spotted in the Anza-Borrego Desert State Park, along S-22 in the Badlands region where wildflowers have bloomed, in crop regions on the western side of the Salton Sea on Highway 86 between the S-22 and La Quinta, and generally within much of the north and east sections of San Diego County.

Residents who have lived in Los Angeles their whole lives and spotted the Painted Ladies have never seen anything like it.

"It's beautiful, something you don't see every day," said Studio City resident Angie Evans in a recent L.A. Times piece.

There are currently so many butterflies on the wing along the 30-mile stretch of Highway 86 between Salton City and La Quinta that drivers can only watch as their windshields turn from clear to yellow splotches by the dozen as swarms of Painted Ladies try, some unsuccessfully, to make it across the highway.

Marc Jorgensen, resource ecologist at the Park, weighed in during an interview with the San Diego Union-Tribune (SDUT).

"Flurries of the butterflies were as thick as falling snow in the desert, and people are feeling guilty," he said. "You can't drive down the road without being responsible for the death of hundreds of them."

Also quoted in the SDUT piece was David Dyer, a naturalist for the Buena Vista Audubon Society and retired entomologist for the County of Los Angeles.

"The little butterfly can travel up to 40 miles per hour and cover hundreds of miles in a single day. Although they may appear to be flying in swarms, they are traveling as individuals. They're like us on the freeway."

With the Super Bloom expected to peak in the coming weeks due to recent rains and rising desert temperatures, these give butterflies more plants to eat and more places to lay their eggs. Female butterflies can lay over hundreds of eggs on one plant. With more Painted Ladies come more caterpillars, and with them will soon come the Swainson's Hawks.

For Borregans wishing to see a true spectacle of nature, keep your news-eyes peeled for a notice by our own Hal Cohen, "The Hawk Guy," and make plans to be there on DiGiorgio Road after the hawks have gorged themselves on caterpillars and leave the Eucalyptus grove.

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