We spotted this Painted Lady butterfly (Vanessa cardui) sunning itself on a carpet of red-purple ice plant (Delosperma cooperi) in west Vacaville on March 20, "the day after the first day of spring."
Each competed for photographic attention: the soothing autumn colors of the butterfly and the brilliance of the spring ice plant.
V. cardui is a migratory butterfly that travels across the deserts of Southern California, up into our area, and then to the Pacific Northwest. Last year, 2019, was a great migratory year for the Painted Ladies, as was 2005.
Butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology who has studied the Central California population of butterflies since 1972, writes on his butterfly website:
"This mass-migrant occurs in much of the Northern Hemisphere. Apparently the entire North American population winters near the US-Mexico border, breeding in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north. In good years (lots of desert rain) they may do so by billions, interfering with traffic and attracting the attention of the media. 2005 was one of the biggest Painted Lady years in history--perhaps the biggest, but how can we know?
"At Sacramento at the height of the migration butterflies were passing in one's field of vision at the rate of about 3 per second! 2006, by contrast, was a La Nina year with very little rain in the desert. The butterflies apparently gave up trying to breed there and flew north in February. They tried to breed but mostly were unsuccessful due to bad weather, resulting in only very sporadic individual sightings of their progeny in May. Northward-migrating Painted Ladies are provisioned with yellow fat and are reproductively immature. They do not stop to feed or have sex until they have burned up their reserves, carried over from the caterpillar stage. They fly in a straight line from SE to NW, like "bats out of Hell," and go over obstacles rather than trying to go around them. (On certain days there may be concerted local movements in the wrong direction. We do not understand these.) Painted Ladies tend to fly parallel to the Sierra Nevada, not across it. They enter the Central Valley through the Inyo-Kern lowland or by crossing the Transverse Ranges. They can apparently make it from Bishop to Davis in three days. In some years the migration is heavier in the Great Basin and on the East slope of the Sierra than farther west."
And as Shapiro will tell you, the Painted Lady is commonly mistaken for the iconic monarch (Danaus plexippus). Last year social media enthusiasts mistakenly acclaimed they'd seen "hundreds and hundreds" of monarchs passing by them.
BugGuide.net says V. cardui, which inhabits every continent except Antarctica and South America, is "commonly and easily raised especially in elementary school classrooms."
But life as we know it, has changed. California closed its classrooms in the throes of the coronavirus pandemic. "Social distancing" and "self-quarantining" are holding our vocabulary hostage. Social butterflies? Not in this environment. But sometimes, you happen upon a serene social scene--an autumn-colored butterfly tucked in a bed of spring ice plant--that takes your breath away.
The honey bee and the Painted Lady.
Apis mellifera and Vanessa cardui.
They both wanted to sip that sweet nectar from a mustard blossom.
The Painted Lady was there first. Sometimes it's "first come, first served" and sometimes it's "I'll have what she's having."
The persistent bee managed to forage a bit around the blossom, but the butterfly, just as persistent, stayed put.
Finally, the bee buzzed over the butterfly, nearly touching it, as it headed for new territory.
Meanwhile, the cardui migration continues, from California through the Pacific Northwest. Millions have already moved through the Davis/Sacramento area on their way up north.
"It's Week 11, Day 81," says butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology. "It's almost over (through this area)."
An article published May 19 in the Idaho Statesman, Boise, announced that "Hundreds of Butterflies Flitted Through Boise This Weekend."
"This weekend, Boiseans found themselves in the middle of a massive migration as hundreds of orange-and-brown butterflies known as painted ladies winged their way through the area," wrote reporter Nicole Blanchard. "Dozens of people on social media shared accounts of seeing the butterflies flying overhead en masse or stopping to snack on spring blooms. Many of the painted lady butterflies, which are often mistaken for monarchs because of their orange coloring, were spotted in the North End and Foothills on Saturday."
One Boise resident related on Twitter that she saw 56 flying northwest through her yard in a period of two minutes.
Want to learn more about Painted Ladies and other butterflies? Check out Art Shapiro's website. He's been monitoring the butterfly populations of Central California since 1972.
On Vanessa carduii: The mass migration begins near the U.S.-Mexico border, Shapiro says. They breed "in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north. In good years (lots of desert rain) they may do so by billions, interfering with traffic and attracting the attention of the media. 2005 was one of the biggest Painted Lady years in history--perhaps the biggest," he says. This year was also a very good year.
"They do not stop to feed or have sex until they have burned up their reserves, carried over from the caterpillar stage," according to Shapiro. "They fly in a straight line from SE to NW, like 'bats out of Hell,' and go over obstacles rather than trying to go around them. (On certain days there may be concerted local movements in the wrong direction. We do not understand these.) Painted Ladies tend to fly parallel to the Sierra Nevada, not across it. They enter the Central Valley through the Inyo-Kern lowland or by crossing the Transverse Ranges. They can apparently make it from Bishop to Davis in three days. In some years the migration is heavier in the Great Basin and on the East slope of the Sierra than farther west. The Painted Lady moves northward in a generational wave as the season progresses. Frequently it disappears altogether from the lowlands in summer. Beginning in August the movement reverses and butterflies head south toward the desert wintering grounds. The southward migration is a more protracted affair, with plenty of adult feeding and some breeding en route. Numbers tend to be highest east of the crest, on Rabbitbrush blossoms in October."
It's been a very good year for these orange-black butterflies, which began arriving in the Davis/Sacramento area on March 17. Just don't confuse them with Monarchs! Shapiro can't begin to count the calls of folks telling him that the Monarch is no longer in trouble; that "there are millions of them!"
The "Painted Ladies" are back in the Davis area.
These are not the two-legged type, but the winged type--Vanessa cardui.
They're migrating and driving UC Davis entomology and ecology students nuts. It's finals week and they'd love to be outdoors watching the migration instead of inside studying for their tests.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology, said that on Tuesday, March 17, St. Patrick's Day, "the front of a significant Painted Lady migration hit Davis about 7:30 this morning. I saw about 30 just in walking from Storer Hall to the Memorial Union bus terminal.
Shapiro then went to Gates Canyon, Vacaville, one of his field study sites, and saw more. It was 77 degrees at Gates Canyon (sorry, Bostonians!). He saw PLs all the way. He counted 81 in the canyon "but the apparent density in the open--Pleasants Valley, Vacaville--was much higher, with about 6 per minute in my field of vision."
"I imagine many were going over my head out of sight at Gates. Back in Davis I was seeing 10 per minute. This is about 1/6 of the density during the legendary 2005 migration."
"They are ALL large, fresh-looking, and on a solid SE-NW course, as usual stopping for nothing and going up and over all obstacles; very few are nectaring. We'll see how long it lasts! The condition suggests these are the offspring of a first round of breeding somewhere in Southern California--not direct from the deserts. We have an exceptional crop of milk thistle (Silybum) this year. May their offspring eat it all!"
You can read about the 2005 migration on Sharpiro's butterfly site. "This mass-migrant occurs in much of the Northern Hemisphere," he wrote. "Apparently the entire North American population winters near the US-Mexico border, breeding in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north."
Painted Ladies on the move. Painted Ladies everywhere. And more on the way. Life is good!
What did you do on Black Friday?
Did you spend the night camped out in front of a store? Or did you join the throngs of people who left home in the wee hours of the morning for the doorbuster deals or stayed on your computer for the online onslaughts?
Last year, according to Wikipedia, approximately 141 million U.S. consumers shopped on Black Friday. They spent--are you ready for this?--a total of $57.4 billion, with online sales reaching $1.2 billion.
Not me. It was Butterfly Friday for me. In between working on major projects, I slipped outside occasionally to see the butterflies landing on the purple lantana.
First, a beautiful Gulf Fritillary (Agraulis vanillae) showed up to gather some nectar. This is a bright reddish-orange butterfly of the family Nymphalidae and subfamily Heliconiinae. Some folks call it "the passion butterfly" as its host plant is Passiflora, the passion flower vine.
Next to show up was a butterfly of the same family, Nymphalidae: a Painted Lady (Vanessa cardui). Some folks call it the "thistle butterfly" as the thistle is one of its host plants. The Painted Lady reminds me of a calico cat, a skittish calico cat. So many earthy colors, and where one ends, another blends. No fashion designer could replicate those hues!
The Gulf Frit challenged the Painted Lady in a game of "It's-mine; I-was-here-first." The Gulf Frit won but the Painted Lady returned.
Meanwhile, no shopping day for us. No camping out, no charging into stores, no racing for would-be presents.
Nope. Final score: Black Friday: 0. Butterfly Friday: 2.
The painted ladies are on move.
Scores of painted ladies (Vanessa cardui) are now migrating north from their overwintering sites near the U.S. Mexico border.
"Fascinatingly, they arrived in Prescott, Ariz., the same day (as the ones spotted in Benicia)," said butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis. "I think they're all from south of the border." The annual migration north varies, but can take place as early as late January and as late as mid-April.
The painted ladies spend the winter in the desert, where in the late winter, they breed on desert annual plants, Shapiro says. The adults emerge in February or March and immediately migrate into the Central Valley and foothills, where they breed. Around May, here in the Central Valley, you'll see the caterpillar offspring munching on borage, thistles, fiddleneck and mallows. Then the adults head toward the Pacific Northwest.
"The painted lady moves northward in a generational wave as the season progresses," Shapiro says on his website. "Frequently it disappears altogether from the lowlands in summer. Beginning in August the movement reverses and butterflies head south toward the desert wintering grounds."
"There is no evidence that this species overwinters successfully anywhere in our area, except for very rare individuals maturing in midwinter from really late autumnal larvae."
The painted lady migration may not be as popular as the monarch (Danaus plexippus) migration, but it's fascinating just the same.
Shapiro, who has monitored the butterfly population of California's Central Valley for 42 years, will be speaking at noon on Monday, March 24 on "Ecological Communities and the March of Time" in the Commonwealth Club, 595 Market St., San Francisco. For program detail and registration, please see the club website. His talk is open to the public. For a discount, access the website and use the coupon code, "friendsforshapiro," said spokesperson Chisako Ress (email@example.com).