In between the rains today, we saw them.
So beautiful! Painted ladies, Vanessa cardui, nectaring in patches of colorful wildflowers in the Biological Orchard and Gardens (BOG), located behind the Mann Laboratory on University of California, Davis campus.
The migratory butterflies, passing through California on their way to the Pacific Northwest, stopped there for some flight fuel: sipping nectar from tidy tips, Layia platyglossa; five-spot, Nemophila maculate, and blue lupine, Lupinus.
They've been in the national news a lot, these butterflies, as has butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology. Known for his expertise on all things butterfly, he's monitored the butterfly population of Central California since 1972 and maintains a research website.
Yes, it's been a big year for painted ladies, thanks to the heavy rainfall and super blooms in the deserts near the Mexican border. And, as Shapiro says, tremendous wildflower blooms are typically great years for the painted ladies.
New York Times reporter Julia Jacobs interviewed Shapiro for her March 17th piece, in which she marveled that millions of the painted ladies are migrating. Shapiro told her: "The striking thing is they're moving very rapidly and directionallly. So it's almost like being in a hail of bullets.”
Rita LeRoy or "Farmer Rita," the self-described "Farm Keeper" on the Loma Vista Farm, Vallejo, part of the Vallejo City Unified School District, saw the butterflies passing through the farm on Monday, March 17. Her description is fabulous:
"They came through Vallejo on Monday," she said. "Art's description was right on. It was like being in a hail of bullets. This was because they were flying so low and it was a constant stream, like standing in the middle of a 500 lane expressway. I kept telling the students, 'Look! Another, another, another...' The path was at least as wide as the farm which is about 200 yards. When I stood in one spot, I would agree they were passing within my vision (about 100') at about 1 every second. They rarely stopped to nectar but were flying in a very direct NE direction when they came through the farm. They flew through nonstop from before 1 p.m. and the flow started to dwindle around 4 p.m. Still enough at that point to show the after school kids. They didn't fly in huddled groups or clouds and they moved fast. I tried taking a video but it was like a bad remake of The Blair Witch Project, with unfocused, whiplash camera moves of uncertain objects since they are so small in the overall background. I'm so glad Art saw them."
Today (Wednesday) we didn't see the hail of bullets, but we did see about a dozen of them grabbing some flight fuel on the UC Davis campus over a 10-minute period.
If you get a chance, check out the Biological Orchard and Gardens. A 24,000-square-foot garden, located behind the Mann lab, off Kleiber Hall Drive, it's planted with several dozen species of heritage fruit trees, and landscaped with flower gardens. The painted ladies are elsewhere on campus, too, including the UC Davis Arboretum and Public Garden.
The painted ladies are on the move.
Have you seen these migratory butterflies, Vanessa cardui, passing through California on their way to the Pacific Northwest?
Me? No! Zero. Zilch. Zip.
But butterfly guru Art Shapiro, distinguished professor of evolution and ecology, who has monitored the butterfly population of Central California for more than four decades and maintains a research website, has seen approximately 400 painted ladies this season--about 300 today.
All I saw today was a lone cabbage white butterfly flying through our pollinator garden in Vacaville.
Guess the painted ladies didn't get the message. The New York Times, did, though.
"The orange butterflies, called painted ladies, are known to travel annually from the deserts of Southern California to the Pacific Northwest," wrote New York Times reporter Julia Jacobs in a March 17th piece. "This month, people are taking notice because of the sheer size of the migration: Scientists estimate the teeming painted ladies number in the millions."
"Substantial rainfall in the deserts near the Mexican border, where the North American painted ladies lay their eggs, is the reason for the unusually large swarms," Jacobs pointed out. "The rain caused plants to thrive, giving the painted lady caterpillars plenty of food to fuel their transformation, said Art Shapiro, a professor of evolution and ecology at the University of California, Davis."
Shapiro told the New York Times that "the striking thing is they're moving very rapidly and directionally. So it's almost like being in a hail of bullets.”
They're passing through Davis, too. Shapiro headed over to the UC Davis Memorial Union patio today and noticed that "the painted ladies are on the upswing. Many are nectaring, suggesting they're running out of fat, but despite the abundance of potential hosts, saw no oviposiiton. Condition extremely variable, from beat-to-hell to looking almost fresh."
The professor witnessed them passing by the Memorial Union "roughly one every 90 seconds." Ironically, no one seemed to notice them, Shapiro said. Well, it is finals week!
The Los Angeles Times reported March 11 that a "massive swarm of at least 1 billion butterflies is traveling across Los Angeles and neighboring counties at a breathtaking speed of almost 20 miles an hour." They're in a "rush to reach their breeding areas in Oregon."
Shapiro says that years of tremendous wildflower blooms are typically big years for the butterflies. The last big year was 2005. He explains the phenonomen on his 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," he writes. "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.
"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."
Well, maybe tomorrow one or more painted ladies will fly my way. Preferably more.
Shapiro just received word of "a major movement through the Kern River Valley. Inyo-Kern is the superhighway from the desert to the Central Valley, so the biggest numbers may yet be on the way."
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!
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 (firstname.lastname@example.org).