Posts Tagged: migration

Welcome Back, Painted Ladies

The painted ladies are on move.

Butterflies.

Scores of painted ladies (Vanessa cardui) are now migrating north from their overwintering sites near the U.S. Mexico border. 

On Saturday, March 8 we saw two of them nectaring on Spanish lavender in the Avan Garden, a community garden at the corner of First and D Streets in Benicia.

"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 (chisakoress@gmail.com).

A female butterfly, a painted lady, nectaring on Spanish lavender on March 8 in the Benicia Community Garden. (Photo by Kathy Keatley Garvey)

A female butterfly, a painted lady, nectaring on Spanish lavender on March 8 in the Benicia Community Garden. (Photo by Kathy Keatley Garvey)

Painted lady twists around for a better shot at the nectar. (Photo by Kathy Keatley Garvey)

Painted lady twists around for a better shot at the nectar. (Photo by Kathy Keatley Garvey)

Painted Ladies Are Back

The painted ladies are back.  

No, not the Victorian and Edwardian homes painted in three colors. No, not women wearing excessive amounts of makeup and pounding the sidewalk with their stiletto heels. 

These are BUTTERFLIES. 

"Another Painted Lady (Vanessa cardui) migration is occurring in north-central California," reports noted butterfly expert Arthur Shapiro of UC Davis. "Painted Ladies showed up very early in the region, in late January, and there are hints of overwintering and breeding somewhere in south-central or southern California somewhere north of the usual desert breeding grounds along the Mexican border." 

Why hints of overwintering and breeding? Because the insects "were in good condition and did not appear to have migrated long distances," Shapiro says. "They also did not show the usual color-and-pattern signs of having been generated in the desert, but they were not produced locally in the Davis-Sacramento region and were seemingly confined to the west side of the Valley."

 Shapiro reports that the  first wave from the desert showed up in mid-March. "We received reports of significant numbers migrating through the Sierra at Mammoth Lakes as of March 15."

We saw them last weekend passing through parts of Solano and Yolo counties. They were moving fast and flying low.

"These butterflies are powered by yellow fat carried over from the caterpillar stage and fly like 'bats out of hell' from the Southeast to the Northwest a few feet off the ground, not stopping for food or sex until their fat reserves become depleted," Shaparo. He spotted a few feeding and one female was laying eggs.

Shapiro is updating the migration on the home page of his Web site.  It's a must-read.  You can learn more about Painted Ladies inside his Web site.  See also pages 48-51 and 195-200 of  his Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions (University of California Press, 2007).

Got a migration report or a video to offer him for his Web site? You can email him at amshapiro@ucdavis.edu.

Meanwhile, those Painted Ladies are absolutely gorgeous. We've heard far too much about ballistic bailouts, burgeoning bonuses and mortage meltdowns--and not enough about the Painted Ladies. 

Bring 'em on!

Painted Lady

PAINTED LADIES are now passing through north-central California. This one passed through during the 2005 migration. (Photo courtesy of Arthur Shapiro)