- Author: Kathy Keatley Garvey
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!"
- Author: Kathy Keatley Garvey
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.
- Author: Kathy Keatley Garvey
A flash of orange.
Usually we see assorted orange butterflies--Gulf Fritillaries (Agraulis vanillae) or Painted Ladies (Vanessa cardui) or Monarchs (Danaus plexippus)--on our butterfly bush (Buddleia davidii).
This time the flash of orange proved to be a California Tortoiseshell (Nymphalis californica).
Its wings are pumpkin orange with huge black spots while the underwings are dullish brown and gray, resembling a dead leaf. What a perfect camouflage!
This particular Cal Tortie is probably a female, according to Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis. He has monitored the Central Valley butterfly population since 1972 and maintains a research website.
"Along with the Painted Lady, this is a mass migrant that makes news at irregular intervals by tying up traffic!" Shapiro says on his website. "The 'Tortie' overwinters as an adult and can sometimes be seen sunning itself in midwinter on mild days. It is generally common in foothill canyons in late winter, ovipositing on the young, tender growth of various species of Wild Lilac (Ceanothus)."
And just as the Gulf Frits can defoliate its host plant, the passionflower vine, so, too, can the Tortie defoliate its host plant.
"The spiny, black-marked-with-yellow larvae feed gregariously, without a web, and in big years can defoliate whole stands of the plants," Shapiro notes on his website. "They often pupate on the bare, leafless stems en masse, the grayish-violet pupae looking like some strange kind of leaf and twitching in unison when disturbed. Adults emerge in late May to early June and almost immediately emigrate, going north or east and upslope."
They're often misidentified as monarchs, Shapiro told the recent Butterfly Summit at Annie's Annuals and Perennials, Richmond. He also mentions this on his website.
"Breeding localities in summer vary widely from year to year - sometimes in the high southern Sierra, sometimes in the Cascades... sometimes only in far northeastern California or even farther north," according to Shapiro's website. "The migrant females lay on the tender growth of high-altitude Ceanothus such as Tobaccobrush and Snowbrush, which again may be defoliated. Adults emerge in late July and migrate to estivating grounds, generally above tree-line. These are often in the high country of Yosemite, Sequoia and Kings Canyon National Parks, but can even be in the Trinity Alps, South Cascades, or (as in 2005) on Mount Rose! Estivating Torties do little but 'hang out,' and many high-altitude hikers have described their encounters with millions of them in mystical terms (they often identify them as Monarchs!). In late September these butterflies scatter downslope to hibernate in the foothills--they are the late-winter butterflies of the new year. Estivators-hibernators thus may live 9 or 10 months as adults." (See more about this amazing butterfly on his website.)
Naturalist and insect photographer Greg Kareofelas, an associate of the Bohart Museum of Entomology, UC Davis, says there are a lot of Cal Torties around now. And when they disperse, "they can end up anywhere, including the valley. So not often seen in the valley, but not all that unusual."
This butterfly ended up on its namesake, the butterfly bush in our Vacaville pollinator garden.
- Author: Kathy Keatley Garvey
Migrating monarchs are fluttering daily into our yard in Vacaville, Calif., one by one, two by two, three by three, and four by four, for a little flight fuel. They're sipping nectar from the Mexican sunflower, Tithonia rotundifolia, and tropical milkweed, Asclepias curassavica.
They're on their way to overwintering sites, such as the Natural Bridges State Park's Monarch Grove Butterfly Natural Preserve, Santa Cruz.
The park's monarch sanctuary "provides a temporary home for thousands of monarchs," according to the website. "In 2016, 8,000 monarch butterflies overwintered at Natural Bridges. From late fall into winter, the monarchs form a 'city in the trees.' The area's mild seaside climate and eucalyptus grove provide a safe place for monarchs to roost until spring."
The numbers typically peak between late October to mid-November. It's an awe-inspiring place, especially if you rear monarchs. And admission is free. The preserve is open to the public from 8 a.m. to sunset daily, or visitors can participate in a free one-hour tour on Saturdays and Sundays at 11 a.m. to 2 p.m.
Meanwhile, scores of monarchs are on their way. Some won't make it. Predators, especially birds, will nail many of them. The weather will deter many others.
We know of at least one that probably won't make it. On Friday, Oct. 27, while we were gathering mllkweed seeds from the Asclepias curassavica, we noticed two lady beetles feasting on aphids.
Wait, what's that beneath that leaf?
Could it be? It was. A monarch caterpillar! Talk about late!
The 'cat is now tucked inside our indoor butterfly habitat, munching on milkweed leaves. With any luck, it will become a mid-life chrysalis and then an adult monarch.
It will take a lot of luck, however, for it to join its buddies in Santa Cruz. Its late start will be exacerbated by the cold, the wind, the rain, the predators....
On a wing and a prayer...
- Author: Kathy Keatley Garvey
A Sept. 7 article in Reuters, headlined "Monarchs in Western United States Risk Extinction, Scientists Say," indicated that "Monarch butterflies west of the Rocky Mountains are teetering on the edge of extinction, with the number wintering in California down more than 90 percent from the 1980s, researchers said in a study published on Thursday."
Reuters' reporter Laura Zuckerman wrote that "The migratory monarchs of the western United States have a 63 percent chance of extinction in 20 years and an 84 percent chance in 50 years if current trends continue, according to the study."
The scientists, led by Washington State University conservation biologist Cheryl Schultz, published their work in the journal Biological Conservation. It was funded by the U.S. Fish and Wildlife Service, which is weighing the prospect of offering federal protection for monarch butterflies through the Endangered Species Act. The Xerces Society for Invertebrate Conservation is among those spearheading the effort.
Noted lepidopterist Arthur Shapiro, UC Davis distinguished professor of evolution and ecology who has studied butterflies, including the monarchs, for more than four decades, doubts that the western monarchs are teetering on the edge of extinction.
Shapiro, who maintains a website, Art's Butterfly World. says that yes, the western monarchs have been declining faster than the eastern monarchs, as per the Biological Conservation paper. However, during the drought, California populations appeared to rebound significantly, and it is not known whether the trend will persist, he says.
Their comprehensive and well-researched work, titled "Understanding a Migratory Species in a Changing World: Climatic Effects and Demographic Declines in the Western Monarch Revealed by Four Decades of Intensive Monitoring," was funded in part by the National Science Foundation. Their Oecologia abstract: "Migratory animals pose unique challenges for conservation biologists, and we have much to learn about how migratory species respond to drivers of global change. Research has cast doubt on the stability of the eastern monarch butterfly (Danaus plexippus) population in North America, but the western monarchs have not been as intensively examined. Using a Bayesia hierarchial model, sightings of western monarchs over approximately 40 years were investigated using summer flight records from ten sites along an elevational transect in Northern California."
"Multiple weather variable were examined, including local and regional temperature and precipitation. Population trends from the ten focal sites and a subset of western overwintering sites were compared to summer and overwintering data from the eastern migration. Records showed western overwintering grounds and western breeding grounds had negative trends over time, with declines concentrated early in the breeding season, which were potentially more severe than in the eastern population."
"Temporal variation in the western monarch also appears to be largely independent of (uncorrelated with) the dynamics in the east. For our focal sits, warmer temperatures had positive effect during spring. These climatic associations add to our understanding of biotic-abiotic interactions in a migratory butterfly, but shifting climatic conditions do not explain the overall, long-term, negative population trajectory observed in our data."
In acknowledgments, Shapiro and his colleagues thanked the Xerces Society for Invertebrate Conservation and the North American Butterfly Association for the monarch counts and making the data publicly available.
Meanwhile, since late August, the western monarchs (Arizona, California, Nevada, Oregon, Washington, Idaho and Utah) have been winging their way to their overwintering spots to forested groves along coastal California.
And then, around February, they will head inland to start the process again.
It's an amazing phenomenon.
As I write this, four monarchs are gathering some flight fuel, nectaring from two M's: milkweed and Mexican sunflower in our little pollinator garden in Vacaville, Calif., part of their migratory path to the coast. They flutter from flower to flower, seemingly unaware of the California scrub jay circling them and a photographer zeroing in on them. Or the rain about to fall.
Resources:
Monarch Conservation, Xerces Society for Invertebrate Conservation
Xerces Society's Western Monarch Thanksgiving Activity Count