It was a dismal year in Vacaville (and other parts of California) for monarch-rearing. Of the 10 caterpillars we collected from milkweed in our pollinator garden in early September and tried to rear, only eight made it.
One caterpillar died when a sibling attacked it. Another caterpillar made it to the chrysalis stage, and then it succumbed.
"The intersegmental membranes are showing," observed butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, who has researched butterflies for more than four decades and maintains a research website at http://butterfly.ucdavis.edu. "Whatever caused that, it opens the door to severe water loss, so the pupa will probably die."
Yes, it did.
Black lines rimmed the non-viable chrysalis, and then it deteriorated almost beyond recognition.
Lynn Epstein, UC Davis emeritus professor of plant pathology, photographed it under a Leica DVM6 microscope on Nov. 2. An amazing image.
Meanwhile, perhaps the eight monarchs we reared and released made it to an overwintering site along the California coast...maybe to the eucalyptus grove at the Natural Bridges State Park, Santa Cruz.
Or maybe they encountered a predator--a praying mantis or a bird.
Regardless, the declining monarch populations at the overwintering sites along coastal California are troubling.
The Xerces Society for Invertebrate Conservation, based in Portland, Ore., noted in a news release Feb. 2, 2018 that the "annual census of monarch butterflies overwintering along California's coast reveals that populations in western North America are at their lowest point in five years, despite recovery efforts. Volunteers with the Xerces Society's Western Monarch Thanksgiving Count visited more sites this past year than have ever been counted since the survey began in 1997, yet they tallied fewer than 200,000 monarchs."
“This year's numbers indicate a continuing decline in the monarch population,” noted Sarina Jepsen, the Xerces Society's endangered species program director. “Two decades ago, more than 1.2 million monarchs were recorded from far fewer coastal sites, and just last year nearly 300,000 monarchs were observed at almost the same number of sites.” Population estimates at individual sites also suggest that the western monarch population has continued to shrink. Of the 15 sites which have been monitored annually for more than two decades, 11 had lower counts than last year."
Also in the news release, Emma Pelton, conservation biologist with Xerces, said: “Counts at some of the state's largest sites were dramatically lower. Pismo Beach State Park was down by 38 percent, a private site in Big Sur was down by 50 percent, and the Monarch Butterfly Sanctuary in Pacific Grove was down 57 percent, from 17,100 to just 7,350 butterflies.”
Xerces Society officials also noted that "the few sites in which monarch numbers remained stable or increased compared to 2016, include Natural Bridges State Park, Moran Lake, and Lighthouse Field State Park, all in Santa Cruz County."
We like to think that The Vacaville Eight were The Lucky Eight.
Ask away at the Science Café.
This is an informative scientific presentation held the second Wednesday of each month in the G St. Wunderbar, 228 G St., Davis. The scientist delivers a brief talk and then engages the public.
Next Wednesday, Oct. 10, biodemography expert James R. Carey, a UC Davis distinguished professor of entomology and an expert on human aging (as well as insects!) will speak at 5:30 p.m. on "Are There Upper Limits to Human Lifespan?"
How long can humans live? Well, supercentarian Jeanne Calment of France (1875-1997), lived to be 122. Born Feb. 21, 1875, she died Aug. 4, 1997. She enjoyed a healthy lifestyle, prayed and exercised daily, and lived a basically stress-free life. But yes, she drank a little wine and smoked a little. She outlived her husband, daughter and grandson.
“Why do we live as long as we do (evolutionary question), why do we age (mechanisms question) and why do we die (closure question)?” Carey asks.
Some of the topics to be discussed at the event, billed as “a conversation and dialogue with a scientist,” include:
- The trends in aging research on extending human lifespan.
- Theoretical arguments for upper limits and empirical evidence in humans
- The impact of disease elimination and organ replacement on longevity
- With the changes in human life expectancy, humans are now being given a second chance-- somewhat like the proverbial cat with nine lives--after an otherwise life-ending disease or incident
- Look to nature for perspectives on the limits of “life duration,” for example 40,000-year-old frozen nematodes; hibernation and dormancy) and limits to “active lifespan.”
An internationally recognized leader and distinguished scholar in insect demography and invasion biology, spanning three decades, Carey also researches health demography, biology of aging, and lifespan theory. He is the author of a landmark study published in the journal Science in 1992 that showed mortality of Mediterranean fruit flies (medflies) slows at older ages. Earlier this year scientists confirmed that this also occurs in humans, citing the study of 105-year-old Italian women.
Carey, who joined the UC Davis faculty in 1980, directed an 11-university, $10 million, 10-year study on biodemography of aging from 2003-2013. He is also known for discovering Carey's Equality or the death distribution in a life table population equals its age structure. He teaches a popular longevity course that draws 250 to 300 students year, and recently authored a book on biodemography, to be published by Princeton University next year.
And, if you want to ask Professor Carey about medflies, he can answer those, too. He was a recent recipient of a UC Davis Academic Senate Distinguished Scholarly Public Service Award for his “outstanding research, outreach and advocacy program involving invasion biology, specifically his significant contributions on two California insect pest invaders, the Mediterranean Fruit Fly (medfly) and the Light Brown Apple Moth (LBAM).”
Professor Jared Shaw, interim chair of the UC Davis Department of Chemistry and founder of the Science Café series, will host the Oct. 10th presentation. Launched in 2012 and initially supported by the National Science Foundation, the popular series now draws support from the Department of Chemistry and Division of Mathematical and Physical Sciences and is promoted by Capital Science Communicators.
See schedule on the UC Davis Department of Chemistry website.
Thar's gold in them thar hills?
Probably not. But thar's definitely gold in that there pollinator garden--our little pollinator garden in Vacaville, Calif.
Gold, black and white--as in the iconic monarch caterpillars.
We've been waiting all year for Mama Monarchs to lay some eggs on our milkweed. We planted four different species, watered them and watched them bloom, fade, and go to seed. The bees sipped nectar from the blossoms, aphids sucked the juices from the stems, lady beetles (aka lady bugs) ate the aphids, and milkweed bugs chewed on the seeds.
All was not going well.
At 9 a.m., we saw FOUR monarch caterpillars munching away on our potted narrow-leaf milkweed, Asclepias fascicularis. Then at 6 tonight, FIVE more on the same batch of narrow-leaf milkweed.
Just when I was thinking I wouldn't be rearing any monarchs this year (in 2016 the tally totaled 60 plus), one or more Monarch Mamas proved me wrong.
I placed the 'cats in a netted butterfly habitat from the Bohart Museum of Entomology to protect them from predators and give them a chance at life, a chance for another generation.
What's going on with monarchs in this area is not good.
Butterfly guru Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis, who has monitored butterfly population trends on a transect across central California for 46 years, from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin, has not seen a single egg or caterpillar this entire calendar year at his low elevation sites.
"Not one!" he told Beth Ruyak on her "Insight with Beth Ruyak" program, Capital Public Radio, Sacramento, last week.
Shapiro, who maintains a research website at http://butterfly.ucdavis.edu, will talk about butterfly population trends (including monarchs) and how climate has affected them at a free public presentation from 6:30 to 7:30 p.m., Tuesday, Sept. 11 at Sierra College, Grass Valley. The event takes place in the Multipurpose Center Building, N-12, Room 103. Parking is $3; permits can be purchased at the kiosk machine at the main entrance to the campus. (For more information, contact the series coordinator, Jason Giuliani at email@example.com.)
And news flash: Shapiro spotted one monarch today, an adult female, in West Sacramento.
Our little pollinator garden in Vacaville, Calif., usually draws dozens of them in the summer as they flutter around, sip nectar from the Mexican sunflower (Tithonia) and lay their eggs on their host plant, milkweed.
Then in late summer and fall, the migratory monarchs from the Pacific Northwest pass through on their way to their overwintering sites in coastal California, including Pacific Grove and Santa Cruz.
Something is happening this year, and it's not good.
As a "monarch mom," I reared and released more than 60 in 2016. This year so far: zero, zip, zilch. In fact, I never saw a single monarch in our pollinator garden this year until Monday, Aug. 13, and then again today (Friday, Aug. 30) when a male fluttered in and hung around for several hours.
This time last year and in 2016? Often five to seven sightings a day.
"What's going on with the monarchs?" I asked butterfly expert Art Shapiro, UC Davis distinguished professor of evolution and ecology, who has monitored the butterfly population in central California for more than four decades and maintains a research website. "All I have on our milkweed are aphids and milkweed bugs, and occasional bees and hover flies."
I also haven't seen a single monarch on the UC Davis campus. Neither have fellow photographers and naturalists who keep an eye out for them.
Background: Shapiro has been surveying fixed routes at 10 sites at approximately two-week intervals since 1972. They range from "the Sacramento River delta, through the Sacramento Valley and Sierra Nevada mountains, to the high desert of the western Great Basin." As he says on his website, "the sites represent the great biological, geological, and climatological diversity of central California." As of the end of 2006, he has logged "5476 site-visits and tallied approximately 83,000 individual records of 159 butterfly species and subspecies. This major effort is continuing and represents the world's largest dataset of intensive site-specific data on butterfly populations collected by one person under a strict protocol. We have also collated monthly climate records for the entire study period from weather stations along the transect."
So, what's going on with the monarchs?
"You are not alone (in not sighting them)," he related in an email yesterday. "I have seen one adult monarch in the Valley in the past five weeks (and about 6 in the Sierra, migrating westward). I have not seen a single wild larva in 2018. Anywhere! Everybody's talking about it. We know there was some breeding at Fallon, Nev., but only a couple of adults have been seen in Reno. Either they are breeding in recondite places, which is possible, or the population is in serious collapse. We will know which by early November when we see what shows up at the overwintering sites. One thing is certain: it's not due to milkweed shortage!"
The statistics on his Looking Backward section of his website indicate these monarch sightings:
- 2015: 100
- 2016: 64
- 2017: 54
- 2018: 20
Note that this is the time of year when citizen scientists in entomologist David James' migratory monarch research program at Washington State University (my alma mater) tag and release them throughout much of the Pacific Northwest. (See Bug Squad)
They should be passing through our area soon. In fact, the third anniversary of "The WSU Traveler" is rapidly approaching: On Labor Day, Sept. 5, 2016, one of the tagged butterflies from James' citizen scientist program in Ashland, Ore., fluttered into our yard (see above photograph). The monarch, a male, hung around for five hours, sipping nectaring and circling around.
The background: Citizen scientist Steven Johnson of Ashland tagged and released the male, No. A6093, on Sunday, Aug. 28. It "flew 285 miles in 7 days or about 40.7 miles per day," James told us. "Pretty amazing. So, I doubt he broke his journey for much more than the five hours you watched him--he could be 100 miles further south by now. Clearly this male is on his way to an overwintering colony and it's possible we may sight him again during the winter in Santa Cruz or Pacific Grove!”
Maybe we'll see another tagged one this year? The odds do not look good.
As the WSU Facebook page, Monarch Butterflies in the Pacific Northwest, related today:
"While the migration from the PNW (Pacific Northwest) to California has been underway for about 2 weeks, September is when it really ramps up. Unlike the migration in eastern USA this year, our migration is subtle and comprised of much smaller numbers of butterflies. In fact there will be very few Monarchs migrating south from British Columbia, Washington and northern Idaho because we simply did not have significant summer populations in these areas this year. However, our research-based WSU breeding/tagging program will result in hundreds of tagged Monarchs migrating from various parts of Washington State. Apart from the celebrated Washington State Penitentiary tagging program, this year we also have more than 30 members of Cowiche Canyon Conservancy (Yakima) and the Washington Butterfly Association (Seattle, Spokane) each rearing and tagging small numbers of Monarchs. The first tagged Monarchs from this program were released yesterday (August 30) so watch out for them as they head south! And please be ready to capture an image on your phone that you can email to us."
So, if you see a tagged monarch butterfly from the WSU program, kindly photograph it and send the information to David James and his fellow researchers at firstname.lastname@example.org.
Every sighting helps.
First monarch butterfly sighting of the year.
A tattered and torn monarch--a male (as identified by Art Shapiro, distinguished professor of evolution and ecology at UC Davis) fluttered into the Kate Frey Pollinator Garden at Sonoma Cornerstone last Sunday and landed on a salvia.
He didn't move for about five minutes. Tattered, torn and tired.
His wings looked like a predator--maybe a bird or a praying mantis--tried to nab him. They did not succeed.
Usually we see monarchs around this time of year in our pollinator garden in Vacaville. The milkweed, butterfly bush and Mexican sunflowers are waiting.
Last year we saw one laying an egg on Aug. 1 on our milkweed.
This year: zero, zilch, zip here in Vacaville.
We remember the recent report by Xerces Society for Invertebrate Conservation that indicated the 2017 Thanksgiving Count at the monarch overwintering sites in California has decreased dramatically:
"The Xerces Society's Western Monarch Thanksgiving Count provides a long-running record of the number of monarchs overwintering in California—including the steep decline of recent decades. Volunteers and biologists who take part in the Thanksgiving Count have been invaluable in monitoring the monarch population each fall for over twenty years. Last year, another count was added with the launch of the New Year's Count—an opportunity to monitor the populations during a later period of the winter. Monarchs are mobile and they move around through the season. Combining the data from the New Year's and Thanksgiving counts allows us to better understand site and rangewide population changes. Monarch numbers at the 115 sites monitored during both of this season's counts decreased by an average of 49% between Thanksgiving and the New Year. This is similar to the change revealed by the previous New Year's Count, which saw a 43% drop at 44 sites." (See text)
As Sarina Jepsen, the endangered species program director for the Xerces Society said: “It's certainly concerning." (See more information on Project Milkweed)