It's not "officially" spring until we see--and photograph--the spectacular Western tiger swallowtail, Papilio rutulus.
One landed March 30 on an aromatic white lilac bush in Alamo Creek Park, Vacaville. It lingered long enough for a few photos and then fluttered away.
Butterfly guru Art Shapiro, UC Davis distinguished professor, Department of Evolution and Ecology, saw his first Papilio rutulus of the year on March 4 in Davis. Butterfly enthusiast and naturalist Greg Kareofelas, an associate of the Bohart Museum of Entomology, UC Davis, saw his first on March 23, also in Davis, "and since then, I've been seeing them regularly."
This butterfly's wings are a brilliant yellow with black stripes. Blue and orange spots accent "the tails" on their hindwings. The one we saw in Vacaville was missing some of its "parts," probably due to a close encounter with a predator, maybe a California scrub jay seeking a quick meal.
Professor Shapiro writes on his website: "The Western Tiger Swallowtail is basically a species of riparian forest, where it glides majestically back and forth along the watercourse. It has expanded into older urban neighborhoods where several of its host genera are grown as shade trees, and behaves as if the street were a watercourse. In the high country and on the Sierran east slope its usual host is Aspen."
"One brood (June-July) at higher elevations; one and a partial second at Washington; 2-3 at lower elevations with a long flight season (late February or March-September or October). An avid puddler. Visits Yerba Santa, California Buckeye, Milkweed, Dogbane, Lilies, Coyotemint, etc., etc. and in gardens frequent at Lilac and Buddleia. Spring individuals are smaller and usually paler than summer. Low-elevation hosts include Sycamore (Platanus), Ash (Fraxinus), Cherry and other stone fruits (Prunus), Willow (Salix), Privet (Ligustrum), Lilac (Syringa) and (in Sacramento County) Sweet Gum (Liquidambar)."
Shapiro has monitored butterfly populations across central California for more than 45 years. It's part of his continuing effort to regularly monitor butterfly population trends on a transect across central California. "Ranging from the Sacramento River delta, through the Sacramento Valley and Sierra Nevada mountains, to the high desert of the western Great Basin, fixed routes at ten sites have been surveyed at approximately two-week intervals since as early as 1972. The sites represent the great biological, geological, and climatological diversity of central California."
And one of the species is the spectacular Western tiger swallowtail, which Shapiro monitors at all 10 of his sites.
Make that "an early, unexpected guest who was given a warm welcome and an even warmer send-off."
Henry is a Marin County winter monarch butterfly.
Winter monarchs are becoming more and more common in the Bay Area and near the coast, according to butterfly experts Art Shapiro, UC Davis distinguished professor, and David James, associate professor at Washington State University.
Karen Gideon's front yard in Greenbrae yielded the caterpillar on her milkweed, “Hello Yellow" Asclepias tuberosa, on Dec. 9. The perennial, also known as "the butterfly weed," is native to eastern and southwestern North America.
Karen gifted the caterpillar to her friend, UC Master Gardener Alanna Brady of Ross, who reared him to adulthood from Dec. 9 to March 4, the day he eclosed.
“There were so many caterpillars in different stages/sizes all over the plant they were eating the stems down, too!” Alanna related. "Karen gave me one small and one large ‘cat since I had none. I think Henry was in his second instar stage, but we don't really know. The larger 'cat was gone the next day--never found, but Henry remained to feast on the entire plant! All other caterpillars left and she didn't find any chrysalids."
While Henry was cycling through metamorphosis, Alanna nicknamed him "Slow Poke."
In the monarch world, the life cycle from egg to caterpillar to chrysalis to adult, goes like this:
- The egg usually hatches into a caterpillar in 3 to 4 days
- The caterpillar generally remains in this stage for 10 to 14 days, and then "J's" and forms a chrysalis
- The chrysalis stage usually lasts 10 to 14 days, when the adult monarch ecloses
Henry the Caterpillar took 43 days to "J" and pupate, doing so on Jan. 21. Then he took 42 days to eclose (March 4) from his chrysalis.
”It was an amazing experience,” Alanna said, noting that this is her first year rearing monarchs. She missed the eclosure. "I missed it—literally within 5 minutes he was out! He took a long time pumping up those wings! He hung around Friday morning and took off in the afternoon. I am ready to do this again! So amazing.”
Why did she name him Henry? “After so many weeks of eating here, he needed a name--and "Henry" suited his voracious appetite--and being a monarch! Henry j'd and attached to our (mobile) teak birdhouse so I could move it into the sun in the afternoons. He remained outside the entire time except for one night below 32 degrees in our shed.”
So, on Friday, March 5, Henry the Winter Monarch fluttered away from his Ross home. Perhaps he soon found some nectar, a sunny spot to warm his wings, and a mate. Who knows?
One thing's for sure: "We miss Henry,” Alanna said.
WSU entomologist David James, who studies monarchs and posts his research on the Monarchs of the Pacific Northwest Facebook page, is keeping a close watch on the winter monarchs.
On Dec. 23, he posted:
"As Director of the Washington State University Monarch tagging program, I would like to appeal to all monarch lovers in California who have milkweed and monarchs still active in their backyards, to carefully check all the monarchs they see for a tag! During late summer and fall, we tagged and released about 1200 monarchs in Oregon, Idaho and Washington and to date seven of these have been found in inland areas of CA around milkweed. None have yet been found at overwintering sites. This is very different from previous years when most sightings of our tagged monarchs occur at overwintering sites. We suspect that a far greater proportion of migrant monarchs this year have become reproductive and are staying inland rather than remaining non reproductive and overwintering at coastal sites. So please check that next incoming monarch for a WSU tag, photograph it and report it here or to the email address on the tag, Your observations are important!"
On Jan. 12, he posted a graph "showing the number of observations of monarch larvae/pupae (as recorded on I-Naturalist) in the San Francisco Bay area during November/December for every year since 2015. The graph showed a huge (>5X) increase in observations in 2020 compared to each of the the previous 6 years."
On Jan. 21, he posted:
"Reports continue to come in on monarch breeding activity in the San Francisco Bay area. In fact, there appears to be a flush of new adults and egg laying. This apparent new generation is likely to be the sons and daughters of the migrant generation that eschewed spending winter at the conventional overwintering sites, in favor of reproduction. I believe the well-being and survival of eggs being laid now and over the next few weeks in the Bay area will play a role in determining the size and extent of western monarch populations this summer. With only 1914 monarchs at overwintering sites (50% sex ratio = estimated 950 females), current Bay area breeding populations may well support at least this number of females."
Note that the U. S. Fish and Wildlife Service, in a Dec. 15, 2020 press release, agreed that the monarch butterfly should be listed under the Endangered Species Act, but said that other priorities preclude that for now.
"After a thorough assessment of the monarch butterfly's status, the U.S. Fish and Wildlife Service has found that adding the monarch butterfly to the list of threatened and endangered species is warranted but precluded by work on higher-priority listing actions," the press release indicated. "With this decision, the monarch becomes a candidate for listing under the Endangered Species Act (ESA), and its status will be reviewed each year until it is no longer a candidate."
Meanwhile, Henry the Winter Monarch is not alone out there!
But climate change, aka global warming, may be an equal, if not more, of a factor.
So indicates a 10-member team of scientists, including UC Davis distinguished professor Art Shapiro, Department of Evolution and Ecology, in the March 4th Science journal.
The research article, "Fewer Butterflies Seen by Community Scientists Across the Warming and Drying Landscapes of the American West," sounds a crucial alarm, alerting us to try to find new ways of protecting our fluttering friends.
"Uncertainty remains regarding the role of anthropogenic climate change in declining insect populations, partly because our understanding of biotic response to climate is often complicated by habitat loss and degradation among other compounding stressors. We addressed this challenge by integrating expert and community scientist datasets that include decades of monitoring across more than 70 locations spanning the western United States. We found a 1.6% annual reduction in the number of individual butterflies observed over the past four decades, associated in particular with warming during fall months. The pervasive declines that we report advance our understanding of climate change impacts and suggest that a new approach is needed for butterfly conservation in the region, focused on suites of species with shared habitat or host associations."
Lead author is UC Davis alumnus Matthew "Matt" Forister, the Trevor J. McMinn Endowed Professor in Biology, and Foundation Professor, Department of Biology, University of Nevada. Forister received his doctorate in ecology from UC Davis in 2004.
As Pennisi points out, "butterflies are at risk in open spaces, too." She writes: "Art Shapiro, an insect ecologist at the University of California, Davis, and colleagues have shown that over the past 35 years, butterflies are disappearing even in pristine protected areas such as the Sierra Nevada mountain range in the western United States."
"To see whether that finding held up elsewhere, Shapiro and Matthew Forister, an insect ecologist at the University of Nevada, Reno, gathered data from the North American Butterfly Association, which has coordinated community scientist butterfly counts across the United States for more than 42 years. The duo also incorporated 15 years of data from iNaturalist, a web portal that collects sightings of plants and animals, including butterflies. In all, the researchers tracked the fates of 450 butterfly species from 70 locations in the western United States."
The research indicates that the butterfly population in the Western United States has decreased an average of 1.6% per year between 1977 and 2018. "Fifty species declined in at least two of the data sets used, including the Edith's checkerspot (Euphydryas editha), the rural skipper (Ochlodes agricola), and the great copper (Lycaena xanthoides)," Pennisi wrote.
The researchers warn that some species may completely disappear from parts of their ranges in the coming decades, as fall temperatures continue to align with or exceed summer temperatures, impacting breeding cycles and plant dependence.
Back in February, 2019, Shapiro told the Environmental Defense Fund's UC Davis meeting on "Recovering the Western Monarch Butterfly Population: Identifying Opportunities for Scaling Monarch Habitat in California's Central Valley," that it's not just monarchs in trouble.
"Monarchs are in trouble in California--but they're hardly alone," Shapiro told the attendees. "If we act as if this is a 'Monarch problem,' we're in danger of missing the real causes of Monarch decline--factors acting at a much broader scale. We've been monitoring entire butterfly faunas--over 150 species--along a transect across California since 1972. Our monitoring sites are matched with climatological data, allowing us to examine statistical relations between climate and butterfly trends. Based on this data set, our group was the first to document and publish evidence of monarch decline here. That's the only reason I'm here."
"At low elevations—below 1000'—entire butterfly faunas have been in long-term decline. We published several papers showing that these declines were about equally correlated with land-use changes and pesticide (especially neonicotinoid) use, with climate change a significant factor but much less important. Remember, these are correlations, not necessarily demonstrations of causation—but they are strongly suggestive. Monarchs were just one of many species going downhill; three once-common species (the Large Marble, Field Crescent and “Common” Sooty-wing) had already gone regionally extinct or nearly so, with others threatening to follow suit."
Butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, spotted a female monarch butterfly at 1:35 today.
As he mentioned in his email: "So, at 1:25 p.m. a female monarch flew directly over my head, roughly 8' off the ground, near the corner of Oak Avenue and 8th Street. It was headed northeast very lazily."
Shapiro noted that Kathy Keatley Garvey saw a monarch in Benicia on Jan. 23, "so this is the second sighting known to me this year in this general area. If there are really only 3000 or fewer overwintered in the whole state, I guess we won the lottery!"
So, the count as we know it:
- Monarch butterfly, gender unknown, flying over 115 West G St, Benicia, on Feb. 23, Garvey sighting
- Monarch butterfly, a male, that the Garveys reared in west Vacaville and released on Feb. 25
- Monarch butterfly, a female, flying near the corner of Oak Avenue and 8th Street, Davis, on March 2, Shapiro sighting
Now some folks are blaming tropical milkweed, Asclepias curassavica, a non-native, as a serious threat in the massive decline of the monarch population.
Don't blame tropical milkweed, agree Shapiro and monarch researcher David James, an entomologist and associate professor at Washington State University (WSU).
James told us in an email: "I have been involved with monarchs for 43 years, and the single, overriding thing that I have learned is that the monarch is a highly adaptable creature! It has an incredible ability to adjust to changing environmental circumstances. In Australia, it took less than 100 years to change its core physiology as part of adaptation to a different climate. Adapting to man-made environmental challenges may take monarchs a while but I believe it can happen."
"I believe that the widespread and intensive use of neonicotinoid insecticides is one likely factor behind the current monarch population decline," James says. "But even with insecticides, insects can develop resistance over generations. The few monarchs that are alive and well in California currently are the survivors, those that have beaten the perils stacked against them. Clearly, we need to try and make life as fruitful as possible for these survivors, to aid in their population recovery. These monarchs will produce progeny that are also ‘fitter' than the general population and we need to ensure that milkweed is there for them, particularly during spring in California."
"The monarch as a species is particularly good at trying different things," James points out. "Thus, while the majority of the population does one thing (like migrate and overwinter), there is always a significant subset exposed to the same environment, that decides to do something different, like not migrate. Most of these of course will die but in some circumstances, some locations, the outcome may be good, giving another option for continuation of the species, should it become necessary. We may be seeing this now with the rise in winter breeding of monarchs in warmer parts of interior California like the LA Basin and SF Bay Area. There is also evidence for the first time of breeding winter monarch survival in far southwestern Oregon."
A post on texasbutterflyranch.com touched on the native/non-native milkweed controversy. "David James takes issue with the loud and persistent claim that non-native milkweeds pose serious threats to monarch butterflies and the viability of their migrations. When asked if he thinks the technically non-native tropical milkweed poses a dire threat to monarch butterflies, James' answer was emphatic."
No, he does not. "Not at all, in fact," he told them.
You can follow David James' research and observations on his group's Facebook page, Monarchs of the Pacific Northwest at https://www.facebook.com/MonarchButterfliesInThePacificNorthwest.
On Jan. 12 James posted a graph showing "the number of observations of monarch larvae/pupae (as recorded on I-Naturalist) in the San Francisco Bay area during November/December for every year since 2015. The graph showed a huge (>5X) increase in observations in 2020 compared to each of the the previous 6 years. I have now extracted data on monarch reports for January 2021 and compared them to the previous six years (see graph below). Once again, the data show a large increase in reports of both adult and immature stage monarchs during the past month in the SF Bay area. In fact, the increase is greater than for Nov-Dec. The average number of larvae/pupae reported on I-Nat during January from 2015-2019 was 1.0. This year the number was 63. Similarly an average of 5.0 adults were reported for January during 2015-19, yet this year there were 58 sightings reported to I-Nat. Of course some of this increase can be explained by increased use of I-Nat in these covid times to report sightings, but I doubt that this explains it all. Interestingly, there were signs last January of an increase in sightings when 10 larvae and 12 adults were reported. But the numbers in January 2021 are on another level."
James' work draws such comments as "You rock, Dr. David James! Thank you for speaking common sense and not regurgitating a hard line which equates to death for the monarchs when milkweed is purposely cut and no milkweed is available for the next generation to consume! I look forward to more findings from you and your honest research reporting. Thank you so much for all you do to help the monarchs thrive not just survive!"
Meanwhile, anyone else see any monarchs flying around the Bay Area and/or in Yolo and Solano counties?
"What are YOU doing here?"
It was Saturday morning, Jan. 23, and the monarch caterpillar seemed to be sunning itself on a milkweed leaf in our family's pollinator garden in Vacaville, Calif., a Solano County city situated between San Francisco and Sacramento.
Yes, Saturday, Jan. 23. The dead of winter. A third-star monarch caterpillar.
"Mama Monarch" must have laid the egg in late December, surmised butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, who has researched butterfly population trends since 1972 and maintains a research website, Art's Butterfly World.
"Evidence of inland winter breeding," he commented. "Nothing surprises me any more..."
Interestingly enough, on the same day that we spotted the monarch caterpillar was the same day that naturalist-photographer Greg Kareofelas, an associate of the Bohart Museum of Entomology, UC Davis, photographed a newly eclosed Gulf Fritillary, Agraulis vanillae, in his yard in Davis.
The temperature on Jan. 23 hovered at 60 degrees. Since then, it's dropped into the 30s, with blustery winds, heavy rain and a strong storm uprooting trees and flash-flooding the LNU Lighting Complex burn scar. And it's c-o-l-d--cold enough to borrow Bernie Sanders' heavy overcoat and mittens, and for good measure, add an Elmer Fudd (trapper) hat, the kind you need in Vermont.
But a monarch caterpillar in January in Solano County?
Last year the monarchs in our garden thrived, as the Danaus plexippus population declined throughout the country, and scientists began talking about extinction. Last year we collected more than 300 monarch eggs or caterpillars in our garden, primarily from two of the three milkweed species. We reared and released them, except for the ones we donated to researchers at the University of California, Davis and the University of Nevada to start their own colonies.
Is the January caterpillar healthy? Will it survive?
Seems so. We moved it inside on Jan. 24 in a Bohart Museum butterfly habitat on our kitchen counter, but only time will tell.
Still, it's like spotting the Easter Bunny handing out candy in December or Santa Claus delivering candy canes on Easter Sunday.