The Xerces Society for Invertebrate Conservation reported this week that its Western Monarch Thanksgiving Count shows a decline for the second consecutive year. “Sadly, fewer than 30,000 monarchs were counted—29,418 to be exact—for the second year in a row, so the western monarch population remains at a critical level,” according to Matthew Shepherd, director of communications and outreach. (See Xerces press release and blog about the population count for this winter.)
Researcher Elizabeth Crone, a professor at Tufts University, Medford, Ma., will shed some light on the issue when she delivers a UC Davis Department of Entomology and Nematology seminar on "Why Are the Monarch Butterflies Declining in the West?" from 4:10 to 5 p.m., Wednesday, Jan. 29 in 122 Briggs Hall, off Kleiber Hall Drive, UC Davis campus. Her longtime collaborator, pollination ecologist and professor Neal Williams, will introduce her.
"Ecologists now face the dual challenge of documenting changes in the environment, and figuring out appropriate strategies for conserving and recovering natural resources in changing environments," says Crone, who is completing a research sabbatical at UC Davis. In her talk, she will focus on “using the tools of population ecology to address both sides of this challenge: quantifying changes in the abundance of western monarch butterflies (and factors associated with these changes), and using theory and data to design strategies and targets for restoration and recovery.”
“Analyses of past dynamics (1980-2017) showed that western monarch butterflies have declined more quickly than their eastern counterparts, and that these declines were most strongly associated with loss of overwintering habitat, and more weakly (but significantly) associated with increased pesticide use and warmer breeding season temperatures,” Crone writes in her abstract. “Analyses of current conditions (2018-2019) suggest that a recent dramatic drop in abundance occurred in spring, between when monarch butterflies leave coastal overwintering sites and arrive in the Central Valley and Sierra Foothills.”
The Xerces Society for Invertebrate Conservation reported this week that its Western Monarch Thanksgiving Count shows a decline for the second consecutive year. “Sadly, fewer than 30,000 monarchs were counted—29,418 to be exact—for the second year in a row, so the western monarch population remains at a critical level,” according to Matthew Shepherd, director of communications and outreach. (See press release and a blog article about the population count for this winter.)
A native of Alexandria, Va., Crone received her bachelor's degree in biology, summa cum laude, from the College of William and Mary, Williamsburg, Va., in 1991, and her doctorate in botany from Duke University in 1995. She served as a postdoctoral researcher at the University of Washington, Seattle, from 1996-1997. Her career encompasses academic appointments at Harvard University, University of Montana, and the University of Calgary.
No stranger to UC Davis, Crone has collaborated with Neal Williams "on and off" for the past 20 years. “We had a National Science Foundation grant to study bumble bee populations from 2014-2019, so I have been visiting regularly since he got here. Starting in winter 2019, I have also had funding to take partial research leave from Tufts and work on western monarchs. I have been about half-time at Tufts and half-time at UC Davis." "I am grateful to Neal and the Entomology Department for hosting me during this extended stay!" she added.
Crone is a co-principal investigator (PI) with PI Cheryl Schultz, associate professor of biological sciences at Washington State University and co-PI Sarina Jepson, endangered species program director, Xerces Society, on a federal grant, "Western Monarch Breeding Phenology" (awarded May 2017-June 2020, with the potential for annual renewal). The grant was funded through the Department of Defense's (DoD) Natural Resources Program, DoD Legacy Program.
Of her research, Crone says "My research focuses on population ecology, especially of plants and insects, and plant-animal interactions. Specifically, I am interested in how environmental changes translate to changes in population dynamics: For example, is there a simple, linear matching of changes in resources to abundance of consumers, or do interactions among individuals and species moderate these responses? Much of my research also involves developing novel quantitative approaches to predict long-term dynamics from small scale observations and experiments. Current projects include studies of butterflies, bees, perennial wildflowers, sugar maples, and acorn-granivore interactions. Past projects include some of the best documented examples of cyclical dynamics in plant populations and spatial metapopulation dynamics in animal populations. I was also one of the first ecologists to adapt generalized linear mixed models to estimate variance terms for stochastic population models."
Her honors and awards are many and varied:
- Project of the Year Award, SERDP (Strategic Environmental Research and Development Program) 2018
- Foreign Member, Finnish Academy of Science and Letters (elected 2017)
- Vice Chair / Chair, Theoretical Ecology Section, Ecological Society of America, 2010-2012
- Ecological Research Award, Ecological Society of Japan, 2014
- Fulbright Fellowship, 2007-2008
- National Science Foundation (NSF) Postdoctoral Fellowship in Biosciences Related to the Environment (1996-1997)
- U.S. Department of Energy Graduate Fellowship for Global Change (1991-1995)
- Baldwin Speece Award (College of William and Mary, for scholarship/service in ecology, 1991)
How did you get interested in science? Was there an "ah ha" moment?
I was in an REU (Research Experiences for Undergraduates) program studying plant-insect interactions in 1990. The thing that made me want to go to grad school was the fun puzzle of designing an experiment AND figuring out how to interpret the data - I had collected data on beetle feeding rates, and when I didn't know how to analyze them my advisor said "read a statistics book" ... so I did--since then I have always especially loved the puzzle of matching models to data.
From an earlier age, I have always enjoyed being outdoors, which is probably why I chose to study biology. But that was the moment when I knew I would enjoy a life of research.
Some of your major accomplishments?
From an applied ecology perspective, the biggest is helping the Fender's blue butterfly move from being listed as endangered to nearly ready for down-listing. From a basic ecology perspective, I figured out the ecological interpretation of variance terms in mixed models as estimates of spatial heterogeneity and environmental stochasticity, and worked out one of the best examples of how mast-seeding species are synchronized by their pollinators.
What fascinates you about monarchs?
The possibility that we can recover the western monarch population from its recent steep decline to being abundant again. This should be a problem we can fix.
What do you like best about science?
The puzzle of matching models to data and the possibility of saving species from extinction.
Any scientists in the family?
My sister is an astronomer. My dad was a math professor. Before him, though, no one in the extended family had even gone to college.
What do you do in your leisure time?
I once gut-renovated a house (with help from carpenters, but doing some of the work myself), I am very proud of my urban pollinator garden in Somerville (near Boston, Mass., and I am a good enough trombonist to (just barely) keep up with my trombonist friends.
I am waiting to find out whether our monarch funding will be extended or whether I will go back to a regular teaching schedule at Tufts. Even if I go back to "full-time" teaching, I am sure I will be doing western monarch and bumble bee research for the indefinite future, and will continue to be at least partly bicoastal.
(Editor's Note: the Xerces Society's site-by-site monarch count data is available at https://www.westernmonarchcount.org/data/. This covers all years since the first count in 1997.)
In fact, he and the Xerces Society for Invertebrate Conservation petitioned the U.S. Fish and Wildlife Service on June 23, 2010 to include the bumble bee on the proposed list. (See UC Davis news story.)
We're glad to see that tomorrow (Aug. 14) the U.S. Fish and Wildlife Service will propose that it be listed as an endangered species. If approved, Franklin's bumble bee would be the first bee in the western United States to be officially recognized under the ESA, according to a Xerces' press release.
Its range, a 13,300-square-mile area confined to Siskiyou and Trinity counties in California; and Jackson, Douglas and Josephine counties in Oregon, is thought to be the smallest range of any other bumble bee in the world.
Thorp, who died at age 85 on June 7 at his home in Davis, had monitored the population closely since 1998, but last saw the bumble bee in August 2006. It was he who sounded the alarm.
Thorp's surveys clearly show the declining population. Sightings decreased from 94 in 1998 to 20 in 1999 to 9 in 2000 to one in 2001. Sightings increased slightly to 20 in 2002, but dropped to three in 2003. Thorp saw none in 2004 and 2005; one in 2006; and none since.
He refused to believe that it may be extinct. “I am still hopeful that Franklin's bumble bee is still out there somewhere,” he told us as late as last year. He excitedly received scores of photos--by email and snail mail--from folks who thought they'd seen it. None was Franklin's bumble bee.
Xerces says that the primary threats to this species are three-fold:
- diseases from managed bees
- pesticides, and
- a small population size
The International Union for Conservation of Nature (IUCN), the world's oldest and largest global environmental network, named Franklin's bumble bee “Species of the Day” on Oct. 21, 2010. IUCN placed it on the “Red List of Threatened Species” and classified it as “critically endangered” and in “imminent danger of extinction.”
Franklin's bumble bee, mostly black, has distinctive yellow markings on the front of its thorax and top of its head, Thorp said. It has a solid black abdomen with just a touch of white at the tip, and an inverted U-shaped design between its wing bases.
“This bumble bee is partly at risk because of its very small range of distribution,” Thorp told us. “Adverse effects within this narrow range can have a much greater effect on it than on more widespread bumble bees.”
If it's given protective status, this could “stimulate research into the probable causes of its decline,” said Thorp, an active member of the Xerces Society. “This may not only lead to its recovery, but also help us better understand environmental threats to pollinators and how to prevent them in future. This petition also serves as a wake-up call to the importance of pollinators and the need to provide protections from the various threats to the health of their populations.”
Thorp hypothesized that the decline of the subgenus Bombus (including B. franklini and its closely related B. occidentalis, and two eastern species B. affinis and B. terricola) is linked to an exotic disease (or diseases) associated with the trafficking of commercially produced bumble bees for pollination of greenhouse tomatoes. Other threats may include pesticides, climate change and competition with nonnative bees.
Named in 1921 for Henry J. Franklin, who monographed the bumble bees of North and South America in 1912-13, Franklin's bumble bee frequents California poppies, lupines, vetch, wild roses, blackberries, clover, sweet peas, horsemint and mountain penny royal during its flight season, from mid-May through September. It collects pollen primarily from lupines and poppies and gathers nectar mainly from mints. According to a Xerces Society press release, bumble bees are declining throughout the world.
“The decline in bumble bees like Franklin's bumble bee should serve as an alarm that we are losing important pollinators,” said Xerces Society Executive Director Scott Hoffman Black in a press release. “We hope that the story of the Franklin's bumble bee will compel us to prevent pollinators across the U.S. from sliding toward extinction.”
Sadly, Robbin Thorp died before knowing if the bumble bee will be protected. But he was told that the U.S. Fish and Wildlife would be proposing "in a few weeks" that Franklin's bumble bee be included on the ESA list. Now the proposal is going through the next steps of the procedure, which includes a comment period. If the proposal is approved, the bumble bee would receive federal protection and funding for its conservation.
Thorp, a member of the UC Davis entomology faculty for 30 years, from 1964-1994, achieved emeritus status in 1994 but continued to engage in research, teaching and public service until a few weeks before his death. A tireless advocate of pollinator species protection and conservation, he was known for his expertise, dedication and passion in protecting native pollinators, especially bumble bees, and for his teaching, research and public service. He was an authority on pollination ecology, ecology and systematics of honey bees, bumble bees, vernal pool bees, conservation of bees, native bees and crop pollination, and bees of urban gardens and agricultural landscapes.
In his retirement, Thorp co-authored two books Bumble Bees of North America: An Identification Guide and California Bees and Blooms: A Guide for Gardeners and Naturalists.
Born Aug. 26, 1933 in Benton Harbor, Mich., Robbin received his bachelor of science degree in zoology (1955) and his master's degree in zoology (1957) from the University of Michigan, Ann Arbor. He earned his doctorate in entomology in 1964 from UC Berkeley, the same year he joined the UC Davis entomology faculty. He taught courses from 1970 to 2006 on insect classification, general entomology, natural history of insects, field entomology, California insect diversity, and pollination ecology.
Every summer from 2002 to 2018, Thorp volunteered his time and expertise to teach at The Bee Course, an annual workshop sponsored by the American Museum of Natural History and held at the Southwestern Research Station, Portal, Ariz. The intensive 9-day workshop, considered the world's premiere native bee biology and taxonomic course, is geared for conservation biologists, pollination ecologists and other biologists.
“Robbin's scientific achievements during his retirement rival the typical career productivity of many other academic scientists,” said Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology, in the obituary on the department's website. “His contributions in support of understanding bee biodiversity and systematics are a true scientific legacy.”
Somewhere, we think Robbin Thorp, tireless advocate of pollinator species protection and conservation, and a true friend of all bees, is smiling.
It is. June 17-21 is the week set aside to celebrate pollinators and how we can protect them.
Actually, National Pollinator Week should be every day.
Launched 12 years ago under U.S. Senate approval, National Pollinator Week zeroes in on the valuable ecosystem services provided by bees, birds, butterflies, bats and beetles, according to Pollinator Partnership, which manages the national celebration. (Other pollinators include syrphid or hover flies, mosquitoes, moths, pollen wasps, and ants. Pollination involves the transfer of pollen from the male anther of a flower to the female stigma.)
On the UC Davis campus, the Häagen-Dazs Honey Bee Haven, operated by the UC Davis Department of Entomology and Nematology, will be a "hive" of activity next week, announced manager Christine Casey, academic program management officer. "We'll be hosting National Pollinator Week events Monday through Friday, June 17 to 21, between 10 a.m. and noon each day." Activities include bee information and identification, solitary bee house making, and catch-and-release bee observation.
The haven volunteers also will sell bee friendly plants and bee houses to support the haven (cash and checks only).
A new event at the haven is hive opening. At 11:45 a.m. on Monday, Wednesday, and Friday, California Master Beekeeper Program volunteers will open the hive in the haven "so visitors may see the girls in action." The haven, installed in the fall of 2009, is located on Bee Biology Road, west of the central campus. It is open from dawn to dark, free admission.
The Xerces Society for Invertebrate Conservation is planning a free webinar Insect Apocalypse? What Is Really Happening, Why It Matters and How Natural Area Managers Can Help on Tuesday, June 18. The webinar, by Scott Hoffman Black, executive director of the Xerces Society begins at noon, Eastern Time, which is 9 a.m., Pacific Time.
Black says he will "explain the latest science on insect declines and highlight important ways natural areas managers can incorporate invertebrate conservation into their land management portfolio. Though they are indisputably the most important creatures on earth, invertebrates are in trouble. Recent regional reports and trends in biomonitoring suggest that insects are experiencing a multi continental crisis evident as reductions in abundance, diversity and biomass. Given the centrality of insects to terrestrial and freshwater aquatic ecosystems and the food chain that supports humans, the potential importance of this crisis cannot be overstated. If we hope to stem the losses of insect diversity and the services they provide, society must take steps at all levels to protect, restore and enhance habitat for insects across landscapes, from wildlands to farmlands to urban cores. Protecting and managing existing habitat is an essential step as natural areas can act as reservoirs for invertebrate diversity." Click here for more information and to register.
Happy Pollinator Week! Think the "b" alliteration: bees, birds, butterflies, bats and beetles. But don't forget the flies, ants, mosquitoes and moths!
(Update, June 19: the webinar can now be viewed on YouTube at https://youtu.be/vrC-BvoQjQk.)
If you traveled to the Natural Bridges State Park in Santa Cruz this fall or to any of the other overwintering monarch sites along coastal California to see these iconic butterflies, did you see very many?
The Xerces Society of Invertebrate Conservation today announced "disturbingly low numbers" of monarch butterflies sightings.
"The Western Monarch Thanksgiving Count (WMTC) has been done annually for the last two decades," wrote Matthew Shepherd, director of communications and outreach. "We're still completing the count for this year, but preliminary results show disturbingly low numbers of monarch butterflies overwintering in California."
"The count results that we have from 97 sites show only 20,456 monarchs. In case you're thinking--'Wait, why say anything now before you have all the data?'--it's worth noting that the sites already reported include many of the most important overwintering groves and combined host the majority of monarchs overwintering in California. In 2017, these sites hosted approximately 148,000 butterflies, more than three quarters of the total monarch overwintering population. The 2018 numbers represents an 86% decline from last year—which was already a low population year."
"We were not expecting this to be a great year because we knew it had been a rough season in the breeding and migratory range, but it's looking worse than anyone had expected," Shepherd related. "If the rest of the Thanksgiving Count data show the same trend as these sites, we anticipate seeing less than 30,000 butterflies overwintering in California this winter. In comparison, last year there were more than 192,000 butterflies counted; in 1997, it was estimated that more than 1 million overwintered; and research suggest that there were at least 4.5 million monarchs overwintering in California in the 1980s."
To read more about the count and what may be causing this abrupt decline in numbers, access the Xerces blog, Early Thanksgiving Counts Show a Critically Low Monarch Population in California.
The Facebook page, Monarch Butterflies in the Pacific Northwest, affiliated with the migratory monarch research projects of Washington State University entomologist David James, knows the situation well.
On Nov. 27, the administrators posted: "This time last year we had found almost 50 of our PNW-tagged Monarchs in California! This year is a very different story with just 10 tag recoveries so far in California. The tenth recovery occurred on November 19 at the Moran Lake overwintering site in Santa Cruz. E5363 was spotted and photographed by John Dayton. This male was reared by Belinda Vos and released in Talent, Oregon on August 17 into extremely smoky skies. Regardless, E5363 flew 367 miles across the landscape to get to Santa Cruz."
And on Nov. 19, the PNW administrators posted:
"Good survival of our small overwintering populations is even more important this year, if we are to see a rebound in numbers next breeding season. However, we may get a boost from the eastern US population which unlike the west had an excellent breeding season in 2018. Back in 1994, the western Monarch population crashed to 'nothingness' then bounced back the next year. The late and revered Monarch researcher, Lincoln Brower connected this remarkable recovery with a likely westward shift of spring migrating Monarchs from the Mexican overwintering sites. He theorized that the western population may be subject to periodic declines from drought and climate cycles and depends on refreshment from Mexico. We will get the opportunity to see if this occurs in spring 2019. If the large summer population of monarchs in the eastern US translates into a large overwintering population, any 'leakage' to west of the Rockies could be significant. Let's keep our fingers crossed!"
And the U.S. Fish and Wildlife Service posted this on its Facebook page yesterday: "The California overwintering monarch population has been reduced to less than 0.5% of its historical size and has declined by 86% compared to 2017."
Want to help them? Here are a few things you can do, according to the U.S. Fish and Wildlife Service:
- Observe and report monarch sightings: https://www.monarchmilkweedmapper.org/
- Plant nectar resources and native plants
- Reduce pesticide use
Meanwhile, brace yourself for a dreary monarch season next year.
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.