If you join the thousands of visitors at the ninth annual UC Davis Biodiversity Museum Day on Saturday, Feb. 15--a free public event showcasing 13 museums or collections--you might--might--see bumble bees (Bombus melanopygus and Bombus vosnesenskiii) in the UC Davis Arboretum or the Häagen-Dazs Honey Bee Haven, but not these four:
- Franklin's bumble bee, Bombus franklini
- Suckley cuckoo bumble bee, Bombus suckleyi
- Western bumble bee, Bombus occidentalis
- Crotch bumble bee, Bombus crotchi
These four subspecies ARE on campus, however. They're mounted specimens in the Bohart Museum of Entomology.
The California Fish and Game Commission voted 3-1 on June 12, 2019 to place these four bumble bees on the proposed endangered species list, as petitioned by the Xerces Society, Center for Food Safety, and Defenders of Wildlife.
But many agricultural interests don't want them listed as endangered species, according to a news story by Capital Public Radio's environmental reporter Ezra David Romero.
Pollination ecologist Neal Williams, professor of entomology, UC Davis Department of Entomology and Nematology was among those interviewed.
"Other points I made were that in addition to these species, there are others that appear to be declining, but might not yet be so rare. We need to look into these more carefully and work to safeguard their populations before they become so precipitously endangered. I also indicated that the biologies and historical distributions of these species are quite distinct and to me this suggests that we need to do more to understand mechanisms behind changes in their numbers. For example, contrast B. franklinii versus B. occidentalis, one that had a very restricted distribution the other that was so widely distributed."
The Xerces Society points out that "Bumble bees are important pollinators of wild flowering plants and agricultural crops. They are able to fly in cooler temperatures and lower light levels than many other bees, making them excellent pollinators—especially at higher elevations and latitudes. They also perform a behavior called 'buzz pollination,' in which the bee grabs the flower in her jaws and vibrates her wing muscles to dislodge pollen from the flower. Many plants, including a number of wildflowers and crops like tomatoes, peppers, and cranberries, benefit from buzz pollination.
The late Robbin Thorp 1933-2019), distinguished emeritus professor of entomology at the University of California, Davis, and a member of the Xerces Society, was one of the strongest proponents of protecting bumble bees. Thorp, a global authority on bees and co-author of Bumble Bees of North America: An Identification Guide and California Bees and Blooms: A Guide for Gardeners and Naturalists, honed in on Franklin's bumble bee, which once occupied one of the smallest ranges of bumble bees in the world. Its 13,300-acre range included Siskiyou and Trinity counties in California; and Jackson, Douglas and Josephine counties in Oregon. Today Franklin's bumble bee is feared extinct; Thorp last saw it in 2006.
Thorp hypothesized that the decline of the subgenus 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.
If Franklin's bumble bee is given protective status, this could “stimulate research into the probable causes of its decline,” Thorp told us in an interview. “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.”
Meanwhile, be sure to attend the ninth annual UC Davis Biodiversity Museum Day on Saturday, Feb. 15, to explore the diversity of life. You'll learn about bees, hawks, carnivorous plants, Native American artifacts, wine, yeast cultures dinosaurs and more. Here's hoping that bumble bees don't go the way of the....dinosaurs. (See some of the UC Davis Biodiversity Museum Day highlights on Bug Squad)
The question is: Where are you? Have you managed to "hide" all these years or are you extinct?
A “search party” of scientists and citizen scientists is forming to look for Franklin's bumble bee and other rare bumble bees from Monday, July 17 through Friday, July 21 at Mt. Ashland, Ore.
Noted bumble bee expert Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, will be there to identify the bees. In addition, he will present a brief introductory training session, showing examples of bumble bees that inhabit the area, “and especially the rare ones we hope to find.”
The event, organized by Jeffrey Dillon, Endangered Species Division Manager, U.S. Fish and Wildlife Service, Portland, Ore., mainly involves searching for Bombus franklini and the endangered Western bumble bee, Bombus occidentalis, in the Mt. Ashland and Siskiyou-Cascade National Monument area. The survey is open to all interested volunteers.
Both bumble bees are on the Red List of Threatened Species of the International Union for Conservation of Nature and Natural Resources (IUCN).
“The objective is to get more eyes out looking for the rare bumble bees,” said Thorp, co-author of Bumble Bees of North America, An Identification Guide.
Thorp will provide a "Bumble Bee 101 Tailgate Course" at 3 p.m. on Monday, July 17. The group will meet him "a few hundred yards west of the Mt. Ashland ski resort (just before reaching the gravel road)," Dillon said. Thorp also will be there Tuesday morning for an informal overview of bumble bees.
Thorp, who has been monitoring Franklin's bumble bee since 1998, hasn't seen the bee since Aug. 9, 2006, when he spotted it in a meadow near Mt. Ashland. In August of 2016 a documentary crew from CNN, headed by John Sutter, followed Thorp to the same meadow. Sutter wrote about Thorp, then 82, in a piece he called "The Old Man and the Bee," a spinoff of Ernest Hemingway's "The Old Man and the Sea."
"That black-and-yellow bee, which looks like so many others except for the characteristic 'U' on is back, is the object of Thorp's obsession," wrote Sutter. "It's a creature he told me flies through his dreams always just out of reach."
Thorp says the distinctively marked bumble bee has the most restricted range of any bumble bee in the world. Its habitat is--or was--a small area of southern Oregon (Douglas, Jackson and Josephine counties) and northern California (Siskiyou and Trinity counties).
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, Thorp points out. It collects pollen primarily from lupines and poppies and gathers nectar mainly from mints.
Thorp sighted 94 in 1998; 20 in 1999; 9 in 2000 and only 1 in 2001. Sightings increased slightly to 20 in 2002, but dropped to 3 in 2003. Thorp saw none in 2004 and 2005; one in 2006; and none since.
In a UC Davis interview in July 2010, Thorp said: “People often ask the value of Franklin's bumble bee. In terms of a direct contribution to the grand scale of human economies, perhaps not much, but no one has measured its contribution in those terms. However, in the grand scheme of our planet and its environmental values, I would say it is priceless.”
“Loss of a species, especially a pollinator, diminishes our global environment,” he said. “Bumble bees provide an important ecological service--pollination. This service is critical to reproduction of a huge diversity of plants that in turn provide shelter, food (seeds, fruits) to diverse wildlife. The potential cascade of effects from the removal of even one localized pollinator may affect us directly and indirectly.”
Meanwhile, Thorp keeps looking.
Dillon emailed survey volunteers that “we plan to spend two full days, Tuesday and Wednesday up on Mt. Ashland, a day over at the Hobart Bluff area (Thursday), and potentially part of a day at Grizzly Peak (Friday morning). Volunteers are welcome for part of the survey or all of it."
Some of the habitat is rugged terrain. All volunteers are encouraged to bring their own nets, and any medication needed if they are allergic to bee stings. Inexperienced folks will be paired with the more experienced, Dillon said.
"If you don't make it over on Monday, we will be up on Mt. Ashland to start the day between 8:30 and 9 a.m. Tuesday and Wednesday. "To find us, go to the Mt. Ashland ski resort. Then continue west past the resort onto the gravel road. Stay basically at the same elevation for about 1 to 1.5 miles past the ski resort--there are other side roads that go down or up oin elevation. You should run into a cluster of vehicles on the side of the road with a number of people nearby that appear to be wandering aimlessly through the alpine meadows with white nets. There will not have been an escape, just fellow bumble bee enthusiasts hoping to be the first to find a Franklin's bumble bee."
“We have already reserved and covered the cost of the group campsite (there is only one) at the Emigrant Lake campground for the week. There are four level tent areas that hold several tents each with plenty of parking space. Showers and restrooms are a short walk away. Everyone is welcome to camp with us if interested.” The campground is located southeast of Ashland on the north edge of Emigrant Lake (reservoir). "Following the main road through the campground, the group site is basically the last campsite area before heading around the lake--it will be on your left. On Monday, July 17, we will probably get there between 5:30 and 6 p.m. We have already covered the cost of the campsite.
For further information, Dillon's office number is (503) 231-6197 and his email is firstname.lastname@example.org
Results of the 2016 U.S. Fish and Wildlife Service, Portland, Ore., survey:
- Bumble bee species found at Mt. Ashland on July 18/19, 2016:
Bombus mixtus, B. melanopygus, B. bifarius, B. vosnesenskii, B. flavifrons, B. occidentalis, B. appositus, and B. insularis. Had a report of a B. vandykei but did not see it.
- Bumble bee species found at Hobart Bluff trailhead area July 20, 2016:
Bombus mixtus, B. vosnesenskii, B. flavifrons, B. appositus, B. californicus, B. griseocollis, B. flavidus, and B. insularis.
- Bumble bee species found at Grizzly Peak area July 21, 2016:
B. vosnesenskii, B. flavifrons, and B. appositus.
Incredible. Absolutely incredible.
The Western bumble bee (Bombus occidentalis) seems to be making a comeback of sorts in some parts of the West.
Reporter Michelle Nijhuis, in an Oct. 14th article in High Country News, wrote that this species was "once among the most common bumble bees in the Western United States (and Western Canada)." The population crashed in the 1990s and "all but disappeared from about a quarter of its historic range." Now, she says, it's recently been spotted in parts of Washington and Oregon.
Someone saw six species of the Western bumble bee pollinating blackberries just north of a Seattle.
That's good news indeed.
We remember last year when native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, was searching for the critically imperiled Franklin's bumble bee in its tiny range in northern California and southern Oregon, when a sole Western bumble bee appeared in front of him and his colleagues from the U.S. Forest Service. It was foraging on buckwheat (Eriogonum sp.) on Mt. Shasta, above 5000 feet.
Thorp and many other scientists fear that the Western bumble bee may go the way of Franklin's bumble bee.
That's why Thorp describes the Seattle find as "very exciting."
"Any finds west of the Sierra-Cascade crest are of prime interest. It is those western populations that took the sharp dive between 1999-2002. They do seem to be increasing, which is indeed encouraging."
"Many populations east of the crest seem to have persisted, through this decline," Thorp noted, "but were not carefully monitored during this time so we don't have the detailed data on their population trends that we would like."
Bombus occidentalis is sometimes called the "white-bottomed bee" due to its distinctive white markings on its abdomen. It is known for pollinating blackberries, cherries, apples and blueberries. It also is "an excellent pollinator of greenhouse tomatoes and cranberries, and has been commercially reared to pollinate these crops," according to the Xerces Society for Invertebrate Conservation website.
Read about the decline of bumble bees on the Xerces website.
And if you live in the West, keep your eyes open for the Western bumble bee.
Many of us in California have never seen the Western bumble bee (Bombus occidentalis)
Many of us never will.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, worries about the declining population and fears it may go the way of Franklin's bumble bee, which he hasn't seen since 2006.
That's why he and his colleagues were so excited to find a male Bombus occidentalis on Mt. Shasta, above 5,000 feet, on Aug. 15. It was foraging on buckwheat (Eriogonum sp.).
Thorp was there with several local U.S. Forest Service employees: wildlife biologist Debbie Derby, who actually netted the bee; and biological technicians Susan Thomas, Kendra Bainbridge and Lauran Yerkes.
"Just as we were celebrating the find, we were joined by two other USFS personnel: Carolyn Napper, district ranger, and Johnny Dame, Panther Campground host," Thorp recalled. "So there were lots of witnesses to the rare find."
A rare find, indeed.
The Western bumble bee, a close relative of Franklin's bumble bee (Bombus franklini), "disappeared from the western part of its range at the same time as Franklin's bumble bee declined," said Thorp, who keeps an eye out for both species on his trips to southern Oregon and northern California.
The habitat of the Franklin's bumble bee, which many fear is extinct, is a 13,300-square-mile area of Siskiyou and Trinity counties in California, and Jackson, Douglas and Josephine counties in Oregon.
"The Western bumble bee occurred throughout the range of Franklin’s, but apparently declined from central California to southern British Columbia west of the Sierra Cascade Range at the same time as the decline of Franklin's bumble bee, " Thorp said.
However, the Western bumble bee "seems to have persisted through most of the rest of its range from Alaska through areas east of the Sierra-Cascade to the Rocky Mountains and south to Arizona and New Mexico," Thorp pointed out. "We have no good idea what the population trends have been within this large area, since no one has been closely monitoring its populations there."
We're glad to see the increased interest in bumble bees. And especially glad to see that this week the Xerces Society for Invertebrate Conservation announced the publication of Bumble Bees of the Western United States, co-authored by Jonathan Koch, James Strange and Paul Williams. You can order it online.
Bombus occidentalis and Bombus franklini are among the Bombus species represented.