photo credit: Noah Abrams/KRCB
Leif Richardson holds a bumble bee net at the Fairfield Osborn
Preserve east of Rohnert Park.

As spring flowers bloom, and bees buzz into action, teams of volunteers set out around the state, from coastal bluffs to mountain meadows, nets in hand.

In this multi part series, KRCB's Noah Abrams joined in on the search for California's native bumble bees.

It's a sunny day at Sonoma State's Fairfield Osborn Preserve, a 450-acre open space on the northwest flank of Sonoma Mountain, with a Penngrove mailing address.

Close to 20 volunteers are on the hunt for bees, led by Leif Richardson.

"The thing that distinguishes bees generally is that they are vegetarians," Richardson said. "In fact, they're probably vegans."

The team of volunteers is looking for California bumble bees to be specific.

"Everybody knows what a honeybee is," Richardson said.

"Bumblebees, they can be smaller or larger, but they're usually larger. They're usually black and yellow striped, as opposed to tan or honey colored, or sort of light brown; and they're very furry," Richardson said.

Richardson is a biologist for the Xerces Society, which works to protect invertebrates like bumblebees and monarch butterflies.

He coordinates a particular project called the California Bumblebee Atlas.

"[It] is this community science effort to look for bumblebees, to figure out where they live, the when and the where of bumblebee occurrence," Richardson explained to the group of volunteers. "We're doing this because we need data to protect these animals, to manage their populations."

Each year, through the spring and summer months, Richardson traverses almost every corner of the state from the Fresno River Parkway to the Arcada Dunes to this hilltop meadow on Sonoma Mountain.

At each stop, he's joined by different volunteers, nets and hand.

"Beginners often will move it at the net about this fast," Richardson said, slowing moving a bee net in front of the assembled volunteers.

"You actually want to move the net more like this fast," Richardson said, quickly swiping the net. "So, when you see the bee and you get ready to swing, swing fast."

After Richardson's quick tutorial and a promise that the bees won't be harmed in the process, our group sets up off up the slopes to one of two Sonoma County locations for this year's survey.

We head through thick oak canopy, squishy seasonal wetlands, and narrow switchbacks to a wildflower-studded clearing.

"All right, let's catch bees," Richardson exclaimed.

From there, the volunteers, like Jane, set out across the meadow, swinging away.

"I get kind of nervous when I'm netting cause I'm always like, 'Should I go now? Should I go wait? Should I you know?' And then by the time I  second guess myself, they're gone," Jane said.

She's a landscape designer and came all the way from Sacramento to take part in the day's survey.

photo credit: Noah Abrams/KRCB
Leif Richardson holds a sedated bee in his palm during a survey for the
California Bumble Bee Atlas at the Fairfield Osborn Preserve in Sonoma County.

Richardson said it's volunteers like Jane who are crucial to the Atlas' success.

"Community science, sometimes called citizen science, although citizenship has nothing to do with it, is the single best way to collect this data," Richardson said.

"I as the over-educated, experienced expert can only do so much work," Richardson said. "I could all summer run around California and do surveys, and maybe I get 100 done or something, but together we get thousands done."

Volunteers, Richardson noted, have helped log over 20,000 different bumble bee records from around the state in the past three years.

All that data, Richardson said, is important to get an accurate picture of the state's bumble bee population.

"In California, we have 25 species," Richardson said. "Five or six of them are considered to be in trouble. One of them may already be extinct."

California state is home not only to many native bumble bees, Richardson noted, but to some 1,700 of the world's 20,000 bee species.

At the Fairfield Osborne Preserve, the oak-dotted hilltops offer for a friendly and relatively undeveloped landscape for bees, but that's not the case in other parts of California, where bees of all stripes deal with a host of threats.

"Development and habitat loss, pesticide exposure, pathogens moved around [by] agriculture, and climate change," Richardson said. "I will add to that competition from non-native species; and here I'm not talking about non-native plants, I'm actually talking about honeybees."

Disease spread is a big concern, Richardson said, from non-native honeybees.

"It's very hard to get rid of those diseases in honeybee colonies," Richardson said. "We can get rid of some of the diseases you've heard about like the mites, but it's the RNA viruses that live inside the bees that we cannot purge the bees of."

"So we knowingly put those bees in wild lands, in the Central Valley, on crops, in our backyards, on the roofs of buildings in cities, and every one of those hives is distributing RNA viruses out into the environment," Richardson said. "Onto flowers where they're picked up by other bees."

For a specialist like Richardson, rethinking our relationship with non-native honeybees, and native bumblebees is an important part of his work.

It's a topic that comes up in other interviews as well, including a 2023 radio feature with NPR's Ailsa Chang.

"One of the things that I have loved about today is we have talked about all the ways that bees are misunderstood animals," said Chang. "They are, they are all of those things. But there is so much more about [them]," responded Richardson.

Back on to those honeybees; native to Eurasia and Africa, Richardson pointed out that they're here to serve a very specific purpose.

"They're not wild animals," Richardson said. "They're a farm animal brought here to do a job, to make honey and wax in the beginning, but now the main job that honeybees perform is pollination of crops."

"So, there's only like 2 million hives of honeybees across the U.S. 50 to 75% of them come here to California in February to pollinate almonds," Richardson said. "Think about that, the stocks of honeybees in this country, the vast majority of them are here in the [Central] Valley for six weeks, all together in this little isolated area where they are covered in pesticides, where they are swapping pathogens, and where they're eating toxic pollen."

"Almonds happen to have some chemicals in the pollen that [are] not very healthy for bees," Richardson said.

Like invasive plants, honeybees have also established themselves in the wild across North and South America; directly competing with, and harming wild bee populations.

For Richardson, that brings up challenging questions about their place in the ecosystem.

"If you are a land manager and you are tasked with protecting biological diversity and you had a lot of invasive plants, I think it's not controversial in this country to pick up the nozzle and use herbicides on those plants, [or] maybe rip them out at the right season," Richardson said. "Imagine if we did that with honeybees. I'm not suggesting that you should do that here, but I do want people to think about how shocking that is to the general public. The idea that we would kill honeybees in wild lands."

"I'm also not advocating for it in front of you, but think about it. It's the same issues," Richardson said.

Richardson noted there are lots of ways less controversial to help reverse the decline of native wild bees.

"Obviously we could use fewer pesticides or we could consume fewer things that need pesticides," Richardson said. "We can do things about climate change if we so desire. We can do very simple things at home. We can plant flowers. That will help bees at least on a very local basis. Supporting various kinds of agriculture that support wild bees is probably a good idea if you want to do that."

photo credit: Noah Abrams/KRCB
California Bumble Bee Atlas volunteers spread out, hunting for bumble bees
at Sonoma State University's Fairfield Osborn Preserve.

Another important way to help is collecting information on wild bees. Back up at the preserve, Richardson and the team of Bumble Bee Atlas volunteers have their noses, or rather nets, to the ground.

"All right, where are these bumblebees?" Richardson said. "Hey, so who's caught a bumblebees so far, and what was the plant?"

The volunteers are spread out across a sea of wildflowers. Some are better for bee netting than others, Richardson said, rattling off the scientific names with ease.

"The white flower here, Nemophila, that might be good," Richardson said to group. "We walked past some shooting star, Primula or Dodecatheon, those pink flowers, those are great for bumblebees."

There's lots of buzzing, flying bugs are on the move in the meadow, and volunteers quickly fill their nets and vials.

"Let's see what you got," Richardson said to one volunteer. "It's not a bumblebee, I don't think," the volunteer said with reservation. "Oh, cool, that's nice though, that's in the genus Osmia, the family is called Megachilidae," Richardson responded.

"Or the leaf cutter family, these bees live above ground in hollow twigs," Richardson said.

The wild bumble bees seem to elude the group.

"I've done about 50 of these and maybe three to five times we've been skunked," Richardson said. 

Then success!

"Got a bumble bee," said one proud volunteer.

The bees, bumble or otherwise, are quickly smuggled into a cooler. The plastic vials are laid on ice. Richardson said it's important to keep them from overheating in the sealed vials, and the cold temperatures act as a natural sedative.

"Oh, this is a very good collection," Richardson remarked, surveying the cold vials. While the bees chilled out, Richardson talked the volunteers through the documentation process, detailing how to take photos so the bees can be accurately cataloged after they're released.

"We want to see the color of the vertex, which is the top of the head," Richardson said.

photo credit: Noah Abrams/KRCB
A recently netted bumble bee is photographed in a handling vial before quickly being put
on ice to safely sedate.

The data from each of these bumble bee surveys helps Richardson and others figure out where bumble bees are at in California. Both their literal locations and the population densities.

"We know that they're somewhere around 1,600 to 1,700 species of bees in California," Richardson said. "That's a lot of diversity compared to other taxonomic groups."

"Unfortunately for the vast majority, we know they exist and we know that they once existed in California, and that is the end of it," Richardson said. "We may only have five observations in history, or maybe we have more, but in many cases we haven't had any survey work done in decades that has turned up a bee."

"So for most of those, I'll say 1600 species, we don't know anything about their status and we need to do some work," Richardson said. "The only group that we have some information about generally speaking is bumble bees."

"Bumble bees have been the subject of study for literally for centuries," Richardson said. "If you read Charles Darwin, bumble bees blew his mind and were part of his whole story. So, bumblebees have gotten a lot of attention for a long time and we're just starting to learn about some of the other ones."

Doing the surveys year on year helps paint a better picture of how the bees are responding to stressors like land development and climate instability.

"In California, every year is different and I think that bumblebees populations kind of boom and bust here," Richardson said.

After the quick talk, Richardson starts to pull the quieted bees from the cooler, one by one opening the vials and showing off the day's catch.

"Now you can see the bee is starting to move," Richardson said. "We know this is a female because of the pollen. Males don't collect and carry pollen."

A big question in all of this is why? Why does Richardson go up and down the state hiking around with a heavy cooler all to handle some anesthetized bees?

He said bumble bees are a good subject. They have a long history of scientific study, and on a practical level, they're hardy enough to survive the netting unharmed, but Richardson said those are far from the only reasons.

"There is a problem and everybody can get involved and help," Richardson said. "So that that is why we work with bumblebees...given that we have so many thousands of species of these animals here, and we know almost nothing about the vast majority of them, and we know we're in a general period of environmental change, we know we're losing some biodiversity here that we haven't even, to be honest, we haven't even found yet."

"So, bumblebees are important important and we will continue doing this work for another three years in California, but the hope is that we expand something like this into an all bee inventory, where we have community scientists helping us find all the bees, and [then] we do status assessments for all of the many thousands of species," Richardson said.

photo credit: Noah Abrams/KRCB
Leif Richardson (left) explaining the documentation process to California
Bumble Bee Atlas volunteers as biologist Sandra von Arb (right) watches on.

"So that is, we figure out where they live, how common they are now, whether their ranges have shifted, and all that good stuff to determine whether they need protections," Richardson said. "That's a very big job."

About those non-native honeybees again, Richardson acknowledged they have their place in landscape and agricultural systems now, but he said that native pollinators and wild bees do much of that same job, and shouldn't be so easily ignored.

"Some people feel there's intrinsic value to them and it's biodiversity, it's something native here and I care about it in an intrinsic kind of way," Richardson said. "I'm one of those people, but if you need a functional reason to care about wild insects, there are some real strong ones for bees."

"One is just pollination," Richardson said. "These wild bees are coming to farms to forage for their food, and in so doing they're moving pollen around flowers and pollinating them."

"There are places where agriculture is entirely dependent on these wild insects, mainly bees for the pollination and they don't even think about bringing honeybees to the site," Richardson said. "In fact, I'm going to go to a blueberry farm up in the Sierra Foothills. 30 or 40 years old, they have never used honey bees, and they have always had full pollination. How are they getting that? It's the wild bees that are coming to the farm. So, this is an example of an ecosystem service. It's the ecosystem giving us something, if you will, of benefit."

"These bees are really important in that way," Richardson said. "They are actually more important than honey bees on average across the world on farms. So, if you think about that, it's just kind of crazy that nature is coming to our doorstep and doing something that we benefit from, and then disappearing back up the hill into nature. And we just don't see it that way."

As Richardson talked, the bees started to warm up. He offers to let volunteers hold them, before they buzz away from his open palms.

The group is happy to have netted the one bumble bee amongst the collection of honey bees, wasps, and solitary bees; and as the survey session winds down, the group circled up, discussing how to clean equipment and getting ready to hike back down the hill.

Jane, the landscape designer from Sacramento, stood off to the side, and it's right then that she made her catch.

"Oh everyone!" Jane called out. "I think I have a nest!"

It was right then that Jane netted a queen bumble bee for everyone to see. A fitting finale for the California Bumble Bee Atlas' surveying stop on Sonoma Mountain.