Why Bumble Bees Are the Fuzzy Heroes We Need

JESSICA WARE (Curator, Division of Invertebrate Zoology): In 2022, California decided this was a fish… kinda. Conservation advocates were trying to protect bumble bee species with the California Endangered Species Act. But that 1984 law only covers native “bird, mammal, fish, amphibian, reptile, or plant” species under threat. So, it seemed like insects and other invertebrates weren’t eligible…

But, under California’s Fish & Game Code, “fish” means “wild fish, mollusks, crustaceans, invertebrates, or amphibians.” Which is casting a pretty wide net. 

So bumble bee lovers argued that bees could be considered fish… and the state court agreed! As of 2024 four bumble bee species are candidates for protection under California law. This means they get pre-emptive safeguards and helps conserve their habitats.

It can be hard to drum up support for insects. And in general, as humans, we tend to suffer from, like, “taxonomic bias. ” We tend to love things that are warm or cuddly, that remind us of mammals or remind us of ourselves. 

But we need these critical pollinators, and they—along with insects around the world—are plummeting in numbers. We’re still trying to understand why, but we do know that bumble bees face some unique threats. Maybe you could help figure out what’s going on…

[INSECTARIUM title animation]

DIRECTOR [off-camera]: Jessica, when I think about risks to bees, I feel like I’ve heard of this thing called Colony Collapse Disorder. What is that?

[On-screen text: Jessica Ware, Ph.D. | Curator, American Museum of Natural History]

WARE: So, Colony Collapse Disorder is when a beehive kind of dies off. And in the late 2000s, this happened to a bunch of hives. And so, the name was kind of coined to describe this new phenomenon that was happening. 

[On-screen text: Susan and Peter J. Solomon Family Insectarium | American Museum of Natural History]

WARE: Colony Collapse Disorder is when a large proportion of the workers die off. So even if queens are left alive or the babies, if the workers aren’t there to do the jobs, then the colony itself collapses.

In the beginning, it was a mystery what was causing Colony Collapse Disorder. A parasitic mite was an early candidate. Then there were ideas about other parasites, diseases, or insecticides. Now what we think is, it’s an additive effect. It’s not just one thing, it’s death by a thousand cuts, causing the colony to collapse.

DIRECTOR [off-camera]: I like honey-

WARE: Who doesn’t?!

DIRECTOR [off-camera]: -but why did Colony Collapse Disorder make headlines?

WARE: You can actually quantify the impact of the loss of bees. Cold, hard cash can actually get people to start talking about, you know, conservation and direct action. So the Obama administration launched this presidential task force that was looking at pollination and the numbers suggested that maybe a loss of these honeybees would be a loss of about $15 billion. So I think this was a wakeup call, maybe, to humans, right? 

DIRECTOR [off-camera]: So, are honey bees the most important pollinators we have?

WARE: No. So, the irony is, of course, Colony Collapse Disorder, the kind of genesis that sparked this educational campaign, was something that was only happening to Apis mellifera, which is the European honeybee. It’s actually not native to North America.

And as an introduced species, honeybees can have negative effects on native species. They can outcompete other bees and even threaten the long-term health of native plants.     

DIRECTOR [off-camera]: Wait- honeybees are competing with native species? What kinds of bees are native here? What do we have?

WARE: We have a lot of species of bees. There are actually thousands of species of bees. 

Like more than 4,000 bee species native to North America—tiny, little ground-nesting bees all the way up to chunky carpenter bees. The majority are loners—solitary bees that build their own nests and don’t live in a colony. In fact, the only truly social bees native to the U.S. are the amazing bees in the genus Bombus! 

[On-screen text: Hillary Sardiñas, Ph.D. | Pollinator Coordinator, California Dept. of Fish and Wildlife]

HILLARY SARDIÑAS (Pollinator Coordinator, California Department of Fish and Wildlife): They’re big, they’re fuzzy, they’re really charismatic. What’s also neat about bumble bees is because they’re hairy and big they are able to withstand cold temperatures. They’re also generalists, and so they will visit a whole bunch of different flower species. They’re not going to go specialize on one- Oh my gosh, I see one!

WARE: Dr. Hillary Sardiñas studies bumble bees in her role as pollinator coordinator for California’s Fish and Wildlife Department. It’s early in the year, but California has some uniquely early risers… 

SARDIÑAS: We’re out here in January. It’s not really a time when you think about being able to find a lot of pollinators, but it’s when queen bumblebees tend to come out from hibernation and pollinate some of these plants that are blooming really early in the year.

WARE: One reason bumble bees are so critical to our ecosystems is because they’re usually the first bees buzzing around in late winter and the last to make the rounds in fall. Their stocky bodies can carry about twice as much pollen as honey bees, and they work faster and longer—pollinating flowers 50-200% more quickly, v And they can do something honey bees can’t…

SARDIÑAS: Bumblebees do buzz pollinate. We’re standing in front of some manzanita plants. And they actually have these things called poricidal anthers. And so, the pollen is trapped inside of them.

WARE: Bumble bees bite down on those anthers and sonicate—they vibrate muscles in their thorax, making this characteristic buzz. The anthers pop open and shoot their pollen onto the bee, which then flies off to its next stop, transferring the pollen and fertilizing some of our favorite berries. Tomatoes and peppers also rely on buzz pollination, and growers will actually check their tomato plants for bumble bee bite marks to make sure flowers have been visited!

So, we need bumble bees for the foods we love. Unfortunately, like many insects, bumble bee population numbers are crashing.

SARDIÑAS: About a quarter of all bumble bee species are threatened or endangered. And that’s true here in California. There’s about eight species that we think are not doing as well as we would hope, and four of those have actually been petitioned for listing under the California Endangered Species Act.

WARE: Things don’t look good for bumble bees across North America and we’re seeing patterns of dramatic decline.

The American bumble bee used to be found in 47 of the lower 48 states. But its population has dropped by nearly 90% since 2000, and it’s completely disappeared from eight states.

SARDIÑAS: There’s not one clear-cut factor. It’s this suite of interacting factors from climate change to habitat loss and degradation, invasive species, disease, right, exposure to chemicals like pesticides that are causing the decline.

WARE: We know that insects are decreasing at a rate that we’ve never seen before, but in addition, bumble bees face some unique threats. While bumble bees are social, they roll with a smaller crew. A bumble bee nest only has around 50 to 500 bees, while a honey bee hive can buzz with tens of thousands.

A small colony inherently has less genetic diversity—fewer bees, fewer genes. And mating with your parents, siblings, or close cousins is, ah, not a good idea. Inbreeding tends to have you accumulate negative, deleterious, “bad” mutations. And that can spread quickly through a population. Without a healthy amount of diversity in its gene pool, a colony is less able to develop resistance to disease and parasites, and less adaptable to things like pollutants and climate change.   

So, if you imagine that you have a lot of inbreeding already, if we further fragment the habitat, that actually reduces the amount of area in which you can have bumble bees existing. And without connecting paths between patches of bumble bee territory, queens are more likely to pair off with close relatives.

So, when it comes to helping bumble bees, we need efforts targeting small-colony species. Protecting habitat is vital. But first, we have to better understand where bumble bees are now. And this is where you can get involved, because we need community scientists to help us figure that out.

One effort that Hillary helps coordinate is the California Bumble Bee Atlas.

SARDIÑAS: Obviously, as the only pollinator coordinator in California, which is a huge state, I can’t cover it. So, we really rely on these impassioned community members to go out and help us collect this valuable data. 

Oh, I see one. 

WARE: Hillary and atlas volunteers are trained to net bumblebees.

SARDIÑAS: I got it! This is a yellow-faced bumblebee. This is our most common bumble bee in California, also known as Bombus vosnesenskii. It’s a queen, I think, given how big she is and the time of year.

WARE: Once she catches a bee, she’ll put it on ice for a few minutes.

SARDIÑAS: Kind of stick it in. And this is gonna chill her back out so that we can take close-up photos of her. 

WARE: Hillary and other atlas-ers take pictures for the record… 

SARDIÑAS: You try and get their abdomen, their underside...

WARE:…and then let the bees warm up and buzz off.

SARDIÑAS: We’re hoping we can get a census of the population—how are they doing now—so that we can see how they’re doing into the future. Are all of the species declining? Is there a specific threat that’s impacting one of them?

WARE: There are bumble bee atlases in many states,  but you can also contribute the observations that you make through iNaturalist or through BumbleBeeWatch.org. And there are other ways to help these fuzzy flower-lovers live their best life.

It can be really great if you could plant a pollinator garden. So, when you say pollinator garden, sometimes you might think, “Well, I don’t have a garden. I don’t have a yard.” That’s okay. It actually doesn’t really matter the size. You could have a small window box, and that’s still providing important habitat for bumble bees.

There’s lots of plants that bumble bees will visit, but they actually prefer native plants. Because, of course, bees have evolved over, you know, millions of years with native plants. They like blue and purple flowers, so those ones are good ones to use. They tend not to be able to see red, so planting red is really just for you. That’s just a you thing. They tend to like to have a variety of sizes of flowers because bumble bees have different sized tongues, and they have to actually be able to drink the nectar. It’s also good to have flowers that kind of are blooming throughout the year, because bees—bumble bees, especially—they need to be able to eat across the seasons.

The other important thing you can do for bees is make sure that they have the habitat to overwinter in. They need to have holes and bits of twigs and leaves that they can nest in.

So, you remember how we talked about taxonomic bias? Well, if there’s one insect that can kind of break through this threshold,, it’s the bumble bee. They’re hard-working, cuddly, warm, fuzzy, curl-up-after-a-long-day, the insect that it really reminds us of ourselves. An insect that we can love. And if we can save the bumble bee, we can save the world! 

Before I reveal our amazing extra credit bee fact… 

Have you heard the buzzzzz? It's Earth Month, everybody! All this month PBS is dropping episodes about our amazing planet, like the new Eons video exploring what Future Earth might look like. Links to that video, and the full PBS Digital Studios Earth Month playlist, in the description!

[Credits roll]

WARE: So, bumble bees are one of the few insects that have shown what we like to call “culture”—where an individual learns something new and passes it on to others. In one  experiment, “demonstrator” bees learned how to  open a complex puzzle box and then showed others how to do the same. 

And just to make them extra adorable, bumble bees have been observed doing something like play. So, if you give bumble bees, especially kind of younger bumble bees, little tiny balls, they actually do a behavior that’s not work—it’s not contributing to their immediate survival, there’s no reward, it’s a different kind of behavior from something they would do if they were looking for food or a mate, and they repeat it (but not obsessively). Forget about “busy as a bee,” these guys are out there having a blast!