Bees + The Climate Crisis: Flooding (Ep. 3)

Is there any aspect of life on Earth that isn’t impacted by the climate crisis? Flooding has devastated many countries this past winter and spring. Extreme rainfall is also highly damaging to bees and other pollinators. In this episode, we’re talking about the disastrous effect of too much rain on bees, their habits, and what we can plant to help them out.

Thanks so much to Dr. Philip Donkersly for his insights. He mentioned one oft-overlooked plant species that benefit bees: trees. Read more in his paper Trees for Bees.  

And for your daily dose of bee love, here’s his Bee Box project.

Did you know?

Think only big fields of hundreds of different wildflower species can save the bees? Think again. Philip’s research has discovered small interventions (like your yard!) can have a significant impact!

Transcript

The climate crisis will affect bees and other pollinators in a variety of ways, not all of which we know of yet. Today I’d like to talk about one situation that has affected a number of countries this winter, and that’s excessive rainfall and flooding. We know this was serious on many levels, but just how does too much rain affect wild and native bee species?

Joining us today is Dr. Philip Donkersly, senior researcher and teaching associate at Lancaster University in England. He specializes in interactions between insects and their environment from a variety of perspectives, studying how the environment both physical and biological, interacts with pollinator physiology.

Philip, thanks so much for being here. Let’s get to it. Spring is typically a very vulnerable time for wild bees. How do wet winners affect them. So these longer wetter winters, they have a number of effects. If you have a wetter winter, that often implies it’s also a warmer winter. The drier winters with the cold air keep everything crisp and these wet winters that we typically.

Seeing these days, they also imply a warmer winter, there’s more nutrients being washed around because of the rain. There’s more warmth and biological activity, and it’s not just the wetness, it’s also just the disruption of the natural cycle of the seasons. So when you have that happening, you inevitably end up with the first problem, which is being

everything wakes up too soon. So all bees, honey bees, bumble bees, solitary bees, they’re inactive during the winter months because there’s no food around. So they have evolved to hibernate over those months. That’s part of the reason why these bee species secure stores of food and when you have these warmer, wetter winters

you end up with these bees emerging sooner because plants are getting going. They can sense through the increasing warmth that the plants are going to be going, so they’ll go out and they’ll secure food and they’ll go out and get things like ivy and dandelion . Even now there are some heathers that are back in flower already.

So the bees will go out, they’ll get these foods and they’ll start ticking up. They, they’ll start increasing their population, they’ll start becoming more and more active and that’s great. Until the rain comes back, it’s on rainy, wet days bees typically don’t fly, so they’ll stay inside the nests and they’ll hunker down and consume what stores they have.

Now, these bees, they spent the whole winter collecting those stores and consuming those stores. They haven’t got much left. They get the signal that it’s warm enough to go outside to, to, forage. They’ll start building up again, and then they’ll go out, they’ll get some food, they’ll come back. There’ll be a little bit of stores inside their hive for them to eat, and then the rain comes.

They don’t go out, but they haven’t recovered from the winter yet. So if there are these long extended periods of rain, it’s stopping bees from getting out. It’s forcing them to wreak to consume stores they haven’t yet properly recovered over past over winter, and then they’re basically starving to death inside their hives during the rainy season.

The other thing of course happens is if the rain is quite as heavy as we have been seeing in recent years, and particularly in pastoral agricultural systems where like large cows, sheep, goats, what have you, are trampling across wet muddy fields, they are then killing off any flowers because the flowers can cope with being stood on.

They can cope with being rained on. They can’t quite cope with everything all at once. So all this lovely food that may have been going, it’s getting destroyed by the rains as well, so it’s yeah, a double whamy effect, isn’t it? So we have our wet winter following into our wet spring. What relief can we hope for the bees?

I mean, one of the things I really love when I was talking about how sensitive field flowers can be wildflower strips. We plant so much in the way of wildflowers don’t we?. That’s one of the main things people think we can do to protect bees. It’s not the only thing you can do , it’s not, the only thing you can plant, and you know what’s really quite resilient to heavy rain and being stood on are trees.

If you end up planting trees that flower, typically trees flower for longer periods of time than wild flowers. They’re also far more resilient and they can avoid this one aspect where bees will run out of food. Another thing, it’s, it’s bit of a sore subject, I guess with some land managers. Ivy Ivy’s are wonderful plants.

It flowers basically from December through to May, which is exactly the time when we need to produce lots of food for bees to recover after winter. And obviously people don’t, not everyone likes Ivy. People think it can damage masonry, which is not true. People think it can kill trees, which is again, not true.

So we end up with people cutting the stems at the base of these beautiful ancient ivy plants that this symbiotic relationship with these very old oak trees. And if we could just stop that . Protect our Ivy. Ivy plants. Protect our interim woodlands better, uh, plant more. Forested areas have the potential to provide more food for bees and be smarter about what kinds of trees we’re planting.

Thinking about seasonality of flowering, we’re planting trees just as we think about seasonality of flowers when we’re planting flower strips. I think a combination of things like black thorn, willow, hawthorne, oak, and some sycamore species and maybe a bit horse chestnut for the bumbles. That all combines to a very nice, nearly constant flower provision for wild bees.

of all kinds. Even when it’s raining? Even well, they don’t get damaged so much when it’s raining. Yeah, but the bee stopping flying when it’s raining. There’s nothing we can sort of do, really do about it. It’s just. That there is some argument, I guess, for rapid evolution from wild pollinators in response to these changing environmental systems.

But we haven’t seen that in other organisms. Like even things like blue tits being synchronized with winter moth caterpillar emergence, they lay their eggs. The eggs hatch exactly when the winter moth larvae, caterpillars do. So there’s always food. That system’s been disrupted by human anthropogenic, climate change, and birds still haven’t quite adapted to that system.

so there’s no evidence that bumblebees or wild pollinators would adapt to that system. Similarly, we could hope. There’s always hope. In the autumn I know bees are collecting, getting ready to over winter. Is there anything different about how rainfall affects them in the autumn because of this special prep time?

Obviously if you are going into winter with less stores, less food provision for yourself. I’m speaking for honeybees right now, but we’ll get to bumblebees in a second. If you’re going into winter with less flying days for provisioning stores, you’re not going survive that winter without a lot of help from beekeepers.

So you will end up with a lot more feeding of sugar syrup. There’s quite a lot of evidence that the nectar collected by bees isn’t just for sugar. There are a large number of chemicals provisioned inside the honey that can form a natural pharmacy. So if your beekeeper is giving your honey bees exclusively, lots and lots of neat grain sugar rather than flower- based nectars, then their resilience to disease is going to be affected as well, as well as just having a net reduced amount of food for winter.

One of the things that affects wild pollinators on the hand is nesting sites. All right, so let’s just take good old favorite bombus terrestris, the buff-tailed bumblebee, that bee in the autumn is provisioning some amount of food, but it’s just provisioning for just one bee the queen, because she’s the only thing that survives over winter.

So she’s going to get enough food in a secure location to feed on over the winter and then emerge the next year to mate and create a proper colony. That bee, and 14 other British bumblebee species are ground nesting. Very typically you’ll find them in abandoned mice nests are the best site for bumblebees to nest.

There’s a lot of access there, including smell which they seem to love, but these are obviously little tiny dugouts in soil below ground level. If you have got heavier rain, more and more flooding occurring than the number of those nests that are going to be destroyed due to flooding. That’s going to severely impact the survivability of those queens over winter because she’s not going to wake up.

She’s not going to leave her nest in the middle of winter because it’s flooded. She’ll just die in that nest, which is obviously quite unpleasant to think about for bumblebees. So increased rainfall is just another struggle for bees and pollinators whose diversity and abundance is already in decline.

What do you see as the biggest threats to bees. Acutely so immediately. Agriculture agricultural practices, be it, uh, huge monoculture of of food plants so that flowers only exist on that site for about a week a year. Or pesticide applications, obviously insecticide applications neonicotinoids . Very direct, very acute impact on bee health herbicides, which are applied

the factor of 10 times as much as any insecticide, possibly 20 times as much. They impact the wild flowers. If you spray a bunch of weed killer weeds are what bees eat, so there are going to be less flowers because of spraying. But there’s also this really fascinating side of things that I’m currently looking into and a number of other researchers in the UK are looking into where specifically glyphosate, where if it’s ingested by bees, kills off a number of the sort of core bacteria living in their guts, and those bacteria are symbiotic to the bee, so they help the bee digest food and they’re eating glyphosates, which kills off those bacteria and basically gives them dysentery.

So they can’t digest food as well. It makes them a bit poorly, it makes it more susceptible to other diseases. And then there’s, even within the UK, we can look also internationally agricultural practices leading to clearing of existing wild habitats. So. Thank you. I want to talk about something a little bit different now.

You led a very interesting project called the Bee Box. Can you tell us a little bit about that? Still leading it. It’s still going. It’s a lovely little project. I feel really happy about it. It has a sort of origins in Blue Peter Heath Robinson style stuff you can do for your garden. So it’s an artificial nest box for bumblebees, which when I looked into it I was kind of shocked that no one’s really tried to do it before at leastnot

properly. So essentially you want to put a a box. You wanna put a little nest box for a bird or bats in your garden. You can buy those. There are millions of them available everywhere. You want to do the same thing for bumblebees. You basically get an old clay plant pot, turn it upside down, and leave it in your garden, and hope for the best

There’s no consideration for what bumblebees need. There’s no consideration for longevity. There’s no consideration for, the very like tree bumblebees versus ground nesting versus subterranean, bumblebees. There’s all these very specific things. So what I did, I partnered up with researchers here at Lancaster in the engineering department who are very smart and can listen to my rambling about.

So it needs to be this shape and it needs to be able to go here and turn it into a 3D printable design so that we’ll basically build virtually a series of different chamber sizes, box sizes, shapes, connectors, fasteners, all that stuff. And then we’ll use this technique called additive manufacturing, which is basically what 3D printing is and just fire off the hundreds of different designs to test how bumblebees respond to it.

It’s just amazing. The idea is long term that we’ll be able to mass produce nest boxes for bumblebees , which people, one people can have in their gardens, two researchers can actually do proper experiments on bumblebee behavior because we don’t have a, an artificial equivalent of what a wild bean nest looks like to test bees with.

And thirdly, we can actually install these as, uh, commercial products. So horticulturalists people who grow food in greenhouses, they buy hundreds of thousands of artificial bumblebee colonies every year for pollination. And they buy that many because they have to keep replacing them because the boxes they buy are not great for bee survivability.

So this, we’re currently working with, uh, a number of companies in the UK who are interested in commercial versions of our Bee Box for their greenhouses that will last ideally longer than two weeks. Um, and then the last one is just a, a paired system with existing conservation approaches for bumblebees, so we want to keep people planting wildflower strips.

We want to keep hedgerow restorations, keep tree planting, and then pair that with, we’re going to give you a bunch of boxes for bumblebees to nest in so that you can give them food and form all these trees and flowers and you can give them somewhere to live in all of our boxes. That is a wonderful project.

There’s a YouTube video where you can see the bees inside the Bee Box , so we’ll post that in the show notes so everyone can enjoy their sitting there in their little box. It’s super cute. Tell me what your favorite bee is.

My favorite bee is Bombus monticola it’s the bilberry bumblebee. And why is this one so special? It’s reasonably rare. And my first job after completing my PhD was to do pollinator surveys in Ingleton, in the Yorkshire Dales, and that was the first rare bumblebee species I ever found that I was paid to find. Of course, it’s adorable. It has a tiny orange bottom with lovely white stripes.

It’s just a very lovely looking bee. That’s great. Anything else you’d like to share with us about excessive rainfall, flooding, or the climate crisis as it relates to bees. We talk about bumblebees, we talk about honey bees, we talk about solitary bees. Sometimes if we’re lucky, they’re not the only pollinators.

We have moths, we have flies, we have bats in some parts of the world and birds that do it. They are all threatened by climate change. Anything that impacts a flower of any kind will have a knock on effect. Because the pollination system isn’t, it’s not super resilient. It’s a very delicate balance because it involves multiple species interacting.

So we have to be very careful with the system that we’ve been blessed with in the form of pollination because we take, we keep taking little bits out of the system. We keep just trying just little tiny bits at a time. And there will be a time when that little change is just a bit too much for the system to handle, and that scares me. Thank you.

The entire pollination system is threatened by climate change. Thanks so much to Dr. Philip Donkersly for his insights on how damaging flooding can be to bees and their habitats. What was really interesting to me from this discussion was how important trees are to bees beyond the obvious fruit bearing ones.

 Don’t forget to check the show notes to watch his Bee Box video. And while you’re there, why not sign up for The Bees News Newsletter? Twice a month, you’ll get all the details on the latest show. You’ll find all this good stuff plus the transcript for this episode at thebeesknees.website. Thanks so much for listening.

I hope you enjoyed today’s show. Please follow The Bees Knees wherever you get your podcasts and tell a friend. It means a lot, not only to the show, but also to the bees. Until next time, keep buzzing.