81 Dr. Valerie Peters – Climate Change, Pollinators and Coffee (in English)

Speaker 1: From the Oregon State University Extension Service, this is Pollination, a podcast that tells the stories of researchers, land managers, and concerned citizens making bold strides to improve the health of pollinators.

I'm your host, Dr. Adoni Melopoulos, assistant professor in pollinator health in the Department of Horticulture. It's a little cold here in Western Oregon. Maybe not as cold as Winnipeg, Canada, but it's cold. And so I thought this was a good opportunity to return to the tropics. Last week we were in Hawaii, and this week we visited with Dr. Valerie Peters, who's an assistant professor in biological sciences at Eastern Kentucky University, where it's also likely cold. But her primary research is in Costa Rica, which is super warm. And in Costa Rica, she's really interested in global stressors like climate change on biodiversity. And she's going to tell us a little bit about her research looking at wild bees, coffee pollination, and climate change. She also is going to tell us a little bit about a really fantastic citizen science project that she has with the Earthwatch Institute, as well as some work that she has in Kentucky. So gather around your podcast for warmth and enjoy this Costa Rica edition of Pollination. Welcome to Pollination, Valerie. Thank you.

Thank you for inviting me. Now we've talked on past episodes about the effects of habitat quality and pesticide exposure on pollinator populations, but we have never addressed another global driver associated with pollinator populations. That's climate change. Can you briefly lay out some of the obvious and maybe less obvious ways climate change might alter the composition of pollinator communities? Yeah.

Speaker 2: So I think that there are basically two predictions of climate change that might be expected to have the greatest impact on pollinator communities. And that would be warming temperatures and changing patterns of precipitation. So with warming temperatures and changing patterns of precipitation, you could have either direct effects or indirect effects on bee communities. So I'm just going to give an example of each of those, an indirect effect and a direct effect. Oh, fantastic. So for example, one direct effect might be that warming temperatures could alter the geographical range of pollinator species, where the prediction would be that species would either move northward latitude in the lay or if they were mountain-dwelling species, then they would move upward altitude in the lay.

Okay. But people really don't know for many pollinator species exactly what might happen. We don't know if the species, and this isn't just for pollinator species, but a lot of species, we don't know if they'll actually be able to successfully move fast enough upward or northward. So the other potential could be that we would just see the loss of species in a particular location or maybe declining pollinator population numbers.

Okay. And then for indirect effects, there's been a lot of work done looking at mutualistic partners of pollinators and how warming temperatures or patterns of precipitation might affect the partners. So that would be the plants. So if warming temperatures are, for instance, accelerating flowering phenology, so the timing of flowering would be earlier or at a different time than what it traditionally would be, then a particular bee species that might have a strong partnership or specialize in that particular plant or depend upon that plant.

If it's not emerging at the same time or its phenology is going to be queued by something that's not climate-related, then the interaction between those partners might not be realized, and that could have detrimental impacts on pollinator communities also.

Speaker 1: Oh, wow. So I can just see how this really can be very complicated and complex. You may have a range of species of bees that are living in an area and it gets hotter and some of them respond don't have any heat tolerance and can't move fast enough. I guess that's the other part that you said and just get trapped and they disappear and some may move northward and some may stay where they are. Right.

Speaker 2: There's a lot of a lot of species, especially where I work in the tropics. They are a lot of small bee species and they only really have maybe from their nest, their foraging patterns are maybe 100 meters or 50 meters.

And so we haven't really studied dispersal rates of those bee species, but if they have small foraging ranges and they don't fly very large ranges, then potentially, those species could be at higher risk. Okay.

Speaker 1: Okay. All right. I'm getting, and then the other part of it is the, are these indirect effects, the plant host, for example, may the bee can move and it's able to move, but its plant host doesn't move with it or looms so early that by the time it comes out, it's gone or something like that. Right. Right. Okay. Gotcha.

Speaker 2: And the other, the other thing I think for where I work, especially in the tropics is the patterns of precipitation, which we don't really think about that much in temperate areas, but potentially that could influence both the plants and the pollinators in the same way. And we actually see that being an even bigger impact in our area because most of the plant species, instead of flowering when temperatures are warm enough, they'll flower in response to precipitation and the patterns of precipitation are becoming more and more erratic. And we see just within short periods, weird plants blooming at weird times of the year and the bee community is completely different than at that time of year.

So it's really interesting. Just this past field season, we saw two plant species in particular, one of them not native, citrus was flowering. And for the first time in June, we were catching lots and lots of bee species.

So it seemed to have a actually a positive impact on the bee community, but in the long term, we don't know what kinds of effects those, strange phenomena will have.

Speaker 1: Are these effects expected to be uniform across the globe or places like the tropics, especially with the way precipitation effects on a set of flowering expected to be more severe?

Speaker 2: So I've read some papers, there's only actually very few and it's mostly through model simulations that people have looked at the effect of precipitation because one of the things about precipitation is that we don't have, we don't collect that data locally and weather stations, like we do a temperature because it's more expensive. So the data is really not out there and that's why we really just have models to tell us what we think might happen, but it should be broad across the tropics. There are also other areas where precipitation is important in Mediterranean climates so in those areas, the prediction for climate would be that wet, wet times of the year would become drier, dry times of the year would become wetter, and there would be more erratic patterns and that's, that's pretty much what wide across the board, but in general people think in those areas where precipitation patterns will be changed that that will have a larger effect, but there are also some predictions that mountainous regions of the tropics where there's a rain shadow effect that those areas, because they are more seasonally dry, that those areas will be the hardest hit.

Speaker 1: Because they have the same kind of disruption of the patterns of precipitation that you would in a dry climate and that could also function the same way.

Speaker 2: Yeah, and the species that live in those areas are more adapted to those shifts in the dry and the wet and a lot of them migrate altitudinally over to Caribbean areas where it's not as dramatic, the dry and the rainy seasons and so they've evolved these really intricate strategies for dealing with the dry and the wet and when it shifts then people don't really know how that's going to impact those species.

Speaker 1: Now you've done some excellent work looking at precipitation and its effect on not just wild species but also an ecosystem service flow back to commercial coffee. Can you tell us what you found?

What's this? I imagine a lot of people just to start didn't know coffee was pollinated or they heard kind of just give us a little primer on coffee pollination and tell us how it's affecting it.

Speaker 2: Yeah, so also the flowering phenology of coffee is really interesting. So I'll explain both what the pollinators of coffee, what the assemblage looks like, and then also how coffee flowers because it's really interesting for me anyway that coffee, I didn't really know this before I started working with coffee but depending on where it's grown in the tropics the flowering phenology is different and that affects how the major pollinators for coffee are bees. Those are the ones that are thought to be the most effective pollinators but whenever I'm out on a coffee farm I'll see all kinds of things visiting coffee flowers including wasps, hummingbirds, surfid flies, and just about anything because they sort of have that very generalist white flower that's very open. So for coffee, it really only grows in the tropics. You can't really grow coffee outside of the tropics and it has a particular elevation range in which it grows and that's about 900 meters to 1400 meters above sea level.

Okay. And below 900 meters it's not really the commercial coffee that's grown there, it's a different species, Caffè Arabuesta. So what I'm talking about is Caffè Arabica, that's the one that we really, most people would drink that the other one is not as good mostly used for household consumption. But again because of how precipitation there's many places in the tropics where there might be two peaks of rainy season times or it might be more seasonal in terms of precipitation and then you have those areas like in Mesoamerica where it's very dry six months of the year and rainy six months of the year. And so across those different areas coffee would either flower sort of continuously and asynchronously throughout the year or what will happen is you'll get these huge mass blooms whenever the rainy season starts. So the actual queue for coffee flowering is just 11 millimeters of rainfall. So all that has to happen is that it has to be dry for a short period and then 11 millimeters of rainfall happens and the coffee will just go crazy, and bloom.

Oh my god, okay. So in the places where it's asynchronous what you'll see is very low-density coffee flowering throughout the year. And then in these very seasonal places, you'll have no coffee flowering for about nine months of the year. You'll get a couple of light blooms in February, a couple of light blooms in March, and then in April the entire coffee plantation just comes alive. There are you know 300, 500 flowers per individual coffee plant and when you walk into the coffee farm it looks like it's snowed and it's an amazing smell. But the flowers when it blooms like that for a mass bloom only lasts 48 hours.

And then everything you walk back to the farm you know four days later and you can't even tell that anything ever happens. So from the pollinator's perspective, it's a very the resource is very short.

Speaker 1: And I can imagine to get all that pollinated you need a blast of bees at the right time.

Speaker 2: Yeah so when I started working with coffee I expected that bees would play a really big role because the studies that had come out saying that species richness of bees contributed to the coffee yield had come from Indonesia where coffee flowers asynchronously. So as species richness increases in those areas, you would see higher yields because coffee actually the experimental studies of coffee pollination and fruit set show that if you self-pollinate a coffee plant you will get a little bit higher of a yield than if the wind just pollinates which wind can pollinate coffee.

Okay. But the yield difference is maybe 45% with wind pollination to 60% with adding in self-pollination. But if you cross-pollinate a coffee plant then you can go up to about 74% fruit set. So what I expected to see when I started working in the coffee plantations was that if I could increase the number of bees in the coffee plantation then I could also increase yield. But what I didn't realize was that during those times of very dense blooms, the bee movements were so small because mainly the ones who were responding to that big bloom were going to be the apis malifera the honeybees. So you get these huge numbers of honeybees moving in some of the we also in the tropics have melaponins which are social stingless bees. So you would get some of the social stingless bees coming in too but not in the same high numbers as apis malifera. And you can watch the apis moving very methodically from one flower to the next to the next to the next but within the same plant. So what I was seeing during those mass blooms even though there were more bees and higher species numbers of species there actually wasn't a higher fruit set because it seems to me I didn't actually measure this because I was looking at my questions or something else but it seems that the bee movements were very short and most of the pollination that was occurring was self-pollination.

Speaker 1: Oh because they were just they honeybees have a real tendency to move and such a density of bloom they'll just stick on one plant and you don't get that boost that they would see in a place where the coffee trees would bloom asynchronously and have fewer blooms per tree.

Okay well, there you go you never know in science eh it doesn't turn out the way you'd expect. Talking about climate change and precipitation and changes in precipitation how does this affect coffee in the tropics?

Speaker 2: Yeah so what I noticed one specific year that I was so I was working my project was actually planting supplemental patches of flowers into coffee plantations to increase bee numbers, bee diversity, and then and to see if that would have an effect on the yield. And the second year of the study as I was working on the project there was very heavy rainfall during the dry season and it was a La Nina year so that is one of you know what we expect will happen more with climate change that we'll see these very wet dry seasons.

So there was rain rain rain all through the months when there wasn't supposed to be and actually what that what that did was one the supplemental flowers that I had planted weren't blooming any any longer but I was paying attention to what was happening happening with the coffee and during the early season blooms it rained when it really shouldn't be raining at that time and so there wasn't a lot of bee activity during those early season blooms for this particular area that's when you would get to see those high yields so in the previous years I was seeing 75% yields during those low blooms because the pollinators were moving the pollen across the individual plants during that that time when it was raining bees weren't active so right right right when whenever if if rain becomes more common during these times when coffee is flowering it's a very short window you have two days for the bees to come if it rains those two or three days the bees weren't visiting the flowers were getting spoiled the pollen itself was getting ruined by the rainfall and so instead of seeing 75% fruit set rates during that time I was seeing 30%

Speaker 1: oh no oh that's terrible news

Speaker 2: yeah but two on the other hand instead of seeing a one mass bloom which you would see almost every year with the onset of the of the major rain rainy season then what we saw was actually two mass blooms the second one came so late it came in May at the time of peak insect emergence and all during every previous time of every previous season of looking at coffee blooms whether it was low density or high density my maximum number of bee species in the farms was only about 10 or 11 bee species that was always across the board this mass the second mass bloom that occurred in May there was 26 different bee species so just because it coincided with this peak bloom and that was again I was trying I was imagining that the yield was going to be much higher but because of the density it was still very low and because of how much how many flowers and how many fruits were produced during those two mass blooms there was a lot of seed abortions so coffee is one plant that will just keep flowering continuously with with rainfall but as the tree gets overexerted from fruit production it's going to abort the majority of its fruit so in reality with the low the early season low fruit production and then the late season high abortion rates it was not a great year for coffee and and in addition to that when the rainy season hit it was very dry and so a lot of farmers experienced problems with a fungal pathogen called leaf rust and the coffee harvest was very bad that year and that's just kind of an indication of what could potentially come in the future for the future for coffee and also people think again that that that climate envelope for coffee is going to push higher up the mountain so it's going to move from 9 to 1400 meters maybe up to you know 1200 meters to 1600 meters and in some cases where the mountains don't go that high that could be a problem for coffee farmers so

Speaker 1: I can imagine the disruption too it's not like a row crop that you can just recultivate somewhere else you've got a lot of investment sunken in the ground in certain places

Speaker 2: yes yeah there's an, especially with the very low-income farmers who you know just have a small smallholder farm and that's their home so for them if if if coffee if they can't grow it well in their farm they can't just go and purchase another piece of land because that's the only land that they own okay

Speaker 1: the wild it's great to kind of like carve out at least knowing some of these patterns or at least getting a handle on these patterns although some of these changes may be upon us already and the capacity to mitigate is going to be very difficult

Speaker 2: yeah yeah I think so from what I've seen in terms of patterns of precipitation it's something I think that we don't necessarily think about that much here but every time I go to Costa Rica all of my friends that are farmers just tell me about how crazy the weather their local weather has gotten and it's been that way probably I've been hearing those stories since 2000 and I want to say 10 so maybe the last 10 or so years every time I go there's more and more stories about how things have changed and so I for me I think especially in those areas the people who are living close to the land and experiencing that can see at first hand and yeah in in those cases it's just anecdotal evidence but I just hear all these stories and I think we don't we don't necessarily we think it's something coming in the future but for people who are living off the land the farmers they already know

Speaker 1: Okay well let's take a break let's come back there you have a whole all right we are back so I wanted to come to another feature of what you do in Costa Rica you've worked really closely with Earthwatch Can you tell us about Earthwatch's collinear work in Costa Rica and what your role is in it?

Speaker 2: Sure so Earthwatch basically works all over their their mission is to engage people worldwide in scientific field research and education to promote the understanding and action necessary for a sustainable environment and so Earthwatch basically achieves that goal by working and partnering with scientists and what the scientists do who are interested in working with Earthwatch is they actually have to submit a research proposal to them okay and it goes through a peer review process and Earthwatch will determine if the research falls in line with their mission and if it does then you're invited back to do it that that's a preliminary proposal then you're invited back back for a full proposal in which you detail the logistics involved in your in your project so from Earthwatch's perspective it's important that the research that they're funding both addresses global issues and has a conservation focus and also that logistically they they can allow volunteers to go and participate so they on their end what what the partnership ends up looking like basically is that Earthwatch can recruit citizen scientists that will come and collect data with you in the field so then your your work that you have the the the research that you're working on you invite the the citizen scientists to come you spend a couple days training them in proper data collection giving them some background about what you're trying to achieve your scientific objectives the conservation goals and then they spend anywhere from you know two to maybe two days to to a week or longer with you in the field collecting data and I've first encountered Earthwatch when I was a PhD student and I wrote a grant for my coffee project actually and at the time was doing both work with birds and with bees and I had volunteers for three years from 2006 to 2010 coming out into the field and walking through coffee plantations collecting data on birds collecting data on bees and they ranged in age during those those years from 16 to 82

Speaker 1: wow everybody yeah

Speaker 2: so yeah I mean there's there's definitely a lot of retirees that come out and help but you get teenagers and I had school groups I had a group of students from West Point I had a group of students from Vermont yeah so it's really it's actually a really I mean from that from that moment I was I was addicted to how how interesting it is to invite these people to come out in the field and to see who who's gonna come out and you know how you can get them inspired because the other one other thing is that you know it's not just those volunteers but you think about well they're out they're seeing firsthand And this project, they're learning all about it. They're actually collecting the data.

Then they get to go home and tell their friends. A lot of people that come are teachers. Earthwatch has a teacher fellows program.

So teachers will come and then they'll use, they'll incorporate those into their lesson plans. There's fellows, there's people from, it's not just the age range. There are people from every country in the world I've had volunteers from Jamaica, Trinidad, Brazil, Japan, the UK, and Australia. Of course, lots of people from the US. So just a really incredible assortment of people, diversity of backgrounds.

And so it's just a fascinating thing. I don't know now, if you're collecting data in the field by yourself with a couple of field assistants, I feel like that would be boring after this experience.

Speaker 1: Well, I can certainly attest to the lifelong learning. I think one of the reasons you're a guest on the show is one of your volunteers was listening to Pollination and said, oh, you have to have Dr. Peters on this episode. So it certainly extends well beyond when they come home and they're in their specific initiatives, they bring that experience back.

Speaker 2: Yeah, I think, I think Earthwatch is a really, a really great organization. And as I said, they have projects all over, all over the world in every country, and with every kind of organism that you can think of. And I think that my project is the only one that focuses on pollinators.

And that's actually really interesting too, because there are other projects in Costa Rica where volunteers can go and patrol beaches for sea turtles or get on boats and look at whales and dolphins. And yet there's, there's so many people. In my groups, I can have up to 15 people per week on a team. And I don't get full teams, but a lot of times I'm getting up to 10 or so people, a lot of groups and student groups coming in from inner city, New York, and places like that. And it's just, it's really inspiring because these are people that are passing opportunities to patrol beaches for sea turtles and coming to do work with pollinators. I can totally get it.

Speaker 1: The amazing bees in Costa Rica. Yeah. So I'm sure there's a bunch of listeners like saying, man, that's where I want to go next. How do they, we'll link to the page on the show notes, but just give us a little glimpse into how you get started. How do you sign up and how do you get involved?

Speaker 2: There is the, on the Earthwatch website, you can go to a region of interest or project of interest. There are different ways to search for projects. And again, mine is the only one with pollinators. So if you search that way, you could find it easily. Also, climate change would be another search term. There are several projects with climate change. And then by region, which would be Central America.

Speaker 1: And when would people need to get their applications in? When should they sort of plan for the next cycle?

Speaker 2: People can sign up pretty much all along. A lot of times we'll get people, sometimes people will say, okay, it's getting cold now and I really want to go somewhere more. And so we're, I'm about to leave this Saturday for two weeks and I have some people who are just signing up. I mean, it's kind of, it's a little late.

Usually, we try to get people, you know, within 30 days prior, but I do have some late additions that are, that are coming in right now. So All right, not too late. Not too late.

It's not too late. And also next summer, when we stay in the field longer and we have about, I think eight weeks. Some of the weeks are taken up by student groups and those are closed off. And we do research both in the highlands and the lowlands. So if you like hot and humid versus mountainous tropical weather, then those are two choices also.

Speaker 1: Fantastic. Well, we'll, we'll link all the information on the show notes of listeners. Come on down, and check it out. So the last thing I did want to ask you about is whether you have active work in Kentucky, where you're, where you're right now around pollinators and mine reclamation. Now I imagine reclamation on a mine is a huge challenge. How do you get plants that even will live in such an inhospitable place as a place where there's been mining for decades?

Speaker 2: Yeah. So we, to get around that issue, because actually unless the mine reclamation process is done very well, you end up with a lot of compacted soil. And actually, many of the mines in southeastern Kentucky are so damaged and not very well put back together that we can't even access the mines.

They're only accessible with four-wheel drive vehicles and even some four-wheel drive vehicles can't make it. So there was a project right before I came to Kentucky where some people here were working on trying to plant cottonwood and some other trees on the sites, but in reality, they weren't able to get those to grow. And so what's really coming back on the mines right now is just a whole bunch of early successional species, a lot of solid egos, and some other very herbaceous weedy plants. The areas that we wanted to work in, we really ended up switching from trying to actively restore and look at how those restoration treatments were affecting these to looking at how when you have this kind of reclamation going on in a landscape, on a landscape scale, how does that impact the populations? And there are there's definitely some examples in Ohio and in Kentucky of a mine reclamation that has been successful, but since we're interested in looking at the effects of mine and reclamation over landscapes, we don't, since those few examples are there, there's not that many of them, we couldn't really replicate those to look at them.

So instead we were looking at how reclamation practices, the current way that it's done, might impact the populations. And what we ended up doing was looking at going to schools that were sort of embedded in landscapes. We looked at all K through 12 schools in a certain number of counties and we chose those schools based on whether they were embedded in a landscape that had heavy mines and reclaimed mines or if they weren't, they didn't have mines.

And we tried to compare those with and without mine. We looked at a bunch of other landscape variables like forest cover, and the percent cover of urban lands. We were actually really surprised because we knew that mines would have a big impact, but we didn't really know what and looking at the data and doing the analysis that almost all of the different functional groups of bees and almost all of the species richness and abundance of bees within the landscapes that we were collecting from the schools, the number one predictor, the biggest impact was coming from whether just whether there was presence or absence of mines. So forest cover played some role. Urbanized land cover played some role too, but the number one impact was from the presence or absence of mines. That's probably because, in addition to removing the mountain, all of that debris is pushed into the nearby valleys. So you have this, even though the mine itself and the reclamation might be sort of on a smaller scale when you look at it on a map, but if you think about all of the other impacts from that mountaintop removal, that's likely why it's having such a big impact on the bee communities.

Speaker 1: Let me get this straight. So you went out, you got these schools involved and then you looked at the bee communities there and then what you found was the biggest predictor of sort of bee community composition was whether these mines were within the vicinity of that school. That is really true, you would have thought these might have been very localized effects, but they seem to have very far-reaching effects in the landscape.

Speaker 2: Right, right. I was really surprised because we used map layers for surface mining only. And when you look at those map layers, if we use a thousand-meter radius circles around the schools, which was very large, and you would just see some of these squiggly lines, a very small proportion of the total land cover in a thousand-meter radius and ranging from about 4% to 15%. And yet that's the land cover, whether they're there or not, not the percentage of it, but just whether they're there or not is having the greatest impact.

Speaker 1: Do you have any hypotheses as to why a small area of coverage is having such a dramatic effect on the community?

Speaker 2: So I think that what the maps are showing are just where the mountain top was removed or just the scene.

Speaker 1: Oh, okay, so it is this valley. Okay.

Speaker 2: So that, but if you actually go out to the fields, then you can see that all of that debris is moved somewhere else. So when you, even though it's a small percentage, based on the total area of that, of just where the scene was mined, but overall, all of that, to get to that scene, there was so much destruction. And I think that's why it's having such a large impact on the bee community because if you take really the actual total land cover, it might be more than 25% of the landscape that has been disrupted and disturbed by the whole process because the trucks coming in, the debris moved into the valley. So it's not just the mountaintop forest to get to the seam that's been completely disturbed and removed. But actually, all of that is placed on top of other land. And then that lands, the forest there are completely disturbed and disrupted too. So even though we say, well, it's only, you know, it's only four or five up to 10% of the landscape, it's really much more than that.

Speaker 1: Wow, Dr. Peters, you are a busy person. There are a lot of different projects that you're involved in. Let's take a quick break. And we've got a couple of questions to ask you that we ask all our guests. All right, well, welcome back. So we ask all our guests these questions. I'm wondering if you have a book that you'd like to recommend to our listeners.

Speaker 2: The book that I, well, okay, it's not just one book because I can never just recommend one book, but it's actually an author. I started reading them, so the author is Alexander Sketch, which is probably for people who are interested in pollinators, it might not make much sense since he was a famous ornithologist. But Alexander Sketch was first trained as a botanist. Then he went to Costa Rica and lived in Costa Rica. He fell in love with Costa Rica when he went there as a botanist. And he started intricately studying all of the bird life around him. And he just wrote volumes and volumes about birds and was given an honorary ornithology degree. He has one of the first books of Birds of Costa Rica. But what probably a lot of people don't know is that he also did some nonfiction writing. And he wrote a lot of books mostly on birds, but sort of ties in a whole bunch of other things about what life is like in the tropics and what's it like to be working in conservation and working around and living among farmers and also maybe people who might not be as empathetic with conservation causes.

And so they're actually really, really interesting books. He has things like Life of the Hummingbird, which does relate to pollination, but also Life of the Flycatcher and Life of a bunch of other different bird groups that are not pollinator groups. But then some other books, Nature Through Tropical Windows and A Naturalist on Tropical Farm, just kind of describe his life and what it was like to live back then when he was living in the 70s and 80s and on his small farm in southern rural Costa Rica. My favorite thing about these books is that it was actually an Earthwatch volunteer who brought me his last book, which he wrote in 2000. And it's all about morals. So he kind of ended his career of writing books, writing a book about moral values. And it's a very, I've actually only ever finished half of it. It's an enormous book and it's very dense and it's one of the best-written and most amazing books that I've ever read. But he, I think was the last book that he wrote. So it's called Moral Foundations. But they're all amazing books.

Speaker 1: That is a great suggestion. I think you may be the first one to recommend an author and their whole suite of work, which is fantastic. It's a great way to smuggle in a bunch of books. But they sound really interesting. And it's, you know, one thing I have to admit is the show has been really focused on the temperate zone. So this is really great, so you're allowed a lot of books.

We're making up for lost time here. Okay, the second question I have is there are go-to tools that you kind of rely on when you do the kind of work you do with pollinators.

Speaker 2: So most of the time when we're out in the field, we try to use a variety of different sampling methods so that we can effectively sample the entire community. But one of the things that I have most recently discovered, it's not necessarily a tool, but since I've been able to add the Earthwatch volunteers into helping me collect data with these, I'm working across three transects in a very, very mountainous terrain. And when I was sampling by myself, I would have to carry gallons and gallons of water up these mountainsides and fill up the beavels to catch the bees. I really only could focus on bees and not other pollinator groups and only the bees that would be collected in beavels, but by adding the Earthwatch volunteers in, I can, we can kind of station people out at these different elevations. And so we can sample the entire day, we can have two volunteers at each of the different elevations. And one of the most interesting groups that I think is going to show really refined elevation patterns. So a lot of these species in the tropics have very narrow thermal tolerances. And we can see that along the elevation gradients that as the, we move upward on the gradient, we, a lot of the bee species that we're working with, we don't see them up here, but we see them down here or vice versa. And so they're very, they're very altitudinally structured. So we want to know more about which bees are at which elevations what the populations are and what the abundances are at those elevations.

And so now with having the volunteers out there, we can have them stay out there longer and gather more data. One of the groups that shows the highest restriction in terms of their thermal tolerance is the social stingless bees. And of course, the social stingless bees are very, very cool because they make honey. We, we don't really have anything besides honeybees here that make honey, but in the tropics, you have, you know, 40 or 50 species just in Costa Rica that are making all these different honey. And so they're one of my favorite groups of bees, to focus on, but we can't collect them in beaples.

They won't, they won't go flying into beaples. And so in my data collection, before having the EarthWatch volunteers, they were completely unrepresented. Now the volunteers will take, all we have to do is take honey spray, a solution of honey spray.

We spray the honey solution directly onto a small patch of vegetation. And we've gone from, in 2016, we, we were only, when we were first trying out the method, we collected 83 individuals during that entire field season. But in 2017, when we were in full force, we captured over 700 stingless bees.

Speaker 1: Oh, so suddenly they're there. Yeah. Yeah. Because of you. So I imagine there are two tools there. The one must be the citizen scientists themselves that allow you to really cover a large area that would have been impossible otherwise.

Speaker 2: Yep, exactly. So it's that, it's that combination of having that wonderful opportunity to have people out there that are willing to collect that data, that are willing to, you know, stay out there. And this is just roadside habitat. There's, you know, just, it's just, they're on the road, walking up and down the road.

There are no bathrooms. They're out there for five or six hours a day, eat their lunch out there. And they have some nets they hand collect from flowers. They hand collect from the honey spray solution. They put out the bowls, they put out vein traps. And sometimes most the days it starts pouring rain around one o'clock.

And, you know, everybody runs and gathers up all of their equipment and comes back a soggy mess. And it's great, great to have people who are willing to do that.

Speaker 1: Well, I think it's remarkable as well because otherwise you would have this, is a really palpable example of how you would really get a skewed idea of bee biodiversity. And you would, all these secrets would be kind of still kind of veiled without having really dedicated volunteers that can go up this elevation gradient and sample. Yes, definitely. Great tool.

All right. The last question I have for you, I mean, you're in, you're traveling to this area with some of the most remarkable pollinator species around. Does any one of them sort of stick out? You're just kind of when you see this species fly by, it's just like, wow, I love that little thing. Yeah.

Speaker 2: So this is a really challenging question because I would love to say that everyone is my favorite. And whenever I ask my grad students this, they always say the orchid bees. Yeah. So I'm definitely not going to say orchid bees, but I do, I guess I do have a favorite bee. And it's actually a small carpenter bee species the one thing about bees is actually they're not so much more diverse as you go towards the tropics, like other groups that we're more familiar with. But the kinds of bees are different. So we don't have andrenids, for instance, there are zero andrenids. Really?

Yeah. But we, that space is filled up. It's about, if you compare the size of Costa Rica to West Virginia, and you look at how many bees are in West Virginia, you would estimate about 400. Well, there are about 400 species in Costa Rica, but it's just completely different from what you'll see. Even looking, an even more fascinating comparison would be that Brazil is about the same size as the whole United States. And we have 4,000 bee species in the US.

Brazil estimates are 1,600. Okay. So it's crazy, but we do have different groups or more species-rich. We have orchid bees, and we have stingless bees, but we don't have andrenids.

Well, for seratina, and seratininis, it's the same. Here on the East Coast, we have about four species. They're all small, tiny green. Well, in the tropics in Costa Rica, so far we've collected about 17 species. Oh, wow. And some of them are about almost as big as honeybees. Whoa.

Speaker 1: Yeah. That's so cool. I want to see one of those.

Speaker 2: Yeah. So that's one, there's one that's really big and it's my favorite. It's actually very, like green, helicted green, like the very bright metallic green, and the hat of the florex and the abdomen is a beautiful, bronzy gold. Oh. Yeah. So it's a beautiful bee and it's also my favorite because I've spent a lot of time working with a particular plant species called Himalaya patterns. It's a plant species that has a narrow red tubular flower, which screams hummingbird pollination, but actually, it's visited by tons of different insects as well as hummingbirds. And the great thing about this plant species is that it flowers all year long. So wherever it grows, it grows from Mexico to Bolivia and it flowers all year long. And these seratina species, probably because of their natural history of burrowing and having their nests in twigs, they'll actually go into the flower.

So they'll go into these flowers and I've watched this hundreds of times where it'll, I'll go up to a Himalaya plant and I'll see those little bronze abdomen poking out just out because the flower, the tube of the flower and the bee length are just about the same length. All you see is this. That bomb is hanging out.

Yeah. And so I'll go and I'll squeeze the flower and then it'll, you know, the bee will vibrate, but buzz a little bit and I can squeeze it and make them come out. And when the beat, when she comes out, she's all covered in pollen and I've seen them stay in there for up to 30 minutes at a time or longer. And so it's a really interesting interaction, but almost everywhere we go and sample these plants, there is a seratina species that is hanging out in the tubes of these flowers and they're probably being more effective pollinators for that plant than the hummingbirds are because they're getting completely covered in pollen.

They're spending a long time there, but I also wonder why are they spending so much time there. These are little like resting places, but it's a really fascinating interaction that I'd like to try to figure out more about and also study because I've never gone to other countries and looked at the plant, but there are probably lots of different seratinas throughout the plant's range that maybe have the same kind of association. So it's not only a beautiful bee, but it's also probably benefiting this really fascinating, important plant that's probably important for many pollinator species. Whereas other pollinators, like the most common stingless bee in our community, will just nectar rob.

So instead of going in to get the nectar, it'll go to the base of the flower, cut a hole in it, nectar rob it, and it's probably not benefiting the plant very much.

Speaker 1: What's the name of the seratina species?

Speaker 2: It's seratina eximia. Eximia.

Speaker 1: Okay, great. We'll go dig it up and put it on the show notes as well. Well, thank you so much. Have a great time in Costa Rica and we'll look forward to hearing about all the things you find in a future episode.

All right, thank you. Thanks so much for listening. Show notes with information discussed in each episode can be found at pollinationpodcast.oregonstate.edu. We'd also love to hear from you and there are several ways to connect. For one, you can visit our website to post an episode-specific comment, suggest a future guest or topic, or ask a question that could be featured in a future episode. You can also email us at [email protected]. Finally, you can tweet questions or comments or join our Facebook or Instagram communities. Just look us up at OSU Pollinator Health. If you like the show, consider letting iTunes know by leaving us a review or rating.

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