12 Scott MacIvor – The Bees of Toronto


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. I love a good book about pollinators.

One that's written in a language that regular people can understand is concisely organized, has beautiful pictures, and that's the exact feeling I got when I picked up my copy of The Bees of Toronto, a new book by the City of Toronto as part of their biodiversity series. And I thought it would be a good opportunity to catch up with Dr. Scott McIver. Dr. McIver is a new assistant professor of urban ecology at the University of Toronto at Scarborough in the Department of Biological Sciences. Although he's new to the position, he's been working on pollinators in their urban landscape for quite a long time. And what makes him really unique is that he's not just an ecologist. As you're going to hear in this episode, he thinks deeply about issues of urban planning, landscape architecture. He's a really innovative thinker.

So as we kind of talk about the book, we talk about these broader questions, which I find really exciting. I think you're going to love this episode. I'm so excited to bring it to you. All right, welcome, Scott, to Pollination.

Thanks for having me. Now, I'm sitting here looking at this magnificent book, Bees of Toronto. And besides having amazing picture and layout, I was immediately struck by the fact that there's 350 bees living in the Greater Toronto area. What makes Toronto such a great place for bees?

Speaker 2: So many things, I have to say. First and foremost, the city of Toronto is a very green city. We're considered one of the most greenest cities in North America for our size. We're the fourth largest city in North and Central America in terms of population. But what really characterizes the city is our really beautiful ravine system. So back in the early 1900s, the city of Toronto experienced a hurricane, which is really rare for our region in Southern Ontario. Generally, we're pretty free of those kinds of natural disasters.

But nonetheless, several dozen people actually passed away. And by and large, it was because of flooding in areas of the city that we've now considered as no-build zones because of this historic flooding event. And these ravines would transseq the entire city. They really actually shape the city. And no neighborhood in the city of Toronto is too far from these wonderful ravine systems, which again, harbor a lot of native plant diversity and lots of other unique habitats. And so we've been able to, through policy, support and maintain and really cultivate these ravines. But also they prefer a real sense of identity for the citizens of Toronto as well, who use it as recreational space.

Speaker 1: So they started off in this dealing with this historic problem, but now they've taken on a life of their own. They have a lot of other purposes for people living in Toronto.

Speaker 2: That's right. And, you know, Toronto is just full of examples like that. You know, another really interesting park we have in Toronto is Tommy Thompson Park. And this is actually built on a human made island that has historically been a dumping site for a lot of the construction, debris and materials that were the, you know, the first generation of buildings in the city of Toronto. And over time, they built up this island out into Lake Ontario, which spontaneously was colonized by all types of vegetation. And has now become a hotspot for songbird migratory species that stop over there.

Many nesting species, but lots of these too. So ravines, we also have a lot of environmentally significant areas, which receive specific policies and programming that reduces development and construction and changes to those landscapes. And so by and large, we have a lot of green space.

We have about 28 percent of the total area of the city is is is forested or treed. And, you know, aside from the green space and kind of the municipal action that's been there to support it, there's a lot of public will and interest in gardening, in cultivating in green space, community gardens and growing food in our hydro corridors. And by and large is gardening and considering biodiversity and how in a number of different facets of the city is is something that, again, is not only promoted from this kind of top down this municipal action, but there's a huge public will, too. So this is bottom up interest in biodiversity and thinking about wildlife in our city and, you know, certainly the immersive and appreciative moments we we gain from experiencing these more biodiverse environments. But of course, the city is learning more and more about these linkages between biodiversity and ecosystem functioning, so functioning environments and, in this case, pollinators. And so it's really cool with respect to, you know, why bees and why Toronto. You know, with this book, we've come to learn that, you know, I'd argue that we know more about our bees in the city of Toronto than most any other city in the world. And I think that's something for all of us to not only be proud of, but it can start to really formulate or really encourage or drive or, you know, influence the way we enact policy around urban landscape, planning and design as we start to think about ways to adapt to and mitigate, you know, the impacts of climate change and, you know, this unknown future. You know, Toronto has actually a really unique history of bee scientists as well, not only honey bees and the domesticated bees that are used in agriculture, which, you know, is a defining feature of southern Ontario where Toronto is.

But the the history of science and research on pollinators and pollination systems at York University, at the University of Toronto, University of Guelph nearby and another number of other places has really set the stage for a greater knowledge of the bees and the environment, but also maybe putting Toronto as a research location for bees in the world. And so, you know, this public will, this bottom up, the municipal action, the top down, it meets somewhere in the middle. And those of us in research can really benefit from this relationship. And, you know, a big part of my interest in terms of bees in the city and Toronto specifically is this synergism that we're creating by linking all these different stakeholders in bees in the city. You know, we all need them. So anyway, great place. Yeah.

Speaker 1: And all of these elements are in the book. And I'm hoping that we're going to have time to sort of cover all of these things that you've put on the table about Toronto and how the book sort of ties them together, because I think it really does create this great story. And I guess, you know, one thing that you mentioned was the kind of biodiversity that you find in the city.

And we talked about this a little bit in a previous episode with David Lohenstein. But Toronto seems really full of surprises. You've got these newly described species. You have species that used to be abundant that are now endangered. You've got cosmopolitan globetrotters. Who are some of these remarkable bees in Toronto? How much time do we have? No.

Speaker 2: There's a whole bunch. You know, it's again, really exciting for me to, you know, I did my PhD in the city of Toronto under Dr. Lawrence Packer, you know, wild bee biologists who really open my eyes to the diversity and the beauty that bees represent, right? They're they're really diverse, not only in terms of their interactions with flowers and wildlife, but also in their structures.

And they're just so captivating. And so again, in the city of Toronto, we've got lots of different species. You mentioned new new species. And, you know, when I arrived in the city of Toronto to begin my PhD back in 2010, I arrived in a lab, Lawrence Packer's lab, where a number of other, you know, bee biologists around Canada were finishing their work as well, like Dr. Corey Sheffield, Dr. Jason Gibbs, Dr. Sheila Cola, Dr. Lana Pinder.

Wow. Many different biologists who are now out practicing still studying bees were there. And one that comes to mind is Jason Gibbs finding a brand new species of bee to science when and where he found it was very interesting for those of you who know Toronto, he found it down near the annex down towards kind of Bathurst and College area. And he named this bee Lacyoglossum effialtem.

And from what I remember, effialtem refers to nightmare. And so this bee was actually a nightmare to identify and determine as a new species. But interestingly enough, when you see surveys in Southern Ontario, since the finding of this new species, this the bee turns up on a lot of species lists now. So again, it makes you think certainly bees tend to do quite well in cities. And there's still lots we don't know about bees in many regions around the world. But it's cool to think that even in cities, there can be these hidden species that are new to science.

Really, cities can still represent a frontier in that context. I don't know. We got a whole bunch of other bees. You know, one that's been on my mind a lot lately is Osmia conjuncta. This is a bee mason bee that's out early. So it's even out now at this time of year. And unlike most mason bees that nest in plant stems or in logs, this bee actually chooses to nest in snail shells on the ground. And so yeah, yeah. So if I find a snail shell, you know, fills it with pollen and nectar and an egg and jams it up with rocks and kind of turns it over and jams it into a tuft of grass. And so what's so cool about this bee to me is when we when my students wrote sampling in parks with nets and in the early spring, this bee turns up in the nets. In fact, it's it's sometimes one of the most common mason bees that we find. Yet you'll never, ever, ever pick up a snail shell and find this bee in a snail shell.

It's such an odd thing. I even send students out sometimes with a bag when they go to certain sites and I say, bring back as many snail shells as you can because we're looking for this bee. And so just this mystery bee around the city. I keep going, you know, one that's received a lot of media attention in the past years, in fact, actually, one of the bees that my close colleague, Dr. Sheila Cole, has been studying, the rusty patch bumblebee. This is a bee that a few years ago is designated as an endangered species in Canada.

It only was just recently given that designation in the United States. But we're still curious as to whether or not this bee is entirely extirpated from our region. You know, this is a bee that likes oak savanna habitats and some of the native habitat types that once characterized Southern Ontario that have now disappeared because of agriculture and urbanization. And so it's one of those bees that, you know, you don't want to call it a loser of urbanization, but there's certainly winners out there. Some bees that seem to do very well in cities, just one that seems to not do so well.

Speaker 1: If I remember as well, Scott, it used to be it was a bee that you could find in Toronto. Like it was a bee that you could find in the ravine system at one point.

Speaker 2: That's right. But definitely before my time in the city. But what I understand, that's the truth that that it was far more common than it has been in recent years.

And of course, it's going to be all kinds of different complex factors that would result in that. But, you know, one little silver lining here is with a program that's been really successful in identifying the locations of different bumblebee species, a website called bumblebeewatch.org. This website allows users to photograph bumblebees, give a lot a lot of lat long or a GIS location. And experts will identify that bumblebee. And so we're building this continuous database of locations of bumblebees. And just so happens that this past summer, somebody was able to successfully photograph a bee in Guelph, Ontario, just south of Toronto. And it was identified by Chile and colleagues to be a rusty patch bumblebee. So they are out there, but we expect them to be pretty much all gone. At the same time, we have other bees that are arriving here and increasing in numbers dramatically. And one of those bees that we've been keeping an eye out for.

Actually, you may have it in Portland or in Oregon. I'm not sure. Megacile sculpturalis. Do you have that one?

That I don't know. OK, it's it's it's now one of our largest bees in Toronto. In terms of size, it's humongous. If you ever get a chance to Google an image of megacile sculpturalis, we call it the large resin bee. And what's interesting about this bee, again, it nests in cavities like a lot of megacile leaf cutter bees. But this one, because it's so large, it will actually take over the nests of our native large carpenter bee. So that bee you may be familiar with, the carpenter bee that likes to nest in our our roofs and the awnings and ornaments and benches and decks. And basically, it loves two by fours. And it's one of the few bees that that can actually chew through wood. And that's an energy intensive process.

It's a lot of work to do. And so they defend these nests fiercely, you know, both from parasites, but also from other carpenter bees that want to take them over. But this megacile sculpturalis is quite a big bee, as I said. And when it does take over a carpenter bee nest, it gobs it, it fills it with with tree sap, which it makes its nest set of tree sap. And so once the tree sap has been jammed in these holes, we expect that they become useless. And so having to re drill nests year over year over year could impose quite a negative cost on our native carpenter bees.

And so we're very interested in that. So cities can be these kind of hot spots for bee, but when you dig a little deeper, like many other organisms from plants and mammals and and and so on birds, often it's these introduced species or borderline invasive. And that's a whole other question. Is there such a thing as an invasive bee? They sometimes do better. So yeah, there's lots of questions that we need to ask about bees and cities. And it's a really exciting time to be studying them.

Speaker 1: I think and, you know, one thing I really like about the book is there is this. It's really accessible in terms of highlighting a couple of these different species that introduce species, common native species. And with a little description that is very readable, is very well put together in terms of helping people make that bridge to some of this bee natural history.

Speaker 2: Yeah, really, I feel the same way. I think it's interesting to know, you know, even with respect to the the introduced bees that we do highlight in the book, that of the over 350 odd species of bee that we identify as being present in the region, about 92 percent of those bees are native species. And even across North America with over 4000 bee species present, only just a little more than one percent of those bees are not originating from North America.

So it's interesting when you contrast that with plants or birds and some other creatures, you know, North America is a hotspot for introduced species and invasive species. But bees, they tend to stay put surprisingly, unless we move them. And, you know, it makes it even more interesting when you think that all these bees that that do, you know, seemingly OK or well in a city like Toronto, we're here far before we altered the landscape to the condition that it's in now.

So what about bees make them almost, you know, pre adapted or capable of surviving in this, you know, constantly changing environment cities? It's it's it's exciting. I love this stuff.

Speaker 1: Well, you know, the one we got to get at some point in this interview, you're going to talk about your own work because you really have taken the urban landscape and turn it into a laboratory. I mean, you've asked so many interesting questions about bees in the city.

But just before we get to that, I just want to get back to the book specific and the kind of way that it's put together. And I'm imagining by now lots of people are picking it up and using it. What did you think? How did you think people were going to use the book? And are you hearing back from people in terms of are they visiting some of the locations that you've outlined of the books and parts of the city? What's been what are you hearing about how people are using it?

Speaker 2: It's it's being certainly widely used. Now, the book itself, it's it's physically printed. It's there's been two printing. Oh, great. Our and yeah. And in fact, all of the copies are given away for free. It's a free book.

Wow. And what we do is we drop off boxes of the books at all of the Toronto Public Libraries and all the Toronto District School Board schools. And so the children of the city get the first crack at a lot of the copies. And anybody can pop by the library and pick up their own copy for free. Of course, it's a very popular series for that reason.

And also, obviously, I would think because of the content. But actually, the Bees of Toronto book is one of us in a series of these books, these Bees of Toronto. There's mushrooms of Toronto, trees of Toronto, birds of Toronto, the the the spiders of Toronto, these the amphibians and reptiles of Toronto. This is a series called the City of Toronto Biodiversity Series. And it's put together by the City of Toronto Planning Division.

So wow. Yeah, it's such a again, an enriching place to work, live and play when you have a city that is putting together these books, giving them away for free, that highlight you know, the local biodiversity that we find in our city. And so just like we have, you know, species checklists and stories about bees and why they're in our city and why they're important and how to help them. There's these kinds of books for all these different taxonomic groups, and they're all for free online as well. So you can go to the City of Toronto website and just type in Bees of Toronto to our Biodiversity Series.

And you can download PDFs of all of these books as well. And so so aside from from from the accessibility, which is really so great, certainly we've been seeing a lot of pollinator gardens and you know, community groups and certainly lots of schools who have this resource and are interested in integrating a pollinator garden into their school grounds, creating a living classroom or some other way to get kids outside and seeing these interactions in action. And of course, being able to link food and food security or other elements of plant growing and participating in that process. Bees and pollinators more generally just add another important and significant dimension to that. So certainly with kids, but you know, again, there's a lot of gardeners in our city.

We've got a really strong Master Gardeners Program and many neighbourhood associations, residence groups that cultivate and maintain spaces and parks. And when you go on the internet as a community group or a citizen who's really keen on doing something to help the bees, often they're bombarded with information that is not very relevant for them or for the City of Toronto. And so, for example, you know, honey beehive or doing some other practices like managing your pesticide use. We have a pesticide ban in the City of Toronto. OK. And so having a resource like the bees of Toronto that really plainly and in many different ways engages you in how to help bees at the local scale, at the individual scale. I don't have to answer your question, but yeah.

Speaker 1: No, totally. You know, the thing I find remarkable about it, it's, you know, it's a crisp little 70 pages. It's got to be a small book about the size of your hand.

Speaker 2: Yeah, it's some.

Speaker 1: Yeah, I would say it's that's about right. You've got so much in there. There's species lists. There's really nice pictures of common species. There are these descriptions of these species that you would routinely see.

Really, you know, places that you'll find actual bee habitat in the city that you can go to visit to all that and 70 pages. It's really nicely. It's really put together, really does serve. It's very Toronto specific and it's really kind of tight. I'm so impressed.

Speaker 2: Well, it was it was a really good group of authors that were able to come together and put this together. And again, not just, you know, academics at York University. This whole project was led by Dr. Lawrence Packer, you know, just a fantastic melatologist, so inspiring. And but again, what's really great was we were able to bring again, city staff in a lot of local artists who use bees and pollination and pollination or, you know, pollinators as a source material, beekeepers, you know, everybody who has, you know, something to say about bees that we could again, package in this nice, tidy way. The lay out is pretty nice to the city did a good job with that.

Speaker 1: All right, welcome back. So Scott, the bees of Toronto doesn't just focus on bees, but also the people who study, create, take care of bees in the city. And it includes everyone from a beloved Canadian novelist to BMX bikers who seem to play a role in helping bees. Who are the people, the bee people of Toronto?

Speaker 2: Well, I think you just spanned the full list there, right? It's true. Everybody, you know, that's the that's the fun answer, the happy answer. Everybody is the bee people of Toronto, right? Everybody plays a role and, you know, increasingly, you know, the bigger picture where we're really interested in mainstreaming biodiversity and trying to get, you know, all people to acknowledge the direct or indirect impacts and roles they play in enriching biodiversity in our city. So, you know, again, when I speak to community groups or in spaces about bees, you know, more often than not, I'm speaking to gardening groups and people who they're already converted, right? They want to help bees and they're attending a talk to learn about bees. But, you know, one thing that we really need to be cognizant of is, you know, how the accountant or the butcher or the, you know, the pesticide sprayer or the banker or whomever in our city who may not be able to make that direct, you know, inextricable link to their work life or play life or day to day life.

To the needs and requirements of pollinators, pollination systems and ecosystem services and so forth. And so I like to say that we all play a role. It's just sometimes it's not so clear to some people the role that they play.

And so I'm really keen on trying to mainstream some of these ideas in unconventional, you know, work environments and so on. So, you know, I don't know where I was going with that, but the point is, is that everybody plays a role. You know, the people who are really doing the heavy lifting include, you know, gardeners and homeowners who buck the trend and, you know, garden the front yard become that kind of community animator, right?

This idea that we all subconsciously influence one another and, you know, your front yard is more similar to those on your street versus three streets over and so on. You know, we all have an influence on one another and certainly homeowners and citizens can play that role if they choose to. And so, you know, gardeners and community gardeners, food gardeners and so forth in public and private spaces, you know, even visitors to parks and gardens and those who appreciate nature in their work or in their time outside of work, all play again a significant role in encouraging and appreciating pollinators and where they live. Because again, many bees live in cities with us and they're part of that urban nature experience that is increasingly becoming the normal nature experience. You know, in Canada, 80% of people live in cities.

What that means is that natural nature experiences with nature are occurring predominantly in an urban realm. And so it's really important that we all recognize no matter perhaps how small we may perceive it to be the role that we play in helping bees. And so we're all bee people.

But again, you know, municipal leaders, you know, our scientists and researchers, certainly our environmentalists and people who volunteer their time with community groups and nature walks and societies, the naturalists. Anyway, you know all this. Everybody knows all this stuff. All these other people that help garden and plant pollinator plants and read books about it. Yes, they're great. But it's really imperative that we try to engage everybody in this process.

Speaker 1: And I think the book does a really great idea of highlighting some of these wonderful initiatives that people, I mean, some of the gardens that have been put in place in Toronto and some of the wild areas are a real testament to everything you've described. But you also have, I think what's really great about the book is that it also highlights sort of unexpected connections. And coming back to your sort of comment about the butcher and the banker, there are people who you may not expect who are not out there necessarily building some of this habitat, who have these really kind of profound connections for nations to write the forward is by Margaret Atwood at Canadian Novelist. And they all have some kind of connection that you wouldn't not have necessarily thought about.

Speaker 2: That, and I think what's neat about the book too, is highlighting some of the people who are promoting and engaging the public, who again may not go to a lecture or read a science paper, but may attend an art exhibit, or may view an installation on the street or photo exhibition. You know, there's a number of artists who are increasingly inspired by natural processes, and bees and pollination are particularly inspiring to many.

You know, one cool thing that unfortunately didn't make it into the book, because it hadn't been erected yet, but there's a wonderful artist, his name's Nick, in the city, and he does a lot of murals. And so right now, downtown Toronto, right in the annex, this really well-known neighborhood in Toronto, there's a massive mural of a bi-colored Agapestimon, Agapestimon Voressens, a bright, brilliant green sweat bee. And it's taken the city. You know, people come from around the city to observe and photograph this big, beautiful mural.

And more and more of them are turning up. And so we're seeing these wild bee murals all over the city. And you know, again, it's just, I think it's important that we all care about the environment.

We want to foster and promote wild bees and their important services. But it's important that we think of many ways to engage different elements of the public in why this stuff matters. And I think art is a really great way to do that.

Speaker 1: Well, let's circle around back to some of the theme that you started the interview on, and you know, the stakes for engaging people. Just maybe outline some of the threats and the drivers of pollinator and bee decline. What are some of the threats that are real city specific? And what can municipalities do about helping boost bee biodiversity? And maybe even just give us a little bit more on what's happening in Toronto, where it seems like it's very progressive.

Speaker 2: Yeah, you know, and that's a really, other really interesting discussion point is, you know, we're hearing about bee declines globally, you know, and there's some really compelling evidence that have been published in all the top journals that illustrate declines populations, not only of honeybee colonies, but of wild bees across Europe and certainly in North America and other places. And when we think about this decline, I should say, simultaneously, we have people who are increasingly doing, you know, biodiversity sampling and monitoring of bee populations in city environments and positing that cities might act as a refuge or as a hotspot for bees, because in the global landscape that is increasingly, you know, agricultural and monotypic, bees don't do so well in those environments, whereas in contrast, cities are this, you know, melting pot of public and private space, wildly different management strategies that lead to this heterogeneity in cities that, you know, might encourage more bees. But I think the question still needs a stronger answer, you know, do bees do better in cities or do some bees do better in cities than outside of cities?

And, you know, it's an interesting conversation. Certainly outside of cities in Southern Ontario, where we are in Toronto, pesticides and, you know, other elements that are used in conventional agricultural systems would be a much larger threat than they are inside the city. So the city of Toronto has a municipal pesticide ban, and we also have a provincial pesticide ban that is related to residential areas. But unlike a lot of other cities across Southern Ontario, the city of Toronto has been really adamant in, you know, not pressuring, but well, no, certainly putting some pressure on the citizens of Toronto to really rethink the use of these kinds of chemicals in their lawns and for cosmetic gardening. And I think actually there's been some really cool data that's been collected to illustrate that I think even between, you know, like 2003, 2007, 2008, there is a deep halving of the amount of people that recorded using pesticides for their cosmetic lawn treatments and so on.

So this gives us, yeah, yeah, I think it's, I think, you know, pesticides, we're learning of course have a pretty negative impact on bees and other creatures. And in the cities, and certainly the city of Toronto, that seems to be less of an issue, but, you know, two big issues we're dealing with in the city of Toronto is increasing population density and urban impervious surfaces. The changing and alteration of the subsurface conditions.

So mixing the ground and changing the original soil structures that would be found in this region and converting them into, you know, graded sand and all the materials that are used around building debris and so on. In the city of Toronto, like many other environments around North America, the majority of bees nest in Toronto, about 75% of our bee species nest in the ground. And we always like to say that of those 75%, about 75% of those bees, we don't know where they nest in the ground. So this is a huge question. And the way that we're treating the ground, as we continue to develop the city, you know, we're expecting another million people in the next decade or so. And then this particular region where we find ourselves, we call it the Golden Horseshoe around Lake Ontario, is expected to grow upwards of, you know, nine million people in the next couple of decades.

So we're really growing fast and we really need to, if we're gonna think about saving the bees, especially urban bees, we need to be thinking about what's beneath our feet. And so subsurface conditions important. But another, of course, like in any city is the prevalence of invasive plant species. Right, everywhere. Yeah, you know, Toronto, just like any other city, we are experiencing some pretty nasty ones.

The dog strangling vine is one really bad one. But you know, like any city, there's a whole host of them. And you know, not only might they be artificially increasing habitat for introduced bees that might be able to utilize these plants as a resource, but of course they're gonna be out competing the native vegetation that a lot of our native bees will be depending on or will frequent on a regular basis. So really altering that pollinator network. And that's becoming a really big interesting question in our lab.

Speaker 1: Can I pick two of those questions up? I mean, it's always, you sometimes look at some of the urban viacology papers and you do see this claim that there aren't many specialist bees left. Those bee communities that were there originally have really, you know, undergone a dramatic transformation.

Do you think that's true or is it a matter of, you know, the sampling effort not being there? Do we have some specialists that are, you know, that have footholds, especially in a place like Toronto where you have these ravine systems that may not have gone completely to invasives yet?

Speaker 2: Well, I have to say in general, in temperate, in back, you know, parts of the world, like we are here in Toronto, there generally is not a lot of specialists. There's a lot of generalists.

Yeah. All of these that can go to, you know, a number of different plants or occupy a number of different kind of nesting conditions, but we do have a few and some of them are actually doing not so bad from what we expect. Now, you know, one thing you mentioned is, you know, this change in the bee community away from these kind of specialists or more historic populations, we actually just don't know.

Yeah, right. Because urban ecology and kind of sampling species, diversity in cities has not, you know, it been very popular until recent times, you know, cities were viewed as not nature. And, you know, the ecologists and biologists that might work in Toronto, well, all their work would be in South America or somewhere else, not in the city.

And so we don't have a lot of good baseline information in terms of what populations were like before the city or after some major change. So that's one limiting factor about studying bees and cities and, you know, making the claim that they can be refuge or a source habitat or hotspots for bee diversity. It may just be that we like to make cities where there's a lot of species diversity, which is generally the case around the world. But, you know, I have to say, there's some pretty interesting stories that are emerging with respect to why cities might act as a refuge for bees. You know, some of the things we're looking at is increases in nesting opportunities, both by gardeners putting out trapness or, you know, building little mounds for groundless and bees, but also that of which is kind of subconsciously integrated into our infrastructure.

And so I can't tell you how many photos I have of people who've sent me, you know, leaf cutter bees and other bees nesting in everything from barbecues to mailboxes and window fills and nail holes and on and on and on. The city is rife with habitat. You know, I often talk in class, I also teach in landscape architecture. And, you know, one of our chances is that, you know, buildings are landscape. The cities are landscape.

And they just modify the community that can be supported. And so nesting habitat in cities is perhaps artificially increasing cavity nesting bees over unnesting bees, which a number of other of our colleagues around the world have suggested. But what we're increasingly interested in our lab is foraging resource and flowering timing and availability across cities. So we often argue that cities have more floral abundance and diversity because of gardening and all this private space that is managed differently, which increases not only the heterogeneity, the, you know, the diversity in the kinds of flowers across the landscape. But what we're really starting to question and be interested in is, do individual flowering species of flowers, shrubs, trees, et cetera, do they have longer flowering periods in cities versus outside of cities? Now we know that cities are hotter than outside of cities. We got this urban heat island effect. And so, you know, increasingly people have suggested that, you know, flowers and plants might flower earlier in cities or, you know, become increasingly decoupled of the populations and so on. You know, one thing that's interesting about cities is there's a lot of microclimatic differences across cities. Take temperature, for example.

In a park, in a city, it's gonna be cooler than near a brick wall that's south facing. And contrast that with roadside, where there's exact contrast that with, you know, street lamps and so forth. There's all of these slight modifications to light levels and temperature levels.

Speaker 1: Oh, so flowering might be extended because you've got so many niches, climatic niches in the city. That's right.

Speaker 2: So it's spatial dependency, right? So over the largest, larger set of neighborhoods or a larger area of the city, you would expect that, let's say, a tree, like the eastern redbud, might flower, you know, in trust specifically, over a longer period in a city than outside the city, you know, in West Virginia and the Appalachian Mountains, where it's from, you know, where the temperature and the climatic factors may be more consistent or more homogenized in that, you know, micro scale. And so if you're a highly mobile bee and you're in one neighborhood in a park where your delicious redbud flowers haven't budded, you know, haven't flowered yet, but if you go two blocks over to where that redbud is in the hot summer sun beside a brick wall that's in full flower right now, you have redbud now and you have redbud for later. And so cities, there may be these other drivers, you know, not only in flower diversity, but also in the timing and the phenology of specific species that might extend the availability of certain plants for certain kinds of bees.

So really starting to tease out these urban drivers at the species-specific level and really starting to try and build these networks and understand plant pollinator networks, their parasites, and I could talk forever about this. Lots of other great things.

Speaker 1: Well, no, it's really exciting, Scott, and that brings me to my last question. The one thing that's really cool about the book, it has these two pages to describe, as you mentioned earlier, this tradition of studying bees in Toronto. And I'm so excited that you are now, you're in that tradition, you've just been hired on the University of Toronto, and you are, but you also have this really unique research interest in biodiversity in cities. What do you expect, what's on your plate? What do you plan to do? What are some of your ideas for the future?

Speaker 2: Well, just on that note too, it's really exciting to be part of this tradition that we have in the city and of my, you know, academic parentage, right? So it's always cool as academics to be able to link back who your supervisor was and their supervisor and so on. And so I was supervised by Lawrence Packer here at York University in Toronto, and he was supervised at the University of Toronto by Dr. Gerd Neur, who is a wild bee biologist who's taught, you know, we learned a lot about our wild bees in the region through his work, and he was supervised by Carl Atwood, so Margaret Atwood's father. So there's these like really, this really nice lineage that I'm so pleased to be a part of.

Speaker 1: It's so typical Toronto. Nobody, you know, you're in Toronto, you never leave.

Speaker 2: Well, Toronto is a welcome spot. People come and go, but, you know, there's something that really holds some of us here because again, it's such an enriching place to be. But, you know, aside from all of that, you know, listen, like of course I'm a melatologist. I'm really interested in wild bees and their interactions. You know, bees are the ultimate interactors in landscapes.

You know, they're visiting, you know, hundreds or perhaps thousands of flowers on the day to day, and these interactions, of course, amount to pollination and ecosystem functioning and the stability and maintenance of natural landscapes. And, you know, I find them just fascinating within that context. But I have two parts to my research agenda here. It's kind of biodiversity in two ways.

And bees play a role in both. So the first, of course, is that biodiversity has a role in the design of urban landscapes. So I do a lot of work in green infrastructure. I do work designing green roofs.

I'm a researcher at the GRIT Lab, the Green Roof Innovation Testing Lab at the University of Toronto, where one of the most instrumented green roof testing facilities in the world. And there we're really interested in stormwater management and building cooling and other functions that we ascribe to plant communities and soil communities when we smash them onto the side of a building, right? And so when we think about green infrastructure and the performance of these functions, like stormwater capture, where we're dealing with flooding in the city actually right now, building cooling, you know, cooling the city and reducing the amount of dependency on air conditioning, all of these functions we ascribe to green infrastructure, we're increasingly learning that by manipulating plants, species diversity or functional diversity, or even phylogenetic diversity. We can actually see additional benefits to these ecosystem functions.

And a recent, well, one of our recent studies, actually when I was doing my masters, we were able to link that when we combine different plant functional groups, so like wildflowers and succulents and grasses, we actually can increase the multifunctionality of these systems. So we increase cooling, we increase capture, and of course we increase habitat value. And so biodiversity can play a really critical role in the execution and services that we ascribe to green infrastructure. So there's an economic value for biodiversity in design. And so we do a lot of work on green versus, as I mentioned, bio-sweils increasingly, and trying to understand how these low impact development technologies can be supported and benefited by biodiversity.

And the second part is, well, how can our designs encourage and support biodiverse wildlife conservation? And so of course cities are one of the fastest growing habitat types around the world. I know that to save the most species in the world, we have to follow this really nice relationship called the species area relationship.

More area means more species. And what that means is that we need to be thinking about cities as an element of that area. So species conservation in cities is required, and we need to be thinking about that, not only for how people engage with nature and biodiversity and reducing that nature deficit disorder we're increasingly aware of, but also just simply all hands on deck. All landscapes need to be conservation areas. And again, with some different kinds of species, like birds and bees and a number of other creatures, cities again seemingly are turning into hotspots.

So I'm encouraged by that. And so really trying to link these two elements of biodiversity and design for biodiversity together. Here I am touting the city of Toronto again, but the city of Toronto has been developing a website called the Open Data Toronto website, and they provide open access availability to over a thousand databases that pertain to the

Speaker 1: local environmental socioeconomic factors in the city. And so with the touch of a few buttons on the city of Toronto website, I have all the land use categories, the location, species identity, and caliper width of every street tree in the entire city. You know, the income levels of every neighborhood, the population densities, the education levels, the top five cultural identities, it's never ending. So your capacity to do research is in Toronto specific, you're the right person's the right place.

Speaker 2: Well, it's interesting to think that we study how landscape factors and fragmentation and so on impact pollinators. And there's thousands of studies that have assessed this in all kinds of landscapes around the world, even urban ones. But what is a huge critical gap in our knowledge is how socioeconomic factors play a role in framing biodiversity in cities. And of course, pollinators are a part of that. You know, there's lots of elements related to wealth and status and neighbors, education and so on that are critical to understand when we're starting to think about cities as biodiversity conservation areas. Because this can create, you know, kind of inequity in ecology, right? You know, where certain people maybe have more access to more biodiversity areas and others not. And I think it's really important that we start to better understand how humans are biodiverse environments. Yeah.

Speaker 1: All right, welcome back. So Scott, this part of the show, we have our guests come through their libraries and we ask them if there's a bee book, either that was important to you or influential, or you just want people to know about. What is that book?

Speaker 2: Well, that's an easy one for me. You know, as an ecologist, I'm really interested in experimenting and studying bees, you know, in nature. And the best book, the one that was so close and so informative for me, and really starting to understand my PhD work and even, you know, even to today, of course, my copy is very well-worn.

This is techniques for pollination biologists by Carol Kearns and David Inouye. It's awesome. It is, yeah. It's a fantastic handbook. It's extraordinarily well-written and so complete. And it really provides everything you need to know when doing pollen limitation studies on flowers or how to stain your pollen grains or what to look for when you're sampling bees in different environments. And it's just chock-a-block of really great, detailed methodology, protocol, you know, that's been, that is timeless.

Speaker 1: One of my favorites in there is they have something like how to apply pollen to a flower and you kind of like take a bee cadaver and you dust it in pollen. It's got like everything in there.

It reminds me of the joy of cooking, like how there's squirrel, you know, how to prepare squirrel and the joy of cooking. It's like that would exist in this book.

Speaker 2: There's a few little moments like that, that, you know, unless you read it from page to page, it's, yeah, it's worthwhile doing it. There's a lot of nice little stories in there. Great information. And I just, I have to have a second.

Yeah, please go. More recent book by Eric Mead, Marla Spivak and Elaine Evans, Managing Alternative Pollinators. Again, my copy is very well-worn. I give lots of public talks and people always ask me, I need a book to better understand how I can help wild bees. And I always recommend this book, one, because it's so neat, it's full of great information and it's a free PDF online. So people can immediately download it. And I don't doubt I've contributed to thousands of downloads, I hope, from many gardeners and other people. It's a great book.

Speaker 1: Well, he just did a few more thousand. Or a 20, let's say. Okay, so next question we ask our guests is, is there a tool that you really couldn't do without or something, a bee research tool or bee conservation tool that you really want people to know about?

Speaker 2: Well, I guess in my own personal history in bee research, I have to go with the nest box.

Speaker 1: Good, okay.

Speaker 2: I was hoping you would choose that. The bee condo, this device that we can use, and of course it comes in many shapes and forms, which has its whole host of interesting details and guidelines and issues with that. But these are devices that are really just a bundling of dark and dry holes, which are put in perhaps some kind of container to keep the rain out. But cavity nesting bees will use these devices to nest. So they're the artificial analog of the natural nesting condition.

Speaker 1: Scott, can you describe yours, the ones that you've been using in Toronto?

Speaker 2: Sure, yeah. So the device that I use in Toronto, it's about $5 to make. It's a piece of PVC pipe. I use a white pipe so that it reflects the sun.

Black pipe, of course, will be quite hot for the bees. Inside the piece of PVC pipe, I insert a piece of insulation board. And into the insulation board, I pop out 30 holes. And those holes I fill with a cardboard tube. And my device is a little bit different from most because I actually solicited a cardboard paper tube company to make me specific dimensions so that I could keep every single nest box of the 200 sites where I surveyed as consistent as possible. And so that may not be the most obvious choice for many people, but another design that works really, really well and can be easily constructed pretty much in any place in the world is to collect the invasive species, fragmites, astralis. This is the common reed.

It's along road sides, all around the world. And it just so happens that this reed has natural nodes, much like a bamboo would. And it just so happens that the reeds are just the perfect dimension for cavity nesting bees.

So you cut them at the node and the length is about six to eight inches. And the inner width where the bee would go into nests would be less than a centimeter. And this is just the perfect dimension for lots of bee species in our region, North America. And this is the primary design kind of practice for a lot of the European studies that have used trap nests. So there's lots of ways in which we can make them.

Speaker 1: He was your favorite bee species.

Speaker 2: It's a super common species, Meg and Kylie wrote in data. You know, I love this bee because it's just so flexible in what it likes to do. You know, I've seen it collect plastic bags to make its nest and our colleague, Corey Sheffield, just had a paper come out that showed it nesting in the grading of a tractor in like a free form nest. So it actually wasn't even nesting in a tube. We found it nesting in paper wasp nests and all over the place. And it's just this quirky, urban bee that is found all over the world. And it's been really important for alternative pollinator management too. So it's a really great one.

Speaker 1: Awesome Scott, thank you so much for joining us. It was a real pleasure. Thanks for having me. Thanks so much Scott. It was a real pleasure. Thanks for having me.

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.

It makes us more visible, which helps others discover pollination. See you next week.

Scott MacIvor is an Assistant Professor of Urban Ecology at the University of Toronto at Scarborough in the Department of Biological Sciences.

Scott is also a researcher at the Green Roof Innovation Testing (GRIT) lab at the University of Toronto in the faculty of Landscape Architecture. Scott has published 12 peer-reviewed articles on green roof ecology and performance, and works with the City of Toronto Planning Division on a number of projects, which have included the ‘Bees of Toronto’ Biodiversity Series book, and the ‘Guidelines for Biodiverse Green Roofs’.

Today we’re talking about the Bees of Toronto book, what makes the city special for pollinators, and why urban habitats are so important for bee conservation.

You can Subscribe and Listen to PolliNation on Apple Podcasts.

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“We are really interested in mainstreaming biodiversity.” – Scott MacIvor

Show Notes:

  • Why Toronto is a great place for bees
  • How the history of Toronto has made it a great place for pollinators
  • The different kinds of bees that you can find in Toronto
  • Is there such a thing as an invasive bee or not?
  • How they came about writing the Bees of Toronto book
  • The many different types of people who care for bees in Toronto
  • Why more and more of people’s experiences with nature are happen within an urban realm
  • How artists are being inspired by pollinators
  • Some of the threats to bee declines in cities
  • Why soil conditions are important for more than 75% of the bees in Toronto
  • The limiting factors of studying bees in cities
  • Why cities might act as a refuge for bees
  • How bees interact with their landscapes in different ways
  • Why all landscapes need to be conservation areas

“We know about our bees in Toronto than almost any other city in the world.” – Scott MacIvor

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