How (and why) the Canadian city is putting native bees at the heart of a proposed pollinator protection strategy
By MATT KELLY
Cities and urban development have gotten a deservedly bad rap for their role in disrupting the bee populations of North America. The fragmentation and literal paving-over of food resources and nesting habitats are key contributors to the decline of bees and other pollinators. But these factors are completely within our control as we design, expand and evolve our urban environments. In fact, when thoughtfully planned, cities have the potential to become nurturing refuges for bees.
Many cities and municipalities are now heading in this direction to varying degrees. Toronto, however, is approaching “pollinator friendly” from a distinctly unique position: putting the primary focus of its strategy on native bees.
“Here in Toronto, we are one of the leading cities in terms of what we know about our native bees,” says Annemarie Baynton. She is a senior environmental planner for the city and the person responsible for shepherding Toronto’s proposed Pollinator Protection Strategy from a nascent concept to the final draft now awaiting approval. Her statement is not mere hyperbole.
There are 364 different types of bees known to live in Toronto and the surrounding area. By way of comparison, neighboring Montréal has 177 documented species; Québec has 154 species. Much farther down the list are major U.S. cities like New York and Chicago with only 54 and 37 types of bees recorded. This comparison should not be taken as evidence that Toronto actually has more bee species than any other North American city; after all, the available studies that provide these numbers are each different in terms of scale, scope and duration. But the comparison certainly does give a sense of how well-informed Toronto is regarding its diverse bee community.
There are around 4,000 different types of bees in North America. The European honey bee – whose color, shape, size, hives and honey are what most people think of as a “bee” – is just one of these species and is not originally from this continent. The vast majority of our bees originated and evolved right here. They come in a diverse range of colors, shapes and sizes. Most are solitary, but some are social. Many make their homes in the ground, others in nooks, crannies and hollows. None of them make honey. And yet, whether most people realize it or not, these native bees have been playing a very real role in the production of the food we eat.
For example, mining bees are valuable in apple orchards because they carry a higher proportion of pollen between flowering trees with fewer contaminants than other bees. The presence of mason bees in almond orchards have been found to increase the pollination effectiveness of honey bees. And bumble bees – with their unique buzz pollination behavior – improve the production of several different crops.
In fact, recent evidence is showing us that healthy populations of wild bees are far more effective at pollinating a wide variety of crops than honey bees are. But, sadly, we’re also finding that the presence of European honey bees can have a negative impact on the populations of native bees by reducing the availability of local pollen and nectar, introducing parasites, increasing the prevalence of disease, and facilitating the spread of non-native plants.
A very real danger is that native bee species are disappearing without us even knowing it. It’s estimated that wild bee abundance has declined over nearly a quarter of the United States within the past decade. Bumble bee species have shown definite losses; the rusty patched bumble bee is now listed as an endangered species in the U.S. because of its quiet extirpation over just the past twenty years. And have you ever even heard of Franklin’s bumble bee? (Chances are it will never be seen again.)
“We can’t replace native bees when they’re lost,” says Baynton. Once they’re gone, they’re gone.
Toronto has plenty of good reasons to build a strategy around preserving the diversity of its bees.
But Baynton is quick to point out that the Toronto plan is not about promoting an “anti-honey bee message”. Any habitat that’s helpful to native pollinators is going to be helpful to honey bees as well, she says. But the opposite is not necessarily true. This is why Toronto has relied heavily on the large community of bee scientists working at its local universities to guide the creation of its strategy.
Sheila Colla and Scott MacIvor are two of those scientists, working at York University and the University of Toronto respectively. Both are members of the city’s strategy advisory board.
“Honey bees are not neutral or beneficial to bee diversity,” says Colla. Acknowledging this fact led to some essential conversations during the crafting of the strategy. As Colla tells the story, when it was proposed that the city’s plan include allowing more dandelions to grow for bees to feed on, the scientific response was pretty clear: Dandelions are primarily good for honey bees and not much else. The focus for native bee food sources should be native flowers.
MacIvor also cautions municipalities to be on the lookout for “bee-washing” (the pollinator equivalent of “green washing”). Specifically, he’s talking about products such as “bee hotels” that make appealing but potentially misleading claims about “saving the bees”; in some cases, these products may in fact have a negative impact on native species. (MacIvor says more research still needs to be done on this.)
What Toronto has learned from its experts is that any city that genuinely aspires to protect a range of bees must give thoughtful consideration to the type, quality and connectedness of habitat needed. For example, more than seventy percent of the bee species in the Toronto area nest in the ground; they prefer sandy soils, the space beneath stones, old logs and even lawns. Obviously, for these species in particular, pavement and asphalt are really bad. But even when earth is left open and unpaved as green spaces, the realities of urban living can have equally detrimental impacts. The greenery becomes much more manicured, and native vegetation is often replaced by ornamental flowers and plants that have little or no value to native pollinators. Fallen trees and brush piles are removed, disrupting the materials used by bees for nesting or getting through the winter. Soil – whether it’s exposed or covered by grass – is often compacted by human traffic.
Furthermore, nesting habitat and food resources are only useful to bees if they can actually get from one to the other. Honey bees can travel over a mile from home when foraging. So too can bumble bees, but the distance they’re willing to go ultimately depends on the diversity of flowers at a destination and the consistency of flower-rich patches along the way. Mining bees are a whole other story: they travel no more than a few hundred yards from their nests, often making short trips, back and forth, all day long. The most beautiful garden in the world isn’t of any value to a bee if it’s too far away from home or surrounded by concrete.
Just like the humans living in a city, bees flourish when they have accessible housing and a viable transportation network to easily get between home and where they need to go.
Toronto is hoping to meet the range of bee needs with some specific actions that include:
- Identifying potential “micro” corridors of small-scale greenery that can connect larger green areas to one another.
- Identifying at least one city-managed site in each of its 44 wards that can be enhanced for pollinators (which would separate these gardens, on average, by a little over two miles).
- Identifying city-owned, closed landfill sites that have the potential to become high-quality habitat.
- Revising the city’s existing pesticide-use policy and growing procedures to include a commitment to use plants and seeds that haven’t been treated with systemic pesticides (such as neonicotinoids).
- And even reviewing the city’s mowing practices to better preserve pollinator habitat (because the frequency of mowing has been shown to affect soil compaction, abundance of flowers and ground-nesting opportunities)
The strategy also puts specific emphasis on green roofs because of their potential benefits to urban bees — if designed, constructed and maintained appropriately. According to the strategy, effective green roofs should include an abundance of seasonally and biologically diverse flowering plants; soil depths of at least six inches; large stones and logs that provide nesting habitat; and should be maintained with practices that leave plant matter over the winter for nesting species. Appropriately designed green roofs must also take into consideration the foraging distance of difference species: Bees that travel short distances between nest and food don’t care whether the distance is horizontal, vertical or a combination of the two dimensions.
(Toronto, by the way, was the first city in North America to require by law that all new commercial, institutional, and multifamily residential buildings of certain sizes have green roofs. By the end of 2016, the city had over 650,000 square feet of green roofs constructed — far and away the most of any North American city.)
The success of Toronto’s plan will depend largely on public outreach and education. Because the public’s enthusiasm about saving bees and their actual habits in response to bees can often be at odds with each other.
“People want bees visiting their flowers but not nesting in their backyards,” says Colla.
For example, on a warm spring day in 2015, thousands bees suddenly emerged from their ground nest. Because the nest was close to a playground, the response of many residents was to call the Toronto Parks supervisor with much concern. (Bees sting, right? They’re dangerous to our kids, right?) Before taking any particular action, city staff identified the bees as a type of mining bee. Turns out these bees’ stingers are too small to break human skin, and the bees are so gentle that city staff chose to refer to them as “Tickle Bees” when communicating with residents. This bit of community outreach (which Colla helped organized) helped turn the local concern into interest and enthusiasm.
Baynton is well aware of the public education that will need to take place. This is especially true when it comes to the cultural norms that guide how we manicure our green spaces — and that often have an adverse effect on the habitat that many bees require. “It’s okay to have a messy garden and you don’t need to mow like a golf course,” she says. “Brown is a color in the garden and it’s okay.”
Toronto’s proposed strategy is still being revised based on input collected from nearly 7,000 residents and stakeholders this past summer and fall. The final draft of the Pollinator Protection Strategy will be presented to the City Council for final approval in early 2018.
Presuming the strategy is given the thumbs-up, how will we know if its proposed actions are ultimately successful at protecting a diverse community of bees? How is success even defined, and how will it be measured? As MacIvor points out, despite our best intentions, the urban environments we create can make existing disparities between species that are winning and losing even worse. “Are we designing cities to support bees that are doing poorly?” he asks. “Or are we just helping the ones already doing well?”
“It is a difficult thing,” admits Baynton. She says the city will continue to rely on the research of its scientific community, as well as the on-going work of citizen science efforts like Bumble Bee Watch, to continue assessing the bee populations of Toronto and to gauge the impact of the strategy. She says the city will also judge its success by how much Toronto contributes to Ontario’s provincial goal of creating one million acres of pollinator habitat.
Our good intentions should always be backed by demonstrable results. However, says Baynton, improving food resources and habitat for bees is never going to be a bad thing. And MacIvor agrees: Of all the difficult and nasty things going on in the world, helping to protect bees is where individuals can definitely make an impact.