What can bees teach us about building better urban ecosystems?

Published in Next City, February 9 2018

Last summer, Paul Maeillo had to clear a vacant lot in North Philadelphia, and he wasn’t happy about it. He’d done it plenty of times before, as part of the Philadelphia Horticultural Society’s LandCare program, which hires local contractors to maintain the neighborhood’s many abandoned parcels. But on this day the lot was full of wildflowers — and wildlife. In fact, it wasn’t vacant at all. He saw snakes and mice and many, many bees, gathering nectar and pollen from the untamed flora. “Just teeming,” Maeillo remembers. “It was kind of wild.”

The lot was an eyesore to humans, and a feast for pollinators. Maeillo didn’t have much of a choice: he mowed it down. But he left a small wild patch in the center. “It seemed not right to take away all their resources,” he says.

Some of those pollinators were probably honeybees from an urban farm a few blocks away. Others were likely wild. Either way, the presence of bees wasn’t an aberration. Groups of entomologists in the U.S. and abroad have increasingly come to the same conclusion: Bees may actually prefer cities. Bee diversity is much higher in St. Louisthan in surrounding rural areas; the same goes for cities in the U.K. At a time when pollinators the world over are struggling, it’s a heartening development, though it comes with a twist. Cities plant pollinator gardens and sign pledges to protect honeybees, and that’s great. But some evidence suggests a surprising environmental correlation to urban pollinators’ health: neglect of land. Bees thrive in cities such as St. Louis and Detroit, which have large tracts of vacant land owing to a steep and steady population decline — a drop of more than 50 percent over the past 60 years.

“People move out, bees move in,” says Gerardo Camilo, an associate professor of biology at St. Louis University. Here, Camilo and his fellow researchers have discovered links between bee diversity and abundance, and a neighborhood’s diversity, density, and wealth. The city’s north side — where wealth is low, human populations have declined precipitously and vacant lots abound — is a prime bee habitat. So is the Middle Corridor, a swath of the city between Delmar Boulevard and Interstate 44 where recent immigrants to the U.S. are planting a wide variety of crops. The least bee-friendly part of St. Louis? The South Side, among the whiter, wealthier, more homogeneous parts of the city. Human diversity, it seems, is good for bee diversity.

The significance of this finding isn’t lost on Camilo. He remembers when he was in his late 20s, listening to famed entomologist E.O. Wilson lecture on how “diversity engenders diversity.” At the time, Camilo understood this within the narrow bounds of “the natural world” — that is, as plants become increasingly specialized, pollinators evolve to specialize as well. It took Camilo a long time to recognize that humans’ contribution to biodiversity is similarly complex. If humanity sits within the evolutionary framework, not outside of it, then we affect biodiversity constantly, not just when we ruin it. “We humans are part of nature,” Camilo says, “And we’re following the exact same rules that every other organism in nature is following.”

And cities? They’re simply another highly specialized ecosystem to which all living things — human, plant, animal, insect — adapt. “If our ecological theory is worth the paper it’s written on,” Cabilo says, “Then the same theories, the same hypotheses, the same models that work on natural ecosystems, they have to also apply in an urban environment. They have to apply in city parks and neighborhoods and community gardens.”

Yet, cities have often gone overlooked in biodiversity discussions. Conservationists often prioritize wild and rural lands. Cities are seen as disruptors of the ecosystem, rather than as part of it. Understandable, considering the extent to which urban development has contributed to habitat loss. But cities have also created new and novel habitats that Camilo thinks conservationists would be remiss to overlook, particularly for bees. The decline of pollinators poses a real threat to our food systems. Bee pollination is responsible for one out of every three bites of food we take. To recognize that bees may flourish in cities and then plan with that in mind — this includes promoting urban agriculture, among other initiatives — could be an urban ecology game-changer, for humans and pollinators alike.

That’s what makes Camilo’s and other researchers’ findings so interesting. Bees are doing especially well in diverse places, places government has neglected — where the housing market has crashed, weeds thrive, and urban agriculture is strong. In short, where the human ecosystem has faltered, and people are trying to reshape it into something new. Just return to that vacant lot in North Philadelphia filled with bees. It exists because of social neglect and economic injustice. But nature abhors a vacuum, and she’s made the most of it. Of course, this doesn’t mean we need more redlining or housing crises. The question now is: how do humans respond to the strange ecosystem that we’ve helped to create? Do we clear the lot for condos, or consider the pollinators (and the neighbors, and plant a garden? To build a better city for people, should we first build a good one for bees?

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Image by Gerardo Camilo