Big Bird in the City

If done carefully, great blue heron habitat and urban development can coexist.

Published December 21, 2016

If you’ve ever been to downtown Vancouver’s False Creek, you’ve likely seen them: tall gray-blue birds stalking in the shallows. To see them in the air, they seem impossible, their long bodies and s-curved necks borne aloft on giant wings. They look like they belong in a marsh, away from humans, not in the middle of the big city.

Yet a recent study makes clear what many Vancouverites frequently witness: these tall, stately birds can live among human-built landscapes with relative ease. The bigger takeaway: even as rampant development encroaches on areas in which the heron has traditionally thrived, all is not lost when it comes to this endangered species. But keeping them safe into the future will take careful management.

The study, led by doctoral candidate Elly Knight, who worked on the project as an undergraduate, drew on records of great blue heron nesting sites dating back to the 1980s to show that the birds are able to live in human-created environments provided they have access to key habitats: specifically, places to forage for small fish and other animals.

“They are very urban, especially in the lower Fraser Valley. You see them everywhere, foraging on Highway 1, and in the fields. It’s really interesting that they’re amongst other human development,” says Knight.

Though individual herons seem unfazed by humans as they wade through the water, the birds are considered an at-risk species. Knight’s research shows that if Vancouver wants to keep its herons, space will need to be intentionally made for them. So far, her work has caught the eye of city planners.

Most successful heron colonies nest within five kilometers of foraging sites. Because of this, Knight suggests the city take a landscape management approach to the issue, keeping key heron foraging space free from development. That means making space for the herons in the landscape of the city, and making sure that space doesn’t get developed. She says it also means preserving potential foraging sites that could be used in the future.

“Colonies don’t last forever. They eventually relocate,” she says.

Though the research shows that great blue herons can live alongside humans, federal ecosystem scientist Ross Vennesland, who worked on the study, says it doesn’t mean the birds wouldn’t thrive better without us. The heron population is still declining.

Vennesland is one of Canada’s foremost heron experts. He first became interested in the birds while doing his graduate work.

“I’ve always been interested in what I call the ungainly elegance of the great blue heron,” he says. “They’re a beautiful bird. Kind of dinosaur-ish.”

A previous study Vennesland was involved in showed that some kinds of human activity, such as having pedestrians nearby, can stress great blue herons. But the new study suggests the birds aren’t quite so sensitive.

“It’s maybe showing us that in some cases benign human activity isn’t a problem for herons,” says Vennesland.

Despite the heron seeming like such an unusual candidate for a city dweller, environmental scientist Erle Ellis says it’s no surprise. The wildlife present in cities is just whatever can subsist around people. If humans occupy the preferred territory of herons, and herons can cope with human presence, then it’s reasonable that the two species can coexist.

“For me, this is a classic example of where design in the city should emphasize both demands—the demands for habitat for these other species, and the demand for use in these areas,” he says. “It’s actually possible to have both, if you have studied it, like [these researchers] have.” Ellis also thinks that because the great blue heron is so visible, people are likely to advocate for it. (Conversely, less charismatic species tend to do less well.)

Ellis studies the interactions between humans and nature, and one of his hypotheses is that, in the modern era, nature is defined by people’s attitudes toward it. If they notice an animal and care about it, he thinks, they’re more likely to deliberately create space where it can live around them rather than unthinkingly stamp out its habitat.

It’s a more realistic message than the thesis that humans will always destroy nature, and that cities always pose a major risk to animals. Many species can and do live in the city, he says. But this is the message of the Anthropocene: “It’s as hopeful as saying, ‘Whatever people do is what we’re going to end up with.’”