What a Giant Snake can Teach us About Designing Cities for the Future

Last week, a jockey at Cannon Racetrack in Cairns, Australia mistook a 15-foot-long Amesthetine Python for a “giant crack” in the raceway.  

He was rounding a corner at full gallop when the snake suddenly appeared before him.

The presence in a dense urban area of such a big reptile—a species notoriously vulnerable to being killed by speeding vehicles—can teach us something about making our growing cities friendlier for wildlife.

Happily, such efforts make cities better for people too.  By 2100, there are projected to be around 11 billion people on Earth—of which an incredible 9 billion will be living in cities.

CITIES CAN SUSTAIN BIODIVERSITY

A surprising amount of biodiversity can persist among the skyscrapers, housing estates, shopping malls, parks, and greenbelts that constitute our modern cities.

Even some vanishingly rare species can use cities.  Imperiled plants have been discovered in weedy abandoned lots, endangered snails in irrigation pipes. 

In northern Queensland, Australia, critically endangered Cassowaries regularly enter homeowners' back yards looking for fruiting plants, so long as dogs are not present.

Of course, many vulnerable species avoid cities—such as forest-interior specialists and strictly arboreal species.  And we won’t want big predators such as Grizzly Bears in cities, no matter how cuddly they look.

But that still leaves a great deal of biodiversity that could potentially use cities if we can make them more wildlife-friendly.

PUSH CONNECTIVITY

First, wildlife benefits greatly from ‘connectivity’—the ability to move from one place to another. 

Whenever possible, that means retaining or creating greenbelts, continuous wildlife corridors, and strips of intact vegetation along rivers and streams. 

Crisscrossing cities with such linear features—the wider, the better—is a winning approach.

ZONE ROADS

Second, we must control our speeding vehicles. 

For endangered species such as Cassowaries and the Florida Panther, roadkill is their biggest threat. 

Many other species forage along roads, bask on warm roads at night, or ‘freeze’ in response to approaching vehicles—making them highly vulnerable.

So, creating road-free zones in urban areas—where foot-traffic and bikes might be allowed, but no roaring vehicles—is a great strategy for nature.

"Roadkill, Ankarafantsika National Park, Madagascar" by Frank.Vassen is licensed under CC BY 2.0. Unmodified.

KILLER PETS

Third, as much as we love them, our domestic dogs and cats are dangerous.  They can create lethal ‘haloes’ for wildlife around human habitations.

They do this not only by killing or harassing wildlife, but simply via their odors and scent-marking—which many wild species avoid.

Ecologists talk about “landscapes of fear”—the fact that predators don't just reduce the numbers of their prey, but also greatly limit their habitat use and times of activity.

For urban and suburban areas, that means keeping pets completely out of wildlife-friendly areas—not merely on a leash.

LOW-DENSITY HOUSING

Fourth, we should avoid low-density housing sprawl into forests and other wildlife habitats.

Houses in such areas have great impacts on nature via the many roads they require, their dogs and cats, and their strong tendency to ‘internally fragment’ habitats.

URBAN ISLANDS

Finally, our cities will have a lot more wildlife if they don’t become urban ‘islands’. 

The goal is to maintain some wild or semi-wild habitat in the broader peri-urban areas surrounding cities—because such lands are a major source of wildlife.

Even isolated patches of habitat can be useful as ‘stepping stones’ for local wildlife—and resting and feeding areas for scores of migratory species, such as many songbirds.

For migratory species, the world is big, and we need to think big if we’re going to invite them into our cities.

HAVE CLEAR GOALS—AND PUSH THEM

These principles just scratch the surface.  The “Singapore Index” provides a broad-based way for cities to gauge and monitor their efforts to conserve biodiversity.

We know that having clear goals is important—but they’ll be useless unless they’re implemented.

Far too often, urban planners don’t understand how to make cities more wildlife-friendly, and the financial and political pressures from land developers are enormous. 

Corruption and back-room deals can play a big role too.

Clearly, decision-makers will only make wildlife-friendly cities a priority if their constituents demand it. 

That means doing things like forming urban-wildlife groups, attending city-council meetings, and lobbying politicians.

And demanding proactive land-use planning—which is far more cost-effective than trying to restore broken cities ecologically, or buying back hyper-expensive urban land for nature.  

HEALTHIER FOR PEOPLE

The great news is that wildlife-friendly cities greatly benefit people too. 

Trees and other vegetation are highly effective in reducing harmful air pollution, limiting flooding, improving water quality, storing carbon, and improving urban climates via shading and evaporative cooling.

And native wildlife can have many benefits, such as limiting pest outbreaks and major disease-vectors like mosquitoes and rats.

Beyond all this, we know that appreciating nature is something people have to learn.  Exposing children in cities to nature—not just animals on TV or video games—is one of the best strategies for educating them about the vital need to make our world more sustainable.

CITIES FOR THE FUTURE

The bottom line: We all have a big stake in making our burgeoning cities friendlier for nature.

Just ask that big python on Cannon Racetrack in Cairns, Australia—which the jockey and his galloping horse happily managed to miss. 

Though in the middle of a city, the racetrack is encircled by trees, and wallabies and other wildlife that the snake would feed on are protected and plentiful.

The snake was obviously happy on the racetrack—it sun-baked there for four hours.