Sharing cities with nature, by design 

In 2021, an urban citizen-science project known as the City Nature Challenge recorded a whopping 1,187 species in eastern Melbourne alone, spotting tawny frogmouths, satin moths, leopard slugs, and golden wattles galore. Even rare and protected species call cities home. Our recent research shows Australians share their cities with more than 300 threatened plants and animals, with Melbourne hosting 46 treasures, such as the golden sun moth, growling grass frog, and charming spider-orchid. These species can survive in the most unexpected urban places, from roadsides to golf courses, even airports. 

With numbers like that, the urban jungles are the perfect place to combat the biodiversity extinction crisis while re-engaging humans with nature. Of course, city-living is challenging – especially when those cities weren’t designed for you. Yet still, nature persists. Imagine what could be achieved if we designed deliberately with nature in mind? 

Take the swift parrot. Each winter, these critically endangered birds migrate from their breeding grounds in Tasmania to warmer feeding grounds on the mainland. Flocks are often sighted gorging on the flowering gums popular in city parks, backyards, and streetscapes. It’s an excellent example of how urban environments provide important resources for threatened species. Unfortunately, there’s a catch. After negotiating the treacherous journey across the Bass Strait, approximately 2% of the already dwindling population die every year after colliding with windows and buildings. Imagine if taking advantage of urban resources didn’t come at such a cost? 

Another urban wonder is the teddy bear bee. Not only is this aptly named fuzz-ball extremely charismatic, but its unusual method of ‘buzz pollination’ – using intense vibrations to shake pollen loose – is essential for native plants like flax lilies and guinea flowers. Teddy bear bees thrive on urban gardens: but they need somewhere safe to nest. Like many Australian bees, they do not form hives but are ‘solitary nesters’, burrowing tunnels in bare soil and clay. But natural materials such as these are scarce in cities, removed in favour of sleek lines, impenetrable surfaces, and tidy open spaces. 

Sometimes, simple solutions do the trick. The squirrel glider (the sugar glider’s stockier cousin) is an incredible aeronaut, soaring from tree to tree with the help of a skin fold between front and rear limbs. But many roads are a gap too far. To solve this problem, we worked with road agencies and engineers to design ‘rope ladders’ and ‘stepping-stone poles’ over the Hume Freeway, allowing gliders to cross safely. My PhD research evaluated their success, with wildlife cameras recording more than 10,000 possums and gliders using the structures. Combining engineering with ecology allowed us to design and test novel approaches, and such structures are now widely adopted. 

Novel interventions for nature in cities are on the rise – from insect hotels embedded in walls, pollinator gardens on roadsides, floating wetlands in city rivers, even artificial perches to replace lost trees. However, efforts are still largely constrained to pockets of ambitious practice, with ecologists and designers often working to solve problems from their separate silos. How can we make such interventions more common, more mainstream, more functional? By bridging disciplinary divides between ecology and design. 

These disciplines bring complementary skills to the problem at hand. Ecologists can provide insights into the species– their needs, habits, and risks, while designers bring frameworks and tools for translating those needs into structures that better mimic the complex geometries, organic materials, and thermal properties of nature, providing broader opportunities for life in cities. By joining forces, the fields could develop entirely new solutions that could not be imagined in isolation. So, in your next project, can you find some space for a teddy bear bee, provide safe passage for swift parrots, or a refuge for the growling grass frog? We have an opportunity to make cities better habitats for humans, and for nature. It will be tragic not to take it.