A beaver glides through a restored wetland in London. Falcons raise chicks atop Chicago skyscrapers. Platypuses paddle through creeks on Sydney’s fringe. Leopard frogs soak up the sun in Las Vegas. Behind these scenes is a rising ecological movement: urban rewilding, where cities become havens for once displaced wildlife.
A new study led by the University of Sydney reveals how cities across the globe are fighting back against biodiversity loss by restoring wildlife to the places it once called home.
The global literature review, led by Dr Patt Finnerty from the University’s Faculty of Science, points to successful examples of animals returning to city environments despite ongoing urban sprawl.
Finnerty and his team analysed 2,800 scientific papers on species reintroduction. Strikingly, fewer than 1% of rewilding programs focus on terrestrial animals in urban areas. Most efforts—about two-thirds—are still limited to vegetation.
But the study, published in BioScience, highlights a major opportunity. “These projects reconnect people with nature – an antidote to what researchers call nature deficit disorder,” says Finnerty. “In today’s urban environments, many children can name hundreds of brands but often not a single native bird or mammal.”
As the world’s urban population barrels toward 10 billion by 2050—nearly 70% of the planet—cities are expected to keep sprawling. That growth, the study argues, must come with a rethink: urban rewilding should be front and centre in ecological restoration.
“Bringing wildlife back into daily life improves mental health, fosters environmental stewardship, and reminds us that nature isn’t something ‘out there’,” says Finnerty.
Sydney has its own rewilding success story. In 2023, ten platypuses were reintroduced into the Royal National Park, marking the return of the iconic species after 50 years of local extinction.
“The reintroduction has exceeded our expectations,” said Dr Gilad Bino from UNSW’s Centre for Ecosystem Science, who led the project. “The platypuses have adapted exceptionally well to the Royal National Park, a testament to the robustness of both the species and the habitat.”
Now, sightings of the elusive monotreme are becoming regular for park visitors.
The researchers emphasise that rewilding isn’t as simple as releasing animals into green spaces. It requires long-term planning, community engagement, and directly addressing the causes of past extinctions—whether pollution, development, or invasive species.
Still, the benefits are profound.
“By integrating wildlife into urban landscapes, we have a unique opportunity to shape healthier and more resilient cities for future generations,” Finnerty says.
Rewilding to repair ecosystems
