Urban rewilding combats global biodiversity decline
Wed 28 May 2025

Media release | A new study led by the University of Sydney reveals how cities around the world are restoring wildlife to their former habitats in the face of ongoing urban sprawl.
The global literature review led by Dr Patrick Finnerty from the University’s Faculty of Science points to successful examples of urban rewilding from around the world:
- Beavers are swimming in London for the first time in 400 years.
- Falcons now nest in American high-rises.
- Leopard frogs have successfully been successfully restored to Las Vegas.
- Howler monkeys are breeding in Rio de Janeiro.
- The oriental pied hornbill has been reintroduced to its historical range in Singapore.
- In Australia, platypus populations are growing on Sydney’s periphery.
Published in Bioscience, the research highlights the emerging global movement of urban rewilding: reintroducing native animals like beavers, hornbills, and even platypuses into city parks, wetlands and reserves.
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Image: Patrick Finnerty |
Dr Finnerty and colleagues reviewed 2,800 scientific papers on reintroducing species to areas where they once thrived. It found fewer than one percent of rewilding programs involved reintroducing terrestrial fauna into cities. Two-thirds of urban conservation programs focus exclusively on vegetation.
Yet the success stories emerging from the review offer insights into unique opportunities for conservation and community engagement in cities, Dr Finnerty said.
About 70 percent of the world’s population of 10 billion people will live in urban areas by 2050. This is a 20 percent increase in current urban populations and will necessitate rapidly expanding urban footprints.
Dr Finnerty and his co-authors propose urban rewilding should be a vital part of broader ecological restoration initiatives, offering a holistic approach to enhancing urban biodiversity while promoting human wellbeing.
These projects do more than boost biodiversity, said Dr Finnerty.
“They reconnect people with nature – an antidote to what researchers call nature deficit disorder,” he said. “In today’s urban environments, many children can name hundreds of brands but often not a single native bird or mammal.
“Bringing wildlife back into daily life improves mental health, fosters environmental stewardship, and reminds us that nature isn't something ‘out there’.”
The authors say successful urban rewilding requires careful planning, community involvement, and addressing the threats that caused local extinctions in the first place. They call for cities to build on existing greening efforts by actively restoring not just habitats, but the species that belong there.
"By integrating wildlife into urban landscapes, we have a unique opportunity to shape healthier and more resilient cities for future generations," Dr Finnerty said.