In an era of accelerating urbanization, the narrative of cities as sterile ‘concrete jungles’ devoid of nature is being powerfully challenged. A growing movement, known as urban rewilding, seeks to intentionally restore and reintegrate natural processes and habitats within our built environments. This isn’t just about adding more parks; it’s a fundamental rethinking of urban spaces as potential thriving ecosystems. Surprisingly, many cities already harbour significant biodiversity, acting as unexpected refuges for numerous species. Urban rewilding aims to build upon this foundation, transforming our cities into vibrant hotspots of biodiversity that benefit both wildlife and human inhabitants, enhancing resilience, health, and our connection to the natural world.
The compelling case for rewilding our cities
The twin crises of global biodiversity loss and climate change demand innovative solutions that bridge the gap between human development and ecological health. With over half the world’s population living in urban areas – a figure projected by the Wageningen University & Research (WUR) to rise to over two-thirds by 2050 – cities are critical arenas for action. Urbanization traditionally leads to habitat fragmentation and loss, contributing to the decline of species worldwide. Yet, paradoxically, cities are proving to be far from biological deserts. Research reveals that urban areas can support a remarkable array of life; a global study found thousands of bird and plant species thriving in cities, including some globally threatened ones. Initiatives like the City Nature Challenge regularly document tens of thousands of species within metropolitan boundaries, as highlighted by The Revelator, showcasing the often-overlooked ecological richness present amidst the bustle. Furthermore, studies suggest cities can act as crucial refuges, sometimes offering conditions where certain species fare better than in surrounding rural landscapes, a point explored by Yale e360. Urban rewilding harnesses this potential, recognizing that restoring nature in cities is essential not only for conservation but also for enhancing climate resilience – tackling issues like urban heat islands (where even a 1°C reduction can limit heatwave mortality) and flooding – and improving human physical and mental well-being through increased access to nature, as detailed by Arup.
Strategies for cultivating urban wilderness
Restoring habitats and natural processes
Urban rewilding employs a diverse toolkit aimed at restoring ecological functions and creating space for nature within the urban matrix. This involves moving beyond traditional manicured landscaping towards approaches that foster self-sustaining ecosystems. Key strategies include creating and restoring diverse habitats, such as constructing wetlands, planting native meadows instead of lawns, installing green roofs and living walls, and revitalizing urban rivers and streams. Equally important is allowing natural processes to unfold where possible. This can mean simple actions like leaving fallen leaves in parks to benefit insects and improve soil, a practice encouraged in Eindhoven as noted by the World Economic Forum. It also includes preserving dead or decaying trees, sometimes called ‘wildlife trees’, as vital habitats for birds (like woodpeckers and owls), insects, and small mammals – Montreal actively educates its citizens on the value of these features. Reducing mowing frequency allows wildflowers to bloom and support pollinators, a strategy successfully implemented in Dublin. In some cases, rewilding may involve the carefully managed reintroduction of keystone species (species with a disproportionately large effect on their environment relative to their abundance), such as beavers, to help shape and maintain habitats through natural processes like dam building, which creates valuable wetlands.
Embracing nature-based solutions and biophilic design
Integrating nature directly into the built environment is a cornerstone of urban rewilding. Nature-based solutions, such as rain gardens and bioswales (specially designed channels that treat stormwater runoff), manage rainwater effectively while creating valuable microhabitats. Green roofs and vertical gardens insulate buildings, reduce the urban heat island effect, and provide ‘stepping stones’ for wildlife moving through the city. The concept of ‘biophilic cities’, explored by The Guardian, takes this further, advocating for the pervasive presence of nature throughout urban design – in buildings, streets, and public spaces – fostering a deeper human connection with the natural world. Examples range from large-scale wetland parks designed for flood management and recreation, like Haerbin’s 34-hectare Qunli National Urban Wetland mentioned by the World Economic Forum, to intricate vertical gardens adorning skyscrapers like Sydney’s One Central Park, demonstrating that ecological function and aesthetic appeal can go hand-in-hand.
Connecting fragmented habitats for resilient ecosystems
Urban landscapes are often highly fragmented, isolating wildlife populations and hindering their movement. A critical element of urban rewilding is therefore enhancing habitat connectivity. This involves identifying, creating, and protecting ecological corridors – strips of habitat that link larger green spaces like parks and reserves. These corridors can take many forms, from linear parks along rivers or disused railway lines (like New York’s High Line) to networks of street trees and wildlife-friendly gardens. Advanced planning tools, discussed in a PMC study, are being used to map ‘resistance surfaces’ (areas representing the difficulty for wildlife to cross, like busy roads or dense development) and pinpoint the most effective routes for creating corridors. Addressing specific conflict points, such as road intersections known for wildlife-vehicle collisions, through targeted mitigation measures like wildlife crossings and fencing, is also crucial for safe passage, as investigated in an MDPI study. Importantly, connectivity planning needs a multispecies approach, considering the diverse needs and movement patterns of different animals and plants to build truly resilient urban ecosystems. As highlighted by ArchDaily, architecture itself can play a role by designing buildings and infrastructure that facilitate rather than obstruct wildlife movement.
Urban rewilding in action Global examples
Across the globe, cities are pioneering innovative approaches to urban rewilding, demonstrating its feasibility and benefits. Singapore, despite its high population density, actively engages citizens in monitoring its remarkable biodiversity (estimated 23,000-28,000 terrestrial species) through a dedicated app, complementing its significant expansion of green spaces (from 36% to 47% between 1970-2020). In the Netherlands, Eindhoven encourages residents to let fallen leaves decompose naturally. Melbourne’s ‘Gardens for Wildlife’ program empowers volunteers to advise homeowners on creating wildlife-friendly gardens, emphasizing native plants over lawns. Montreal educates the public on the ecological value of retaining dead trees in parks, which provide crucial habitat. Dublin has transformed 80% of its green spaces to be ‘pollinator-friendly’ by altering mowing regimes. Several German cities are part of the ‘Städte Wagen Wildnis’ (Cities Venturing into Wilderness) project, deliberately allowing designated areas to return to a wilder state, resulting in increased sightings of butterflies, birds, and hedgehogs. In the UK, the Rewild London Fund, backed by significant funding (£850,000 in round two, £710,000 in round three), supports numerous projects across London’s key ‘Sites of Importance for Nature Conservation’ (SINCs) – areas designated for their ecological value. These projects range from river restoration (Yeading Brook, Old Lea River) and beaver reintroduction in Ealing (explicitly linking back to the strategy mentioned earlier) to creating pollinator corridors in Thamesmead and improving habitats for specific species like water voles and harvest mice, aiming to restore or create over 116 hectares of priority habitat. Finland’s city of Turku is developing ambitious ‘Urban Biodiversity Parks’, starting with the 20-hectare Skanssi area (a former sand quarry), aiming to become a global leader by integrating ecological restoration with recreation and education, as detailed by Portico. Even smaller community-led projects, like the Wild Tolworth Rewilding Project near London, showcase how peri-urban areas can be revitalized for both nature and people through rewilding principles and local engagement.
Navigating challenges on the path forward
Hurdles in planning and policy
Despite the growing momentum, realizing the full potential of urban rewilding faces challenges. A significant hurdle lies in urban planning itself. A global review highlighted by SESYNC revealed that while many city plans acknowledge biodiversity, they often lack specific, measurable, quantitative targets, making progress difficult to track and potentially hindering effective implementation. Furthermore, planning often treats biodiversity and ecosystem services as separate issues rather than adopting an integrated, holistic approach. The sheer ecological footprint of cities, extending far beyond their boundaries in terms of resource consumption and pollution, also presents a major challenge, as noted by the IUCN Urban Alliance. Ensuring that the benefits of urban greening and rewilding are distributed equitably across all communities, avoiding ‘green gentrification’ (where environmental improvements drive up property values and displace lower-income residents), is another critical consideration for social justice.
The crucial role of people and perspective
Overcoming these challenges requires a concerted effort involving robust planning, supportive policies, and active community participation. A fundamental shift is needed in how we perceive ‘urban wildlife’. As discussed in Biodiversity and Conservation, conservation efforts have traditionally focused on charismatic vertebrates, often overlooking the vital roles played by plants, insects, fungi, and other less conspicuous organisms. Promoting a more inclusive definition that values all components of urban ecosystems is essential for truly effective rewilding. Integrating ecological knowledge into the core of urban planning and design processes is fundamental. This means moving beyond seeing nature as an add-on and instead designing cities with biodiversity and ecological function in mind from the outset, for example, by mandating ecological impact assessments for new developments or incorporating biodiversity metrics into planning regulations, as advocated by sources like WUR. Stronger policy mandates at local, regional, or national levels can drive more comprehensive planning for biodiversity. Equally vital is empowering citizens. Community involvement through citizen science programs (like Singapore’s app), volunteering for habitat restoration projects, and participating in co-design processes ensures that rewilding initiatives are locally relevant and supported. Collaboration between government agencies, researchers, businesses, landscape architects, and community groups is key to developing and implementing successful, sustainable urban rewilding strategies. Initiatives like the World Economic Forum’s ‘BiodiverCities by 2030’ aim to foster such collaborations globally, recognizing the potential for nature-positive development to create significant economic opportunities.
Beyond parks weaving nature into the urban fabric
Urban rewilding offers a profound opportunity to reshape our cities and our relationship with the natural world. It beckons us to move beyond the traditional model of confining nature to designated parks and reserves, and instead to actively weave ecological complexity and wildness into the very fabric of urban life. It envisions cities not as adversaries of nature, but as dynamic, living ecosystems where humans and wildlife can coexist and thrive. This transformation requires more than just ecological restoration; it demands a shift in perspective, recognizing the intrinsic value of urban biodiversity and its crucial contributions to our own well-being and resilience. By embracing spontaneity, designing for ecological function, connecting habitats, and fostering a culture of care for our urban nature, we can unlock the potential for our cities to become genuine hotspots of biodiversity – healthier, more vibrant, and more inspiring places for all inhabitants, great and small.