Dossier thématique

The benefits and risks of rewilding

  • Rewilding aims to restore ecosystems and reverse biodiversity declines by allowing wildlife and natural processes to reclaim areas no longer under human management.
  • Misunderstanding of the rewilding concept has led to applications that harm communities and biodiversity, and threaten to undermine an approach with enormous conservation potential.
  • Well-applied rewilding can restore ecosystems at a landscape scale, help mitigate climate change, and provide socio-economic opportunities for communities.
  • Evidence-based rewilding principles will guide practitioners to rewild safely, help assess the effectiveness of projects, and incorporate rewilding into global conservation targets.

June 2021

What is the issue ? 

Rewilding aims to restore healthy ecosystems by creating wild, biodiverse spaces. It rebuilds ecosystems that have previously been modified by human disturbance, using the plant and animal life that would have been present had the disturbance never occurred. In doing so rewilding restores the natural processes that provide humanity with clean air, water, food, shelter and medicine.

This idea of reversing biodiversity loss and creating wild landscapes by allowing nature to reclaim areas no longer under human management has gained much attention as an optimistic approach to conservation. Well-intentioned governments, NGOs, communities and individuals are more frequently adopting ‘rewilding’ strategies but the principles are inconsistently defined, and often misrepresented and misapplied.

featured image

Attention can focus on the reintroduction of large predators like grey wolves (Canis lupus), but rewilding principles apply more broadly

© christels, pixabay

Misuse of the increasingly popular rewilding concept risks alienating communities, harming existing biodiversity and undermining confidence in a technique with enormous conservation potential.

Rewilding principles agreed between over 150 rewilding experts guide practitioners to rewild safely, and suggest mechanisms for policymakers and funding agencies to assess the effectiveness of projects and so prioritise support.

Why is it important ?

Human activity is degrading ecosystems and driving biodiversity loss faster than ever before. The need to reverse these trends is formalised in Sustainable Development Goals 14 and 15. The UN Decade on Ecosystem Restoration and the post-2020 global biodiversity framework provide opportunities to rebuild the biodiverse ecosystems which sustain all life on Earth. Rewilding has the potential to do so at a landscape scale, and brings other important benefits for society.

Rewilded ecosystems can help mitigate climate change by increasing carbon removal from the atmosphere and protect against climate change impacts by reducing soil erosion and flood risk, for example. Rewilded ecosystems can also create socio-economic opportunities for local communities, reduce the effects of and costs associated with environmental hazards (such as flooding), and improve human health and wellbeing by improving access to nature.

A project in Chacabuco Valley in northern Chile is one example of successfully applied rewilding. Following a land purchase in 2004, Rewilding Patagonia removed livestock and farming infrastructure from 890 km2. Native vegetation and wildlife have since recreated Patagonian steppe and temperate beech forest systems which function without human intervention. The project also supports ranchers around the rewilded landscapes to implement sustainable land management practices.

Poorly managed rewilding, however, carries risks for biodiversity and local people.

 A 2019 study evaluates the Oostvaardersplassen (OVP) project in the Netherlands which began in 1983 with the introduction of Heck cattle, Konik horses and red deer to reclaimed land. Their numbers were not managed and the animals could not move to new habitats, so populations were largely regulated by food availability. Native vegetation was degraded by overgrazing, and up to 30% of the animals died over winter periods when food was scarce. In 2018 the management plan for OVP was revised, with reduced herbivore numbers.

featured image

Rewilding projects should identify core rewilded areas and ways to connect them.

© Soulé and Noss, 1998

Without proper consultation rewilding may not benefit local communities, especially those with histories of traditional land management such as hunting, farming, forestry and fisheries. Inappropriate plans to reinstate natural habitats and reintroduce animals that may have originally been extirpated because of conflicts with human interests are often controversial. Projects risk alienating local people unless stakeholders are involved in planning that identifies and mitigates such concerns. In several cases, a lack of consultation has led to local anti-rewilding campaigns causing projects to be abandoned.

What can be done?

IUCN welcomes efforts by governments, conservation agencies and other partners to rewild in certain parts of the world. It stresses the need to consider ecological, economic and societal issues in the development of rewilding initiatives and to engage all relevant stakeholders from the onset. In consultation with over 150 rewilding experts, IUCN’s Commission on Ecosystem Management (CEM) Rewilding Thematic Group (RTG) has developed ten principles to guide rewilding initiatives:


1. Rewilding uses wildlife to restore food webs and food chains. 
2. Rewilding plans should identify core rewilded areas, ways to connect them, and ensure outcomes are to the mutual benefit of people and nature.
3. Rewilding requires local engagement and community support.
4. Rewilding focuses on the recovery of ecological processes, interactions and conditions based on similar healthy ecosystems.
5. Rewilding recognises that ecosystems are dynamic and constantly changing.
6. Rewilding should anticipate the effects of climate change and act as a tool to mitigate its impacts. 
7. Rewilding is informed by science and considers local knowledge.  
8. Rewilding recognises the intrinsic value of all species.
9. Rewilding is adaptive and dependent on monitoring and feedback. 
10. Rewilding is a paradigm shift in the coexistence of humans and nature.


These ten principles provide a reference point for rewilding, and support the incorporation of the technique into global conservation targets.

Governments and civil society should consider these principles and follow IUCN's Guidelines for Reintroductions and Other Conservation Translocations throughout rewilding projects. This is one way to ensure that rewilding does not negatively impact the lives and livelihoods of local people, or harm the environment.

While the overall aim is a self-sustaining ecosystem, the rewilding process can involve significant activity and investment. Governments, financial institutions, private funders, and businesses should recognise the potential of evidence-based rewilding. With cross-societal support, this approach to rewilding can offer an effective nature-based solution to help achieve sustainable development. In addition to the ten principles outlined above, actors and investors can apply the IUCN Global Standard for Nature-based Solutions during project design and implementation.

More information