Definition
Introduced predator-managed or excluded areas within cities that provide secure habitat for Indigenous species otherwise unable to persist in urban environments. Urban wildlife sanctuaries are also sometimes called ecological islands.
What this strategy does
Creates protected habitat patches through introduced predator control, fencing, and habitat restoration, and supports dispersal into the surrounding urban matrix. Sustained threat management is required.
Context
In Aotearoa New Zealand, many native species evolved without mammalian predators and require intensive predator management to survive in cities, where invasive mammals are ubiquitous and ongoing pressure would otherwise prevent population recovery.
Technical considerations
Design considerations
Patch configuration
Prioritise configuration, context, and edge condition over patch size alone when selecting sanctuary sites, as these factors strongly influence ecological performance in urban settings.
Habitat structure and vegetation
Restore complex, predominantly Indigenous vegetation using successional planting, enrichment, and attention to regeneration filters. Aim to maximise interior habitat and minimise edge effects through buffers and simplified boundaries.
Predator control and fencing
Use predator-proof fencing or peninsula fencing where objectives include highly vulnerable taxa, enabling reintroductions and acting as source populations for the wider landscape. Coordinate with broader pest control beyond the fence to support community-level recovery.
Target species framework
Select a small number of target species from the regional species pool based on site habitat potential and full life-cycle requirements, and use these to inform spatial design and coexistence measures.
Bicultural design
Embed mātauranga Māori and principles such as kaitiakitanga and ki uta ki tai to align ecological outcomes with cultural values and intergenerational wellbeing.
Implementation considerations
Design priority
Plan sanctuaries as part of a core–buffer system, integrating fencing, habitat quality, and surrounding matrix management.
Key constraint
Long-term predator control, weeding, monitoring, and funding are required; short-term interventions alone will likely be insufficient.
Issues and barriers
Invasive predators
Populations of rats, possums, hedgehogs, cats, and mice persist even in high-quality green spaces, meaning habitat enhancement alone rarely restores native fauna.
Weed invasion
The urban context means there is significant ongoing pressure driving weed invasion that needs to be controlled.
Patch quality and configuration
Large amounts of urban green cover may still fail to meet minimum requirements for Indigenous fauna under climate change if spatial pattern and structure are poor.
Fragmentation and densification
Low green-space provision in dense urban cores constrains opportunities for effective sanctuaries and corridors.
Policy and resourcing gaps
Planning frameworks often protect only “significant” remnants and lack clear biodiversity performance thresholds or monitoring requirements.
Human–wildlife conflict
Domestic cats and differing public attitudes to predators and “messy” habitats complicate implementation and acceptance.
Synergies and opportunities
Climate change
Urban blue-green systems associated with sanctuaries moderate heat, manage stormwater, and improve water quality, contributing to climate adaptation and resilience.
Human wellbeing
Exposure to birds and naturalistic green spaces is associated with improved mental wellbeing, recreation, education, and strengthened biocultural identity.
Empowerment
Community-initiated ecosanctuaries build local ownership, skills, and participation, and support socially just, mana whenua-led nature-based solutions.
Financial case
Ecosystem services and performance value
Value type
Long-term gains through avoided costs and co-benefits from biodiversity enhancement, climate regulation, recreation, and tourism.
Cost-effectiveness
Investment logic
Well-designed biodiversity programmes in Aotearoa New Zealand have demonstrated benefit–cost ratios exceeding 100:1 in some contexts, indicating strong potential net social benefits.
Monitoring and evaluation metrics
Core metric
Native species richness, abundance, and occupancy for key taxa using the NZ Biodiversity Assessment Framework.
Advanced or long-term metrics
- Recruitment of late-successional species and sensitive guilds as indicators of forest recovery.
- Predator indices (e.g. tracking tunnels, trap catch per unit effort).
- Indigenous vegetation cover and habitat structure metrics.
- Visitor numbers and demographic access to assess social equity.
- Volunteer participation and citizen-science records supporting multi-taxa urban indices.
Case study
Zealandia
Related design strategies
- Animal movement infrastructure
- Green wildlife corridors bridges and belts
- Monitoring for biodiversity
- Planting for biodiversity
- Stepping stone habitats
- Urban blue spaces
Additional resources or tools
NUWAO – Urban wildlife sanctuaries
https://nuwao.org.nz/urban-wildlife-sanctuaries/
Conserving and Restoring Biodiversity in New Zealand Urban and Rural Environments (Manaaki Whenua)
https://www.landcareresearch.co.nz/assets/researchpubs/Conserving-and-Restoring-Biodiversity-in-New-Zealand-Urban-and-Rural-Environments.pdf
Te Aranga Māori Design Principles
https://www.aucklanddesignmanual.co.nz/en/places-and-spaces/maori-design/te-aranga-principles.html