A Regional Red List is a systematic assessment of the extinction risk of species within a specific geographic area, such as a country, state, province, or other defined sub-global region. It adapts the methodology and criteria developed by the International Union for Conservation of Nature (IUCN) for its global Red List of Threatened Species, but applies them to a localized context.
Purpose and Significance: The primary purpose of a Regional Red List is to provide an evidence-based tool for informing conservation policy and action at a sub-global level. It serves to:
- Identify species most at risk of extinction within a given region.
- Highlight regions or ecosystems with high concentrations of threatened species.
- Guide conservation planning and resource allocation.
- Influence land-use planning, environmental impact assessments, and legislative decisions.
- Raise public awareness about regional biodiversity threats.
Relationship to the IUCN Red List: While based on the IUCN Red List framework, a Regional Red List differs significantly:
- Geographic Scope: The global IUCN Red List assesses a species' risk of extinction across its entire global range. A Regional Red List, conversely, assesses this risk only within the boundaries of a specific region.
- Extinction Risk Discrepancies: A species might be classified as "Least Concern" globally but "Critically Endangered" within a particular region due to localized threats, habitat loss, or small population size within that specific area. Conversely, a globally threatened species might be relatively stable or even abundant in a specific region.
- Adaptation of Criteria: Regional Red Lists often adapt the IUCN criteria to account for regional dynamics such as immigration and emigration (the "rescue effect"), connectivity with populations outside the region, and regional-specific threats. For instance, the presence of a healthy population just outside the assessed region might influence the regional assessment, making a species less threatened than if it were isolated.
Methodology and Categories: Regional Red Lists typically follow the IUCN Red List Categories and Criteria (version 3.1 or later), which classify species into nine categories based on five quantitative criteria related to population size, trend, geographic range, and population structure:
- Extinct (EX): No known living individuals remaining.
- Extinct in the Wild (EW): Known only to survive in captivity or as naturalized populations outside its historic range.
- Regionally Extinct (RE): The species no longer exists in the region, though it may persist elsewhere.
- Critically Endangered (CR): Facing an extremely high risk of extinction in the wild in the immediate future.
- Endangered (EN): Facing a very high risk of extinction in the wild in the near future.
- Vulnerable (VU): Facing a high risk of extinction in the wild in the medium-term future.
- Near Threatened (NT): Likely to qualify for a threatened category in the near future.
- Least Concern (LC): Widespread and abundant taxa.
- Data Deficient (DD): Insufficient information to make a direct, or indirect, assessment of its risk of extinction.
- Not Evaluated (NE): Has not yet been evaluated against the criteria.
The assessment process involves compiling the best available scientific data on a species' population size, trends, distribution, habitat, threats, and conservation measures within the defined region. Expert working groups typically conduct these assessments.
Applications: Regional Red Lists are vital tools for:
- National and Subnational Conservation Strategies: Guiding the development of biodiversity action plans and species recovery programs.
- Environmental Policy: Informing legislation, protected area designations, and environmental impact assessments.
- Resource Management: Prioritizing funding and efforts for species and habitat protection.
- Public Awareness and Education: Engaging stakeholders and the general public in conservation efforts.
Many countries and subnational jurisdictions (e.g., states, provinces, cantons) have developed their own Regional Red Lists, often coordinated by national environmental agencies, academic institutions, or NGOs, working in collaboration with the IUCN.