Applying the IUCN Categories and Criteria at the national/regional level


In order to assess extinction risk nationally or regionally, the IUCN has prepared guidelines in English, French and Spanish (plus additional languages) to apply the IUCN Categories and Criteria at sub-global levels, by accounting for potential source and sink effects that result from interchange with populations beyond the national borders.

This means that the assessment process follows the following outline:

Step 1 – Identify taxa to assess

This step is important in order to discuss and decide on any rules to implement for identifying introduced versus naturalised taxa, vagrants, etc. and deciding on which taxa are not to be included in the assessment process (see section on Which taxa to include in the assessment).


Step 2 – Preliminary assessment

In this step, the IUCN Red List Categories and Criteria are applied to the entire population occurring within the region, and all populations outside of the assessment region are ignored and the Red List criteria are applied without any modifications to thresholds, etc.


Step 3 – Producing the final regional assessment

In this step, the potential rescue effects from populations occurring outside of the assessment region are evaluated, which may lead to an up- or down-listing of the species’ extinction risk status at the regional level. To decide on whether a species should be up- or down-listed from the preliminary category, the IUCN has prepared a flow diagram to decide:




More information on applying the IUCN Categories and Criteria at the national/regional level can be found in the IUCN training pages (The Importance of Regional Red Lists).

The final step: The final regional Red List status should feed into a conservation priority setting process, but other factors must also be considered for conservation priority setting (e.g., economic and cultural importance of the species, phylogenetic uniqueness of the species, national obligations to international agreements and legislation (CITES, CMS, Ramsar, etc.), availability of funds and staff to develop and implement conservation actions, probability of conservation actions being successful for the species, etc.).