Required Supporting Information - Specific Assessments

The table below outlines the required supporting information for IUCN Red List assessments under specific conditions. The list of required supporting information (under specific conditions) is essential for all assessments that meet the conditions outlined in Table 2. Any assessments of taxa meeting these conditions that do not include the information listed in this table will be returned to Assessors

Table 2: Required supporting information under specific conditions

The guidance notes provided in this table often refer to the IUCN Species Information Service (SIS) as this is the central database used by Assessors within the IUCN SSC Specialist Group, Red List Authority, and  Red List Partner networks.

Required Information

(under specific conditions)

Specific Condition Purpose Guidance Notes
1. Name of subpopulation. For subpopulation level assessment. To identify what is being assessed below the species level.  
2. Major synonyms. For taxa with commonly used synonyms or that have been treated taxonomically differently in the past on the IUCN Red List.

(a) To support IUCN Red List website functionality.

(b) To identify which taxon is being assessed.

 
3. Plant growth forms. For plants.

(a) To support IUCN Red List website functionality.

(b) To allow basic analyses.

 
4. Information on the reason for change in IUCN Red List Category of the taxon. For taxa being reassessed. To distinguish up- or down-listings resulting from genuine improvement or deterioration, from those resulting from revised taxonomy, improved knowledge, etc. This should be coded regardless of whether a species qualifies in the same or for a different IUCN Red List Category.
5. Date last recorded (in the wild, if taxon survives in captivity) and details of surveys which have been conducted to search for the taxon. For Extinct and Extinct in the Wild taxa, and for Critically Endangered taxa tagged as Possibly Extinct or Possibly Extinct in the Wild.

(a) To justify use of the Extinct or Extinct in the Wild Category (to underpin assessments in which extinction is confirmed or thought highly likely).

(b) To allow basic analyses.

 
6. Possibly Extinct or Possibly Extinct in the Wild tag. For Critically Endangered taxa that are considered highly likely to be Extinct or Extinct in the Wild but for which confirmation is required.

(a) To underpin assessments in which extinction is thought highly likely but which requires confirmation.

(b) To allow basic analyses.

(c) To support IUCN Red List website functionality.

See section 11.2 in the current version of the Guidelines for Using the IUCN Red List Categories and Criteria for further information on this.
7. Documentation of available data, sources of uncertainty and justification for why the criteria cannot be applied; including, where appropriate, one or both of the Data Deficient tags Unknown provenance and Uncertain taxonomic status explains lack of data. For Data Deficient taxa. To justify use of the Data Deficient Category.  
8. Coding as Severely Fragmented, or the number of locations. Taxa listed as threatened using criteria B1a or B2a. To justify the IUCN Red List Category and Criteria used. For definitions of severely fragmented and locations refer to the current version of the Guidelines for Using the IUCN Red List Categories and Criteria.
9. Generation length. For taxa listed as threatened under criteria A and C1. To justify the IUCN Red List Category and Criteria used. For definition of generation length refer to the current version of the Guidelines for Using the IUCN Red List Categories and Criteria.
10. Time period over which 3-generation decline is measured around the present. For taxa listed as threatened under criterion A4. To justify the IUCN Red List Category and Criteria used. Record this in SIS as the start year for the 3-generation time period.
11. The data, assumptions, structural equations, and Population Viability Analysis model if used. For taxa listed under Criterion E. To justify the IUCN Red List Category and Criteria used.  
12. Coding and justification of the criteria that are nearly met or the reasons for the classification (e.g., dependence on ongoing conservation measures). For taxa listed as Near Threatened. To justify the IUCN Red List Category and Criteria used.  
13. Taxonomic notes.

(a) For taxa previously treated as a different taxonomic concept (e.g., “split” or “lumped”) on The IUCN Red List.

(b) For taxa for which there is widespread taxonomic ambiguity or uncertainty in the literature.

(c) For species that may represent a species complex.

(d) For taxa assessed as Data Deficient because of Taxonomic uncertainty.

(a) To identify which taxon is being assessed.

(b) To allow comparison of taxa previously assessed on The IUCN Red List.

(c) To justify use of the Data Deficient Category.

 
14. Major threats to the taxon (coded to lowest level in Threats Classification Scheme). For taxa listed as Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, and Near Threatened.

(a) To justify the IUCN Red List Category and Criteria used.

(b) To support IUCN Red List website functionality.

(c) To allow basic analyses.

Only major threats to the species are required.

Coding of timing (past, ongoing, future, unknown) and stresses not strictly required for the IUCN Red List assessment, but are recommended.

Coding of scope and severity are discretionary (i.e., optional).

If Assessors decide to also record minor threats, then Scope and Severity must be recorded for all threat records for the taxon (to allow major and minor threats to be clearly identified).

Major threats are not required for Least Concern or Data Deficient taxa, but may be recorded if relevant (but with appropriate Timing, Scope and Severity codes).

15. Narrative text about the geographic range, population, habitat and ecology, and threats. For taxa listed as Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, and Data Deficient. To justify the IUCN Red List Category and Criteria used.

Required for supporting the assessment with contextual and explanatory information covering, among other things, the relevant data sources, uncertainties, subtleties and interpretations of data made by Assessors.

Although general text would also be helpful for Least Concern taxa, this is not required.

16. Additional supporting information as detailed in section 2.6 of the Documentation Standards and Consistency Checks for IUCN Red List Assessments and Species Accounts. If the RAMAS® Red List software is used for an assessment. To justify the IUCN Red List Category and Criteria assigned using RAMAS.