IUCN Red List - Categories & Criterias

IUCN Red List Categories 3.1

The IUCN Red List Categories are intended to be an easily and widely understood system for classifying species at high risk of global extinction. The general aim of the system is to provide an explicit, objective framework for the classification of the broadest range of species according to their extinction risk. However, while the Red List may focus attention on those taxa at the highest risk, it is not the sole means of setting priorities for conservation measures for their protection.

Extensive consultation and testing in the development of the system strongly suggest that it is robust across most organisms. However, it should be noted that, although the system places species into the threatened categories with a high degree of consistency, the criteria do not take into account the life histories of every species. Hence, in certain individual cases, the risk of extinction may be under- or over-estimated.

Summary of IUCN Red List Criteria PDF

Structure of the Red List Categories Version V 3.1.

Guidelines / Regional Guidelines

The IUCN Red List Categories and Criteria were developed for classifying species at high risk of global extinction, i.e. for assessment at the global level. At regional, national and local levels (hereafter referred to as regional level) there are essentially two options:

1. To publish an unaltered subset of the global Red List encompassing those species that reproduce in the region or at any stage regularly visit the region. This may be a feasible option, particularly when the region has a high number of endemics or threatened near endemics, or when there is currently a pronounced overall deficiency of data pertaining to species status within the region.

2. To assess species’ extinction risk and publish Red Lists within the specific region. For the purposes of regional conservation assessments there are important reasons to assess species’ extinction risk and publish Red Lists within specific geographically defined areas. Developping Red Lists for a species includes thorough research on the species status in a certain region. In this regard, important background information is compiled, which is needed to develop successful conservation measures. 

Guidelines for using the IUCN Categories and Criteria PDF

Guidelines for Application of IUCN Red List Criteria at Regional and National Levels PDF