Established in 1964, the International Union for Conservation of Nature’s Red List of Threatened Species1 has evolved to become the world’s most comprehensive information source on the global extinction risk status of animal, fungus and plant species.
1 IUCN 2020. The IUCN Red List of Threatened Species. Version 2020-1. https://www.iucnredlist.org
There are nine clearly defined categories into which every taxon in the world (excluding micro-organisms) can be classified. Extinct means that there is no reasonable doubt that the last individual has died. Extinct in the Wild means that the taxon is extinct in its natural habitat. The following three categories, Critically Endangered, Endangered and Vulnerable, are assigned to taxa on the basis of quantitative criteria that are designed to reflect varying degrees of threat of extinction; taxa in any of these three categories are collectively referred to as ‘threatened’. The category Near Threatened is applied to taxa that do not qualify as threatened now, but may be close to qualifying as threatened, and to taxa that do not currently meet the criteria for a threatened category, but are likely to do so if ongoing conservation actions abate or cease. The category Least Concern is applied to taxa that do not qualify (and are not close to qualifying) as threatened or Near Threatened. It is important to emphasize that “least concern” simply means that, in terms of extinction risk, these species are of lesser concern than species in other threat categories. It does not imply that these species are of no conservation concern.