Categories for assessing species extinction risk defined by the International Union for Conservation of Nature (IUCN).
Overview
IUCN Red List Categories
The IUCN Red List, established by the International Union for Conservation of Nature (IUCN) in 1964, is the world's most comprehensive information source on the extinction risk of species. It classifies species into nine categories (Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern, Data Deficient, Not Evaluated) to objectively assess their risk of extinction in the wild. The three categories CR, EN, and VU are collectively called 'threatened species' and are widely used to prioritize conservation efforts.
IUCN
Red List
threatened species
biodiversity
conservation
environment
ecosystem
wildlife
plants
| code | slug | name | description | order | riskLevel |
|---|---|---|---|---|---|
| EX | extinct | Extinct | There is no reasonable doubt that the last individual has died. | 1 | extinct |
| EW | extinct-in-the-wild | Extinct in the Wild | Known only to survive in captivity, cultivation, or as a naturalized population outside its past range. | 2 | extinct |
| CR | critically-endangered | Critically Endangered | Facing an extremely high risk of extinction in the wild. | 3 | threatened |
| EN | endangered | Endangered | Facing a very high risk of extinction in the wild. | 4 | threatened |
| VU | vulnerable | Vulnerable | Facing a high risk of extinction in the wild. | 5 | threatened |
| NT | near-threatened | Near Threatened | Close to qualifying for or likely to qualify for a threatened category in the near future. | 6 | near-threatened |
| LC | least-concern | Least Concern | Widespread and abundant species with a low risk of extinction. | 7 | least-concern |
| DD | data-deficient | Data Deficient | Inadequate information to make a direct or indirect assessment of extinction risk. | 8 | unknown |
| NE | not-evaluated | Not Evaluated | Has not yet been evaluated against the criteria. | 9 | unknown |