IUCN Red List - Categories

Categories

Summary of 2006 IUCN Red List categories.

Species are classified by the IUCN Red List into nine groups, set through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation.

  • Extinct (EX) – No known individuals remaining.
  • Extinct in the Wild (EW) – Known only to survive in captivity, or as a naturalized population outside its historic range.
  • Critically Endangered (CR) – Extremely high risk of extinction in the wild.
  • Endangered (EN) – High risk of extinction in the wild.
  • Vulnerable (VU) – High risk of endangerment in the wild.
  • Near Threatened (NT) – Likely to become endangered in the near future.
  • Least Concern (LC) – Lowest risk. Does not qualify for a more at risk category. Widespread and abundant taxa are included in this category.
  • Data Deficient (DD) – Not enough data to make an assessment of its risk of extinction.
  • Not Evaluated (NE) – Has not yet been evaluated against the criteria.

When discussing the IUCN Red List, the official term "threatened" is a grouping of three categories: Critically Endangered, Endangered, and Vulnerable.

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