Glossary

IUCN Red List

The international inventory of how close species are to extinction, which sorts them into categories from Least Concern to Extinct.

Also called: Red List of Threatened Species, IUCN Red List categories, conservation status

The IUCN Red List of Threatened Species is a global assessment of the extinction risk of plants, animals and fungi, run by the International Union for Conservation of Nature. Experts review a species using evidence on population size, trends, range and threats. The result is a category, and the assessment is dated, since status can change when new data arrive.

The main categories, from lowest to highest risk, are Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in the Wild and Extinct. Data Deficient means there is too little information, and Not Evaluated means no assessment has been made. Vulnerable, Endangered and Critically Endangered are grouped as threatened.

Among cats, the tiger is listed as Endangered, the lion as Vulnerable and the jaguar as Near Threatened in recent assessments, while the domestic cat is not assessed as a wild species. The IUCN Cat Specialist Group helps assess the wild cats. A listing is advice, not a law. It guides governments and conservation groups but does not itself protect an animal. The category is also not the same as legal status such as an endangered species listing under national law. Always check the year of an assessment before quoting a status or population number.

Last reviewed November 7, 2026

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Related terms

Endangered species A species at high risk of extinction, either under the IUCN Endangered category or on a legal list that protects it, which are different systems. Felid Any member of the cat family, Felidae, from the house cat to the tiger, and including extinct cats such as the sabre-toothed cats. Big cat An informal name for the largest wild cats, usually the lion, tiger, leopard and jaguar, and often the snow leopard, cheetah and cougar too. Poaching The illegal killing or capture of wild animals, often for their skins, bones, teeth or meat, a major threat to tigers, leopards and other wild cats. Captive breeding Breeding a threatened species under human care, in zoos or breeding centres, to keep a safe population and sometimes supply animals for release.