IUCN Red List

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological species. A series of Regional Red Lists, which assess the risk of extinction to species within a political management unit, are also produced by countries and organizations.

The goals of the Red List are to provide scientifically based information on the status of species and subspecies at a global level, to draw attention to the magnitude and importance of threatened biodiversity, to influence national and international policy and decision-making, and to provide information to guide actions to conserve biological diversity.

Major species assessors include BirdLife International, the Institute of Zoology (the research division of the Zoological Society of London), the World Conservation Monitoring Centre, and many Specialist Groups within the IUCN Species Survival Commission (SSC). Collectively, assessments by these organizations and groups account for nearly half the species on the Red List.

The IUCN aims to have the category of every species re-evaluated at least every ten years, and every five years if possible. This is done in a peer reviewed manner through IUCN Species Survival Commission Specialist Groups (SSC), which are Red List Authorities (RLA) responsible for a species, group of species or specific geographic area, or in the case of BirdLife International, an entire class (Aves). The red list unit works with staff from the IUCN Global Species Programme as well as current program partners to recommend new partners or networks to join as new Red List Authorities.

The number of species which have been assessed for the Red List has been increasing over time. As of 2023,^[update] of 150,388 species surveyed, 42,108 are considered at risk of extinction because of human activity, in particular overfishing, hunting, and land development.

The idea for a Red Data Book was suggested by Peter Scott in 1963.

Initially the Red Data Lists were designed for specialists and were issued in a loose-leaf format that could be easily changed.

The first two volumes of Red Lists were published in 1966 by conservationist Noel Simon, one for mammals and one for birds.