The IUCN Red List of Threatened Species
(also known as the IUCN Red List
or Red Data List
), created in 1963, is the world's most comprehensive inventory of the global conservation
status of plant and animal species
. The International Union for the Conservation of Nature and Natural Resources
(IUCN) is the world's main authority on the conservation status of species.
The IUCN Red List is set upon precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. The aim is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to try to reduce species extinction.
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's Species Survival Commission (SSC). Collectively, assessments by these organizations and groups account for nearly half the species on the Red List.
IUCN Red List is widely considered to be the most objective and authoritative system for classifying species in terms of the risk of extinction.
The IUCN aims to have the category of every species re-evaluated every 5 years if possible, or at least every ten years. This is done in a peer reviewed manner through IUCN Species Survival Commission (SSC) Specialist Groups, which are Red List Authorities responsible for a species, group of species or specific geographic area, or in the case of BirdLife International, an entire class (Aves).
Red List, released on 4 May
evaluated 40,168 species as a whole, plus an additional 2,160 subspecies
, aquatic stocks
, and subpopulations
From the species evaluated as a whole, 16,118 were considered threatened. Of these, 7,725 were animals, 8,390 were plants, and three were lichen and mushrooms.
This release listed 784 species extinctions recorded since 1500 CE, unchanged from the 2004 release. This was an increase of 18 from the 766 listed as of 2000. Each year a small number of "extinct" species may be rediscovered, becoming Lazarus species, or may be reclassified as "data deficient". In 2002, the extinction list dropped to 759 species, but has been rising ever since.
On September 12
, 2007, the World Conservation Union
(IUCN) released the 2007 IUCN Red List of Threatened Species
, the latest update to their online database
risks. In this release, they have raised their classification
of both the Western Lowland Gorilla
(Gorilla gorilla gorilla
) and the Cross River Gorilla
(Gorilla gorilla diehli
) from Endangered
to Critically Endangered
, which is the last category
before Extinct in the Wild
, due to Ebola virus
, along with other factors. Russ Mittermeier, chief of Swiss
-based IUCN's Primate Specialist Group, stated that 16,306 species are endangered with extinction, 188 more than in 2006 (total of 41,415 species on the Red List). The Red List includes the Sumatran Orangutan
) in the Critically Endangered category and the Bornean Orangutan
) in the Endangered category.
Red List was released on 6 October
, at the IUCN World Conservation Congress in Barcelona
, and "has confirmed an extinction crisis, with almost one in four at risk of disappearing forever" . The study shows at least 1,141 of the 5,487 mammals on Earth are known to be threatened with extinction, and 836 are listed as Data Deficient
Species are classified in nine groups, set through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation.
When discussing the IUCN Red List, the official term "threatened" is a grouping of three categories: Critically Endangered, Endangered, and Vulnerable.
1994 categories and criteria
The older 1994
has only a single "Lower Risk" category which contained three subcategories:
In the 2001 system, Near Threatened and Least Concern have now become their own categories, while Conservation Dependent is no longer used and has been merged into Near Threatened.
The additional category of Possibly Extinct
(PE) is used by Birdlife International
, the Red List Authority for birds for the IUCN Red List. Birdlife International has recommended PE become an official category. BirdLife International has not stated whether a "Possibly Extinct in the Wild" category should also be added, although it is mentioned that Spix's Macaw
has this status. "Possibly Extinct" can be considered a subcategory of "Critically Endangered".
The IUCN Red List has come under criticism on the grounds of secrecy
(or at least poor documentation) surrounding the sources of data.
The allegations have led to efforts by the IUCN to improve its documentation and data quality, and to include peer reviews of taxa on the Red List. The list is also open to petitions against its classifications, on the basis of documentation or criteria.
It has been suggested that the IUCN Red List and similar works are prone to misuse by governments and other groups, to draw possibly inappropriate conclusions on the state of the environment or to affect exploitation of natural resources.
- IUCN, 2006. Summary Statistics for Globally Threatened Species (1, 3a, 3b). Retrieved 5 May, 2006.
- IUCN, 1994. Categories & Criteria (version 2.3) Retrieved February 12, 2005.
- IUCN, 2001. Categories & Criteria (version 3.1) Retrieved February 12, 2005.
- Rodrigues, A.S.L., Pilgrim, J.D., Lamoreux, J.F., Hoffmann, M. & Brooks, T.M. 2006. The value of the IUCN Red List for conservation Trends in Ecology & Evolution 21(2): 71-76.