IUCN Red List

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also called the IUCN Red List or Red Data Book, was started in 1964. It is a list of how safe the world's biological species are. It shows the conservation status of each species and how likely it is to die out, which is called extinction. Some countries and groups also make Regional Red Lists. These check the risk of extinction for species in one area that a government manages.

The Red List shares facts based on science about species and subspecies around the world. It shows how many threatened species there are and why they matter. It helps guide decisions and rules made by countries and the world. It also gives ideas for ways to protect the variety of life on Earth.

Several groups do most of the species checks. These include BirdLife International, the Institute of Zoology (the research part of the Zoological Society of London), the World Conservation Monitoring Centre, and many expert groups in the IUCN Species Survival Commission (SSC). Together, these groups have checked nearly half of the species on the Red List.

The IUCN tries to check the status of every species at least every ten years, and every five years if it can. Other experts review this work carefully. The checks are done by SSC expert groups. Each group is in charge of one species, a group of species, or a certain area. BirdLife International is in charge of an entire class of animals, Aves, which are birds.

As of 2023, 42,108 of the 150,388 species studied were at risk of dying out because of human activity. The main dangers include overfishing, hunting, and land development.

History

At first, the Red Data Lists were made for experts. They were printed in a loose-leaf format that was easy to update. In 1966, conservationist Noel Simon published the first two volumes, one on mammals and one on birds. Later volumes covered reptiles and amphibians, created by René E. Honegger in 1968, and plants (angiosperms only), compiled by Ronald Melville in 1970. The last loose-leaf volume, on freshwater fishes, was published in 1979 by Robert Rush Miller. In 1969, The Red Book: Wildlife in Danger was the first attempt to reach a general audience. It focused mostly on mammals and birds, with smaller sections on reptiles, amphibians, fishes, and plants.

The 2006 Red List was released on 4 May 2006. It looked at 40,168 species as a whole. It also looked at 2,160 more groups, including subspecies, varieties, aquatic stocks, and subpopulations. On 12 September 2007, the World Conservation Union (IUCN) released the 2007 list. It moved the western lowland gorilla and the Cross River gorilla to critically endangered, the last category before extinct in the wild. Problems like Ebola virus and poaching were part of the reason. Russ Mittermeier, who leads the Primate Specialist Group of the IUCN, which is based in Switzerland, said that 16,306 species were in danger of dying out. The list also placed the Sumatran orangutan in the Critically Endangered category and the Bornean orangutan in the Endangered category. In 2008, the Blue List was released in Barcelona. It showed that many animals were at risk. At least 1,141 of the 5,487 mammals on Earth were threatened, and 836 were listed as Data Deficient, which means there was not enough information about them. The 2012 Red List was released at the Rio+20 Earth Summit. It added nearly 2,000 species and found that 19,817 of the 63,837 species checked were threatened with extinction.

Categories

The IUCN Red List sorts species into nine groups. Scientists look at things like how fast a species is shrinking, how many members it has, how large an area it lives in, and how broken up its homes are. Sometimes information is missing, so they may also use possible future threats, as long as these can reasonably be supported. Extinct means there is no real doubt that the species is gone. Extinct in the wild means it survives only in captivity, in cultivation, or outside its natural home, after careful searching. Critically endangered species are in an extremely serious state. Endangered species have a very high risk of disappearing from the wild. Vulnerable species are at high risk of becoming extinct unless people help them. Near Threatened species are close to being endangered in the near future, while Least Concern species are widespread and plentiful. Data Deficient means there is not enough information to judge the risk, and Not Evaluated means the species has not been checked yet. "Threatened" is the name for Critically Endangered, Endangered, and Vulnerable species together.

The older 1994 list had one "Lower Risk" group with three parts: Conservation Dependent, Near Threatened, and Least Concern. In the 2001 system, Near Threatened and Least Concern became their own categories, and Conservation Dependent was removed and combined with Near Threatened. BirdLife International, the Red List authority for birds, uses a "possibly extinct" (PE) tag. It suggested that PE become an official tag for Critically Endangered species, and this has now been accepted. A "Possibly Extinct in the Wild" tag has also been added for species that survive in captivity but are likely extinct in the wild.

Versions

The Red List has had several versions since 1991. It started with Version 1.0 and reached Version 3.1 in 2001.

Since 2001, all new IUCN assessments have used version 3.1 of the categories and criteria. These are the rules used to sort species by how likely they are to die out.

Criticism

In 1997, people said the IUCN Red List was secretive. They said it did not clearly show where its information came from. The IUCN worked to improve how it recorded its documents and data. It also started having other experts check the species on the list. The list accepts requests to challenge its classifications, based on documents or rules.

In 2002, an article in Trends in Ecology & Evolution said that the Red List and similar works could be misused by governments and other groups. These groups might draw wrong conclusions about the environment, or use the lists to influence how natural resources are used. In 2016, a research article in Science Advances said the IUCN's way of classifying species has problems. The researchers said the process is "out-dated, and leaves room for improvement." They said easy-to-use location data, such as satellite and aerial images, is valuable. They believe that using this kind of data could greatly increase the number of species that should be moved to a higher risk category.