Dhanus Micro Notes: Threatened species and IUCN Red List categories

Threatened species and IUCN Red List categories

The World Conservation Union was founded as the International Union for the Protection of Nature in October 1948 in Fontainebleau, France. It changed its name to the International Union for Conservation of Nature and Natural Resources (IUCN) in 1956 and was also known as the World Conservation Union (IUCN) from 1990 to 2008. This is the world’s oldest global environmental organization. Its headquarters are in Gland, Switz. The IUCN maintains the IUCN Red List of Threatened Species.

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species or the IUCN Red List or Red Data List was founded in 1964.

It is an inventory aimed for the global conservation of biological species. It is the world’s most comprehensive information source on the global conservation status of animal, fungi and plant species. It provides information about range, population size, habitat and ecology, use and/or trade, threats, and conservation actions that will help inform necessary conservation decisions.

The IUCN uses a set of five quantitative criteria to assess the extinction risk of a given species. These criteria are

A. The rate of population decline

B. The geographic range

C. Whether the species already possesses a small population size

D. Whether the species is very small or lives in a restricted area

E. Whether the results of a quantitative analysis indicate a high probability of extinction in the wild

Based on the data on these criteria, IUCN Red List classify species into nine groups. They are

1. Extinct (EX) – the species is no longer existing. They are the species species in which the last individual has died or where systematic and time-appropriate surveys failed to log even a single individual

2. Extinct in the wild (EW) – the members of the species survive only in captivity, cultivation and/or outside their native geographical range

3. Critically endangered (CR) – these are in a particularly and extremely critical state. These are the species having a rapid population declines of 80 - 90 % over the previous 10 years (or three generations) or a current population size of less than 50 individuals or other factors.

4. Endangered (EN) – very high risk of extinction in the wild, meets any of criteria A to E for Endangered. These species possess a very high risk of extinction as a result of rapid population declines of 50 - 70 % over the previous 10 years (or three generations) or a current population size of less than 250 individuals, or other factors

5. Vulnerable (VU) – meets one of the 5 red list criteria and thus considered to be at high risk extinction without further human intervention. These species possess a very high risk of extinction as a result of rapid population declines of 30 - 50 % over the previous 10 years (or three generations) or a current population size of less than 1000 individuals, or other factors

6. Near threatened (NT) – these species are close to being at high risk of extinction in the near future.

7. Least concern (LC) – unlikely to become extinct in the near future. The population is abundant

8. Data deficient (DD) – these are the species regarding which the data related to their risk of extinction is unavailable.

9. Not evaluated (NE) – this is a category used to include any of the species known and identified by scientific community but not assessed by the IUCN

In the IUCN Red List, "threatened" includes the categories of Critically Endangered, Endangered, and Vulnerable.

Every year scientists around the world assess and reassess species and the IUCN Red List is updated with these new data. By 2019, 96,500 species were assessed by using the IUCN Red List categories and criteria and more than 26,500 species fall into the threatened categories (CR, EN, and VU). Using the IUCN list, National governments and conservation organizations plan and implement species-protection efforts.

Extinct (EX)