IUCN Categories Explained

What is the IUCN? 

The IUCN stands for the International Union for Conservation of Nature. It is an organisation that is devoted to nature conservation and sustainability of our natural resources. The IUCN has a membership span of over 1,200 governments and non-governmental organisations (NGOs). It also has over 11,000 ecologists, conservationists, scientists and experts contributing to its cause and functioning. Its headquarters are located in Switzerland and it has been established since 1948.

IUCN Categories

The IUCN has 9 categories; Extinct (EX), Extinct in the Wild (EW), Critically Endangered (CR), Endangered (EN), Vulnerable (VU), Near Threatened (NT), Least Concern (LC), Data Deficient (DD) and Not Evaluated (NE).

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Extinct (EX) 

A taxon is deemed to be extinct according to the IUCN when “there is no reasonable doubt that the last individual has died“. A taxon is stated to be extinct in the case of extensive studies and surveying done that can confirm that there are absolutely no more individuals of the species remaining on the planet.

Extinction in the Wild (EW)

A taxon is categorised as extinct in the wild according to the IUCN in the case that there are individuals surviving in captivity, cultivation or a naturalised population outside of their natural historical range. Often the remaining individuals are in captivity to prevent the complete extinction of the species and to increase the mating level and produce higher populations of the species with the intention of re-introduction to the wild in the future – this however is not always the case.

Critically Endangered (CR)

A taxon is considered to be critically endangered when according to the IUCN “the best available evidence indicates it meets any of the criteria A to E for critically endangered“. This means that the species are thought to be currently facing a severely high level of difficulty surviving in the wild and are ultimately facing a huge risk of extinction in the wild.

Endangered (EN)

According to the IUCN a species is thought to be endangered when the best available evidence suggests that the species “meets any of the criteria A to E for endangered“. This generally means that the species are experiencing a very large risk of extinction in the wild at present.

Vulnerable (VU)

A taxon is classed as vulnerable when the “best available evidence indicates that it meets any of the criteria A to E for Vulnerable“. This refers to the species beginning to experience a very probable risk of extinction in the wild if it continues to operate in the same way is has been.

Near Threatened (NT) 

A taxon is defined as near threatened in the case that the evaluated criteria has shown that it does not quality for critically endangered, endangered or vulnerable due to the population size and direction it is going in. This category must be monitored extensively to ensure that the species does not become vulnerable or endangered in the future.

Least Concern (LC)

A species is categorised as least concern in the case that extensive research of this species in the wild has shown that there is a satisfactory amount of the species on the planet and that there is not much concern, if any, for the potential of the species to become extinct in the wild.

Data Deficient (DD)

When a taxon is classed as Data Deficient when there isn’t enough information about them to make a direct assessment of its potential risk of extinction based on factors like its distribution, population status or abundance.

Not Evaluated (NE)

Not evaluated taxon simply means that the species have not yet been evaluated, studied, assessed etc. and therefore the species cant be categorised because no information is known of the species distribution, size or status.

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