Conservation status
Conservation status is a measure of how likely a species or other group of living things is to die out. Scientists give a species a conservation status after looking at evidence about how many individuals are left, how quickly their numbers are changing and how large an area they live in. The best-known system is the IUCN Red List of the International Union for Conservation of Nature, and many countries use the same rules to make their own lists.[1]
The IUCN categories
The IUCN Red List Categories and Criteria (version 3.1, published in 2001) sort species into categories. From the greatest risk to the least, a species can be listed as Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened or Least Concern. Two further categories are used when there is not enough information (Data Deficient) or when a species has not yet been checked (Not Evaluated).[2]
Species in the Critically Endangered, Endangered and Vulnerable categories are together called "threatened". A Vulnerable species, for example, is one that the best available evidence shows to be facing a high risk of extinction in the wild.[3]
To decide which category fits, assessors test a species against five sets of rules, called criteria A to E. These cover a fall in population size, a small geographic range, a small and declining population, a very small or restricted population, and a mathematical estimate of the chance of extinction. Meeting any one criterion is enough to place a species at that level.[4]
Global and national lists
A species can have different statuses on different lists. There are two types of red list: global lists, which look at a species across the whole world, and regional or national lists, which look at it in one area.[5] In Great Britain, national red lists cover England, Scotland and Wales, but not Northern Ireland or the Channel Islands.[6]
Red lists measure the risk of extinction. They are not, by themselves, a list of which species should be protected first.[7]
Legal protection and other designations
Conservation status is different from legal protection. A species may also be named in laws or international agreements, such as the Wildlife and Countryside Act in the United Kingdom. These listings are sometimes called "badges". They show that a species has special protection or importance, but they are not the same as a red list category of extinction risk.[8]
References
- ↑ "Red lists in Great Britain". Joint Nature Conservation Committee. Retrieved 20 October 2026.
Red lists are a globally recognised way of identifying the threat of extinction to species, using the internationally accepted Red List guidelines developed by the International Union for Conservation of Nature (IUCN)
- ↑ "IUCN Red List Categories and Criteria: Version 3.1" (PDF). International Union for Conservation of Nature. 2001. Retrieved 20 October 2026.
Together these categories are described as 'threatened'.
- ↑ "IUCN Red List Categories and Criteria: Version 3.1" (PDF). International Union for Conservation of Nature. 2001. Retrieved 20 October 2026.
to be facing a high risk of extinction in the wild.
- ↑ "IUCN Red List Categories and Criteria: Version 3.1" (PDF). International Union for Conservation of Nature. 2001. Retrieved 20 October 2026.
meeting any one of these criteria qualifies a taxon for listing at that level of threat
- ↑ "Red lists in Great Britain". Joint Nature Conservation Committee. Retrieved 20 October 2026.
There are two types of red list: global lists and regional/national lists.
- ↑ "Red lists in Great Britain". Joint Nature Conservation Committee. Retrieved 20 October 2026.
GB Red Lists cover England, Scotland, and Wales – they do not cover Northern Ireland and the Channel Islands.
- ↑ "Red lists in Great Britain". Joint Nature Conservation Committee. Retrieved 20 October 2026.
This information can help make decisions about conserving biodiversity at local to global levels, but are not a list of conservation priorities per se.
- ↑ "Conservation designations for UK taxa". Joint Nature Conservation Committee. 9 June 2026. Retrieved 20 October 2026.
Badges refer to species listed in international agreements, UK legislation, UK country lists, or which have a particular status (e.g. red list species).