The IUCN Red List Categories define the extinction risk of species assessed. In descending order of threat, the IUCN Red List threat categories are: - Extinct or Extinct in the Wild - Critically Endangered, Endangered and Vulnerable (species threatened with global extinction) - Near Threatened (species close to the threatened thresholds or that would be threatened without ongoing conservation measures) - Least Concern (species evaluated with a lower risk of extinction) - Data Deficient (no assessment because of insufficient data) Source: [https://www.iucn.org/resources/conservation-tools/iucn-red-list-threatened-species]