A taxon is Critically Endangered (according to the International Union for the Conservation of Nature) when it is facing an extremely high risk of extinction in the wild in the immediate future.
A taxon is Endangered when it is not Critically Endangered but is facing a very high risk of extinction in the wild in the near future
Species that are Endangered (according to the US Endangered Species Act) have a 20% chance of extinction in the wild within the next 20 years (or 5 of the species' generations).
Species that are Threatened are likely to become Endangered in the wild in the near future.
A taxon is Vulnerable when it is not Critically Endangered or Endangered but is facing a high risk of extinction in the wild in the medium-term future.
Taxa which do not qualify for Conservation Dependent, but which are close to qualifying for Vulnerable..
A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status.
