| Designation |
Description |
| Extinct |
Taxa which are no longer known to exist in the wild after
repeated searches of their localities and other known likely
places.Superseded by new IUCN categories in 1994, but still
applicable to lists that have not been reviewed since 1994. |
| Extinct in the Wild |
A taxon is Extinct in the wild when it is known to survive only
in cultivation, in captivity or as a naturalised population (or
populations) well outside the past range. A taxon is presumed
extinct in the wild when exhaustive surveys in known and/or
expected habitat, at appropriate times (diurnal, seasonal, annual)
throughout its range have failed to record an individual. Surveys
should be over a time frame appropriate to the taxon's life cycle
and life form. |
| Critically Endangered |
A taxon is Critically Endangered when it is facing an extremely
high risk of extinction in the wild in the immediate future, as
defined by any of the criteria A to E. |
| Endangered |
Taxa in danger of extinction and whose survival is unlikely if
the causal factors continue operating. Superseded by new IUCN
categories in 1994, but still applicable to lists that have not
been reviewed since 1994. |
| Vulnerable |
Taxa believed likely to move into the Endangered category in
the near future if the causal factors continue operating.
Superseded by new IUCN categories in 1994, but still applicable to
lists that have not been reviewed since 1994. |
| Rare |
Taxa with small populations that are not at present Endangered
or Vulnerable, but are at risk. (In GB, this was interpreted as
species which exist in fifteen or fewer 10km squares). Superseded
by new IUCN categories in 1994, but still applicable to lists that
have not been reviewed since 1994. |
| Lower risk - conservation dependent |
Taxa which are the focus of a continuing taxon-specific or
habitat-specific conservation programme targeted towards the taxon
in question, the cessation of which would result in the taxon
qualifying for one of the threatened categories above within a
period of five years. |
| Lower risk - least concern |
Taxa which do not qualify for Lower Risk (conservation
dependent) or Lower Risk (near threatened) or (in Britain)
Nationally Scarce. |
| Data Defficient |
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. A taxon in this
category may be well studied, and its biology well known, but
appropriate data on abundance and/or distribution are lacking. Data
Deficient is therefore not a category of threat or Lower Risk.
Listing of taxa in this category indicates that more information is
required and acknowledges the possibility that future research will
show that a threatened category is appropriate. |
| Near Threatened |
Taxa which do not qualify for Lower Risk (conservation
dependent), but which are close to qualifying for Vulnerable. In
Britain, this category includes species which occur in 15 or fewer
hectads but do not qualify as Critically Endangered, Endangered or
Vulnerable. |