1994 IUCN Red List Categories
Extinct (EX) A taxon is Extinct when there is no
reasonable doubt that the last individual has died.
Extinct in the Wild (EW) A taxon is Extinct in the
Wild when it is known only to survive in cultivation, in captivity or as a
naturalized 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
historic 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 (CR) A taxon is Critically
Endangered when it is facing an extremely high risk of extinction in the wild
in the immediate future.
Endangered (EN) 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.
Vulnerable (VU) 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.
Lower Risk (LR) A taxon is Lower Risk when it has
been evaluated, but does not satisfy the criteria for any of the categories
Critically Endangered, Endangered or Vulnerable. Taxa included in the
Lower
Risk category can be separated into three subcategories:
1. Conservation Dependent
(cd). 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.
2. Near Threatened (nt).
Taxa which do not qualify for Conservation Dependent, but which are close to
qualifying for Vulnerable.
3. Least Concern (lc). Taxa
which do not qualify for Conservation Dependent or Near Threatened.
Data Deficient (DD) 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 thatthreatened classification is
appropriate. It is important to make positive use of whatever data are
available. In many cases great care should be exercised in choosing between DD
and threatened status. If the range of a taxon is suspected to be relatively
circumscribed, if a considerable period of time has elapsed since the last
record of the taxon, threatened status may well be justified.
Not Evaluated (NE) A taxon is Not Evaluated when it
is has not yet been assessed against the criteria.