The World Conservation Union (IUCN) has developed a clear set of categories and criteria to assess the risk of extinction of a species.

Red Data Book or IUCN red list provides an indication of the probability of extinction. There are nine categories:

Extinct (EX): A species is Extinct when there is no reasonable doubt that the last individual has died.

Extinct in the wild (EW): A species is Extinct in the Wild when it is known only to survive in cultivation, in captivity or as a naturalised population (or populations) well outside the past range.

Critically endangered (CR): A species is Critically Endangered it is considered to be facing an extremely high risk of extinction in the wild.

Endangered (EN): A species is Endangered when it is considered to be facing a very high risk of extinction in the wild.

Vulnerable (VU): A species is Vulnerable when it is considered to be facing a high risk of extinction in the wild.

Near threatened (NT): A species is Near Threatened when it is close to qualifying for or is likely to qualify for a threatened category in the near future.

Least concern (LC): A species is Least Concern when it is widespread and abundant.

Data deficient (DD): A species 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.

Not evaluated (NE): A species is Not Evaluated when it is has not yet been evaluated.

The Gauteng Conservation Plan (C-Plan) refers to other categories. C-Plan focuses on the mapping and management of biodiversity priority areas within Gauteng. The C-Plan includes protected areas, irreplaceable and important sites due to the presence of Red Data species, endemic species and potential habitat for these species to occur. Definitions follow:

Important Site: A site designated as important in meeting targets set for the conservation of biodiversity, the significance of which is subject to ground truthing. The site is important to protect in some way, but not essential and can be replaced by a similar site, but a trade-off in the efficiency of the conservation plan may be the result.

Irreplaceable Site:  A site designated as essential in meeting targets set for the conservation of biodiversity. Options for achieving these targets will be reduced should the site not be protected.

South Africa has been ranked the third most biologically diverse country on Earth based on an index of species diversity and endemism, and is one of 12 megadiverse countries which collectively contain more than two-thirds of global biodiversity (World Conservation Monitoring Centre, 1992).

Red Data Books explicitly document and highlight biodiversity losses at the species level and are important for guiding conservation activities. These books are widely recognised as the most comprehensive, apolitical evaluation of the conservation status of plant and animal species as well as measures of the success or failure of various conservation initiatives.

Download Red Data Book here. 

Read more about particiating formally in protecting biodiversity on www.stewardship.co.za