in Sri Lanka - Ministry of Environment

Data Deficient (DD)A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessmentof its risk of extinction based on its distribution and/or population status. A taxon in this category maybe well studied, and its biology well known, but appropriate data on abundance and/or distribution arelacking. Data Deficient is therefore not a category of threat. Listing of taxa in this category indicatesthat more information is required and acknowledges the possibility that future research will showthat threatened classification is appropriate. It is important to make positive use of whatever data areavailable. In many cases great care should be exercised in choosing between DD and a threatenedstatus. If the range of a taxon is suspected to be relatively circumscribed, and a considerable period oftime 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 evaluated against the criteria.Critically Endangered ‘Possibly Extinct’ CR (PE)Although an evidentiary approach to classifying extinctions is appropriate, this approach biases analysesof recent extinctions when based only on those species classified as Extinct or Extinct in the Wild (whenindividuals survive only in captivity). For example, the number of recent extinctions documented on theIUCN Red List is likely to be a significant underestimate, even for well-known taxa such as birds. The tagof ‘possibly extinct’ has therefore been developed to identify those Critically Endangered species thatare likely already Extinct, but for which confirmation is required. Taxa tagged as possibly extinct wouldthen be included within bounded estimates of the number of recent extinctions to indicate plausibleuncertainty in contemporary rates of extinction.Note that ‘possibly extinct’ is a tag, and not a new Red List Category.451