Species cannot be assigned the "Least Concern" category unless they have had their population status evaluated. That is, adequate information is needed to make a direct, or indirect, assessment of its risk ofextinction based on itsdistribution or population status.
Since 2001 the category has had the abbreviation "LC", following the IUCN 2001 Categories & Criteria (version 3.1).[1] Before 2001 "least concern" was a subcategory of the "Lower Risk" category and assigned the code "LR/lc" or lc. Around 20% of least concerntaxa (3261 of 15,636) in the IUCN database still use the code "LR/lc", which indicates they have not been re-evaluated since 2000.
While "least concern" is not considered ared listed category by the IUCN, the 2006IUCN Red List still assigns the category to 15,636 taxa. The number of animal species listed in this category totals 14,033 (which includes severalundescribed species such as a frog from the genusPhilautus[2]). There are also 101 animal subspecies listed and 1500 plant taxa (1410 species, 55 subspecies, and 35 varieties). Nofungi orprotista have the classification, though only four species in those kingdoms have been evaluated by the IUCN.Humans were formally assessed[3] as a species of least concern in 2008.
