Number of species of terrestrial vertebrates held in ISIS zoos broken down by IUCN Red List category.

*VU, EN and CR are collectively referred to as threatened species.
†The reptile assessment by IUCN is not yet complete, so these results only refer to the species assessed in the IUCN Red List version 3.2 (2009).
The seven IUCN Red List categories are DD = Data Deficient, LC = Least Concern, NT = Near Threatened, VU = Vulnerable, EN = Endangered, CR = Critically Endangered, EW = Extinct in the Wild. We further break down the accounting by taxonomic class. Note: In parenthesis are the percentages of threatened species with respect to the species present in ISIS zoos and not with respect to the total number of the world's threatened terrestrial vertebrate species (that information is available in Conde et al. [3]).