Endangered species (IUCN status)

Endangered species as classified by the International Union for Conservation of Nature (IUCN), are species which have been categorized as very likely to become extinct in the near future. On the IUCN Red List, endangered is the second most severe conservation status for wild populations in the IUCN's schema after Critically endangered (CR). In 2012, the IUCN Red List featured 3,079 animal and 2,655 plant species as endangered (EN) worldwide. The figures for 1998 were 1,102 and 1,197 respectively. 
IUCN Red List.
Though labelled a list, the IUCN Red List is a system of assessing the global conservation status of species that includes "Data Deficient" (DD) species – species for which more data and assessment is required before their situation may be determined – as well species comprehensively assessed by the IUCN's species assessment process. Those species of "Near Threatened" (NT) and "Least Concern" (LC) status have been assessed and found to have relatively robust and healthy populations, though these may be in decline. Unlike their more general use elsewhere, the List uses the terms "endangered species" and "threatened species" with particular meanings: "Endangered" (EN) species lie between "Vulnerable" (VU) and "Critically Endangered" (CR) species, while "Threatened" species are those species determined to be Vulnerable, Endangered or Critically Endangered.
Some examples of species classified as endangered by the IUCN are listed below: 
Criteria for endangered status.
A species is listed as endangered when it meets any of the following criteria from A to E.
A) Reduction in population size based on any of the following:
B) Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:
C) Population estimated to number fewer than 2,500 mature individuals and either:
D) Population size estimated to number fewer than 250 mature individuals.
E) Quantitative analysis showing the probability of extinction in the wild is at least 20% within 20 years or five generations, whichever is the longer (up to a maximum of 100 years).