Comparison of Red list classes above
and NatureServe status below
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 their known native ranges 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. In 2012, the IUCN Red List featured 3,079 animal and 2,655 plant species as endangered worldwide. [ citation needed ]The figures for 1998 were 1,102 and 1,197 respectively.
The IUCN Red List is a list of species which have been assessed according to a system of assigning a global conservation status. According to the latest system used by the IUCN, a species can be "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. A species can be "Near Threatened" (NT) and "Least Concern" (LC), these are species which are considered to have relatively robust and healthy populations, according to the assessment authors. "Endangered" (EN) species lie between "Vulnerable" (VU) and "Critically Endangered" (CR) species. A species must adhere to certain criteria in order to be placed in any of the afore-mentioned conversation status categories, according to the assessment.
"Threatened" is a category including all those species determined to be Vulnerable, Endangered or Critically Endangered.
Although in general conversation the terms "endangered species" and "threatened species" may mean other things, for the purposes of the current IUCN system, the List uses the terms "endangered" and "threatened" to denote species to which certain criteria apply. Note older or other, such as national, status systems may use other criteria.
Some examples of species classified as endangered by the IUCN are listed below:
As more information becomes available, or as the conservation status criteria has changed, numerous species have been re-assessed as not endangered, nonetheless the total number of species considered endangered has increased as more new species are assessed for the first time each year.
According to the 3.1 version of the IUCN conservation status system from 2001, 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:
1. An observed, estimated, inferred or suspected population size reduction of ≥ 70% over the last 10 years or three generations, whichever is the longer, where the causes of the reduction are reversible AND understood AND ceased, based on (and specifying) any of the following:
2. An observed, estimated, inferred or suspected population size reduction of ≥ 50% occurred over the last 10 years or three generations. Whichever is the longer, where the reduction or its causes may not have ceased OR may not be understood OR may not be reversible, based on (and specifying) any of (a) to (e) under A1. 3. A population size reduction of ≥ 50%, projected or suspected to be met within the next 10 years or three generations, whichever is the longer (up to a maximum of 100 years), based on (and specifying) any of (b) to (e) under A1. 4. An observed, estimated, inferred, projected or suspected population size reduction of ≥ 50% over any 10 year or three-generation period, whichever is longer (up to a maximum of 100 years in the future), where the time period must include both the past and the future, and where the reduction or its causes may not have ceased OR may not be understood OR may not be reversible, based on (and specifying) any of (a) to (e) under A1.
B) Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:
1. Extent of occurrence estimated to be less than 5,000 km², and estimates indicating at least two of a-c:
2. Area of occupancy estimated to be less than 500 km², and estimates indicating at least two of a-c:
C) Population estimated to number fewer than 2,500 mature individuals and either:
1. An estimated continuing decline of at least 20% within five years or two generations, whichever is longer, (up to a maximum of 100 years in the future) OR 2. A continuing decline, observed, projected, or inferred, in numbers of mature individuals AND at least one of the follow (a-b):
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).
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.
Lear's macaw, also known as the indigo macaw, is a large all-blue Brazilian parrot, a member of a large group of neotropical parrots known as macaws. It was first described by Charles Lucien Bonaparte in 1856. Lear's macaw is 70–75 cm long and weighs around 950 g. It is coloured almost completely blue, with a yellow patch of skin at the base of the heavy, black bill.
Sanzinia madagascariensis, also known as the Malagasy tree boa, or Madagascar tree boa) is a non-venomous boa species endemic to the island of Madagascar. It was considered conspecific with the Nosy Komba ground boa.
Acrantophis dumerili, commonly known as Dumeril's boa, is a non-venomous boa species found on Madagascar. No subspecies are currently recognized.
Acrantophis madagascariensis is a species of boid snake in the subfamily Sanziniinae that is endemic to the island of Madagascar. Its common names include Malagasy ground boa and Madagascar boa.
Montivipera albizona, the central Turkish mountain viper, is a venomous viper species endemic to the mountainous regions of central Turkey. No subspecies are currently recognized.
Macrovipera schweizeri is a species of venomous snake in the family Viperidae. The species is endemic to the Cyclades Archipelago in the Aegean sea. No subspecies are currently recognized.
Vipera kaznakovi is a species of venomous snake in the subfamily Viperinae of the family Viperidae. The species is endemic to Turkey, Georgia, and Russia. No subspecies are currently recognized.
An IUCN Red List Critically Endangered (CR) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of 2021, of the 120,372 species currently tracked by the IUCN, there are 8,404 species that are considered to be Critically Endangered.
The Warner sucker is a rare species of freshwater ray-finned fish in the family Catostomidae. Native to Oregon in the United States and found only in the Warner Basin, its distribution extends just into Nevada and California. It is a federally listed threatened species. Its other common name is redhorse. The International Union for Conservation of Nature has rated this fish as an endangered species because of its small extent of occurrence, the small number of locations in which it is found, and the extreme fluctuations in area of occupancy resulting from drought and water abstraction. Conservation efforts have been put in place.
Bothrops pirajai is a species of venomous snake, a pit viper in the subfamily Crotalinae of the family Viperidae. The species is endemic to Brazil. There are no subspecies that are recognized as being valid.
Protea comptonii, also known as saddleback sugarbush, is a smallish tree of the genus Protea in the family Proteaceae. It is found in South Africa and Eswatini.
Bothriechis rowleyi is a species of pit viper, a venomous snake, in the subfamily Crotalinae of the family Viperidae. The species is endemic to Mexico. There are no subspecies that are recognized as being valid.
Heterodon simus, commonly known as the southern hog-nosed snake, is a harmless snake species endemic to the southeastern United States. No subspecies are currently recognized.
Monachoides vicinus is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Hygromiidae, the hairy snails and their allies.
A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature that is threatened with extinction unless the circumstances that are threatening its survival and reproduction improve.
The Appalachia darter is a small species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is found in the New River system above Kanawha Falls.
Podonephelium subaequilaterum is a tree species endemic to the sclerophyllous forests of New Caledonia. This species of trees suffers from forest reduction and fragmentation due to agriculture on the west coast of the country. The main threat to the species comes from habitat destruction due to the Javan rusa deer and uncontrolled forest fires. Its area of occupancy (AOO) is estimated to be 12 square kilometres (4.6 sq mi) and its extent of occurrence (EOO) is around 15 square kilometres (5.8 sq mi). The species is observed to be in a continuing decline of its quality of habitat, number of subpopulations, extent of occurrence, area of occupancy and the number of mature individuals.
Ozimops ridei is a species of molossid bat found in eastern Australia.
Photuris bethaniensis is a species of firefly in the genus Photuris.