Resources
Conservation Status Definitions as prescribed by the IUCN (International Union for the Conservation of Nature)
RESOURCES
LEAST CONCERN (LC)
Taxon which has been categorized by the IUCN, evaluated as not being a focus of species conservation. They do not qualify as being threatened, near threatened, or conservation dependent. Taxa cannot be assigned the Least Concern category unless they have had their population status evaluated. That is, more adequate information is needed to make a direct, or indirect, assessment of its risk of extinction based on its distribution or population status. Examples of Least Concern species include the Nepal gray langur (Semnopithecus schistaceus), Brolga crane (Antigone rubicunda), Jalisco mud turtle (Kinosternon chimolhuaco), Red-eyed tree frog (Agalychnis callidryas), and the West African lungfish (Protopterus annectens), etc.
Species that are Least Concerned should not go ignored or unmanaged by zoological parks, aquariums, or field conservation groups. The now extinct passenger pigeon (Ectopistes migrotorius) was once considered North America's most common bird species. During their migrations, they would blacken the skies for as long as 3 days at a time.
In 1914 they went extinct due to over-hunting and over-harvesting. Because of their abundance, nobody engaging in such activities imagined that their extinction could happen. The last individual alive was a female named "Martha", who lived at the Cincinnati Zoo in Cincinnati, Hamilton County, Ohio. The zoo has a building known as the Passenger Pigeon Memorial. This building has great educational value, in that it teaches about extinctions caused by human activities, and the importance of conservation. Today the species can only be seen in Natural History Museums such as Naturalis Biodiversity Center in Leiden, The Netherlands, Academy of Natural Sciences of Drexel University in Philadelphia, Pennsylvania, and the Field Museum of Natural History in Chicago, Illinois amongst others. (Thus, the importance of Natural History Museums).
CONSERVATION DEPENDENT (CD)
Categorized as dependent on conservation efforts to prevent it from becoming threatened with extinction. Such taxa must be the focus of a continuing taxon-specific and or/habitat-specific conservation program, the cessation of which would result in the taxon qualifying for one of the threatened categories within a period of five years. Examples of Conservation Dependent species include the Black caiman (Melanosuchus niger), the Sinarapan fish (Mistichthys luzonensis), California ground cricket (Neonemobius eurynotus), and the flowering plant Garcinia hermonii.
VULNERABLE (VU)
A taxon which has been categorized by the IUCN as likely to become endangered unless the circumstances that are threatening its survival and reproduction improve. Vulnerability is mainly caused by habitat loss or destruction of the taxon's home. Vulnerable habitats or taxa are monitored and can become increasingly threatened. Some species listed as vulnerable may be common in captivity, an example being the Military macaw (Aro militaris). Other examples of vulnerable species include the Oregon slender salamander (Betrachoseps wrighti), Blue crane (Grus poradisea), Giant guitarfish (Rhynochobotus dijiddensis), Nilgiri langur (Semnopithecus johnii), and Giant Asian pond turtle (Heosemys grandis) etc.
ENDANGERED (EN)
A taxon which has been categorized as very likely to become extinct in the near future. Endangered, as categorized by the IUCN is the 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. Many nations have laws that protect conservation-reliant taxa: for example, forbidding hunting, forbidding or restricting land development or creating protected areas. Examples of endangered taxa include the Iberian lynx (Lynx pardinus), Speke's gazelle (Gazella spekii), Grevy's zebra (Equus grevyi), African penguin (Spheniscus demersus), and Mexican gray wolf (Canis lupus baileyi) etc.
CRITICALLY ENDANGERED (CR)
Categorized by the IUCN as a taxon that is facing an extremely high-risk extinction in the wild. As of 2014, there were 2,464 animal and 2,104 plant species with this assessment. As the IUCN does not consider a taxon extinct until extensive, targeted surveys have been conducted, species that are possibly extinct are still listed as critically endangered. IUCN maintains a list of "possibly extinct" and "possibly extinct in the wild" taxa modelled on categories used by BirdLife International to categorize these taxa. To be defined as critically endangered in the Red List, a taxon must meet any of the following criteria (A-E) ("3G/10Y" signifies three generations or ten years - whichever is longer - over a maximum of 100 years; "MI" signifies Mature Individuals):
A: Population size reduction: 1. If the reasons for population reduction no longer occur and can be reversed, the population needs to have been reduced by at least 90%, 2.3. and 4. If not, then the population needs to have been reduced by at least 80%.
B: Occurring over less than 100 square kilometers or the area of occupancy is less than 10 square kilometers: 1. Severe habitat fragmentation or existing at one location, 2. Decline in extent of occurrence, area of occupancy, area/extent/quality of habitat, number of locations/subpopulations or amount of MI.
C: Declining population of less than 250 Ml and either: 1. A decline of 25% over 3G/10Y, 2. Extreme fluctuations or over 90% of MI in any one sub-population.
D: Numbers less than 50 MI.
E: At least 50% chance of going Extinct in the Wild over 3G/10Y.
Examples of critically endangered taxa include the Chinese giant salamander (Andrias dovidionus), Red vented cockatoo (Limectis hoematuropygia), Bawean deer (Hyelaphus kuhlii), Anganoka tortoise (Astrochelys yniphora), Russian sturgeon (Acipenser gueldenstaedtil), and Australian dawn ant (Nothomyrmecia macrops).
EXTINCT IN THE WILD (EW)
A species that is extinct in the wild is one that has been categorized by the IUCN as known only by living members kept in captivity or as a naturalized population outside its historic range due to massive habitat loss. Examples of such species include the South China tiger (Panthera tigris amoyensis), Pere David's deer (Elaphurus davidianus), Scimitar horned oryx (Oryx dommoh), Guam kingfisher (Todiramphus cinnamominus), Guam rail (Gallirallus owstoni), Hawaiian crow (Corvus hawaiiensis), Socorro dove (Zenaida graysoni), Spix's macaw (Cyanopsitta spixii), Alagoas currasow (Mitu mitu), Black softshell turtle (Nilssonia nigricans), Kihansi spray toad (Nectophrynoides asperginis), and Wyoming toad (Anoxyurus baxteri).
EXTINCT (EX)
Extinction is the termination of an organism or of a group of organisms (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. Examples of taxa whose extinctions were caused by human activity include the Bramble Cay melomys (Melomys rubicola) in 2015, the Thylacine/Tasmanian tiger (Thylacinus cynocephalus) in 1936, the Bubal hartebeest (Alcelaphus buselaphus) in 1925, the Passenger pigeon (Ectopistes migratorius) in 1914, the Bluebuck (Hippotragus leucophoeus) in 1799 or 1800, the Quagga (Equus quagga quagga) in 1883, the Steller's sea cow (Hydrodamalis gigas) in 1768 etc.
POPULATION TRENDS
Of the proposed conservation statuses within those designations are what is called "population trends", defined as Increasing, Stable, Decreasing, Unspecified and Unknown. Taxa designated as Least Concern whose population trend is increasing may not have high conservation priority but may, instead, have great educational value. One animal species that is Least Concern with an increasing population trend is the Japanese serow (Capricornis crispus). Once hunted nearly to extinction, and severely poached after hunting restrictions, the government enacted conservation laws listing them as a “special natural monument", including stricter safeguards and monitoring against poaching. As a result, Japanese serow populations began to increase and populations continue to grow to this day.
CONSERVATION STATUS OF HABITATS
It is not just organisms that can be classified under designated conservation statuses, but also the habitats and ecosystems where they live. Different terminology and classification is used for habitats. An example of a habitat that is classified as critically/endangered is Deccan Thorn Scrub Forest in southern India and Sri Lanka. An example of a habitat that is classified as Vulnerable is Western Australian Mulga Shrublands, and an example of a habitat that is classified as Stable/Intact iş Eritrean coastal desert which runs from the southern coast of the Red Sea from Balfạir Assoli in Eritrea to Ras Bir near Obock in Djibouti. (www.worldwildlife.org/ecoregions). Even if a habitat is considered Stable/Entact, there could be species or subspecies endemic to that habitat that are threatened or endangered. Though habitat may be considered vulnerable or critical/endangered, it may have taxa within it that are not threatened, however those taxa would likely be found in ecosystems outside of that habitat.
