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|By risk of extinction|
Extinct in the Wild (List)
|Critically Endangered (List)|
|At lower risk|
|Conservation Dependent (List)|
Near Threatened (List)
IUCN Red List
International Union for Conservation of Nature
Lists of organisms by population
An endangered species is a species of organisms facing a very high risk of extinction. The phrase is used vaguely in common parlance for any species fitting this description, but its use by conservation biologists typically refers to those designated Endangered in the IUCN Red List, where it is the second most severe conservation status for wild populations, following Critically Endangered. There are currently 3079 animals and 2655 plants classified as Endangered worldwide, compared with 1998 levels of 1102 and 1197, respectively. The amount, population trend, and conservation status of each species can be found in the Lists of organisms by population.
The conservation status of a species is an indicator of the likelihood of that endangered species becoming extinct. Many factors are taken into account when assessing the conservation status of a species, including statistics such as the number remaining, the overall increase or decrease in the population over time, breeding success rates, known threats, and so on. The IUCN Red List of Threatened Species is the best-known worldwide conservation status listing and ranking system.
It has been estimated that over 40% of all living species on Earth are at risk of going extinct. Internationally, 199 countries have signed an accord agreeing to create Biodiversity Action Plans to protect endangered and other threatened species. In the United States this plan is usually called a species Recovery Plan.
IUCN Red List refers to a specific category of threatened species, and may include critically endangered species. The IUCN Red List uses the term endangered species as a specific category of imperilment, rather than as a general term. Under the IUCN Categories and Criteria, endangered species is between critically endangered and vulnerable. Also critically endangered species may also be counted as endangered species and fill all the criteria
The more general term used by the IUCN for species at risk of extinction is threatened species, which also includes the less-at-risk category of vulnerable species together with endangered and critically endangered.
IUCN categories, and some animals in those categories, include:
Under the Endangered Species Act in the United States, "endangered" is the more protected of the two categories. The Salt Creek tiger beetle (Cicindela nevadica lincolniana) is an example of an endangered subspecies protected under the ESA.
In the United States alone, the "known species threatened with extinction is ten times higher than the number protected under the Endangered Species Act" (Wilcove & Master, 2008, p. 414). The US Fish and Wildlife Service as well as the National Marine Fisheries Service are held responsible for classifying and protecting endangered species, yet, adding a particular species to the list is a long, controversial process and in reality it represents only a fraction of imperiled plant and animal life (Wilcove & Master, 2008, p. 414).
Some endangered species laws are controversial. Typical areas of controversy include: criteria for placing a species on the endangered species list, and criteria for removing a species from the list once its population has recovered; whether restrictions on land development constitute a "taking" of land by the government; the related question of whether private landowners should be compensated for the loss of uses of their lands; and obtaining reasonable exceptions to protection laws. Also lobbying from hunters and various industries like the petroleum industry, construction industry, and logging, has been an obstacle in establishing endangered species laws.
The Bush administration lifted a policy that required federal officials to consult a wildlife expert before taking actions that could damage endangered species. Under the Obama administration, this policy has been reinstated.
Being listed as an endangered species can have negative effect since it could make a species more desirable for collectors and poachers. This effect is potentially reducible, such as in China where commercially farmed turtles may be reducing some of the pressure to poach endangered species.
Another problem with the listing species is its effect of inciting the use of the "shoot, shovel, and shut-up" method of clearing endangered species from an area of land. Some landowners currently may perceive a diminution in value for their land after finding an endangered animal on it. They have allegedly opted to silently kill and bury the animals or destroy habitat, thus removing the problem from their land, but at the same time further reducing the population of an endangered species. The effectiveness of the Endangered Species Act, which coined the term "endangered species", has been questioned by business advocacy groups and their publications, but is nevertheless widely recognized as an effective recovery tool by wildlife scientists who work with the species. Nineteen species have been delisted and recovered and 93% of listed species in the northeastern United States have a recovering or stable population.
Currently, 1,556 known species in the world have been identified as endangered, or near extinction, and are under protection by government law (Glenn, 2006, Webpage). This approximation, however, does not take into consideration the number of species threatened with endangerment that are not included under the protection of such laws as the Endangered Species Act. According to NatureServe's global conservation status, approximately thirteen percent of vertebrates (excluding marine fish), seventeen percent of vascular plants, and six to eighteen percent of fungi are considered imperiled (Wilcove & Master, 2008, p. 415-416). Thus, in total, between seven and eighteen percent of the United States' known animals, fungi, and plants are near extinction (Wilcove & Master, 2008, p. 416). This total is substantially more than the number of species protected under the Endangered Species Act in the United States.
NatureServe and its member programs and collaborators use a suite of factors to assess the conservation status of plant, animal, and fungal species, as well as ecological communities and systems. These assessments lead to the designation of a conservation status rank. For species these ranks provide an estimate of extinction risk, while for ecological communities and systems they provide an estimate of the risk of elimination. Conservation status ranks for how ecological systems in North America are currently under development.
Conservation status ranks are based on a one to five scale, ranging from critically imperiled (G1) to demonstrably secure (G5). Status is assessed and documented at three distinct geographic scales-global (G), national (N), and state/province (S). The numbers have the following meaning:
For example, G1 would indicate that a species is critically imperiled across its entire range (i.e., globally). In this sense the species as a whole is regarded as being at very high risk of extinction. A rank of S3 would indicate the species is vulnerable and at moderate risk within a particular state or province, even though it may be more secure elsewhere.
Species and ecosystems are designated with either an "X" (presumed extinct or extirpated) if there is no expectation that they still survive, or an "H" (possibly extinct or extirpated) if they are known only from historical records but there is a chance they may still exist. Other variants and qualifiers are used to add information or indicate any range of uncertainty. See the following conservation status rank definitions for complete descriptions of ranks and qualifiers.
Before anthropogenic global warming, species were subjected mainly to regional pressures, such as overhunting and habitat destruction. With the acceleration of anthropogenic global warming since the industrial revolution, climate change has begun to influence species safety. Nigel Stork, in the article "Re-assessing Extinction Rate" explains, "the key cause of extinction being climate change, and in particular rising temperatures, rather than deforestation alone." Stork believes climate change is the major issue as to why species are becoming endangered. Stork claims rising temperature on a local and global level are making it harder for species to reproduce. As global warming continues, species are no longer able to survive and their kind starts to deteriorate. This is a repeating cycle that is starting to increase at a rapid rate because of climate change therefore landing many species on the endangered species list.
Captive breeding is the process of breeding rare or endangered species in human controlled environments with restricted settings, such as wildlife preserves, zoos and other conservation facilities. Captive breeding is meant to save species from going extinct. It is supposed to stabilize the population of the species so it is no longer at risk for disappearing.
This technique has been used with success for many species for some time, with probably the oldest known such instances of captive mating being attributed to menageries of European and Asian rulers, a case in point being the Père David's deer. However, captive breeding techniques are usually difficult to implement for highly mobile species like some migratory birds (e.g. cranes) and fishes (e.g. hilsa). Additionally, if the captive breeding population is too small, inbreeding may occur due to a reduced gene pool; this may lead to the population lacking immunity to diseases.
Whereas poaching causes substantial reductions in endangered animal populations, legal private farming for profit has the opposite effect. Legal private farming has caused substantial increases in the populations of both the southern black rhinoceros and the southern white rhinoceros. Dr Richard Emslie, a scientific officer at the IUCN, said of such programs, "Effective law enforcement has become much easier now that the animals are largely privately owned... We have been able to bring local communities into the conservation programmes. There are increasingly strong economic incentives attached to looking after rhinos rather than simply poaching: from eco-tourism or selling them on for a profit. So many owners are keeping them secure. The private sector has been key to helping our work."
Conservation experts view the effect of China's turtle farming on the wild turtle populations of China and South-Eastern Asia—many of which are endangered—as "poorly understood". While they commend the gradual replacement of wild-caught turtles with farm-raised turtles in the marketplace (the percentage of farm-raised individuals in the "visible" trade grew from around 30% in 2000 to around 70% in 2007), they are concerned with the fact that a lot of wild animals are caught to provide farmers with breeding stock. As the conservation expert Peter Paul van Dijk noted, turtle farmers often believe in the superiority of wild-caught animals as the breeding stock, which may create an incentive for turtle hunters to seek and catch the very last remaining wild specimens of some endangered turtle species.
In 2009, researchers in Australia managed for the first time to coax southern bluefin tuna to breed in landlocked tanks, opening up the possibility of using fish farming as a way to save the species from the problems of overfishing in the wild.
The endangered island fox
The endangered sea otter
American bison skull heap. There were as few as 750 bison in 1890 from economic-driven overhunting.
Immature California condor
The Siberian tiger is a subspecies of tiger that is endangered