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An endangered (EN) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as likely to become extinct. Conservation biologists use the IUCN Red List, where "endangered" is the second most severe conservation status for wild populations, following critically endangered.

3079 animals and 2655 plants are 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.

Many nations have laws that protect conservation reliant species: for example, forbidding hunting, restricting land development, or creating preserves. We talk about extension when the prejudice of the container ready of the cause exclusively attributes the hand of the man with hunting, alterations of the environment, distraction of the natural habits, the contamination, the introduction of foreign species that makes them native, Etc.

We talk about extension when the prejudice of the container ready of the cause exclusively attributes the hand of the man with hunting, alterations of the environment, distraction of the natural habits, the contamination, the introduction of foreign species that makes them native, Etc.

Conservation status

The conservation status of a species indicates the likelihood that it will become extinct. Many factors are considered when assessing the conservation status of a species; e.g., such statistics as the number remaining, the overall increase or decrease in the population over time, breeding success rates, or known threats.​ The IUCN Red List of Threatened Species is the best-known worldwide conservation status listing and ranking system.​

Over 40% of species are estimated to be at risk extinction.​ Internationally, 199 countries have signed an accord to create Biodiversity Action Plans that will protect endangered and other threatened species. In the United States this plan is usually called a species Recovery Plan.^{[cita requerida]}

IUCN Red List

The Siberian tiger is a subspecies of tiger that is endangered; three subspecies of tiger are already extinct. (See: List of carnivorans by population)​

The IUCN Red List is far more than simply a list of threatened species; it is a system of assessing the global conservation status of species. It includes all species that have been assessed through the IUCN species assessment process and also includes species for which assessments have been attempted, but ultimately require more data to make a status determination - known as Data Deficient species. Next along the IUCN Red List spectrum are species of Least Concern and Near Threatened Species, both of which have been assessed and whose populations are relatively robust and healthy (although they may be in decline). Threatened Species refer collectively to the IUCN Red List categories of Vulnerable, Endangered, and 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.

IUCN categories, and some animals in those categories, include:

• Extinct: Aurochs, Bali tiger, blackfin cisco, Caribbean monk seal, Carolina parakeet, Caspian tiger, dodo, dusky seaside sparrow, eastern cougar, golden toad, great auk, Japanese sea lion, Javan tiger, labrador duck, passenger pigeon, Schomburgk's deer, Steller's sea cow, thylacine, toolache wallaby, western black rhinoceros

• Extinct in the wild: captive individuals survive, but there is no free-living, natural population. Examples: Barbary lion, Catarina pupfish, Hawaiian crow, Père David's deer, Scimitar oryx, Socorro dove, Wyoming toad

• Critically endangered: faces an extremely high risk of extinction in the immediate future. Examples: addax, African wild ass, Alabama cavefish, Amur leopard, Arakan forest turtle, Asiatic cheetah, axolotl, bactrian camel, Black Rhino, Blue-throated macaw, Brazilian merganser, brown spider monkey, California condor, Chinese alligator, Chinese giant salamander, gharial, Hawaiian monk seal, Iberian lynx, Javan rhino, kakapo, Mediterranean monk seal, mountain gorilla, Northern hairy-nosed wombat, Philippine eagle, red wolf, saiga, Siamese crocodile, Spix's macaw, southern bluefin tuna, Sumatran orangutan, Sumatran rhinoceros, vaquita, Yangtze river dolphin, northern white rhinoceros

• Endangered: faces a very high risk of extinction in the near future. Examples: African penguin, African wild dog, Asian elephant, Asian lion, blue whale, bonobo, Bornean orangutan, common chimpanzee, dhole, eastern lowland gorilla, Ethiopian wolf, hispid hare, giant otter, giant panda, Goliath frog, green sea turtle, Grevy's zebra, hyacinth macaw, Japanese crane, Lear's macaw, Malayan tapir, markhor, Persian leopard, proboscis monkey, pygmy hippopotamus, red-breasted goose, Rothschild's giraffe, snow leopard, Takhi, tiger, Vietnamese pheasant, volcano rabbit, wild water buffalo, fishing cat

• Vulnerable: faces a high risk of extinction in the medium-term. Examples: African grey parrot, African bush elephant(is likely to differ in areas with poaching threats), African lion(may differ in areas with poaching treats), American paddlefish, common carp, clouded leopard, cheetah, dugong, far eastern curlew, fossa, Galapagos tortoise(may differ with rising tourism), gaur, blue-eyed cockatoo, golden hamster, whale shark, hippopotamus, Humboldt penguin, Indian rhinoceros, Komodo dragon(may differ with the small number of females), lesser white-fronted goose, mandrill, maned sloth, mountain zebra, polar bear, red panda, sloth bear, takin, yak

• Near threatened: may be considered threatened in the near future. Examples: American bison, Asian golden cat, blue-billed duck, emperor goose, emperor penguin, Eurasian curlew, jaguar, leopard, Larch Mountain salamander, Magellanic penguin, maned wolf, narwhal, solitary eagle, white rhinoceros, striped hyena, tiger shark, white eared pheasant

• Least concern: no immediate threat to the survival of the species. Examples: American alligator, American crow, Indian peafowl, olive baboon, bald eagle, brown bear, brown rat, brown-throated sloth, Canada goose, cane toad, common wood pigeon, cougar, common frog, giraffe, grey wolf, house mouse, wolverine,​ human, palm cockatoo, mallard, meerkat, mute swan, platypus, red-billed quelea, red-tailed hawk, rock pigeon, scarlet macaw, southern elephant seal, milk shark, red howler monkey

United States

Endangered Species Act

"Endangered" in relation to "threatened" under the ESA

Under the Endangered Species Act in the United States, species may be listed as "endangered" or "threatened". The Salt Creek tiger beetle (Cicindela nevadica lincolniana) is an example of an endangered subspecies protected under the ESA. The US Fish and Wildlife Service as well as the National Marine Fisheries Service are held responsible for classifying and protecting endangered species, and adding a particular species to the list can be a long, controversial process (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.

Over-hunting

Over-hunting and over-fishing have been a problem ever since mankind started to hunt, and it is no different today. Animals like the bald eagle, grizzly bear, American bison, timber wolf, and sea turtles have all been hunted nearly to extinction, and these are the lucky ones. Others such as the dodo, passenger pigeon, great auk, Tasmanian devil, and Stellar’s sea cows were not as lucky as they were hunted to extinction. All of these animals started off as a food source or ones almost necessary for survival, but the need turned into greed and sport and the populations of these animals were greatly depleted. A present day example of the over-hunting of a species can be seen in the oceans as populations of certain whales have been greatly reduced. Large whales like the blue whale, bowhead whale, finback whale, gray whale, sperm whale, and humpback whale are some of the eight whales which are currently still included on the Endangered Species List. Actions have been taken to try to reduce whaling and increase population sizes, including prohibiting all whaling in United States waters, the formation of the CITES treaty which protects all whales, along with the formation of the International Whaling Commission (IWC). But even though all of these movements have been put in place, countries like Japan claim that they are whaling for “scientific” purposes and continue to harvest whales.​ Over-hunting,climatic change and habitat loss leads in landing species in endangered species list and could mean that extinction rates could increase to a large extent in the future.

Invasive Species

Invasive species are primarily spread by human activities, often unintentionally. People, and the goods we use, travel around the world very quickly, and they often carry uninvited species with them. Invasive species cause harm to wildlife in many ways. When a new and aggressive species is introduced into an ecosystem, it might not have any natural predators or controls. It can breed and spread quickly, taking over an area.

Higher average temperatures and changes in rain and snow patterns caused by global warming will enable some invasive plant species

The also worry about the role of the animals as a sustainable solution in the humane and development programs. The life of the animals in the persons are fundamentally linked. The estimation is the 10 million people in the world depend on animals for correct a limitation, having a job, staying healthy, also for companion as a pet. For consequence, the protection of animals must develop a more centralized in any response effectively to disaster. The introduction of non indigenous species to an area can disrupt the ecosystem to such an extent that native species become endangered. Such introductions may be termed alien or invasive species. In some cases the invasive species compete with the native species for food or prey on the natives. In other cases a stable ecological balance may be upset by predation or other causes leading to unexpected species decline. New species may also carry diseases to which the native species have no resistance.​

Conservation

The most endangered Asiatic top predator, the dhole, is on the edge of extinction.

Captive breeding

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 extinction and so stabilize the population of the species that it will not disappear.​

This technique has worked 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, an example being the Père David's deer. However, captive breeding techniques are usually difficult to implement for such highly mobile species as some migratory birds (e.g. cranes) and fishes (e.g. hilsa). Additionally, if the captive breeding population is too small, then inbreeding may occur due to a reduced gene pool and reduce immunity.

Private farming

Whereas poaching substantially reduces endangered animal populations, legal, for-profit, private farming does the opposite. It has substantially increased the populations of the southern black rhinoceros and 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."​ The also worry about the role of the animals as a sustainable solution in the humane and development programs. The life of the animals in the persons are fundamentally linked. The estimation is the 10 million people in the world depend on animals for correct a limitation, having a job, staying healthy, also for companion as a pet. For consequence, the protection of animals must develop a more centralized in any response effectively to disaster.

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".​ Although 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 worry that many wild animals are caught to provide farmers with breeding stock. The conservation expert Peter Paul van Dijk noted that turtle farmers often believe that wild-caught animals are superior breeding stock; turtle farmers may therefore seek and catch the very last remaining wild specimens of some endangered turtle species.​

In 2009, researchers in Australia first coaxed southern bluefin tuna to breed in landlocked tanks, raising the possibility that fish farming may be able to save the species from overfishing.​

Gallery

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  The endangered island fox
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  The endangered sea otter
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  American bison skull heap. There were as few as 750 bison in 1890 from economic-driven overhunting.
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  Immature California condor
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  Loggerhead sea turtle
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  An Asian arowana
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  The Siberian tiger is a subspecies of tiger that is endangered

Véase también

• Categoría:Especies en peligro de extinción
• Anexo:Especies en peligro de extinción en España
• Extinción
• Extinción masiva
• Especie en peligro crítico de extinción
• Especie amenazada
• Dinámica de sistemas

Bibliography

• Glenn, C. R. 2006. "Earth's Endangered Creatures".
• Ishwaran, N., & Erdelen, W. (2005, May). Biodiversity Futures, Frontiers in Ecology and the Environment, 3(4), 179.
• Kotiaho, J. S., Kaitala, V., Komonen, A., Päivinen, J. P., & Ehrlich, P. R. (2005, February 8). Predicting the Risk of Extinction from Shared Ecological Characteristics, proceedings of the National Academy of Sciences of the United States of America, 102(6), 1963-1967.
• Minteer, B. A., & Collins, J. P. (2005, August). Why we need an "Ecological Ethics", Frontiers in Ecology and the Environment, 3(6), 332-337.
• Raloff, J. (2006, August 5). Preserving Paradise, Science News, 170(6), 92.
• Wilcove, D. S., & Master L. L. (2008, October). How Many Endangered Species are there in the United States? Frontiers in Ecology and the Environment, 3(8), 414-420.
• Freedman, Bill. "Endangered species." Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. 4th ed. Detroit: Gale Group, 2008. Discovering Collection. Gale.
• Chiras, Daniel D. "Invader Species." Grolier Multimedia Encyclopedia. Grolier Online, 2011.
• "Endangered Species." Current Issues: Macmillian Social Science Library. Detroit: Gale, 2010.

External links

• List of species with the category Endangered as identified by the IUCN Red List of Threatened Species
• Endangered Species from UCB Libraries GovPubs
• Endangered Species & Wetlands Report Independent print and online newsletter covering the ESA, wetlands and regulatory takings.
• USFWS numerical summary of listed species in US and elsewhere
• https://worldwildlife.org/species
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