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Writing Videos for Kids: How to Evaluate Sources for Relevance

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Evaluating Websites   (for Elementary students)

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A.4.1, 4.2. 4.3
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What sources are reliable and relevant, and how do I know? Why do I need to cite my sources?

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How to Write a Research Paper for Kids | Episode 3 | Researching

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How to Write a Research Paper for Kids | Episode 2 | Making a Plan

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How to Write a Research Paper for Kids | Episode 1 | Brainstorming Topics

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How to Evaluate Sources for Reliability - Writing for Kids

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A citation or source citation is a reference to a published work (for example, a book, article, image, etc.,) that is used when creating a written work. It shows readers where specific pieces of information came from and where readers can locate it for themselves. It acknowledges or gives credit to the author who actually created the content being used in a paper. The opposite of a citation is plagiarism, or not giving credit to others for their ideas, concepts, or images. Plagiarism, especially in Academia, is considered taking the work of others and presenting it as one's own. The penalties for plagiarism can be severe. Source citations also give a work credibility. In other words, it shows the information is simply not made up.

What to cite

In general, different academic situations will have different rules for what to cite and how to cite it. Some use ← footnotes while others may require in-text (also called inline) source citations.( This is an inline source citation) Some may require a bibliography which lists all works that were used. In some cases, it may only be necessary to provide a list of "works cited." It is important to know in advance what protocols must be used and what citation style (see below) is preferred.

Quotations Anything taken word-for-word from a source must be shown in quotation marks (" "). The quotation must have a source citation showing where the quoted text came from.

For example: "Quality or junk? How do you want your research described by others?"

Paraphrase To paraphrase is to take someone's words or ideas and put them in the words of the person writing the paper. Anything paraphrased should be source cited. A paraphrase is usually about the same number of words as the original but does not use quotation marks.

Example (original text): "And there is only one fault so obvious, so fundamental, that it instantly brands a piece of work as the product of an amateur or careless researcher: poor source citations". Paraphrased: Poor quality source citations usually indicate that a piece of work is either careless research or the work of an amateur.

Summarize A summary is a short version of another work in the writer's own words. A summary is usually shorter than the original. When summarizing someone else's work, a source citation is necessary.

Example (original text): "When you don't know when to cite, you end up plagiarizing which is just a big word for stealing and that's mean. And when you plagiarize, you also get an "F" and people think, "Dude, that kid is one dumb bunny." Let's avoid that, shall we?" Summarized: When you do not understand source citations, it is easy to plagiarize someone else's work. So you do not get an "F" for your work, the following are the basic rules.

Facts and ideas Using facts and information to support an argument generally requires a source citation. Facts do not always need to be source cited, especially if they are commonly known (e.g. water freezes at 32 degrees Fahrenheit). Ideas, however, should always be cited.

What is not necessary to cite

You do not need to cite anything that is common knowledge. These are things that would be known by nearly everyone. Examples of common knowledge are:

But when in doubt, cite it.

Images for kids

xkcd webcomic titled "Wikipedian Protester". The sign says: "[CITATION NEEDED]".

In Spanish: Referencia bibliográfica para niños

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An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration.

Human activity is a significant cause in causing some species to become endangered.

Conservation status

The conservation status of a species indicates the likelihood that it will become extinct. Multiple factors are considered when assessing the 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 50% of the world's species are estimated to be at risk of extinction, but the frontier between categories such as 'endangered', 'rare', or 'locally extinct' species is often difficult to draw given the general paucity of data on most of these species. This is notably the case in the world Ocean where endangered species not seen for decades may go extinct unnoticed.

Internationally, 195 countries have signed an accord to create Biodiversity Action Plans that will protect endangered and other threatened species. In the United States, such plans are usually called Species Recovery Plans.

IUCN Red List

Though labeled 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. The species under the index include: mammals, birds, amphibians, cycads, and corals. 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. In 2012, the IUCN Red List listed 3,079 animal and 2,655 plant species as endangered (EN) worldwide.

Brazil is one of the most biodiverse countries in the world, if not the most. It houses not only the Amazon forest but the Atlantic forest, the savanna-like Cerrado among other biomes. Due to the high density of some of its well-preserved rainforests, wildlife trafficking, which along with deforestation is the one of the biggest endangerment drivers in Brazil, has become a challenge. The country has a broad legal system meant to protect the environment, including its Constitution, as well as several federal, state and local government agencies tasked with protecting the fauna and flora, fining individuals or companies linked to environmental crimes and confiscating illegally taken wildlife. Though such agencies can collect their data, each system operates relatively on its own when it comes to wildlife trafficking. However, both the agencies and the NGO's working in Brazil agree that the birds account for about 80% of trafficked species in the country.

The relation between wildlife smuggling, other environment crimes under the Brazilian law such as deforestation, and endangered species is particularly intricate and troubling since the rarer the animal or plant gets the most targeted and valuable they become in the black market, which leads to more endangered species in its turn.

Additionally, many environment experts and scientists point to the disbanding of environment agencies and the repeal of laws in Brazil under the presidency of Jair Bolsonaro as one of the reasons behind a surge in the number of endangered species. In one occasion during his presidency some fines totaling US $3.1 billion on environment criminals were revoked and at least one fine (related to illegal fishing) imposed on Bolsonaro himself was cancelled and the agent who fined him was demoted.

In the past, Brazil has successfully saved the endemic golden lion tamarin from extinction. Massive campaigns to raise awareness among people by NGO's and governments, which included printing depictions of the golden lion tamarin in the 20 reais Brazilian banknotes (still in circulation), are credited with getting the species out of the critically-endangered animals list.

In the United States

There is data from the United States that shows a correlation between human populations and threatened and endangered species. Using species data from the Database on the Economics and Management of Endangered Species (DEMES) database and the period that the Endangered Species Act (ESA) has been in existence, 1970 to 1997, a table was created that suggests a positive relationship between human activity and species endangerment.

Endangered Species Act

Under the Endangered Species Act of 1973 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. They are also responsible for adding a particular species to the list, which can be a long, controversial process.

Some endangered species laws are controversial. Typical areas of controversy include criteria for placing a species on the endangered species list and rules 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 areas; 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 was 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 kill and bury the animals or destroy habitat silently. 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 by wildlife scientists who work with the species as an effective recovery tool. 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 endangered species are under protection by government law. This approximation, however, does not take into consideration the species threatened with endangerment that are not included under the protection of laws like 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. Thus, in total, between seven and eighteen percent of the United States' known animals, fungi and plants are near extinction. This total is substantially more than the number of species protected in the United States under the Endangered Species Act.

Ever since humankind began hunting to preserve itself, over-hunting and fishing have been a large and dangerous problem. Of all the species who became extinct due to interference from humankind, the dodo, passenger pigeon, great auk, Tasmanian tiger and Steller's sea cow are some of the more well known examples; with the bald eagle, grizzly bear, American bison, Eastern timber wolf and sea turtle having been poached to near-extinction. Many began as food sources seen as necessary for survival but became the target of sport. However, due to major efforts to prevent extinction, the bald eagle, or Haliaeetus leucocephalus is now under the category of Least Concern on the red list. 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 attempt a reduction in whaling and increase population sizes. The actions include 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 such as Japan continue to hunt and harvest whales under the claim of "scientific purposes". Over-hunting, climatic change and habitat loss leads in landing species in endangered species list. It could mean that extinction rates could increase to a large extent in the future.

Endangered species are addressed through Canada's Species at Risk Act. A species is deemed threatened or endangered when it is on the verge of extinction or extirpation. Once a species is deemed threatened or endangered, the Act requires that a recovery plan to be developed that indicates how to stop or reverse the species' population decline. As of 2021, the Committee on the Status of Endangered Wildlife In Canada (COSEWIC) has assessed 369 species as being endangered in Canada.

The World Wide Fund-India raises concern in the longevity of the following animal species: the Red Panda, the Bengal Tiger, the Ganges River Dolphin, the Asian Elephant.

India signed the Wildlife Protection Act and the also joined the Convention on the International Trade in 1976, to prevent poaching from harming its wildlife.

Invasive species

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 exposure or resistance.

Conservation

Captive breeding

Main page: Captive breeding

Captive breeding is the process of breeding rare or endangered species in human controlled environments with restricted settings, such as wildlife reserves, zoos, and other conservation facilities. Captive breeding is meant to save species from extinction and so stabilise 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 resistance.

In 1981, the Association of Zoos and Aquariums (AZA) created a Species Survival Plan (SSP) to help preserve specific endangered and threatened species through captive breeding. With over 450 SSP Plans, some endangered species are covered by the AZA with plans to cover population management goals and recommendations for breeding for a diverse and healthy population, created by Taxon Advisory Groups. These programs are commonly created as a last resort effort. SSP Programs regularly participate in species recovery, veterinary care for wildlife disease outbreaks, and some other wildlife conservation efforts. The AZA's Species Survival Plan also has breeding and transfer programs, both within and outside of AZA - certified zoos and aquariums. Some animals that are part of SSP programs are giant pandas, lowland gorillas, and California condors.

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 conservation programs. 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". Although they commend the gradual replacement of turtles caught wild 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 animals caught wild are superior breeding stock. Turtle farmers may, therefore, seek and catch the last remaining wild specimens of some endangered turtle species.

In 2015, researchers in Australia managed to coax southern bluefin tuna to breed in landlocked tanks, raising the possibility that fish farming may be able to save the species from overfishing.

In Spanish: Especie en peligro de extinción para niños

IUCN Red List

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What Is An Endangered Species? | Kids Discover Online

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An endangered species is any type of plant or animal that is in danger of disappearing forever. If a species, or type, of plant or animal dies out completely, it becomes...

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Learn interesting information about endangered animals for kids. Find out which animals are endangered and improve your knowledge with DK Find Out.

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What is an "Endangered Species"?

An endangered species is an animal or plant that's considered at risk of extinction. A species can be listed as endangered at the state, federal, and international level. On the federal level, the endangered species list is managed under the Endangered Species Act.

The Endangered Species Act (ESA) was enacted by Congress in 1973. Under the ESA, the federal government has the responsibility to protect endangered species (species that are likely to become extinct throughout all or a large portion of their range), threatened species (species that are likely to become endangered in the near future), and critical habitat (areas vital to the survival of endangered or threatened species).

The Endangered Species Act has lists of protected plant and animal species both nationally and worldwide. When a species is given ESA protection, it is said to be a "listed" species. Many additional species are evaluated for possible protection under the ESA, and they are called "candidate" species.

Why We Protect Them

The Endangered Species Act is very important because it saves our native fish, plants, and other wildlife from going extinct. Once gone, they're gone forever, and there's no going back. Losing even a single species can have disastrous impacts on the rest of the ecosystem, because the effects will be felt throughout the food chain. From providing cures to deadly diseases to maintaining natural ecosystems and improving overall quality of life, the benefits of preserving threatened and endangered species are invaluable.

How a Species Gets Listed

When the U.S. Fish & Wildlife Service or the National Marine Fisheries Service is investigating the health of a species, they look at scientific data collected by local, state, and national scientists. In order to be listed as a candidate, a species has to qualify for protected status under the Endangered Species Act. Whether or not a species is listed as endangered or threatened then depends on a number of factors, including the urgency and whether adequate protections exist through other means.

When deciding whether a species should be added to the Endangered Species List, the following criteria are evaluated:

Has a large percentage of the species' vital habitat been degraded or destroyed?

Has the species been over-consumed by commercial, recreational, scientific or educational uses?

Is the species threatened by disease or predation?

Do current regulations or legislation inadequately protect the species?

Are there other man-made factors threatening the long-term survival of the species?

If the answer to one or more of the above questions is yes, then the species can be listed under the Endangered Species Act.

Species Protections

Once a species becomes listed as "threatened" or "endangered," it receives special protections by the federal government. Animals are protected from "take" and being traded or sold. A listed plant is protected if on federal property or if federal actions are involved, such as the issuing of a federal permit on private land.

The term "take" is used in the Endangered Species Act to include "harass, harm, pursue, hunt, shoot, wound, kill trap, capture, or collect, or to attempt to engage in any such conduct." The law also protects against interfering in vital breeding and behavioral activities or degrading critical habitat.

The primary goal of the Endangered Species Act is to make species' populations healthy and vital so they can be delisted from the Endangered Species Act. Under the Endangered Species Act, the U.S. Fish & Wildlife Service oversees the listing and protection of all terrestrial animals and plants as well as freshwater fish. NOAA's National Marine Fisheries Service oversees marine fish and wildlife. The two organizations actively invest time and resources to help bring endangered or threatened species back from the brink of extinction.

Endangered Species Day

Endangered Species Day, which falls on the third Friday in May each year, is a day to celebrate endangered species success stories and learn about species still in danger. Learn what the National Wildlife Federation is doing to protect endangered species and how to support Endangered Species Day.

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Endangered Species | National Wildlife Federation

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Learn how and why animals and plants are listed under the Endangered Species Act.

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An endangered species is a type of organism that is threatened by extinction. Species become endangered for two main reasons: loss of habitat and loss of genetic variation.

Loss of Habitat
A loss of habitat can happen naturally. Dinosaurs, for instance, lost their habitat about 65 million years ago. The hot, dry climate of the Cretaceous period changed very quickly, most likely because of an asteroid striking the Earth. The impact of the asteroid forced debris into the atmosphere, reducing the amount of heat and light that reached Earth's surface. The dinosaurs were unable to adapt to this new, cooler habitat. Dinosaurs became endangered, then extinct.

Human activity can also contribute to a loss of habitat. Development for housing, industry, and agriculture reduces the habitat of native organisms. This can happen in a number of different ways.

Development can eliminate habitat and native species directly. In the Amazon rain forest of South America, developers have cleared hundreds of thousands of acres. To "clear" a piece of land is to remove all trees and vegetation from it. The Amazon rain forest is cleared for cattle ranches, logging, and urban use.

Development can also endanger species indirectly. Some species, such as fig trees of the rain forest, may provide habitat for other species. As trees are destroyed, species that depend on that tree habitat may also become endangered. Tree crowns provide habitat in the canopy, or top layer, of a rainforest. Plants such as vines, fungi such as mushrooms, and insects such as butterflies live in the rain forest canopy. So do hundreds of species of tropical birds and mammals such as monkeys. As trees are cut down, this habitat is lost. Species have less room to live and reproduce.

Loss of habitat may happen as development takes place in a species range. Many animals have a range of hundreds of square kilometers. The mountain lion of North America, for instance, has a range of up to 1,000 square kilometers (386 square miles). To successfully live and reproduce, a single mountain lion patrols this much territory. Urban areas, such as Los Angeles, California, and Vancouver, British Columbia, Canada, grew rapidly during the 20th century. As these areas expanded into the wilderness, the mountain lion's habitat became smaller. That means the habitat can support fewer mountain lions. Because enormous parts of the Sierra Nevada, Rocky, and Cascade mountain ranges remain undeveloped, however, mountain lions are not endangered.

Loss of habitat can also lead to increased encounters between wild species and people. As development brings people deeper into a species range, they may have more exposure to wild species. Poisonous plants and fungi may grow closer to homes and schools. Wild animals are also spotted more frequently. These animals are simply patrolling their range, but interaction with people can be deadly. Polar bears, mountain lions, and alligators are all predators brought into close contact with people as they lose their habitat to homes, farms, and businesses. As people kill these wild animals, through pesticides, accidents such as collisions with cars, or hunting, native species may become endangered.

Loss of Genetic Variation
Genetic variation is the diversity found within a species. It's why human beings may have blond, red, brown, or black hair. Genetic variation allows species to adapt to changes in the environment. Usually, the greater the population of a species, the greater its genetic variation.

Inbreeding is reproduction with close family members. Groups of species that have a tendency to inbreed usually have little genetic variation, because no new genetic information is introduced to the group. Disease is much more common, and much more deadly, among inbred groups. Inbred species do not have the genetic variation to develop resistance to the disease. For this reason, fewer offspring of inbred groups survive to maturity.

Loss of genetic variation can occur naturally. Cheetahs are a threatened species native to Africa and Asia. These big cats have very little genetic variation. Biologists say that during the last ice age, cheetahs went through a long period of inbreeding. As a result, there are very few genetic differences between cheetahs. They cannot adapt to changes in the environment as quickly as other animals, and fewer cheetahs survive to maturity. Cheetahs are also much more difficult to breed in captivity than other big cats, such as lions.

Human activity can also lead to a loss of genetic variation. Overhunting and overfishing have reduced the populations of many animals. Reduced population means there are fewer breeding pairs. A breeding pair is made up of two mature members of the species that are not closely related and can produce healthy offspring. With fewer breeding pairs, genetic variation shrinks.

Monoculture, the agricultural method of growing a single crop, can also reduce genetic variation. Modern agribusiness relies on monocultures. Almost all potatoes cultivated, sold, and consumed, for instance, are from a single species, the Russet Burbank. Potatoes, native to the Andes Mountains of South America, have dozens of natural varieties. The genetic variation of wild potatoes allows them to adapt to climate change and disease. For Russet Burbanks, however, farmers must use fertilizers and pesticides to ensure healthy crops because the plant has almost no genetic variation.

Plant breeders often go back to wild varieties to collect genes that will help cultivated plants resist pests and drought, and adapt to climate change. However, climate change is also threatening wild varieties. That means domesticated plants may lose an important source of traits that help them overcome new threats.

The Red List
The International Union for Conservation of Nature (IUCN) keeps a "Red List of Threatened Species." The Red List defines the severity and specific causes of a species' threat of extinction. The Red List has seven levels of conservation: least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild, and extinct. Each category represents a different threat level.

Species that are not threatened by extinction are placed within the first two categories-least concern and near-threatened. Those that are most threatened are placed within the next three categories, known as the threatened categories-vulnerable, endangered, and critically endangered. Those species that are extinct in some form are placed within the last two categories-extinct in the wild and extinct.

Classifying a species as endangered has to do with its range and habitat, as well as its actual population. For this reason, a species can be of least concern in one area and endangered in another. The gray whale, for instance, has a healthy population in the eastern Pacific Ocean, along the coast of North and South America. The population in the western Pacific, however, is critically endangered.

Least Concern
Least concern is the lowest level of conservation. A species of least concern is one that has a widespread and abundant population. Human beings are a species of least concern, along with most domestic animals, such as dogs and cats. Many wild animals, such as pigeons and houseflies, are also classified as least concern.

Near Threatened
A near threatened species is one that is likely to qualify for a threatened category in the near future.

Many species of violets, native to tropical jungles in South America and Africa, are near threatened, for instance. They have healthy populations, but their rain forest habitat is disappearing at a fast pace. People are cutting down huge areas of rain forest for development and timber. Many violet species are likely to become threatened.

The definitions of the three threatened categories (vulnerable, endangered, and critically endangered) are based on five criteria: population reduction rate, geographic range, population size, population restrictions, and probability of extinction.
Vulnerable Species
Threatened categories have different thresholds for these criteria. As the population and range of the species decreases, the species becomes more threatened.

1) Population reduction rate
A species is classified as vulnerable if its population has declined between 30 and 50 percent. This decline is measured over 10 years or three generations of the species, whichever is longer. A generation is the period of time between the birth of an animal and the time it is able to reproduce. Mice are able to reproduce when they are about one month old. Mouse populations are mostly tracked over 10-year periods. An elephant's generation lasts about 15 years. So, elephant populations are measured over 45-year periods.

A species is vulnerable if its population has declined at least 50 percent and the cause of the decline is known. Habitat loss is the leading known cause of population decline.

A species is also classified as vulnerable if its population has declined at least 30 percent and the cause of the decline is not known. A new, unknown virus, for example, could kill hundreds or even thousands of individuals before being identified.

2) Geographic range
A species is vulnerable if its "extent of occurrence" is estimated to be less than 20,000 square kilometers (7,722 square miles). An extent of occurrence is the smallest area that could contain all sites of a species' population. If all members of a species could survive in a single area, the size of that area is the species' extent of occurrence.

A species is also classified as vulnerable if its "area of occupancy" is estimated to be less than 2,000 square kilometers (772 square miles). An area of occupancy is where a specific population of that species resides. This area is often a breeding or nesting site in a species range.

3) Population size
Species with fewer than 10,000 mature individuals are vulnerable. The species is also vulnerable if that population declines by at least 10 percent within 10 years or three generations, whichever is longer.

4) Population restrictions
Population restriction is a combination of population and area of occupancy. A species is vulnerable if it is restricted to less than 1,000 mature individuals or an area of occupancy of less than 20 square kilometers (8 square miles).

5) Probability of extinction in the wild is at least 10 percent within 100 years.
Biologists, anthropologists, meteorologists, and other scientists have developed complex ways to determine a species' probability of extinction. These formulas calculate the chances a species can survive, without human protection, in the wild.

Vulnerable Species: Ethiopian Banana Frog
The Ethiopian banana frog ( Afrixalus enseticola) is a small frog native to high-altitude areas of southern Ethiopia. It is a vulnerable species because its area of occupancy is less than 2,000 square kilometers (772 square miles). The extent and quality of its forest habitat are in decline. Threats to this habitat include forest clearance, mostly for housing and agriculture.

Vulnerable Species: Snaggletooth Shark
The snaggletooth shark ( Hemipristis elongatus) is found in the tropical, coastal waters of the Indian and Pacific Oceans. Its area of occupancy is enormous, from southeast Africa to the Philippines, and from China to Australia.

However, the snaggletooth shark is a vulnerable species because of a severe population reduction rate. Its population has fallen more than 10 percent over 10 years. The number of sharks is declining due to fisheries, especially in the Java Sea and Gulf of Thailand. The snaggletooth shark's flesh, fins, and liver are considered high-quality foods. They are sold in commercial fish markets, as well as restaurants.

Vulnerable Species: Galapagos Kelp
Galapagos kelp ( Eisenia galapagensis) is a type of seaweed only found near the Galapagos Islands in the Pacific Ocean. Galapagos kelp is classified as vulnerable because its population has declined more than 10 percent over 10 years.

Climate change is the leading cause of decline among Galapagos kelp. El Nino, the natural weather pattern that brings unusually warm water to the Galapagos, is the leading agent of climate change in this area. Galapagos kelp is a cold-water species and does not adapt quickly to changes in water temperature.

Endangered Species
1) Population reduction rate
A species is classified as endangered when its population has declined between 50 and 70 percent. This decline is measured over 10 years or three generations of the species, whichever is longer.

A species is classified as endangered when its population has declined at least 70 percent and the cause of the decline is known. A species is also classified as endangered when its population has declined at least 50 percent and the cause of the decline is not known.

2) Geographic range
An endangered species' extent of occurrence is less than 5,000 square kilometers (1,930 square miles). An endangered species' area of occupancy is less than 500 square kilometers (193 square miles).

3) Population size
A species is classified as endangered when there are fewer than 2,500 mature individuals. When a species population declines by at least 20 percent within five years or two generations, it is also classified as endangered.

4) Population restrictions
A species is classified as endangered when its population is restricted to less than 250 mature individuals. When a species' population is this low, its area of occupancy is not considered.

5) Probability of extinction in the wild is at least 20 percent within 20 years or five generations, whichever is longer.

Endangered Species: Siberian Sturgeon
The Siberian sturgeon ( Acipenser baerii) is a large fish found in rivers and lakes throughout the Siberian region of Russia. The Siberian sturgeon is a benthic species. Benthic species live at the bottom of a body of water.

The Siberian sturgeon is an endangered species because its total population has declined between 50 and 80 percent during the past 60 years (three generations of sturgeon). Overfishing, poaching, and dam construction have caused this decline. Pollution from mining activities has also contributed to abnormalities in the sturgeon's reproductive system.

Endangered Species: Tahiti Reed-warbler
The Tahiti reed-warbler ( Acrocephalus caffer) is a songbird found on the Pacific island of Tahiti. It is an endangered species because it has a very small population. The bird is only found on a single island, meaning both its extent of occurrence and area of occupancy are very small.

The Tahiti reed-warbler is also endangered because of human activity. The tropical weed Miconia is a non-native species that has taken over much of Tahiti's native vegetation. The reed-warbler lives almost exclusively in Tahiti's bamboo forests. The bird nests in bamboo and feeds on flowers and insects that live there. As development and invasive species such as Miconia destroy the bamboo forests, the population of Tahiti reed-warblers continues to shrink.

Endangered Species: Ebony
Ebony ( Diospyros crassiflora) is a tree native to the rain forests of central Africa, including Congo, Cameroon, and Gabon. Ebony is an endangered species because many biologists calculate its probability of extinction in the wild is at least 20 percent within five generations.

Ebony is threatened due to overharvesting. Ebony trees produce a very heavy, dark wood. When polished, ebony can be mistaken for black marble or other stone. For centuries, ebony trees have been harvested for furniture and sculptural uses such as chess pieces. Most ebony, however, is harvested to make musical instruments such as piano keys and the fingerboards of stringed instruments.

Critically Endangered Species
1) Population reduction rate
A critically endangered species' population has declined between 80 and 90 percent. This decline is measured over 10 years or three generations of the species, whichever is longer.

A species is classified as critically endangered when its population has declined at least 90 percent and the cause of the decline is known. A species is also classified as endangered when its population has declined at least 80 percent and the cause of the decline is not known.

2) Geographic range
A critically endangered species' extent of occurrence is less than 100 square kilometers (39 square miles). A critically endangered species' area of occupancy is estimated to be less than 10 square kilometers (4 square miles).

3) Population size
A species is classified as critically endangered when there are fewer than 250 mature individuals. A species is also classified as critically endangered when the number of mature individuals declines by at least 25 percent within three years or one generation, whichever is longer.

4) Population restrictions
A species is classified as critically endangered when its population is restricted to less than 50 mature individuals. When a species' population is this low, its area of occupancy is not considered.

5) Probability of extinction in the wild is at least 50 percent within 10 years or three generations, whichever is longer.

Critically Endangered Species: Bolivian Chinchilla Rat
The Bolivian chinchilla rat ( Abrocoma boliviensis) is a rodent found in a small section of the Santa Cruz region of Bolivia. It is critically endangered because its extent of occurrence is less than 100 square kilometers (39 square miles).

The major threat to this species is loss of its cloud forest habitat. People are clearing forests to create cattle pastures.

Critically Endangered Species: Transcaucasian Racerunner
The Transcaucasian racerunner ( Eremias pleskei) is a lizard found on the Armenian Plateau, located in Armenia, Azerbaijan, Iran, and Turkey. The Transcaucasian racerunner is a critically endangered species because of a huge population decline, estimated at more than 80 percent during the past 10 years.

Threats to this species include the salination, or increased saltiness, of soil. Fertilizers used for agricultural development seep into the soil, increasing its saltiness. Racerunners live in and among the rocks and soil, and cannot adapt to the increased salt in their food and shelter. The racerunner is also losing habitat as people create trash dumps on their area of occupancy.

Critically Endangered Species: White Ferula Mushroom
The white ferula mushroom ( Pleurotus nebrodensis) is a critically endangered species of fungus. The mushroom is critically endangered because its extent of occurrence is less than 100 square kilometers (39 square miles). It is only found in the northern part of the Italian island of Sicily, in the Mediterranean Sea.

The leading threats to white ferula mushrooms are loss of habitat and overharvesting. White ferula mushrooms are a gourmet food item. Farmers and amateur mushroom hunters harvest the fungus for food and profit. The mushrooms can be sold for up to $100 per kilogram (2.2 pounds).

Extinct In The Wild
A species is extinct in the wild when it only survives in cultivation (plants), in captivity (animals), or as a population well outside its established range. A species may be listed as extinct in the wild only after years of surveys have failed to record an individual in its native or expected habitat.

Extinct in the Wild: Scimitar-horned Oryx
The scimitar-horned oryx ( Oryx dammah) is a species of antelope with long horns. Its range extends across northern Africa. The scimitar-horned oryx is listed as extinct in the wild because the last confirmed sighting of one was in 1988. Overhunting and habitat loss, including competition with domestic livestock, are the main reasons for the extinction of the oryx's wild population.

Captive herds are now kept in protected areas of Tunisia, Senegal, and Morocco. Scimitar-horned oryxes are also found in many zoos.

Extinct in the Wild: Black Soft-shell Turtle
The black soft-shell turtle ( Nilssonia nigricans) is a freshwater turtle that exists only in one man-made pond, at the Baizid Bostami Shrine near Chittagong, Bangladesh. The 150 to 300 turtles that live at the pond rely entirely on humans for food. Until 2000, black soft-shell turtles lived throughout the wetlands of the Brahmaputra River, feeding mostly on freshwater fish.

Unlike other animals that are extinct in the wild, black soft-shell turtles are not found in many zoos. The shrine's caretakers do not allow anyone, including scientists, to take the turtles. The reptiles are considered to be the descendants of people who were miraculously turned into turtles by a saint during the 13th century.

Extinct in the Wild: Mt. Kaala Cyanea
The Mt. Kaala cyanea ( Cyanea superba) is a large, flowering tree native to the island of Oahu, in the U.S. state of Hawaii. The Mt. Kaala cyanea has large, broad leaves and fleshy fruit. The tree is extinct in the wild largely because of invasive species. Non-native plants crowded the cyanea out of its habitat, and non-native animals such as pigs, rats, and slugs ate its fruit more quickly than it could reproduce.

Mt. Kaala cyanea trees survive in tropical nurseries and botanical gardens. Many botanists and conservationists look forward to establishing a new population in the wild.

Extinct
A species is extinct when there is no reasonable doubt that the last remaining individual of that species has died.

Extinct: Cuban Macaw
The Cuban macaw ( Ara tricolor) was a tropical parrot native to Cuba and a small Cuban island, Isla de la Juventud. Hunting and collecting the birds for pets led to the bird's extinction. The last specimen of the Cuban macaw was collected in 1864.

Extinct: Ridley's Stick Insect
Ridley's stick insect ( Pseudobactricia ridleyi) was native to the tropical jungle of the island of Singapore. This insect, whose long, segmented body resembled a tree limb, is only known through a single specimen, collected more than 100 years ago. During the 20th century, Singapore experienced rapid development. Almost the entire jungle was cleared, depriving the insect of its habitat.

Extinct: Sri Lankan Legume Tree
The Sri Lankan legume tree ( Crudia zeylanica), native only to the island of Sri Lanka in the Indian Ocean, was a giant species of legume. Peas and peanuts are smaller types of legumes.

Habitat loss from development in the 20th century is the main reason the tree went extinct in the wild. A single specimen survived at the Royal Botanical Garden in Peradeniya, Sri Lanka, until 1990, when that, too, was lost.

Endangered Species and People
When a species is classified as endangered, governments and international organizations can work to protect it. Laws may limit hunting and destruction of the species' habitat. Individuals and organizations that break these laws may face huge fines. Because of such actions, many species have recovered from their endangered status.

The brown pelican was taken off the endangered species list in 2009, for instance. This seabird is native to the coasts of North America and South America, as well as the islands of the Caribbean Sea. It is the state bird of the U.S. state of Louisiana. In 1970, the number of brown pelicans in the wild was estimated at 10,000. The bird was classified as vulnerable.

During the 1970s and 1980s, governments and conservation groups worked to help the brown pelican recover. Young chicks were reared in hatching sites, then released into the wild. Human access to nesting sites was severely restricted. The pesticide DDT, which damaged the eggs of the brown pelican, was banned. During the 1980s, the number of brown pelicans soared. In 1988, the IUCN "delisted" the brown pelican. The bird, whose population is now in the hundreds of thousands, is now in the category of least concern.

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An endangered species is a type of organism that is threatened by extinction. Species become endangered for two main reasons: loss of habitat and loss of genetic variation.

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Species List | Endangered, Vulnerable, and Threatened Animals | WWF

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WWF is committed to saving endangered species. Learn more about the species we are working to protecting from becoming endangered or extinct.