An endangered species is a type of animal or plant that may disappear soon, either around the world or in a certain place. These species often face dangers like losing their homes, being hunted illegally, being harmed by non-native species, or changes in the environment caused by humans. The International Union for Conservation of Nature (IUCN) Red List shows the conservation status of many species worldwide, and other groups check the status of species in specific areas. Many countries have laws to protect species that need help, such as banning hunting or cutting down trees, limiting construction on land, or setting up protected areas. Some endangered species receive special care, like breeding them in captivity or fixing their habitats. Human actions are a major reason why species become endangered.

Conservation status

The conservation status of a species shows how likely it is to disappear. Scientists use many factors to decide a species' status, such as how many are left, whether their numbers are increasing or decreasing, how well they reproduce, and what dangers they face. The IUCN Red List of Threatened Species is the most well-known system worldwide for listing and ranking species' conservation status.

The IUCN Red List, created by the International Union for Conservation of Nature, groups species into nine categories based on rules like how quickly their numbers are dropping, how large their population is, how much area they live in, and how separated their groups are.

The list also includes species that have disappeared since 1500 CE. When talking about the IUCN Red List, the term "threatened" includes three groups: critically endangered, endangered, and vulnerable.

• Extinct (EX) – No living members are known
• Extinct in the wild (EW) – Survives only in captivity or outside its original habitat
• Critically Endangered (CR) – At the highest risk of disappearing in the wild
• Endangered (EN) – At a high risk of disappearing in the wild
• Vulnerable (VU) – At a high risk of disappearing in the wild
• Near Threatened (NT) – Likely to become endangered soon
• Conservation Dependent (CD) – Low risk, but needs protection to avoid becoming more at risk
• Least Concern (LC) – Very low risk, not likely to be threatened soon. These species are common and widespread
• Data Deficient (DD) – Not enough information is available to assess their risk
• Not Evaluated (NE) – Has not been checked against the criteria

More than half of the world's species are thought to be at risk of disappearing. However, it is often hard to decide where to draw lines between categories like "endangered," "rare," or "locally extinct" because there is not enough information about most species. This is especially true in the oceans, where large distances and lack of observation can make it hard to notice when species disappear.

Internationally, 195 countries have agreed to create Biodiversity Action Plans to protect endangered and other threatened species. In the United States, these plans are usually called Species Recovery Plans.

IUCN Red List

Although it is called a list, the IUCN Red List is a system used to evaluate the global conservation status of species. This system includes "Data Deficient" (DD) species, which are species that need more information and assessment before their situation can be understood. It also includes species that have been thoroughly evaluated by the IUCN's species assessment process. The species included in the index are mammals, birds, amphibians, cycads, and corals. Species with "Near Threatened" (NT) and "Least Concern" (LC) status have been assessed and found to have strong and healthy populations, even though these populations may be decreasing. The Red List uses the terms "endangered species" and "threatened species" with specific meanings: "Endangered" (EN) species are 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.

• The Siberian tiger is an Endangered (EN) tiger subspecies. Three tiger subspecies are already extinct (see List of carnivorans by population).
• Blue-throated macaw, a critically endangered bird.
• Brown spider monkey, a critically endangered mammal.
• Siamese crocodile, a critically endangered reptile.
• American burying beetle, an endangered species of insect.
• Kemp's ridley sea turtle, a critically endangered reptile.
• The Mexican wolf, the most endangered subspecies of the North American grey wolf. Approximately 143 are living in the wild.
• Pusa hispida saimensis, also known as Saimaa ringed seal, from 1956. Living only in Lake Saimaa, Finland, Saimaa ringed seals are among the most endangered seals in the world, with a total population of about 400 individuals.

In Brazil

Brazil is one of the most diverse countries in the world, with many different types of plants and animals. It includes the Amazon rainforest, the Atlantic forest, and the Cerrado, a grassland-like area, among other ecosystems. Because some of its rainforests are well-preserved, illegal trade of wildlife, which is a major threat to the environment along with deforestation, has become a serious problem. Brazil has laws to protect the environment, including its Constitution, and many government agencies at different levels that work to protect plants and animals, punish people or companies involved in environmental crimes, and take away illegally captured wildlife. While these agencies collect information, they often operate independently when dealing with wildlife trafficking. However, both government agencies and non-governmental organizations (NGOs) in Brazil agree that birds make up about 80% of the animals illegally traded in the country.

The connection between illegal wildlife trade, other environmental crimes like deforestation, and endangered species is complex and concerning. The rarer an animal or plant becomes, the more valuable it is in the black market, which leads to more species becoming endangered.

Some scientists and environmental experts say that the weakening of environmental agencies and the removal of certain laws during the presidency of Jair Bolsonaro contributed to an increase in endangered species. During his presidency, some fines totaling US$6.7 billion against environmental criminals were canceled, and at least one fine related to illegal fishing that was imposed on Bolsonaro himself was removed. The person who issued the fine was also demoted.

In the past, Brazil successfully helped save the golden lion tamarin, a species that was once close to extinction. Large efforts by governments and NGOs, including printing images of the golden lion tamarin on Brazilian 20-real banknotes (still in use today), are credited with helping the species move off the list of critically endangered animals.

In the United States

There is information from the United States that shows a connection between human populations and species that are at risk of disappearing. Using data from the Database on the Economics and Management of Endangered Species and the time period when the Endangered Species Act (ESA) was active, from 1970 to 1997, a table was made that suggests a link between human activity and species becoming endangered.

Carbon dioxide in Earth's atmosphere is said to be a major cause of animals becoming endangered. According to the US National Park Service:

Under the Endangered Species Act of 1973 in the United States, species can be listed as "endangered" or "threatened." The Salt Creek tiger beetle is an example of an endangered subspecies protected under the ESA. The US Fish and Wildlife Service and the National Marine Fisheries Service are responsible for classifying and protecting endangered species. They also decide which species are added to the list, a process that can be long and cause disagreement. The ESA includes other rules, such as identifying important habitats for endangered species and creating plans to help them recover. The ESA also stops endangered species from being harmed by government actions. For example, federal agencies must ask the Fish and Wildlife Service or the National Marine Fisheries Service for help before taking actions that could harm endangered species or their homes.

Some endangered species laws are debated. Common issues include the rules for adding a species to the endangered list and removing it once its population improves. There is also disagreement about whether rules that stop land development count as the government taking land and whether landowners should be paid for losing the use of their land. Other debates include making exceptions to protection laws. Groups like hunters and industries such as oil, construction, and logging have also made it harder to create endangered species laws.

The Bush administration stopped a rule that required federal officials to ask wildlife experts before taking actions that might harm endangered species. The Obama administration brought this rule back.

Being listed as an endangered species can sometimes cause problems because people might want to collect or hunt the species more because it is rare. This issue can be lessened, as seen in China, where farmed turtles help reduce the pressure to hunt wild turtles.

Another issue with listing species is that it may lead to people using a method called "shoot, shovel, and shut-up" to remove endangered animals from their land. Some landowners may think their land is less valuable if they find an endangered animal on it. They may kill the animals and hide them or destroy their homes to avoid problems. This action harms endangered species by reducing their numbers further. While some groups criticize the ESA for being too strict, many scientists believe it has helped save species. Nineteen species have recovered and been removed from the list, and 93% of listed species in the northeastern United States have stable or growing populations.

Currently, 1,556 endangered species are protected by government laws. However, this number does not include species that are at risk but not protected by laws like the ESA. According to NatureServe's global conservation status, about 13% of vertebrates (excluding marine fish), 17% of vascular plants, and 6 to 18% of fungi are in danger. This means between 7 and 18% of the United States' known animals, fungi, and plants are close to extinction. This total is much higher than the number of species protected under the ESA.

Since humans began hunting to survive, over-hunting and fishing have caused many species to go extinct. Some well-known examples include the dodo, passenger pigeon, great auk, Tasmanian tiger, and Steller's sea cow. Other species, like the bald eagle, grizzly bear, American bison, Eastern timber wolf, West African black rhinoceros, ivory-billed woodpecker, and sea turtle, were hunted almost to extinction. Many were hunted for food, but later became targets for sport. Due to conservation efforts, the bald eagle is now listed as "Least Concern" on the red list.

Today, over-hunting is still a problem in the oceans, where whale populations have dropped. Large whales like the blue whale, bowhead whale, finback whale, gray whale, sperm whale, and humpback whale are still on the Endangered Species List. Actions to reduce whaling and increase whale numbers include banning whaling in US waters, forming the CITES treaty to protect whales, and creating the International Whaling Commission (IWC). However, some countries, like Japan, continue to hunt whales under the claim of "scientific purposes." Over-hunting, climate change, and habitat loss contribute to species being listed as endangered. These factors could lead to more species becoming extinct in the future.

In Canada

Canada's Species at Risk Act helps protect animals and plants that are in danger of disappearing. A species is considered threatened or endangered if it is close to disappearing completely or no longer living in a specific area. When a species is classified as threatened or endangered, the Act requires that a recovery plan be created to help stop or reverse the decline in its population. As of 2024, there are 339 Canadian species listed as endangered by the IUCN Red List.

In India

The World Wide Fund-India expresses concern about the survival of the following animal species: the Red Panda, the Bengal Tiger, the Ganges River Dolphin, and the Asian Elephant. India has experienced very high rates of poaching and illegal animal trade, which endanger many species in the country. Since 1987, more than half of all tigers seized during illegal trade have been found in India. To protect wildlife, the government passed the Wildlife Protection Act and joined the Convention on the International Trade in 1976.

Introduced species

Introducing non-native species to an area can harm the ecosystem so badly that native species may become endangered. These species are often called introduced or invasive species. Sometimes, invasive species compete with native species for food or hunt them. In other cases, they may cause an imbalance in the ecosystem through hunting or other actions, leading to a sudden drop in the numbers of native species. New species can also bring diseases that native species have never encountered before. Oceania is especially affected because the invasive birds and mammals there have no natural predators. The danger from these species might be greater than expected because some threats to endangered species have not caused problems yet but could in the future.

Climate change

The World Wildlife Fund (WWF) says the Earth is warming faster than at any time in the past 10,000 years. This change forces species to adapt to new conditions, such as different rainfall patterns and longer, warmer summers. For example, the U.S. Fish & Wildlife Service works to study and reduce the effects of climate change on species through research, models, and conservation efforts. This includes checking how species are doing, how their genes differ, and how changes in their environment might affect their survival.

The International Union for Conservation of Nature (IUCN) reports that the 1 °C rise in Earth’s average temperature, caused by human activities, is harming species. This includes changes in how many species there are, how their genes differ, their behavior, and their chances of surviving. The IUCN says reducing CO₂ emissions through environmental policies is important to help species. Tools like the IUCN Red List and guidelines for evaluating how climate change affects species are key to conservation efforts.

Climate change can also cause species to leave areas where they used to live, either by moving to new places or dying out due to harsh conditions, invasive species, or habitat loss. A study by the WWF found that one out of every six species could go extinct from climate change if no action is taken. When species move to find new or shrinking homes, it shows how global warming directly affects biodiversity. Another problem is rising ocean acidity, caused by too much CO₂ in the air. This makes the ocean more acidic, creating a harmful environment for fish, plants, and important species like coral reefs.

For example, Emperor Penguins depend on Antarctic sea ice for breeding, shelter, and food. They are directly threatened by melting ice. Similarly, the Mount Rainier white-tailed ptarmigan, which lives on alpine mountain tops, loses habitat because of changes in snowfall and rising temperatures.

Another example is the Salton Sea in California. This area is important for many endangered and protected species, as well as migratory birds. However, climate change and farming in nearby areas have damaged the ecosystem. Rising temperatures have caused large amounts of water to evaporate, making the sea saltier and exposing more dry land. This harms air quality and has led to fish deaths, as shown in the image below. These changes have made the area unsuitable for birds and endangered species that rely on it.

Conservation

Captive breeding is when people breed rare or endangered animals in places like zoos, wildlife reserves, and other conservation centers. This method helps protect species from disappearing and keeps their populations stable.

This technique has been used for many years. One of the earliest examples was in the menageries of European and Asian rulers, such as the Père David's deer. However, it is often hard to use captive breeding for animals that move a lot, like some migratory birds (such as cranes) and fish (like hilsa). If the number of animals in a captive breeding program is too small, inbreeding can happen because there are not enough different genes, which weakens the animals’ health.

In 1981, the Association of Zoos and Aquariums (AZA) started the Species Survival Plan (SSP) to help save endangered animals through captive breeding. The SSP has over 450 plans that guide how to manage and breed animals to keep their populations healthy and diverse. These plans are usually used when other methods have failed. SSP programs also help with saving species from disease, protecting animals during emergencies, and working with other conservation efforts. Some animals in SSP programs include giant pandas, lowland gorillas, and California condors.

Poaching, which is illegal hunting, greatly reduces the numbers of endangered animals. However, legal, for-profit private farming has helped increase the populations of some animals, like the southern black rhinoceros and southern white rhinoceros. Richard Emslie, a scientist at the IUCN, explained that when animals are privately owned, it is easier to stop poaching. Local communities now have economic reasons to protect rhinos, such as through ecotourism or selling rhinos for profit.

Conservation experts are unsure about the effects of turtle farming in China and Southeast Asia on wild turtle populations. While more turtles raised in farms are being sold instead of wild ones (from about 30% in 2000 to 70% in 2007), some wild turtles are still captured to use as breeding stock. Farmers often believe that wild turtles make better parents, so they may catch the last wild turtles of endangered species.

In 2015, scientists in Australia successfully bred southern bluefin tuna in landlocked tanks. This achievement shows that fish farming might help save tuna from overfishing.

Some scientists suggest changing how recovery goals for endangered species are set if extinction seems likely. This change allows for more realistic goals but is used only after other methods fail. Strategies might include moving animals to better habitats, letting them breed with similar species, or accepting that modern populations may be smaller than in the past. For example, Florida panthers were helped by introducing cougars from Texas, creating hybrids that survived better in their environment.

Hawaiian monk seals are among the most endangered seals in the world. Conservation efforts have focused on reducing conflicts between humans and seals, treating injured seals, and closely watching their populations. These actions have slowly increased their numbers.

Bald eagles were once nearly extinct in the U.S. due to pesticides and habitat loss, with only 417 nesting pairs in 1963. By 2020, their numbers had grown to 71,400 nesting pairs. This recovery happened because of habitat protection, legal laws, and banning the pesticide DDT. Bald eagles are no longer listed as endangered.

In 1995 and 1996, 31 gray wolves from Canada were moved to Yellowstone National Park and kept in temporary enclosures before being released. This helped restore a key predator to the ecosystem, which changed how wildlife lived in the park. By 2017, gray wolves were no longer considered endangered in Montana, Idaho, and Wyoming.

Starting in 1999, the Channel Islands National Park began a recovery program for island foxes. Strategies included breeding them in captivity, removing golden eagles that harmed them, bringing back bald eagles, and removing non-native animals. This effort was the fastest recovery for an endangered mammal in the U.S. By 2016, three island fox subspecies were no longer endangered.

The Purple Emperor butterfly, found in the UK, has grown in numbers and expanded its range from southern England to much of the British Isles. Conservation groups helped by planting goat willows, a key food source for the butterfly’s young. Because the butterfly is territorial, many willows had to be planted over a large area. Groups like Butterfly Conservation made this recovery possible.

Gallery

• The sea otter is endangered, but it has a larger population than some other endangered animals.
• A photo from the 1870s shows American bison skulls. By 1890, overhunting caused the population to drop to 750.
• Knowlton cactus
• Loggerhead sea turtle
• Asian arowana
• Hawksbill sea turtle
• Cantor's giant softshell turtle
• The dhole, Asia's most endangered top predator, is very close to becoming extinct.