The term "endangered" is used to describe species that are facing a very high risk of extinction in the wild. This can be due to a number of factors, including habitat loss, hunting, pollution, and climate change.
The International Union for Conservation of Nature (IUCN) is the international authority on the conservation status of species. The IUCN Red List of Threatened Species is the world's most comprehensive information source on the global extinction risk status of animal, plant and fungus species. It is a critical indicator of the health of the world's biodiversity.
The IUCN Red List categories and criteria are used to evaluate the extinction risk of thousands of species and subspecies. The categories are:
* Extinct (EX): No known individuals of the species remain alive.
* Extinct in the Wild (EW): The species survives only in captivity, with no populations remaining in their natural habitat.
* Critically Endangered (CR): The species faces an extremely high risk of extinction in the wild.
* Endangered (EN): The species faces a very high risk of extinction in the wild.
* Vulnerable (VU): The species faces a high risk of endangerment in the wild.
* Near Threatened (NT): The species is close to being considered Vulnerable, but is not yet classified as such.
* Least Concern (LC): The species is widespread and abundant, and is not considered to be at risk of extinction.
The IUCN Red List is a dynamic tool, and the status of species can change over time. This is because the factors that affect extinction risk can change, such as changes in habitat, hunting pressure, or pollution levels.
For example, the black rhinoceros was once classified as Vulnerable, but is now Critically Endangered due to poaching. The giant panda was once classified as Endangered, but is now Vulnerable due to conservation efforts.
The IUCN Red List is an important tool for conservationists and policymakers, as it helps to identify species that are most in need of conservation action.