How do species get on the endangered list?

The International Union for Conservation of Nature (IUCN) is the international authority on the conservation status of species. IUCN Red List criteria are used to evaluate the extinction risk of thousands of species and subspecies. The IUCN Red List 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.

Species are added to the endangered list based on a set of criteria that assess the risk of extinction. These criteria include:

* Population size: The size of the species' population is a key factor in determining its extinction risk. Species with small populations are more vulnerable to extinction than species with large populations.

* Population trend: The trend in the species' population size is also important. Species whose populations are declining are more likely to become extinct than species whose populations are stable or increasing.

* Geographic range: The geographic range of the species is also a factor in determining its extinction risk. Species with small geographic ranges are more vulnerable to extinction than species with large geographic ranges.

* Habitat quality: The quality of the species' habitat is also important. Species that live in degraded or fragmented habitats are more likely to become extinct than species that live in high-quality habitats.

* Threats: The presence of threats to the species, such as hunting, habitat loss, or climate change, is also a factor in determining its extinction risk.

Species are added to the endangered list when they meet one or more of these criteria. The IUCN Red List is updated regularly as new information becomes available, so the status of species can change over time.