Critically endangered

A critically endangered species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. This means that these plants, animals, fungi, and other living things are in big trouble and could disappear forever if we don't help them.

As of March 2026, out of the 172,620 species on the IUCN Red List, 10,774 are listed as critically endangered. That means about 6 out of every 100 species on the list are in this very serious situation. Some of these might even already be gone, but we still list them as critically endangered until we are sure.

More than half of the critically endangered species are plants. There are also many animal species, some fungi, and a few chromista species that are in this danger zone. The IUCN Red List helps everyone understand how close these species are to disappearing and what we can do to protect them.

Criteria

A species is considered critically endangered if it meets any of these rules:

• Population size drop: If a species' population has dropped by ≥ 90% in the last 10 years or three generations, and the reasons for the drop are known and can be fixed. If the drop is ≥ 80% and the reasons aren't fully known or fixed, it also counts.

• Geographic range: If a species' area is very small (less than 100 km² or even 10 km^{2</sup;) and it's shrinking or fluctuating a lot, it can be critically endangered.}

• Very small population: If there are fewer than 250 mature individuals, and the numbers are falling by at least 25% in ten years or three generations, or if most live in one small group, it's critically endangered.

• Extremely small population: If there are fewer than 50 mature individuals, it's critically endangered.

• High risk of disappearing: If scientists calculate there's at least a 50% chance the species will disappear in the wild within 10 years or three generations, it's critically endangered.

Causes

Many plants and animals are at risk of disappearing because of changes made by humans. The biggest reason is when we destroy their homes, called habitats. This happens through things like pollution, building cities, and farming. When animals lose their homes, they struggle to find food and shelter, which makes their numbers go down.

Another reason some species are in danger is when new, foreign animals or plants are brought into an area. These invaders can take over and use up the resources that the native species need, which can push them toward extinction. Diseases can also be a problem. When a new sickness arrives in a place, animals that aren’t used to it may get very sick, which can cause their populations to drop.

Examples

Main article: Lists of IUCN Red List critically endangered species

Many animals and plants are in danger of disappearing forever. Some famous examples include the Vaquita, a small whale, and the Amur leopard, one of the world's rarest big cats. Birds like the Kākāpō and California condor are also at risk. Fish such as the Devils Hole pupfish, reptiles like the Hawksbill sea turtle, and special animals like the Axolotl are critically endangered too. The Wollemi pine is a rare plant that is also in danger.