Critically Endangered

An IUCN Red List Critically Endangered (CR) 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. As of 2021, there are 6,811 species that are considered to be Critically Endangered. This is out of the 120,372 species currently tracked by the IUCN.
The IUCN Red List provides the public with information regarding the conservation status of animal, fungi, and plant species. It divides various species into seven different categories of conservation that are based on habitat range, population size, habitat, threats, etc. Each category representing a different level of global extinction risk. Species that are considered to be Critically Endangered are placed within the "threatened" category.
As the IUCN Red List does not consider a species extinct until extensive, targeted surveys have been conducted, species that are possibly extinct are still listed as Critically Endangered. IUCN maintains a list of "possibly extinct" and "possibly extinct in the wild" species, modelled on categories used by BirdLife International to categorize these taxa.
Criteria for Critically Endangered Species.
To be defined as Critically Endangered in the Red List, a species must meet "any" of the following criteria (A–E) ("3G/10Y" signifies three generations or ten years—whichever is longer—over a maximum of 100 years; "MI" signifies Mature Individuals):
Causes.
The current extinction crisis is witnessing extinction rates that are occurring at a faster rate than that of the natural extinction rate. It has largely been credited towards human impacts on climate change and the loss of biodiversity. This is along with natural forces that may create stress on the species or cause an animal population to become extinct. The main causes for Critically Endangered species is the following.
Conservation.
A high percentage of species have become extinct and are considered to be Critically Endangered. Conservation methods are necessary in order to provide relief and recovery for species that are facing extinction. This is due to the declining rate of biodiversity as ecosystems collapse alongside its extinct and Critically Endangered species. It would take years before another species population would return to the habitat and increase its biodiversity rate. Conservation methods such as the following allow for human imposed threats of these Critically Endangered species to be lessened.