Species are classified as critically endangered when they meet one of the following criteria:
* Population size: Fewer than 50 mature individuals remaining.
* Geographic range: Limited to a single location or a small number of isolated locations.
* Habitat quality: Severe fragmentation or degradation of habitat.
* Population trend: Rapidly declining population size.
Critically endangered species are considered to be in imminent danger of extinction and are often the focus of conservation efforts aimed at preventing their extinction. These efforts may include habitat conservation, captive breeding programs, and reintroduction projects.