A species present in such small numbers that it is at risk of extinction.
A plant or animal species existing in such small numbers that it is in danger of becoming extinct, especially such a species placed in jeopardy as a result of human activity. One of the principal factors in the endangerment or extinction of a species is the destruction or pollution of its native habitat. Other factors include overhunting, intentional extermination, and the accidental or intentional introduction of alien species that outcompete the native species for environmental resources.
A species of animal or plant in danger of becoming extinct.