Habitat loss, disease, invasion of exotic species, and pollution are some of the reasons that native animal and plant species may face extinction. The Endangered Species Act of 1973 has afforded some measure of protection and recognized the aesthetic, educational, historic, and scientific value of these species. It also allows for the classification of species as threatened or endangered and mandates legal protection for species so listed.
Threatened species: Any species that is in danger of becoming endangered throughout its range.
Endangered species: Any species that is in danger of extinction throughout its range.
Candidate species: Any species that is likely to be added to the threatened or endangered list soon.