Critical habitats are particular regions crucial to the conservation of an endangered species. The primary purpose of critical habitats is to protect these species in a secure area. It helps them to thrive safely without the threat of extinction.In the US, if the number of species decreases rapidly, the species must be listed as critically endangered under the Endangered Species Act (ESA) of 1973. Then Federal agencies can designate and authorize a specific place to be critical habitat for that species.