The federal Endangered Species Act (ESA) (16 U.S.C. 1531-1544) provides protection for plants and animals whose populations are dwindling to levels that are no longer sustainable in the wild. The Act sets out a process for listing species, which allows for petition from any party to list a plant or animal. Depending on the species, either the U.S. Fish and Wildlife Service or the National Marine Fisheries Service will determine whether listing the species is warranted. If it is warranted, the species will be listed as either threatened or endangered. The difference between the two categories is one of degree, with endangered species receiving more protections under the statute.
The ESA also requires that all federal agencies ensure that their actions will not jeopardize the continued existence of a listed species. These actions include actions on federal property, such as National Forests, and actions taken as a result of federal involvement, such as building a state highway where some of the monies come from the federal government. The federal agency develops an analysis of its actions and the potential impact on the listed species. The analysis is then reviewed either by the U.S. Fish and Wildlife Service or the National Marine Fisheries Service, depending on which agency has jurisdiction over the species in question. These agencies respond with a "Biological Opinion" as to the results of the federal action. The federal agency pursuing the action makes the final determination as to whether and under what conditions to go forward with an action.
Section 9 of the ESA prohibits the "take" of listed fish and wildlife species, but not plant species. This provision applies to every person. The definition of "take" includes, by regulation, "significant habitat modification or degradation that actually kills or injures wildlife." 50 C.F.R. § 17.3. Through these provisions, the ESA applies to all land throughout the United States. A landowner who wants to do something which isn't intended to take a listed animal but the action might still result in "take" can seek an incidental take permit through Section 10 of the ESA. The application for a Section 10 permit requires the development of a Habitat Conservation Plan (HCP). The plan must demonstrate how the landowner will minimize any impact on the listed animal and mitigate any impacts that might still result from the action.
The list of endangered and threatened species found on Service lands includes 180 species of animals and 78 species of plants. This includes such species as the bald eagle, peregrine falcon, piping plover, whooping crane, West Indian manatee, green sea turtle, eastern indigo snake, Wheeler's peperomia and others. Of the 257 threatened and endangered species found on wildlife refuges: 5 are amphibians, 57 are birds, 10 are clams, 4 are crustaceans, 30 are fish, 9 are insects, 43 are mammals, 20 are reptiles, 2 are snails, and 77 are plants.
(Always refer to the most current version of the law, either by checking the compiled laws, or referring to the U.S.Code Service site above.)