Book excerpt: This report first outlines the ESA provisions most relevant to the act’s impacts on private property, and then surveys the major ESA-relevant principles of Fifth Amendment takings law. The report then proceeds to its core topic: the court decisions adjudicating whether government measures based on the ESA effect a taking of property under the Fifth Amendment. The cases address four kinds of ESA measures: (1) restrictions on land uses that might adversely affect species listed as endangered or threatened; (2) reductions in water delivery to preserve lake levels or instream flows needed by listed fish; (3) restrictions on the defensive measures a property owner may take to protect his/her property from listed animals; and (4) restrictions on commercial dealings in members of listed species.