A proposed policy for interpreting ‘significant portion of its range’for the US Endangered Species Act, 1973

摘要: The Endangered Species Act (ESA) defines an endangered species as being “in danger of extinction throughout all or a significant portion of its range…”(16 USC § 1532). The phrase “significant portion of its range”(SPR) has received considerable attention by academics, policy makers, and the courts. The Fish and Wildlife Service (FWS) has developed five interpretations of SPR over the past two decades. Each interpretation has been rejected by one or more court opinions. We show how the minimum requirements for an acceptable interpretation of SPR emerge from a synthesis of law and science. An element of this synthesis is science pertaining to the biodiversity crisis, which unambiguously indicates that the biodiversity crisis is fundamentally about the extirpation of most species from alarming portions of their historic range. As a result, a disturbingly large portion of Earth’s land has lost startlingly large portions of native fauna. These losses are a biodiversity crisis because ecosystem health depends on species manifesting their ecological value (sensu, 16 USC § 1531) but they cannot do so on unoccupied portions of their range. Another element of this synthesis is the ESA’s purpose (16 USC § 1532), which is clearly aligned with the aforementioned science and incontrovertibly extends beyond avoiding global extinction to also include preventing unacceptable harm to species’ ecological value which cannot be manifest on the portion of a species’ range from which it has been extirpated. The Service may have intended to fulfill this purpose (or some version of these purposes) through § 4 (a)(1) of the ESA (16 USC § 1533), which pertains to …