Endangered Species Law & Policy

On April 17, 2025, the U.S. Fish & Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS) (collectively, Services) published a notice in the Federal Register proposing to rescind the Services’ respective definitions of “harm” under the Endangered Species Act (ESA) (Proposed Rule). The notice indicates the Services will accept comments on the Proposed Rule until May 18.

Section 9 of the ESA prohibits “take” of endangered species and the Services have extended the “take” prohibition, by regulation, to many species listed as threatened under the ...

On March 29, 2025, the U.S. District Court for the Western District of Texas (District Court) vacated the Endangered Species Act (ESA) special 4(d) rule for the northern distinct population segment (DPS) of the lesser prairie-chicken (LEPC). The 4(d) rule had prohibited, in most circumstances, “take” of the species’ northern DPS. Plaintiffs challenged the 4(d) rule in a number of ways, including on grounds that the U.S. Fish and Wildlife Service (Service) should have considered the economic impact of the 4(d) rule prior to its promulgation. As a result of the vacatur, it ...

On February 6, the U.S. District Court for the Northern District of California sided with the Bureau of Reclamation (Reclamation) and plaintiffs Institute for Fisheries Resources, Pacific Coast Federation of Fishermen’s Associations, and the Yurok Tribe, in holding that an order governing Reclamation’s operation of Upper Klamath Lake (UKL) from the Oregon Water Resources Department (OWRD) is preempted by the Endangered Species Act (ESA). The order, issued in the midst of a recent drought to meet the needs of irrigators, mandated Reclamation to “immediately preclude or ...

Reversing the district court, a divided panel of the Ninth Circuit held that that the Bureau of Reclamation and a local water agency have discretion to release water from Twitchell Dam on the Santa Maria River on the Central Coast of California to comply with the federal Endangered Species Act. San Luis Obispo Coastkeeper v. Santa Maria Valley Water Conservation Dist. (Ninth Cir. No. 21-55479, Sept. 23, 2022). The court concluded that a 1958 federal law (P.L. 774) authorizing the operation of the dam for purposes other than irrigation, flood control, and water conservation provided ...

On June 24, 2022, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (collectively, Services) published a final rule rescinding the Trump administration’s 2020 final rule defining “habitat” for the purpose of informing designation of areas as “critical habitat” (2020 Rule) under the Endangered Species Act (ESA). In rescinding the definition of “habitat,” the Services explained they were removing an “excessive constraint” on the agencies’ ability to designate critical habitat under the ESA. Specifically, the Services ...

On June 4, 2021, the Biden administration announced its intent to rescind or revise several implementing regulations for the Endangered Species Act (ESA) finalized under the prior administration. The U.S. Fish and Wildlife Service (Service) has not yet published these proposed rules in the Federal Register, nor has the Service provided the exact dates when it intends to publish the proposed rules.

In its announcement, the Service indicates its intent to rescind regulations governing how the Service conducts critical habitat exclusion analyses under ESA section 4(b)(2) and how ...

On December 15, 2020, the U.S. Fish and Wildlife Service and National Marine Fisheries Service (collectively, the agencies) released a pre-publication version of a final rule providing a definition of “habitat” for the purpose of informing designation of areas as “critical habitat” under the Endangered Species Act.  The agencies released a proposed rule defining habitat in August 2020 in response to a unanimous decision by the U.S. Supreme Court in 2019 overturning a lower court decision that upheld a controversial determination of critical habitat by the U.S. Fish and ...