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 statute. “Take” is defined by the ESA as to “harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” The term “harm” is not defined by the ESA; instead, USFWS and NMFS have each promulgated definitions of the term which captures, under certain circumstances, modifying habitat of ESA-listed species.

USFWS’ definition of “harm” was upheld by the U.S. Supreme Court (SCOTUS) in a case styled Babbitt v. Sweet Home Chapter of Communities for a Greater Oregon. In that case, SCOTUS upheld the definition applying Chevron deference. In the preamble to the Proposed Rule, the Services explain that following the recent SCOTUS decision in Loper Bright Enterprises v. Raimondo, which overturned Chevron deference, the Services took a fresh look at the “harm” definition and concluded that the definition does not “match the single, best meaning of the statute.”

The Services indicate in the preamble to the Proposed Rule that a new definition of “harm” will not be promulgated and that the rescission will not affect ESA permits that have been issued as of the date of any final regulation.