On July 14, 2026, the US Fish and Wildlife Service and the National Marine Fisheries Service issued a final rule rescinding the regulatory definition of “harm” under the Endangered Species Act.
The rule removes habitat modification from the scope of prohibited “take” under the act, marking a significant shift in how federal agencies interpret species protection law.
The final rule will become effective 60 days after publication, meaning it takes force on September 14, 2026, barring any successful legal challenge.
Under the Endangered Species Act, “take” is defined as “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.”
For decades, implementing regulations defined “harm” to include “significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding or sheltering.”
That longstanding interpretation was upheld by the Supreme Court in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon in 1995, partly on the basis of Chevron deference applied to agency rulemaking.
The dissent in that case, authored by Justice Scalia, argued that interpreting “take” to cover habitat modification represented too broad a reading of the statute.
The agencies now rely heavily on Justice Scalia’s dissent and the Supreme Court’s more recent decision in Loper Bright Enterprises v. Raimondo, which eliminated Chevron deference, to justify rescinding the prior definition.
In their view, “harm,” like the other verbs in the statutory definition of “take,” is better understood to require an affirmative act directed immediately and intentionally against a particular animal, not an act or omission that indirectly and accidentally causes injury to a population of animals.
The final rule rescinds the regulatory definition of “harm” in its entirety, with the agencies maintaining that a replacement regulatory definition is unnecessary given the clarity of the statutory text.
The revision is prospective only, and the agencies state the rule does not require that any prior permit or incidental take statement that relied on the prior definition of “harm” be reevaluated.
The rule preamble notes it may lessen existing burdens where a permittee “chooses to return their permit in order to not have to continue expending resources to mitigate” for habitat impacts previously considered “take.”
The final rule has already attracted legal challenges in three separate suits filed on the same day it was issued, brought by environmental organisations and two Native American tribes.
The Swinomish Indian Tribal Community and the Squaxin Island Tribe joined environmental non-governmental organisations in seeking declaratory and injunctive relief to declare the rule unlawful.
All three suits seek to set aside the rule under the Administrative Procedure Act, the Endangered Species Act, and the National Environmental Policy Act, with court decisions on emergency relief expected over the coming months.
For project developers, the practical effect is that incidental take authorisation will no longer be required for activities that result only in habitat modification, rather than direct harm to listed species.
Habitat modification can still be considered in section 7 consultations when evaluating whether a proposed action threatens the continued existence of listed species or the destruction of critical habitat.
Developers are advised to track pending litigation closely, as the outcome of legal challenges could affect the rule’s implementation and alter project planning strategies in the months ahead.