A rule finalized Friday eliminates a 50-year-old regulatory definition that treated habitat destruction as harm to protected species — a change that legal groups say conflicts with a 1995 Supreme Court ruling and will face immediate court challenges from at least two major environmental organizations and 16 state attorneys general.
WASHINGTON — The Trump administration on Friday finalized a rule dismantling a foundational element of the nation’s landmark wildlife protection law, eliminating the regulatory definition that for five decades has treated significant habitat modification and degradation as illegal “harm” to endangered species under the Endangered Species Act of 1973.
The change, announced jointly by the Departments of the Interior and Commerce, means that oil and gas drilling, mining, logging, and other commercial development activities may now proceed on or adjacent to critical wildlife habitat — as long as animals are not directly killed or physically injured in the process. The destruction of the places where they live, breed, feed, and shelter will no longer trigger federal permitting requirements or consultations under the law’s enforcement framework.
Interior Secretary Doug Burgum framed the rule as a correction of what the administration characterized as decades of federal overreach, stating that agencies had “abused the ESA to obstruct lawful land use and burden American families and businesses,” and that the move “follows the statute Congress actually passed.” Commerce Secretary Howard Lutnick, whose department oversees the National Marine Fisheries Service, said the change would relieve fishermen from regulations he described as “overly broad and burdensome.”
Environmental and legal organizations reacted with immediate condemnation, and multiple groups signaled imminent lawsuits. Attorneys general from 16 states — including Arizona, California, Illinois and New York — denounced the rationale as “arbitrary, capricious, an abuse of discretion and contrary to law.”
“For the first time ever, a presidential administration now claims that species protected by the Endangered Species Act shouldn’t be safe from habitat modification that destroys where they live, raise their young, or search for food.” — Kristen Boyles, Earthjustice
A definition five decades in the making
The regulatory definition at the center of the dispute has its origins not in the 1973 act itself but in implementing regulations issued by the U.S. Fish and Wildlife Service beginning in 1975. Those regulations defined “harm” — one of ten verbs Congress used in the act’s prohibition on “taking” an endangered species — to include not only direct physical acts against individual animals, but also indirect injury caused by significant modification or degradation of their habitat.
The definition was refined in 1981 to add a threshold requirement: the habitat destruction had to actually kill or injure wildlife by significantly impairing essential behavioral patterns, including breeding, feeding and sheltering. That formulation — codified at 50 C.F.R. § 17.3 for the Fish and Wildlife Service and § 222.102 for the National Marine Fisheries Service — remained in force for more than four decades.
The definition’s legal authority was tested and upheld by the Supreme Court in 1995, in the case Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, in which a coalition of logging companies and landowners from the Pacific Northwest argued that including habitat modification within the meaning of “harm” extended the act beyond congressional intent. The Court ruled 6-3 that the broader definition was a permissible interpretation of the statute, relying in part on the Chevron doctrine of administrative deference. Justice Antonin Scalia dissented, joined by Chief Justice William Rehnquist and Justice Clarence Thomas, arguing that the definition was unsustainable even under that framework.
Legislative and legal timeline
The legal argument — and the Loper Bright factor
The administration’s legal justification rests heavily on the Supreme Court’s 2024 decision in Loper Bright Enterprises v. Raimondo, which overturned the 40-year-old Chevron doctrine that had required courts to defer to federal agencies’ reasonable interpretations of ambiguous statutes. In the Federal Register notice published when the rule was proposed in April 2025, the Fish and Wildlife Service argued that, freed from Chevron’s framework, the “single, best meaning” of the term “take” in the ESA does not encompass habitat modification — relying explicitly on Justice Scalia’s dissent in the 1995 Sweet Home case as a guide to correct statutory interpretation.
Environmental attorneys contest that reasoning sharply. Earthjustice attorney Kristen Boyles argued that the rule appears to conflict not only with the 1995 ruling itself but with other provisions of the ESA that explicitly reference habitat, including the act’s stated purpose of providing “a means whereby the ecosystems upon which endangered and threatened species depend may be conserved.” Cornell University wildlife policy professor Dr. Steve Osofsky put the practical implication plainly: “You can cut down the last forest species X needs to survive or drain the last body of water species Y persists in, and that’s no problem — since you are not directly harming the members of that species.”
Which species and industries are most affected
The rule’s effects will be felt most acutely in regions where commercially valuable industries — oil and gas extraction, mining, logging and large-scale agriculture — overlap with the ranges of listed species. The administration cited the dunes sagebrush lizard, listed as endangered by the Biden administration in 2024, as a concrete example of what it described as disproportionate regulatory burden in Texas’s Permian Basin, one of the most productive oil-producing regions in the world. The lesser prairie chicken, whose federal protections have drawn sustained opposition from farmers, ranchers and energy developers across New Mexico, Texas, Oklahoma, Kansas and Colorado, was also cited.
Conservation groups have identified a broader array of species likely to be affected. The monarch butterfly, whose overwintering forests in California provide habitat protected under the existing framework, faces potential loss of that legal shield. Whooping cranes — whose population fell to just 15 individuals by 1938 before federal protection enabled a partial recovery — depend on wetland stopover sites along a 2,500-mile migration corridor that the rule would now leave without federal habitat protection. Hellbenders, North America’s largest salamander, were proposed for ESA listing in 2024 and have already lost populations to habitat degradation in the same Appalachian watersheds affected by the change. Florida panthers, whose only remaining habitat protections under federal law came specifically from the harm-as-habitat-destruction framework, are also named as directly exposed.
The ESA is credited by conservation scientists and federal agencies with saving the bald eagle, the American alligator, the California condor, and dozens of other species from extinction. The National Mining Association, in comments submitted when the rule was proposed, had argued that the existing habitat-based harm definition immediately triggered costly federal consultation requirements “the mere threat of any habitat modification,” adding what the group characterized as unacceptable delay to project permitting.
Voices on the rule — on the record
- Doug Burgum, Interior Secretary: Said the rule “restores common sense, respects private property, provides much-needed certainty for landowners and follows the statute Congress actually passed.”
- Howard Lutnick, Commerce Secretary: Said the change would benefit fishermen who had suffered from “overly broad and burdensome regulations” and return the ESA to “its foundational purpose.”
- Kristen Boyles, Earthjustice attorney: Said the rule conflicts with the ESA’s own text and the 1995 Supreme Court ruling, adding: “If animals don’t have a place to live, they can’t live.”
- Aaron Weiss, Center for Western Priorities: Called it “one of the most horrific attempts to harm wildlife in American history and a gift to the oil barons and foreign mining companies.”
- Tara Zuardo, Center for Biological Diversity: Described habitat destruction as the “number one threat to endangered species” and said the rule opens the door to extinction-level outcomes.
- Dr. Steve Osofsky, Cornell University: Said the rule means an actor could legally destroy the last viable habitat for a listed species as long as no animal is directly struck or killed.
- 16 state attorneys general (including California, New York, Arizona, Illinois): Condemned the rule as “arbitrary, capricious, an abuse of discretion and contrary to law.”
Opposition, legal exposure and what comes next
Earthjustice and the Center for Biological Diversity both indicated they would file suit promptly, with the Center’s Noah Greenwald, endangered species co-director, having signaled the challenge in April when the rule was first proposed. The rule is expected to be published in the Federal Register early this week, at which point the 60-day window for legal challenges under the Administrative Procedure Act begins.
The rule exists within a broader pattern of ESA rollbacks by the administration. In March 2026, the Endangered Species Committee — a Cabinet-level body known informally as the “God Squad,” convened under a rarely-used provision of the act — voted unanimously to exempt all oil and gas drilling operations in the Gulf of Mexico from the ESA’s restrictions, a decision that conservation groups argue endangers the critically endangered Rice’s whale and multiple sea turtle species. That exemption also faces pending legal challenge.
The administration did not replace the rescinded “harm” definition with a new one, leaving the term undefined in federal regulation for the first time since 1975. The Fish and Wildlife Service stated that the act’s statutory language is sufficient on its own. Legal analysts at Harvard’s Environmental and Energy Law Program have noted that in the post-Loper Bright environment, courts will be required to determine for themselves what “harm” means under the ESA — a question that now appears destined for protracted litigation, potentially returning the issue to the Supreme Court.
Sources: U.S. Department of the Interior press release; Federal Register, 90 Fed. Reg. 16,102 (Apr. 17, 2025); Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687 (1995); Loper Bright Enterprises v. Raimondo (2024); Bloomberg Law; Reuters; NPR; CNN; ABC News; Harvard Environmental and Energy Law Program; Center for Biological Diversity; Earthjustice; American Veterinary Medical Association; University of Wyoming College of Law.
