The Word That Protected Habitat: Inside the ESA 'Harm' Rescission

On 14 July 2026, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service published a final rule in the Federal Register removing a single regulatory definition from the books.

The word was harm. The definition had stood since 1975.

Its removal does not change one word of the Endangered Species Act itself. That distinction — between the statute Congress wrote and the regulation the agencies wrote to interpret it — is the whole story.

What the definition said

The Endangered Species Act makes it unlawful to "take" a listed species. Congress defined take in the statute: to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect."

Congress did not define harm. The agencies did, by regulation, in 1975:

Harm in the definition of "take" in the Act means an act which actually kills or injures wildlife. Such act may include significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding or sheltering.

The operative clause is the second sentence. It is the reason that, for five decades, bulldozing the last stand of a bird's nesting forest could be a violation even if no bird was ever touched.

The final rule strikes that definition from 50 CFR Part 17 (Fish and Wildlife Service) and 50 CFR Part 222 (National Marine Fisheries Service).

What the agencies say they did

The Department of the Interior framed the action as "restoring clear ESA enforcement" by rescinding what it called a "misguided" definition.

The stated legal basis is the Supreme Court's 2024 decision in Loper Bright Enterprises v. Raimondo, which ended Chevron deference — the doctrine that courts should defer to an agency's reasonable interpretation of an ambiguous statute. The agencies' position is that after Loper Bright they must apply the single best reading of the statute rather than an expansive regulatory gloss, and that the best reading of harm is an act directed at an animal, not at the place it lives.

The complication nobody disputes

There is a Supreme Court case directly on this definition.

In Babbitt v. Sweet Home Chapter of Communities for a Great Oregon (1995), the Court upheld the habitat-inclusive definition of harm as a reasonable interpretation of the statute. It was a 6–3 decision.

Sweet Home was decided under the Chevron framework that Loper Bright has since dismantled. That is the crux of the coming legal fight, and it is a genuinely contested question rather than a settled one:

• The agencies' view: Sweet Home upheld the definition as permissible under Chevron. It did not hold the definition was required. Remove Chevron and the agencies are free to read the statute afresh.
• The challengers' view: Sweet Home engaged the statute's text, structure and legislative history directly, not merely its ambiguity. A holding grounded in text survives the death of deference.

Neither reading is frivolous. A court will decide which is right.

The litigation

Earthjustice, with more than half a dozen environmental organisations, filed suit in federal district court in Seattle shortly after the rule was published.

What has not changed

Precision matters here, because both the loudest supporters and the loudest critics of this rule have reasons to overstate it.

Still fully in force:

• The statute. Congress's definition of take is untouched. "Harm" remains a prohibited act — it simply no longer carries a regulatory definition that names habitat modification.
• Section 7 consultation. Federal agencies must still consult with FWS/NMFS and must not jeopardise a listed species or destroy or adversely modify designated critical habitat. This is a separate statutory provision with its own machinery, and this rule does not touch it.
• Critical habitat designations themselves.
• State law. Several states have their own endangered-species statutes with their own habitat provisions.
• Other federal law. The Migratory Bird Treaty Act, the Marine Mammal Protection Act, the Clean Water Act and NEPA all continue to operate.

What changes: the reach of Section 9, which applies to everyone — private landowners and developers included, not just federal agencies. Section 7 only bites where there is a federal nexus. Section 9 is the provision that reached purely private conduct on private land, and habitat modification was how it did so.

That is the gap. It is narrower than "endangered species are no longer protected," and considerably wider than "nothing has changed."

An honest note on the effective date

Reporting diverges. Several outlets give 14 September 2026; others describe the rule as effective 60 days after publication, which computes to 12 September 2026. We have not resolved which is correct from the primary document and are not going to guess. The Federal Register entry is the controlling text.

Why this is on AEDO1

Roughly 1,300 species are listed as endangered or threatened in the United States — grizzly bears, Florida panthers, California condors, gray wolves, North Atlantic right whales among them. For most of them, the threat has never primarily been a person with a rifle. It has been the steady subtraction of the places they live.

Whether that subtraction is a federal offence is the question this rule reopens, and a court in Seattle will now answer it.