Washington — Interior Narrows Endangered Species Act's 'Harm' Rule

A memo distributed to U.S. Fish and Wildlife Service field offices on September 14 instructs staff to stop treating accidental or incidental animal deaths as violations of the Endangered Species Act, according to Ars Technica, which reviewed reporting first published by The New York Times.

What does the FWS memo actually change?

FWS Director Brian Nesvik's memo redefines a "take" under the ESA to cover only conduct "specifically intending to target an animal," Ars Technica reported. The memo offers two examples: "A vessel that inadvertently strikes a whale has not taken it because the vessel's course was not set against the whale," and "Felling a tree is not a take of the bats roosting in it unless the tree is felled for the purpose of killing or capturing them." Previously, the ESA's harm prohibition covered habitat modifications that killed or injured protected species regardless of intent, requiring businesses to conduct environmental reviews, mitigate habitat damage, or obtain permits offsetting incidental deaths.

How does this differ from the earlier habitat rule change?

An earlier 2026 rule change removed habitat destruction from the ESA's definition of "harm," which the administration described as relief for landowners when animals were not directly endangered, Ars Technica reported. The September 14 memo goes further: it permits animals to be killed as a side effect of an action, so long as killing the animal was not the landowner's purpose. Earthjustice senior attorney Ben Levitan told Stateline, as cited by Ars Technica, that conservationists felt "falsely reassured" the habitat-definition change would not be used to excuse preventable deaths, calling the sequence "an incredibly sneaky and disingenuous way of going about things."

What legal reasoning does the administration cite?

The administration argues that a 1995 Supreme Court ruling interpreting the ESA to prohibit habitat modification causing harm was undercut by the Court's later decision ending the Chevron doctrine, which had given agencies deference to interpret ambiguous statutes, according to Ars Technica. The 1995 case is the origin point the administration is revisiting; Ars Technica notes the policy shift draws on reasoning associated with a 1995 dissent by Justice Antonin Scalia, who argued against the broader reading of harm that the majority adopted that year.

What are conservationists saying?

Advocates argue incidental takings are the most common way listed species die, meaning the memo could affect entire populations rather than isolated animals, Ars Technica reported. FWS did not respond to Ars Technica's request to clarify whether the policy has taken effect.

By the numbers

• September 14, 2026 — date of the FWS memo reinterpreting "take" under the ESA.
• 1995 — year of the Supreme Court ruling on habitat modification that the administration says the Chevron reversal undercuts.

What to watch

• Whether FWS confirms the memo is in effect or issues formal rulemaking.
• Litigation from groups such as Earthjustice challenging the reinterpretation.
• Whether Congress or courts revisit the 1995 precedent in light of the Chevron doctrine's end.
• Industry responses from sectors like shipping and forestry that face reduced permitting burdens.