On April 17, 2025, the United States Fish and Wildlife Service (“FWS”) together with the National Marine Fisheries Service (“NMFS”) (collectively, “the Services”) introduced a proposed rule to rescind the regulatory definition of “harm” under the Endangered Species Act (“ESA”). The term “harm” is found in the ESA’s statutory definition of “take,” and for decades has been defined through regulation as an action that either kills or seriously injures protected wildlife through actions that include habitat modification. Removing the regulatory definition of “harm” would ultimately redefine what constitutes “take” of a species.
“Take” and the ESA
The ESA became law in 1973 for the primary purpose of conserving endangered species of wildlife and the ecosystems on which those species depend. 16 U.S.C. § 1531(b). The statute is implemented jointly by the Services who are responsible for identifying species of wildlife that should be protected by the Act. Species protected under the ESA are categorized as either “threatened” or “endangered” depending on the current risk the species is facing. A species will be listed as endangered if it is “in danger of extinction throughout all or a significant portion of its range,” or as threatened if it is “likely to become an endangered species within the foreseeable future.” 16 U.S.C. § 1532(6), (20).
Once a species is listed as threatened or endangered under the ESA, it receives the various protections that the Act has to offer. At the heart of those protections is the prohibition against “take” of a listed species. Under the ESA, it is “unlawful for any person” to “take” any listed species. 16 U.S.C. § 1538(a)(1)(B). The statute defines “take” as “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” 16 U.S.C. § 1532(19). The statutory definition of “take” is relatively broad, and when the Services adopted regulations to fully implement the ESA in 1975, they chose to further define some of the words included in the “take” definition. Specifically, the Services chose to define “harm” for the purposes of “take” as “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 behavior patterns, including breeding, feeding, or sheltering.” 50 C.F.R. § 17.3. In other words, since 1975 “take” of a species has included any activity that modifies or destroys the habitat of a protected species in such a way that the species essential behavior patterns are significantly impaired ultimately causing injury or death to the species.
Because the prohibition on “take” of a species applies to everyone, the current definition of “harm” can make it unlawful for a private party operating on private property to damage or destroy habitat for listed species unless the private party receives a permit from the Services authorizing “take” of a species.
Proposed Change
In mid-April, the Services published a proposal in the Federal Register to completely remove the regulatory definition of “harm” under the ESA. Instead of proposing a new or altered definition, the Services propose to rescind the definition entirely. Should the proposal become finalized, “take” of a species would no longer include activities that modify or degrade species habitat in such a way that species are actually killed or injured. While “take” would still prohibit activities that directly injure or kill wildlife through the term’s inclusion of the words “wound” and “kill,” rescinding the definition of “harm” would result in habitat modification or destruction no longer being considered a violation of the ESA.
In the explanation for why the change to the definition of “harm” has been proposed, the Services reference a Supreme Court case from 1995 known as Babbit v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687 (1995). In that case, a coalition of private landowners challenged the regulatory definition of “harm” under the ESA. While the Court ultimately upheld the definition, the Services claim that the Court never held that the regulatory definition of “harm” was the best meaning of the statutory text of the ESA, only that it was a permissible definition. Because the Babbit v. Sweet Home decision was based on the judicial doctrine of Chevron deference which the Supreme Court overturned in 2024 with its landmark ruling in Loper Bright Enters. v. Raimondo, No. 22-451 (2024), the Services conclude that rescinding the regulatory definition of “harm” is appropriate. To learn more about the Court’s decision in Loper Bright, click here. The Services also highlight the dissent in Babbit v. Sweet Home which was authored by Justice Scalia to support a more limited definition of “harm.” Because the Services rely on Babbit v. Sweet Home as part of their reasoning for rescinding the current regulatory definition of “harm,” it is helpful to take a closer look at the ruling.
Babbit v. Sweet Home Chapter of Communities for a Great Oregon
The group of plaintiffs that initiated Babbit v. Sweet Home was made up of small landowners, logging companies, and others who depended on the forest products industries in Oregon and the rest of the Pacific Northwest. They initially filed the lawsuit to challenge the regulatory definition of “harm,” arguing that the inclusion of habitat modification and degradation in the definition had injured them economically by limiting logging activities that would result in modification or destruction of habitat for the protected red-cockaded woodpecker and northern spotted owl. The plaintiffs argued that Congress did not intend for “take” to include habitat modification and that the word “harm” should be interpreted as applying only to a “direct application of force” taken against a member of a protected species.
Ultimately, the Supreme Court disagreed with the plaintiffs. According to the Court, there were three reasons why the text of the ESA did not support the definition of “harm” that the plaintiffs put forward. First, the statutory definition of “take” already included words such as “wound” and “kill” that prohibited a “direct application of force” taken against a protected species. According to the Court, if “harm” did not include both direct and indirect action, the word would have “no meaning.” Second, the Court found that the “broad purpose of the ESA” supports including habitat modification in the definition of “harm” because the text of the Act states that one of its primary goals is to “provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved.” 16 U.S.C. § 1531(b). Finally, the Court noted that Congress amended the ESA in 1982 to allow the Services to issue permits to authorize “take” of species that is incidental to otherwise legal activities. According to the Court, Congress understood that “take” of species was defined to include indirect injury as a result of otherwise lawful habitat modification and instead of changing the definition of “take,” it created a permit system that would instead authorize such activity in certain circumstances.
While the Supreme Court identified three reasons why it did not believe the text of the ESA supported the argument that “harm” should be limited to direct applications of force, the Court also relied on the doctrine of Chevron deference. Under that doctrine, if the language of a statute is ambiguous as to the intention of Congress, then an agency’s reasonable interpretation of the language should be upheld in court. In Babbit v. Sweet Home, the Supreme Court found that Congress granted the Services broad authority to interpret and enforce the ESA, and that the regulatory definition of “harm” was a reasonable interpretation of the statute. For those reasons, the Court upheld the definition of “harm” to include habitat modification.
The Babbit v. Sweet Home decision included a dissent authored by Justice Scalia. In that dissent, Justice Scalia argued that the regulatory definition of “harm” was not supported by the structure of the ESA.
Specifically, the dissent argued that the definition of “take” found in the text of the ESA contains a list of actions that describe “affirmative conduct intentional directed against a particular animal or animals.” In contrast, the regulatory definition of “harm” would include habitat modification that ultimately results in injury to protected wildlife even though that was not the intention of the activity. Justice Scalia claimed that the broader definition of “harm” would not be reasonable because the rest of the words used to define “take” refer to intentional actions such as intentionally wounding, killing, trapping, or pursuing a member of a protected species. Additionally, Justice Scalia claimed that defining “harm” to include habitat modification is not necessarily because the definition of “take” would already prohibit habitat modifications that are specifically intended to injure or kill a protected species.
Going Forward
A comment period on the proposal to rescind the regulatory definition of “harm” under the ESA is open through May 19, 2025. Should the proposal become finalized, it would mean that “take” under the ESA would no longer include acts that cause death or injury to protected wildlife as a result of significant habitat modification or degradation. Currently, it is not clear whether the Services intend to issue a new regulatory definition of “harm.” Whether a new definition is issued or not, it is likely that the final rule will be challenged in court.
To view the proposal and learn how to submit a comment, click here.
To read the Supreme Court’s decision in Babbit v. Sweet Home, click here.
To view the text of the ESA, click here.
For more National Agricultural Law Center resources on the ESA, click here.