The Endangered Species Act is perhaps the most famous and effective wildlife conservation law in the nation, but the Trump Administration has recently proposed a change that would significantly weaken the Act and put species at risk.
To understand the threat, it’s important to first understand how the Endangered Species Act works. Once a species is determined to deserve protection, the Act prohibits the “take” of that species. The official definition of “take” included in the Act covers a wide variety of actions, including harming, harassing, hunting, shooting, or collecting listed species.
But the word “harm” inside the ESA’s definition of “take” has been controversial. What, exactly, does it mean to “harm” an endangered species? Opponents of the Act want “harm” to mean something very narrow and direct, such as causing immediate injury to a species. Proponents of the Act understand that species are harmed by less-direct actions, including impacting the habitat that a species needs to survive. This latter, broader definition of “harm” is the definition that has been followed by the Federal Government since the Act’s passage in 1973.
It’s a critical question, because habitat loss is a major and growing threat to wildlife, and potential impacts to habitat are a more common threat than direct harassment or killing. For example, endangered Piping Plovers have long been a conservation priority for Maine Audubon. Some of the threats to Piping Plovers are direct, such as harassment by dogs. But other threats are impacts to Piping Plover habitat, such as ripping up dune grass, raking beaches without adequate spotting for nests, shoreline alteration , or stabilization projects. These habitat impacts may not cause immediate harm to Piping Plovers—the birds may not even be in Maine when the actions occur—but they undoubtedly cause harm to the plovers by destroying areas they need to nest and raise their young.
There are many such potential examples of habitat modification harming endangered species in Maine. Damming a river may destroy habitat for Atlantic Salmon despite not killing the fish directly. Altering forest habitat may degrade nesting, denning, or feeding features for Canada Lynx or Northern Long-eared Bat. The ESA as originally written understood that a species cannot survive without its habitat.
The Supreme Court agrees. The dispute over the word “harm” was argued in front of the Court in 1992, and it held that the broader definition was the right one. In Babbitt v. Sweet Home Chapter of Communities for a Great Oregon the Court held that habitat modification is a legitimate application of the word “harm.” According to Oyez.com:
…the Court determined that the ordinary meaning of harm would in fact include changes in habitat that hurt the endangered animals. Also, the Court held that the intent of the Act to give broad protection to endangered species must include even actions that may have minimal or unforeseeable effects.
That, for many decades, has been understood by all. The federal government, the implementers of the Endangered Species Act, buoyed by the Supreme Court’s endorsement of their definition of “harm,” continued to protect wildlife by regulating activities that both directly injured or killed animals or modified their habitat.
However, things appear to be changing. On April 17, 2025, the U.S. Fish and Wildlife Service and National Marine Fisheries Service jointly published a Notice of Proposed Rulemaking in the Federal Register titled “Rescinding the Definition of Harm under the Endangered Species Act.” The agencies say they are:
proposing to rescind the regulatory definition of “harm” in our Endangered Species Act … regulations. The existing regulatory definition of “harm,” which includes habitat modification, runs contrary to the best meaning of the statutory term “take.” We are undertaking this change to adhere to the single, best meaning of the ESA.
This about-face on that long-established and Supreme Court-backed definition of “harm” is a huge potential blow to American wildlife conservation. The proposed change would severely limit the scope of what is considered a “take” of a threatened or endangered species, potentially making it much easier to conduct activities that damage important habitat.
The conservation community strongly opposes these changes. Maine Audubon has submitted official comments (read them here), and is joining dozens of local and national organizations in signing letters opposing this change.
In addition to making our opposition known to those newly in charge of our federal wildlife agencies, it’s important for Maine’s Congressional delegation to know about Mainers’ support for the Endangered Species Act. To that end, we’ve launched this petition in support of the ESA that will help remind our representatives about the importance of this vital law.
