WHEN DOES “HARM” BEGIN?
Can We Protect an Endangered Species Without Protecting What It Needs to Survive?
It seems like a simple question:
If the law prohibits killing an endangered animal, should it also protect the habitat that animal requires to survive?
For decades, federal regulations implementing the Endangered Species Act recognized that significant habitat modification could constitute “harm” when it actually killed or injured protected wildlife.
That is about to change.
On July 14, 2026, the U.S. Fish and Wildlife Service and NOAA Fisheries published a final rule rescinding the longstanding regulatory definition of one word:
“Harm.”
The change is scheduled to take effect September 14, 2026.
The administration argues that the previous interpretation extended the ESA’s prohibition on “take” beyond what Congress intended and that habitat remains protected through other provisions of the law.
But wildlife biology presents a different question:
What happens when an animal is protected from direct killing—but loses the habitat necessary to remain alive?
The law can redefine “harm.”
Biology cannot redefine survival.
WHAT IS CHANGING?
The Endangered Species Act prohibits the unauthorized “take” of protected wildlife.
Congress defined “take” to include actions such as:
harass – harm – pursue – hunt – shoot – wound – kill – trap – capture – collect
But Congress did not separately define “harm.”
Federal wildlife agencies did.
Under the longstanding regulation, “harm” meant an act that actually kills or injures wildlife. Importantly, that could include significant habitat modification or degradation when it actually killed or injured wildlife by significantly impairing essential behaviors such as breeding, feeding or sheltering.
That distinction is important.
The regulation did not make every alteration of endangered-species habitat an illegal “take.”
There had to be a connection to actual injury or death.
The new rule removes that regulatory definition entirely. The agencies say the statutory prohibition on “take” should focus on actions directed against animals rather than using “harm” to regulate habitat modification. (Federal Register)
THE SUPREME COURT HAS BEEN HERE BEFORE:
This isn’t a new legal debate.
In 1995, the U.S. Supreme Court considered the habitat component of “harm” in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon.
The Court upheld the government’s interpretation that significant habitat modification could constitute “harm” when it actually killed or injured protected wildlife. (Legal Information Institute)
That interpretation remained embedded in federal ESA regulations for decades.
The administration now takes a different position, arguing that the regulatory definition does not represent the best reading of the statute. (Federal Register)
HABITAT PROTECTION ISN’T DISAPPEARING:
This deserves emphasis.
The 2026 rule does not eliminate all habitat protection under the Endangered Species Act.
Section 7 remains intact. Federal agencies must still ensure that actions they authorize, fund or carry out are not likely to jeopardize listed species or destroy or adversely modify designated critical habitat.
Other habitat-conservation mechanisms also remain. (Federal Register)
But the ESA’s prohibition against unauthorized “take” applies much more broadly, including to private actors.
The question, therefore, isn’t whether the ESA will contain any habitat protection.
It’s whether habitat modification that actually kills or injures protected wildlife should continue to fall within the meaning of prohibited “harm.”
WHAT DOES THE SCIENCE SAY?
This is where the debate moves beyond statutory interpretation.
A scientific analysis highlighted by UC Davis examined threats affecting species listed under the ESA between 1975 and 2017.
Its finding was striking:
81% of listed species faced habitat loss or degradation as a primary threat.
Compared with:
17% primarily threatened by direct killing such as hunting or poaching. (UC Davis)
For many imperiled species, the greatest danger isn’t someone intentionally killing the remaining animals.
It’s losing the places where those animals can continue to live.
More recent scientific research continues to identify habitat loss, degradation and fragmentation as major drivers of declining populations and biodiversity.
Different species.
Different ecosystems.
Different studies.
But the biological principle remains remarkably consistent:
Wildlife cannot survive without the ecological conditions necessary for survival.
CONSIDER THE DIFFERENCE:
Imagine an endangered woodpecker.
Shooting the bird directly is clearly an act against the animal.
But what if the forest containing its nesting cavities, food and shelter disappears?
Consider an endangered salmon.
Killing the fish directly is clearly harm.
But what happens when alterations to its river eliminate the conditions necessary for spawning?
Or a sea turtle whose nesting habitat disappears?
From a legal perspective, policymakers and courts determine which actions fall within a statutory definition.
From a biological perspective, the distinction may mean very little to the animal.
SCIENCE AND LAW ARE ANSWERING DIFFERENT QUESTIONS
SCIENCE ASKS:
What happens to an endangered species when habitat necessary for feeding, breeding, shelter or survival is destroyed?
LAW ASKS:
When does causing that consequence legally constitute “harm” or “take”?
Science cannot determine what Congress intended a particular word to mean.
But changing the legal meaning of a word cannot change the biological consequences of habitat loss.
The law can redefine “harm.”
Biology cannot redefine survival.
SO WHERE DOES “HARM” BEGIN?
Does harm begin only when someone directly kills an animal?
Or can it begin when we eliminate the forest where it nests?
The river where it reproduces?
The food it requires?
The landscape connecting one population to another?
Those aren’t accessories to wildlife conservation.
They are the conditions that make wildlife possible.
The debate over the 2026 rule will undoubtedly continue.
The administration maintains that habitat conservation belongs elsewhere within the Endangered Species Act and that “take” should not be expanded through the regulatory definition of “harm.” (Federal Register)
Conservation scientists and legal experts have raised concerns that eliminating the longstanding interpretation removes an important mechanism for addressing habitat modification that actually kills or injures protected wildlife. (UC Davis)
But underneath that legal debate lies a much simpler scientific question:
Does habitat loss threaten wildlife survival?
The evidence overwhelmingly tells us that it can—and frequently does.
EVIDENCE SHOULD INFORM CONSERVATION:
Good wildlife policy should withstand scrutiny.
That means understanding what regulators actually changed.
Acknowledging what protections remain.
Considering competing legal interpretations.
And then asking what scientific evidence tells us about the consequences.
Science cannot write our laws for us.
But when laws are intended to protect wildlife, biology should matter.
Because ultimately:
You cannot protect wildlife without protecting what makes its survival possible.
Sources & Further Reading
U.S. Fish & Wildlife Service / NOAA Fisheries — Final Rule, Rescinding the Definition of “Harm” Under the Endangered Species Act, July 14, 2026; effective September 14, 2026.
U.S. Supreme Court — Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687 (1995).
UC Davis — How Redefining One Word Strips the Endangered Species Act’s Ability to Protect Vital Habitat, July 22, 2026.
Additional peer-reviewed research discussed examines habitat loss, degradation and fragmentation and their effects on wildlife populations and biodiversity.
Evidence • Education • Accountability
