Under the Endangered Species Act, the wildlife take definition reaches far beyond killing a protected animal. Section 3 of the Act defines “take” as ten specific actions against a listed animal: harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, plus any attempt to do any of those things. That last clause matters: a failed attempt is still a violation. The prohibition can pull in activities most people would never associate with wildlife law, from clearing trees on your own property to running equipment near a nest, and violations carry criminal fines up to $50,000, up to a year in prison, and civil penalties up to $25,000 per violation.
The Ten Prohibited Acts
Congress wrote the list at 16 U.S.C. § 1532(19) to be broad on purpose. The ten verbs cover the obvious conduct anyone would expect: shooting, trapping, hunting, wounding, killing. They also cover conduct that stops short of contact, like pursuing or harassing. And the attempt language sweeps in unsuccessful conduct that produced no injury at all.
The prohibition itself sits in Section 9 of the Act. It makes it unlawful for any person subject to U.S. jurisdiction to take any endangered species of fish or wildlife within the United States or its territorial sea. The only ways out are the exceptions the statute carves elsewhere, chiefly the Section 7 consultation process for federal actions and the Section 10 permit process for private parties.
What “Harm” and “Harass” Actually Mean
Two of the ten verbs do most of the work in real cases: “harm” and “harass.” Federal regulations at 50 C.F.R. § 17.3 define both terms well beyond their everyday sense.
“Harm” is an act that actually kills or injures wildlife. Significant habitat modification or degradation counts if it kills or injures wildlife by significantly impairing essential behavioral patterns like breeding, feeding, or sheltering. The word “actually” carries a lot of weight. Not every change to habitat qualifies. The modification has to produce real, demonstrable death or injury to identifiable animals.
“Harass” is an intentional or negligent act or omission that creates the likelihood of injury to wildlife by annoying it to the point of significantly disrupting normal behavioral patterns. Unlike harm, harassment doesn’t require proof that an animal actually died or was physically injured. Creating the likelihood of injury through serious disruption is enough. For captive wildlife, routine animal husbandry, breeding, and veterinary care that meet Animal Welfare Act standards are excluded from the harassment definition.
When Habitat Destruction Counts as Take
Whether destroying habitat could be an illegal take was contested for years. The Supreme Court settled it in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687 (1995). The Court upheld the regulatory definition of “harm” and confirmed that the take prohibition reaches conduct that destroys the environment a species depends on, not only conduct aimed at the animals themselves.
The Court also identified three built-in limits. The habitat modification has to be significant. It has to actually kill or injure wildlife. And the injury has to result from the modification. A landowner who clears timber and causes the death of a protected bird nesting in those trees is within the definition. A landowner whose property changes have no demonstrable effect on any identifiable animal is not.
Justice O’Connor’s concurrence added a proximate-cause requirement: the habitat modification must foreseeably cause the death or injury. A farmer whose fertilizer is carried by a tornado into a wildlife refuge and kills protected animals is not the proximate cause of that harm. A landowner who drains a pond and kills endangered fish living in it almost certainly is. The foreseeability limit keeps the regulation from reaching truly freakish chains of events.
Penalties for an Unauthorized Take
Section 11 of the Act splits enforcement into criminal and civil tracks, and the criminal track has two tiers depending on what was violated.
- A knowing violation of the take prohibition or other core Section 9 provisions carries fines up to $50,000 and up to one year in prison per violation.
- A knowing violation of other regulations issued under the Act carries fines up to $25,000 and up to six months in prison.
- Civil penalties run up to $25,000 for each violation, assessed by the Secretary without any criminal conviction.
The word “knowingly” matters on the criminal side. Prosecution requires proof that the person knew they were violating the law, a permit condition, or a regulation. Civil penalties don’t carry the same intent requirement, which is why they end up being the more common enforcement tool.
The Self-Defense Exception
The Act carves out a narrow exception for protecting human life. Under 16 U.S.C. § 1540(a)(3) for civil cases and § 1540(b)(3) for criminal cases, a person avoids penalties by showing a good-faith belief that they were acting to protect themselves, a family member, or any other person from bodily harm caused by an endangered or threatened species. In civil cases the standard is preponderance of the evidence. In criminal cases it functions as an affirmative defense.
The exception does not cover protecting property. If a listed predator is killing your livestock, this provision does not apply to you. For some threatened species and certain experimental populations, administrative regulations may offer more flexibility, but the statutory self-defense provision itself is limited to protecting people.
Which Species the Prohibition Covers
The blanket take prohibition applies directly to species listed as endangered. Any unauthorized take of an endangered animal violates Section 9 regardless of intent or circumstance.
Threatened species are handled differently. Section 4(d) directs the Secretary of the Interior to issue regulations “necessary and advisable” for the conservation of each threatened species. In practice, threatened species generally receive the same take protections as endangered species through a blanket rule, but a species-specific 4(d) rule can carve out exceptions for particular activities, such as certain forestry practices done under specified conditions. If you’re dealing with a threatened species, check the specific 4(d) rule for that species; the answer is not automatic.
One boundary that surprises people: the take prohibition applies only to animals. The Act defines “fish or wildlife” as members of the animal kingdom and defines “plant” separately. Section 9(a)(2) still makes it unlawful to remove or damage an endangered plant on federal land, to trade listed plants commercially across state lines, or to remove a listed plant from non-federal land in knowing violation of state law. But there is no federal take prohibition against destroying a listed plant on private land unless a state law independently forbids it and you knowingly violate that state law. Because “take” doesn’t apply to plants, there is also no incidental take permit for them.
How to Take Legally
Two mechanisms let take happen without violating Section 9. Which one applies depends on who is doing the activity.
Federal Actions: Section 7 Consultation
When a federal agency funds, authorizes, or carries out an action that may affect a listed species, it must consult with the U.S. Fish and Wildlife Service (for land and freshwater species) or NOAA Fisheries (for marine and anadromous species). If the action will cause some incidental take but is not likely to jeopardize the species, the consulting agency issues a biological opinion with an Incidental Take Statement. That statement specifies the amount or extent of take authorized and the non-discretionary terms and conditions the agency has to follow. Comply with those terms, and the incidental take is not treated as a Section 9 violation.
Private Parties: Section 10 Incidental Take Permits
Private landowners, developers, and other non-federal entities go through Section 10(a)(1)(B). The Secretary can issue an Incidental Take Permit when the take is incidental to, and not the purpose of, an otherwise lawful activity. The applicant submits a Habitat Conservation Plan addressing four statutory requirements:
- The likely impact on the species from the proposed taking.
- Steps the applicant will take to minimize and mitigate those impacts, plus the funding to do so.
- Alternatives considered and why they were rejected.
- Any additional measures the Secretary requires.
Before issuing the permit, the Service has to find that the taking will not appreciably reduce the likelihood of the species’ survival and recovery in the wild. The draft plan goes through public comment before final approval.
Permit holders also get assurances under the No Surprises Rule at 50 C.F.R. § 17.22(b)(5). If circumstances change after approval, the government cannot demand additional land, water, or financial commitments beyond what the plan required, as long as the permittee is properly implementing it. Related programs, including Safe Harbor Agreements for landowners who voluntarily improve habitat and Candidate Conservation Agreements with Assurances for species not yet listed, extend similar protections against future regulatory burdens for landowners who take on conservation obligations early.