Habitat Conservation
Assistance Network
Proactive Conservation for Working Lands

The Endangered Species Act


Candidate Species: a species that is being reviewed for protection under the Endangered Species Act. This is a species that is not listed, but may become listed in the future.
Critical Habitat: the geographical area where the species resides plus areas outside the area where the species resides that is deemed essential for the conservation of the species. This is the area that contains the physical and biological features essential to the species’ conservation and may require increased management or protection.
Endangered Species: a species that is in danger of extinction throughout all or a significant portion of its range.
Listed: when the US Fish and Wildlife finds that a species requires protection under the Endangered Species Act, it ‘lists’ the species as either threatened or endangered.
Take: to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct. Significant habitat destruction that actually kills or injures a species is also considered a take.
Threatened Species: a species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.


The Endangered Species Act of 1973 (ESA) is a federal environmental regulation that promotes endangered and threatened species conservation. When enacting the law Congress found that “various species of fish, wildlife, and plants in the United States have been rendered extinct as a consequence of economic growth and development untempered by adequate concern and conservation.” Therefore, the ESA provides a means to preserve the ecosystems that endangered and threatened species rely on and create a program that develops plans for species recovery.

Listing Process:

The ESA is administered by the Secretary of the Interior, acting through the U.S. Fish and Wildlife Service, and the Secretary of Commerce, acting through the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service. In general, the FWS oversees terrestrial species and NMFS oversees aquatic species.

The ESA authorizes the Secretaries to list species as endangered or threatened and designate critical habitat area. If a species is listed as endangered the ESA prohibits the unauthorized take, possession, sale or transport of it, and provides the Secretaries with authority to acquire land, establish cooperatives, and initiate state conservation programs. A recovery plan will also be created, which guides conservation of the species habitat within the critical habitat area.

A species that is listed as threatened will be protected under the ESA to the extent to which the Secretaries deem it ‘necessary and advisable’. This means that they can create special rules (known as 4(d) rules) depending on what they think is needed to recover the species habitat and population. In general, 4(d) rules tend to offer the same protection as what is afforded endangered species, but can provide for exemptions.

A species may become listed by a petition from a nonfederal party or the Secretaries themselves. A listing will be based on the best scientific evidence available showing that there is substantial threat to the species habitat, the overuse of the species for commercial, recreational or scientific purposes, disease or predation, the lack of existing regulatory mechanisms, or other natural and manmade factors affecting the species existence.

Protections for Landowners:

The ESA has traditionally been applied to federal land and specifically obligates federal agencies to conserve listed species. Federal agencies must carry out programs for listed species and must consult with the Secretaries and preform extensive environmental reviews anytime an agency action may affect the recovery of a listed species or its habitat. This includes any time a federal agency authorizes, funds, or carries out an action.

However, more and more species that are being listed reside on private land. This has brought up heated debate on whether listing a species constitutes an unconstitutional taking of private land for public benefit without compensation. In order to diffuse some of this tension, the ESA has been interpreted to provide some protections for private landowners.

Some of the exemptions offered allow for the take of a species for scientific purposes and by Native Americans. There is also the option to apply for a permit that allows for the incidental take of the species. An incidental take permit is issued when the applicant develops a conservation plan that minimizes and mitigates the impact of the taking and will not significantly reduce the likelihood of species recovery.

The conservation plan is called a Habitat Conservation Plan, which describes the anticipated effects of the taking, how the impact will be minimized or mitigated, and how the plan will be funded. A HCP is required for issuing an incidental take permit and is generally included in a variety of other agreements that private landowners can enter in to receive protection from ESA regulations.

Candidate Conservation Agreements (CCAs) and Candidate Conservation Agreements with Assurances (CCAAs) are agreements that landowners can enter into with a regulatory agency before a species is listed, or when it is a candidate species. A CCA is a formal written agreement where participants voluntarily commit to implement agreed upon conservation actions in order to remove or reduce threats to a species. The goal is to conserve enough habitat so that it becomes unnecessary to list the species.

A CCAA is a similar agreement specific to non-Federal land. In a CCAA a landowner agrees to engage in voluntary conservation activities and receives assurances that they will not be required to implement additional conservation measures beyond what is agreed to in the CCAA. The ‘assurance’ is that if the species is listed the applicant will receive an incidental take permit and can continue to use their land according to the terms of the CCAA, even if it results in a take of the species.

Safe Harbor Agreements are agreements entered into after a species is listed. Like a CCAA, the agreement provides that if a non-Federal property owner initiates conservation practices on their land that contribute to the recovery of the listed species they will be assured that if they fulfill the terms of the agreement they will not be required to do any additional or different management activities.

Landowners may also consider participating in a conservation bank, which is permanently protected land that is conserved and managed specifically for a species. A landowner that places permanent protections on their land, such as a conservation easement, and manages it for a species can be approved for habitat or species credits issued by the U.S. Fish and Wildlife Service. These credits can be sold to developers or others that want to compensate for unavoidable adverse impacts they have on the species habitat elsewhere.