Endangered Species Act: An Overview


The Endangered Species Act (ESA) was enacted in 1973 for the purpose of providing federal protection to species of wildlife that are in danger of becoming extinct. Although the ESA is considered the most powerful piece of legislation dedicated to conserving wildlife, it is not the first piece of legislation with that purpose. In 1966, Congress passed the Endangered Species Preservation Act which authorized the Secretary of the Interior to put together a list of endangered species and provided the Fish & Wildlife Service (FWS) with $15 million per year to buy habitat for the species on that list. Three years later in 1969, Congress passed the Endangered Species Conservation Act which allowed the Secretary of Interior to list foreign species and prohibited the importation of products made from such species. The ESA ultimately replaced the 1969 Act, providing endangered species with more protection than any legislation that had come before it.

The ESA differentiates between “threatened” and “endangered” species; allows listing of a species that is only endangered through part of its range; allows the listing of plant and animal species; makes it illegal to “take” a species; and requires that when a species is listed for protection, its habitat has to be protected as well. The ESA is administered by two agencies, the U.S. Fish & Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS). FWS is in charge of administering the ESA for all terrestrial and freshwater species while NMFS administers the ESA for all marine species. The agencies are generally referred to as the listing agencies.

“Threatened” vs. “Endangered” Species

An important feature of the ESA is its distinction between endangered and threatened species. The ESA defines an endangered species as “any species which is in danger of extinction throughout all or a significant portion of its range.” A threatened species is defined as “any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” If a species is listed as endangered under the ESA, that species is provided the full protection of the Act. However, if a species is listed as threatened, then the listing agency has the authority to determine which protections should apply to each threatened species.

While listing a species as endangered provides the species with a greater protective status, there are two great benefits to granting a species threatened status. First, it provides the species with federal protection before the species reaches the point of near-extinction; second, if a species was initially listed as endangered, the threatened status allows the scaling back of ESA protection as the species recovers and is no longer in need of maximum protections.

“Take” and Take Permits

Perhaps one of the most well-known components of the ESA is the section 9 prohibition against take of a species. The term “take” under the ESA is quite broadly defined. The Act defines “take” as “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” The term “harm” is further defined by regulation as “an act which actually kills of injuries wildlife. Such an act may include significant habitat modification or degradation where it actually kills of injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding, or sheltering.”

When a species is listed as endangered under the ESA, any “take” of that species is expressly prohibited without a take permit. Take permits may be obtained by both public and private parties. A take permit authorizes a taking of a listed species provided that the take is incidental to some other lawful activity. These permits are usually very precise, detailing exactly which species is authorized for incidental take and how many individual members of that species will be covered by the permit. An incidental take permit will only be issued after completion of a Habitat Conservation Plan.

Listing and Delisting

Under the ESA, the appropriate Secretary (either the Secretary of Interior or the Secretary of Commerce depending on whether FWS or NMFS is handling the listing) makes the final decision about whether to list a species. When making a listing decision, the listing Secretary must base the decision solely on the best available scientific and commercial information. When evaluating a species for listing, there are many factors that the listing Secretary may consider including: damage to, or destruction of the species’ habitat; overutilization of the species for commercial, recreational, scientific, or educational purposes; disease or predation; inadequacy of existing protection. and other natural or manmade factors that affect the continuation of the species. Prior to 2019, economic considerations were not allowed to impact the listing Secretary’s decision-making. However, new regulations introduced in August of 2019 granted the Secretaries the authority to consider economic impacts when making listing decisions. The question of whether a species should be listed as threatened or endangered depends on the severity of its population decline and the threats to its continued survival.

Species may be listed on the initiative of the appropriate Secretary, but more commonly a species will be listed by a petition from an individual, group, or state agency. The ESA requires that “to the maximum extent possible,” FWS and NMFS must make an initial determination on a species’ status within 90 days of receiving a listing petition. The 90-day determination allows the agency to assess whether the petition provides sufficient information to support a finding that the petitioned action may be warranted. If the agency determines that the petition presents sufficient information, then the agency has 12 months to conduct a status review of the species. There are three possible outcomes of a status review: (1) the agency finds that the petitioned action is not warranted; (2) the agency finds that the petitioned action is warranted and listing proposal will soon be published in the federal registrar; or (3) the agency finds that the petitioned action is warranted, but the action will not take place because it is precluded by a species with a higher listing priority. As of September 13, 2019, there are 2,348 species listed as either threatened or endangered under the ESA.

Delisting – the act of removing a species from the list of threatened and endangered species – follows the same process as the initial listing decision. The decision to delist a species must be made solely upon the basis of the best available scientific and commercial information, with the decision-maker considering a number of factors including population size, stability of habitat quality and quantity, and control or elimination of threats. A species will typically be delisted when it has made a sufficient recovery, when new populations of the species are discovered making the species no longer in danger of becoming extinct, or if the species has suffered extinction. As of 2019, only 86 species have ever been delisted.

Critical Habitat

When a species is listed under the ESA, the listing agency must also designate critical habitat, unless publication of the species’ critical habitat would not be “prudent” because it would harm the species (for example, by encouraging poachers or vandals). Critical habitat is the geographic area that contains the physical or biological features essential to the conservation of the species that the area if designated for. Designation of critical habitat, like all listing decisions, must be made based on the best available scientific and commercial data. Unlike listing determinations, agencies have always been permitted to take economic factors into account when making critical habitat determinations.

Prior to 2019, critical habitat could be a geographical area already occupied by a listed species as well as a geographical area not currently occupied by a listed species so long as the area was necessary for the conservation of a species. However, regulations that were released in August of 2019 altered this rule so that a geographical area not containing a listed species could only be designated as critical habitat if a designation limited to geographical areas occupied by a species would be inadequate to ensure the conservation of the species.

Any area, whether federally or privately owned, may be designated as critical habitat. However, a critical habitat designation will only affect private land if some federal action is also involved. The ESA instructs all federal agencies to avoid destruction or adverse modification of critical habitat, either through direct action or through projects that they fund. This same prohibition is not placed upon private landowners who are only required to ensure that they not take a listed species.

Cooperation with Federal Agencies

Section 7 of the ESA requires that all federal agencies must promote the Act’s conservation purposes by consulting with FWS and NMFS to ensure that any federally authorized, funded, or direct action is not likely to jeopardize the continued survival of a listed species or adversely modify any critical habitat. The consultation process results in a document known as a Biological Opinion (BiOp) which details the affect the proposed federal project would have on any listed species within the project area. If FWS or NMFS concludes in a BiOp that a proposed project is like to place a listed species in “jeopardy,” then the consulting agency will offer “reasonable and prudent alternatives” about how the proposed project could be modified to avoid causing harm.

Recovery Plans

In addition to designating critical habitat, FWS and NMFS are tasked with developing recovery plans for every listed species. Recovery plans outline the steps needed to return a species to ecological health. The plans include when and where the steps will need to take place along with the estimated cost of recovery and a general timeline. However, neither the ESA or its regulations provide a large amount of detail on requirements for the recovery plans, and the plans are not binding on federal agencies.

Habitat Conservation Plans

Habitat Conservation Plans (HCP) are planning documents required under the ESA as part of an application for an incidental take permit. HCPs describe the anticipated effects of the proposed taking as well as how the impacts of the taking will be minimized or mitigated, and how the HCP will be funded. HCPs are primarily used by private parties carrying out otherwise legal activities that are likely to result in the take of a listed species.