Table 2. Summary of the Endangered Species Act (ESA) and its key provisions (Benson 2012).

Provision Description and enforceability
Policy mandate:
ESA Section 2 (16 U.S.C. § 1531)
The ESA has become a primary driver of many adaptive management efforts in the United States because of its uncompromising position against biodiversity loss. Its overall policy is to provide “a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved, to provide a program for the conservation of such endangered species and threatened species.” As a result, it operationalizes many key provisions that drive environmental protection.
Prohibition against take:
ESA Section 3 (16 U.S.C. § 1532)
The ESA protects endangered species from “take.” Take is broadly defined to include any actions that harm the species, including “habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavior patterns, including breeding, feeding, or sheltering.”
Critical habitat designation:
ESA Sections 3 and 4 (16 U.S.C. § 1532 (5)(A), 1533(a)(3)(A))
Once a species is listed, the appropriate wildlife agency has 1 yr to determine its “critical habitat.” Critical habitat is defined as: (1) specific areas within the geographical area occupied by the species at the time of listing, if they contain physical or biological features essential to conservation, and those features may require special management considerations or protection; and (2) specific areas outside the geographical area occupied by the species if the agency determines that the area itself is essential for conservation. Economic factors are considered in the designation. Alteration of critical habitat triggers the consultation requirement.
Consultation process:
ESA Section 7 (16 U.S.C. § 1536)
The law requires all federal agencies to consult with the appropriate wildlife agency to ensure that their actions are not likely to jeopardize the continued existence of listed species or result in destruction or adverse modification of critical habitat. Engagement in consultation is legally enforceable. The consultation process concludes with the wildlife agency issuing a Biological Opinion that includes appropriate measures that must be taken to avoid “take,” in addition to an incidental take permit.
Citizen enforcement mechanism:
ESA Section 11 (16 § U.S.C. 1540 (g))
Section 11 provides for civil and criminal penalties for ESA enforcement. Subsection (g) allows any citizen to petition for listing of a species and/or compel the government to perform nondiscretionary duties under the law (e.g., engage in consultation under Section 7).