The Endangered Species Act: A Primer

M. Lynne Corn
Specialist in Natural Resources Policy

Kristina Alexander
Legislative Attorney

Eugene H. Buck
Specialist in Natural Resources Policy

The Endangered Species Act (ESA) protects species identified as endangered or threatened with extinction and attempts to protect the habitat on which they depend. It is administered primarily by the Fish and Wildlife Service, and by the National Marine Fisheries Service for certain marine and anadromous species. Dwindling species are listed as either endangered or threatened according to assessments of the risk of their extinction. Once a species is listed, legal tools are available to aid its recovery and to protect its habitat. The ESA can become the visible focal point for underlying situations involving the allocation of scarce or diminishing lands or resources, especially in instances where societal values may be changing, such as for the forests of the Pacific Northwest, the waters of the Klamath River Basin, or the polar environment. This report discusses the major provisions of the ESA, both domestic and international, and also discusses some of the background issues, such as extinction in general, and the effectiveness of the statute. 

The discussion is expanded for three aspects of the ESA and its implementation that have raised concerns and promoted debate—listing species, designating critical habitat, and consulting on projects. This report provides much of the context for understanding individual legislative initiatives discussed in CRS Report R40185, The Endangered Species Act (ESA) in the 111th Congress: Conflicting Values and Difficult Choices, by Eugene H. Buck et al. This report will be updated as circumstances warrant. .


Date of Report: January 26, 2010
Number of Pages: 26
Order Number: RL31654
Price: $29.95

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