Indiana Law Journal

Document Type


Publication Date

Spring 2008

Publication Citation

83 Indiana Law Journal 529 (2008)


The U.S. Endangered Species Act requires the US. Fish and Wildlife Service to use the "best available" information when deciding whether to list species as threatened or endangered, and when regulating conservation for species already listed. The agency has discretion to determine the types, quantity, and quality of the information it uses as "best available, "but little discretion to defer decision making in cases where important scientific information is lacking. Complexities of nature, obscurity of many species' life history, and changing environmental circumstances are only some of the reasons why information is rarely complete, and why decisions are almost always made in the face of uncertainties. These uncertainties could lead to decision errors, and the consequences might be failure to prevent extinction or imposition of unnecessary regulatory requirements. Furthermore, real or perceived errors could lead to legal action and loss of the agency's credibility. This Paper discusses some recent examples of how the Fish and Wildlife Service has dealt explicitly with uncertainty in its administration of the Endangered Species Act.

Symposium: Missing Information: The Scientific Data Gap in Conservation and Chemical Regulation, held on March 24, 2006 at Indiana University School of Law- Bloomington.