Southwest Center for Biological Diversity v. Babbitt

Opinion for the Court filed by Chief Judge HARRY T. EDWARDS.

HARRY T. EDWARDS, Chief Judge:

The only issue raised on appeal in this case is whether the Endangered Species Act (“Act”) requires the Fish and Wildlife Service to conduct an on-site population count of birds when the currently available data are sparse and calculations of a bird species population must of necessity be based on estimates. The Act provides that the Secretary of the Interior must make decisions whether to list a species as endangered or threatened “solely on the basis of the best scientific and commercial data available…