Furthermore, the USFWS emphasized the intended application of best available information in making listing and critical habitat decisions. A Closer Look at the New Endangered Species Act Regulations www.lockelord.com | 2 of 4 Revisions to Regulations for Listing and Delisting Species and Designation of Critical Habitat Listing and Delisting of Species Section 4(b)(1)(A) of the ESA requires the Services to make listing determinations based “solely on the basis of the best scientific or 512-476-0891. [CDATA[// >