Norton

The Defenders of Wildlife (“Defenders”) appeal from an order of the district court granting summary judgment in favor of the Secretary of the Interior (the “Secretary”). The order upheld a decision by the Secretary not to designate the flat-tailed horned lizard for protection as a threatened species under the Endangered Species Act (“ESA”). 16 U.S1C. § 1531 et seq. We find that, in making that decision, the Secretary both relied on an improper standard and failed to consider important factors relevant to the listing process. Accordingly, we find her decision arbitrary and capricious and reverse the district court’s order.

I. Background

The Endangered Species Act protects species of fish, wildlife and plants which the Secretary identifies as either “endangered” or “threatened.” A species is “endangered” if it “is in danger of extinction throughout all or a significant portion of its range.” 16 U.S.C. § 1532 (6). Similarly, a species is “threatened” if it “is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” 16 U.S.C. § 1532 (20).

If the Secretary decides that, based on “the best scientific and commercial…