On August 17, 2012, the DC Circuit Court overturned a district court ruling that the Fish and Wildlife Service violated the Endangered Species Act (16 U.S.C. §1531 et seq.) by delisting the West Virginia Northern Flying Squirrel when several criteria in the squirrel's recovery plan remained unfulfilled. The court instead held that a recovery plan adopted pursuant to the ESA is not binding on the Secretary of the Interior when making delisting decisions.
The squirrel is native to West Virginia and Virginia, with its habitat historically consisting of the spruce-fir and northern hardwood forests of the southern Appalachian Mountains. In 1985, the Service determined that the squirrel was endangered, based on scientists’ documenting only ten living squirrels, and suggested that although the squirrels' population “may have been declining since the Pleistocene, ․ [t]heir decline ha[d] probably been accelerated through clearing of forests and other disturbances by people.” 50 Fed.Reg. 26,999, 26,999 (July 1, 1985).
The Service created a Recovery Plan for conservation and survival of the squirrel pursuant to Section 4(f) of the ESA. The Recovery Plan established the following criteria for determining when the squirrel would be removed from the list of endangered species:
- Squirrel populations are stable or expanding in a minimum of 80% of all Geographic Recovery Areas (GRAs) designated for the subspecies;
- Sufficient ecological data and timber management data have been accumulated to assure future protection and management;
- GRAs are managed in perpetuity to ensure: (a) sufficient habitat and (b) habitat corridors; and
- The existence of the high elevation forests on which the squirrels depend is not itself threatened by introduced pests or by environmental pollutants.
In 2002, the Service hired a biologist to study whether the squirrel should be delisted. A report was published in 2006 that concluded that the Recovery Plan, which had been created in 1990, did not have up to date recovery criteria, and that the squirrel did not meet the ESA's definition of endangered or threatened because it “persist[ed] throughout its historic range.”Based on that conclusion, the Service proposed to delist the squirrel. The Service further stated that the Recovery Plan was not binding in terms of delisting decisions because its criteria do not specifically address the five threat factors used for listing a species and that such plans are advisory documents and not regulatory documents. The Service emphasized its view that delisting the squirrel was appropriate because, among other things, monitoring data provided strong evidence of its continued presence throughout its range and habitat trends were moving in a positive direction in terms of forest regeneration and conservation.
Friends of Blackwater filed a complaint in the district court claiming (1) promulgation of the delisting rule violated the ESA by ignoring the objective: measurable criteria in the Recovery Plan; and (2) the rule itself was arbitrary and capricious because it was not based upon the best available science. The district court entered summary judgment for the plaintiff on the ground that the Service was bound by the criteria in the Recovery Plan and its decision to delist the squirrel without following those criteria therefore constituted a revision to that plan, made without going through notice and comment rulemaking as required by the ESA.
The circuit court overturned the district court decision, holding that the ESA requires that a decision to either list or delist a species be made on the basis of the five criteria established in Section 4(a)(1). While the ESA requires the Service to develop a recovery plan, it does not require the Secretary to consult the criteria in the Recovery Plan when making a delisting decision. As such, the court found that the Service's interpretation of the ESA to be a fair interpretation and therefore granted it deference pursuant to the Chevron test for statutory interpretation. 
Friends of Blackwater also argued that the Service's decision was arbitrary and capricious because it had relied on data on the species' “persistence,” rather than data on its population and population trends, and had also failed to adequately to explain its departure from the population-based criterion in the Recovery Plan, thereby violating the statutory requirement that it use the “best data available.” However, the court dismissed this argument, stating that the "best data available" standard does not compel the Service to commission new studies, but rather to rely on the best existing data available to the agency. In this case, the court found that the scientific estimates of the squirrel's population from the 2006 Report reasonably supported the Service's conclusion that the species' survival was no longer threatened by loss of habitat.
Finally, the Friends of Blackwater argued that the Service failed to conduct an independent analysis of the fourth statutory factor, “the inadequacy of existing regulatory mechanisms,” which it claimed must be analyzed without regard to whether there are any threats arising under the other provisions of Section 4(a)(1). The court quickly dismissed this argument, pointing out that it would be bizarre to require there to be a regulatory scheme protecting a species that was not threatened.