ELR Citation: 55 ELR 20119
No(s). 24-5075 (D.C. Cir. Aug 22, 2025)

The D.C. Circuit affirmed summary judgment for FWS in a challenge to its rejection of a petition to remove the southwestern willow flycatcher from the list of endangered subspecies. A group of ranchers argued the southwestern willow flycatcher was not a valid subspecies and thus did not qualify for listing as an endangered species. The appellate court found the group's critique of the non-clinical geographical variation standard used by FWS for evaluating the appropriateness of the classification boiled down to disagreement with the Service's reasonable assessment of competing scientific studies, which survived arbitrary and capricious review. It further held FWS' decision not to delist the subspecies was reasonable, supported, and adequately explained, and that its decision as to what constituted the best available scientific evidence was well within its zone of expertise. It affirmed summary judgment for FWS.