On November 4, 2014, the U.S. District Court for the District of Arizona issued an opinion in Ctr. for Biological Diversity v. Jewell,2014 U.S. Dist. LEXIS 157436(D. Ariz.Nov. 4, 2014) finding that the Fish and Wildlife Service (FWS) did not abuse its discretion by finding that the Sonoran Desert population of bald eagles is not a distinct population segment. The Bald eagle was originally listed as an endangered species under the precursor to the Endangered Species Act (ESA) in 1967, after FWS found that less than 500 breeding pairs remained in 1963. Under ESA protections, the bald eagle’s numbers flourished, and nearly 10,000 breeding pairs existed in 2007. The bald eagle’s status was changed to threatened in all states in 1995. 60 Fed. Reg. 36,000 (pdf). Due to its remarkable recovery, FWS removed the bald eagle from the threatened list in 2007. 72 Fed. Reg. 37,346 (pdf).

As FWS was considering delisting the bald eagle in 2004, the Center for Biological Diversity (CBD) filed a petition seeking to have the Sonoran Desert population of bald eagles listed as a distinct population segment (DPS). Based on the information in CBD’s 2004 petition, FWS found that there was insufficient information that the Sonoran Desert population was a DPS. CBD challenged the FWS finding under the Administrative Procedures Act as “arbitrary and capricious” and succeeded in having FWS’s decision set aside by the Arizona District Court in 2008. Ctr. for Biological Diversity v. Kempthorne, 2008 U.S. Dist. LEXIS 17517 (D. Ariz. Mar. 6, 2008). The court’s 2008 decision rested largely on the fact that the FWS had been given “marching orders” from Washington D.C. officials to deny CBD’s petition. FWS was ordered to conduct a full status review of the Sonoran Desert population and to determine whether the Sonoran Desert population constitutes a DPS based on the status review.

In 2010, FWS issued its revised finding, again concluding that the Sonoran Desert population does not constitute a DPS. CBD again challenged FWS’s finding and succeeded in having it set aside for failure to follow the notice, comment, and consultation requirements of the ESA. Ctr. for Biological Diversity v. Salazar, 2011 U.S. Dist. LEXIS 138307 (D. Ariz. Nov. 30, 2011). The matter was again remanded to FWS to complete a new finding. FWS issued its finding on May 1, 2012, again concluding that the Sonoran Desert population is not a DPS and finding that the Sonoran Desert population is neither threatened nor endangered. 77 Fed. Reg. 25,792 (May 1, 2012) (pdf). CBD filed suit a third time, claiming that FWS 2012 finding regarding the significance of the Sonoran Desert population was arbitrary and capricious. CBD alleged that FWS’s analysis failed in four respects: (1) failure to follow its own policy for distinguishing DPS; (2) failure to consider all relevant evidence; (3) ignoring available scientific evidence; and (4) failing to consider the impact of climate change on bald eagles generally.

Determinations whether a species constitutes a DPS rest on three factors – the discreteness of the population (e.g. how isolated the population is), the significance of the population (e.g. whether or not a loss of the population would cause a gap in the range of the species), and the conservation status of the species and the population. CBD’s challenge focused on the second factor – significance – based on the fact that the Sonoran Desert population persists in an ecological setting unique for the species. FWS found, and the court agreed, that bald eagles are habitat generalists and occur in a wide range of habitats that are very dry, very wet, very hot, very cold, seaside, and inland. Based on that finding and the evidence supporting it, the court could not determine that the Sonoran Desert population was significant to the species as a whole. The court went on to find that FWS’s failure to include a 2009 memorandum’s statement to the contrary was neither arbitrary nor capricious as it represented only a “diversity of opinion by local or lower-level agency representatives.” Because FWS concluded, based on available scientific and commercial data, that the Sonoran Desert population possessed no unique adaptations or genetic characteristics allowing it to survive in warmer conditions, the court found no need for FWS to address climate change specifically. The court declined to address whether or not the population should have been listed as threatened or endangered, finding that the Sonoran Desert population did not qualify as a DPS and could therefore not be listed under the ESA.