In a published opinion (pdf) affirming the denial of preliminary injunctive relief, the U.S. Court of Appeals for the Ninth Circuit held that "there is no statutory mandate to consider cumulative effects during informal consultation."  Conservation Congress v. U.S. Forest Serv., No. 12-16452 (June 13, 2012).

In order to address issues in the Shasta-Trinity National Forest, the U.S. Forest Service proposed the Mudflow Vegetation Management Project (Project).  The Project included a variety of activities, including thinning, sanitation, and regeneration.  Because the Project area included designated critical habitat for the threatened Northern Spotted Owl (Strix occidentalis caurina), the Forest Service prepared a biological assessment (BA) analyzing the impacts of the Project on the Owl and its critical habitat.  The BA concluded that the Project "may affect, but is not likely to adversely affect" the Owl or its critical habitat.  Shortly after preparing the BA, per the requirements of section 7 of the Endangered Species Act (ESA), the Forest Service initiated informal consultation with the U.S. Fish and Wildlife Service.  The Fish and Wildlife Service subsequently concurred with the "not likely to adversely affect" determination, thereby ending the consultation process.  

Because of new literature, updated information, and a revision to the Owl's designated critical habitat, the Forest Service and Fish and Wildlife Service informally reconsulted two more times.  Each time the Forest Service concluded that the project was "not likely to adversely affect" the Owl or its critical habitat, and each time the Fish and Wildlife Service concurred in the Forest Service's determination. 

In 2011, the plaintiff filed a complaint in federal court alleging that the Forest Service and Fish and Wildlife Service violated the ESA and National Environmental Policy Act.  With respect to the ESA, the complaint alleged the Forest Service's BA failed to adequately evaluate the potential effects of the Project, and the Fish and Wildlife Service's concurrence with the "not likely to adversely affect" determination was arbitrary or capricious.  After filing the complaint, the plaintiff moved for preliminary injunctive relief in order to enjoin the Forest Service from proceeding with the Project.  The plaintiff argued that the Forest Service was required to perform a "cumulative effects" analysis as part of its informal consultation with the Fish and Wildlife Service, and the Fish and Wildlife Service improperly disregarded evidence demonstrating that the Project would adversely affect the Owl or its critical habitat.  The district court denied injunctive relief, and the plaintiff appealed.

The Ninth Circuit, interpreting section 7 and its implementing regulations, held that the plaintiff could not demonstrate a likelihood of success on the "cumulative effects" argument because "there is simply no statutory mandate to consider cumulative effects during informal consultation."  The Ninth Circuit reasoned that because the Fish and Wildlife Service promulgated regulations requiring the consideration of cumulative effects during the formal consultation process, and a similar regulation had not been promulgated for the informal consultation process, the consideration of cumulative effects during the informal consultation process was not mandatory.  In reaching this conclusion, the Ninth Circuit also distinguished prior Ninth Circuit precedent stating that the evaluation of cumulative effects is a crucial step in the section 7 consultation process, explaining that in those cases the Court was considering challenges to biological opinions issued through the formal consultation process.

The Ninth Circuit also made short work of the plaintiff's evidentiary argument, finding that in light of the totality of the evidence and the deferential standard of review, the defendants "reasonably concluded" that the Project was not likely to adversely affect the Owl or its critical habitat.  Accordingly, the Ninth Circuit affirmed the district court's denial of preliminary injunctive relief.