On November 27, 2018, the U.S. Supreme Court ruled that an area is eligible to be designated as “critical habitat” under the Endangered Species Act (ESA) only if the area is habitat for the relevant threatened or endangered species.  Weyerhaeuser Co. v. U.S. Fish and Wildlife Service, Dkt. No. 17-71.  The Court vacated the U.S. Court of Appeals for the Fifth Circuit’s decision, which held that the ESA has no habitability requirement, and remanded the case to the Fifth Circuit to consider the meaning of “habitat” under the ESA.  Additionally, the Court held that a decision by the U.S. Fish and Wildlife Service (Service) not to exclude an area from designated “critical habitat” is subject to judicial review.  These two holdings are likely to limit the Service’s expansive interpretation of its authority and provide the regulated community with the ability to challenge critical habitat designations where such actions have adverse economic consequences.

Under the ESA, “critical habitat” may include areas that are not currently occupied by a listed species, if the Service determines that such areas are “essential for the conservation of the species.”  When the Service designated critical habitat for the dusky gopher frog (Rana sevosa) in 2012, it identified four areas in Mississippi with existing frog populations and designated those areas as critical habitat.  But the Service determined that these four occupied areas were not adequate to ensure the frog’s conservation, and so also designated a 1544-acre area in Louisiana (described as “Unit 1”) as unoccupied critical habitat for the dusky gopher frog.  In doing so, the Service acknowledged that Unit 1 would not sustain the frog in its current condition, but concluded that the uplands forest, currently managed for timber production, could be restored to open canopy forest and made into suitable frog habitat with “reasonable efforts.”  Unit 1 is located on privately owned land and the owners of Unit 1 had no intention of converting the uplands to  frog habitat, as they were considering developing housing on the land, which is located not far from the New Orleans metropolitan area.

The landowners sought to have the critical habitat designation of Unit 1 vacated as inconsistent with ESA requirements and not supported by the administrative record.  They argued that, as a matter of law, an area cannot be “critical habitat” for a species if it is not currently habitable by that species, and that the unoccupied parcel in Louisiana is not habitable by the dusky gopher frog.  The critical habitat designation was upheld by the federal district court and a divided panel of the Fifth Circuit, which held (based only on the ESA’s definition of “critical habitat”): “There is no habitability requirement in the ESA or the implementing regulations.”

The Supreme Court rejected the suggestion that the criteria for unoccupied critical habitat are limited to the ESA’s definitions.  It looked instead to ESA section 4, the provision that directs the Service to designate critical habit, and stated its conclusion quite succinctly: “Only the ‘habitat’ of the endangered species is eligible for designation as critical habitat.”

The Supreme Court also concluded that the ESA’s definition of “critical habitat” allows the Service “to identify the subset of habitat that is critical, but leaves the larger category of habitat undefined.”  The Court noted the competing definitions of “habitat” offered by the Service and Weyerhaeuser (on behalf of the landowners of Unit 1).  The Service argued that habitat includes areas that, like Unit 1, require some degree of modification to sustain a species, while Weyerhaeuser, insisted that an area cannot be habitat if it cannot currently support a species.  The Court also noted the factual dispute between the parties regarding whether or not Unit 1 could currently support a dusky gopher frog population.  It remanded the case to the Fifth Circuit to consider those questions.

The Court’s limited holding that critical habitat must be habitat, reserving the meaning of habitat and the factual question of whether Unit 1 is habitat for the dusky gopher frog for further consideration by the lower courts, likely reflects the efforts of Chief Justice Roberts to find common ground and forge a unanimous decision among the eight justices who heard argument in the case.  Justice Kavanaugh, who was confirmed after the case was argued, did not participate in the decision.  With an eight justice panel, there was real potential for an even split on the question of whether an area must be currently habitable to be deemed critical habitat.  If the Supreme Court had split evenly, the Fifth Circuit’s holding that the ESA does not require habitability for critical habitat would have remained in place.  As the unanimous decision indicates, all the justices agreed that the Fifth Circuit was wrong on this central legal point and that critical habitat must be habitat.

The Supreme Court also overturned the Fifth Circuit’s determination regarding courts’ abilities to review a Service decision whether to exclude an area from critical habitat based on economic impacts.  The Fifth Circuit held that this determination is committed to agency discretion by law and not reviewable by the courts.  The Supreme Court reversed, holding that a Service decision to not exclude an area from critical habitat, like its decision to designate critical habitat areas, is reviewable for abuse of discretion.  This aspect of the decision is at least as important as the holding with respect to the definition of critical habitat, as it provides the regulated community with the ability to challenge the Service’s conclusions regarding the costs and benefits of excluding areas from critical habitat.