## Facts

- The U.S. Fish and Wildlife Service (FWS) listed the coastal California gnatcatcher as a threatened species under the Endangered Species Act (ESA).
- ESA § 4 generally requires FWS to designate critical habitat concurrently with listing “to the maximum extent prudent and determinable.”
- FWS refused to designate critical habitat, finding designation “not prudent” for two reasons:
  - Publicly identifying habitat would allegedly increase deliberate destruction by landowners.
  - Most habitat was privately owned, so FWS concluded designation would provide little benefit because ESA § 7 consultation typically applies to federal actions.
- Conservation organizations and an individual plaintiff challenged the “not prudent” finding, citing ongoing development pressures affecting coastal sage scrub habitat.
- The district court granted summary judgment to the federal defendants; plaintiffs appealed.

## Issues

1. Whether FWS’s “not prudent” determination declining to designate critical habitat for the coastal California gnatcatcher complied with ESA § 4 and was supported by the administrative record under APA review.
2. Whether FWS may invoke speculative concerns about landowner preemptive habitat destruction or perceived limited benefit on private lands to avoid critical habitat designation.

## Decision

- The Ninth Circuit reversed the district court’s judgment for the defendants.
- The court held FWS’s “not prudent” finding was contrary to the ESA and arbitrary and capricious under the APA.
- The court rejected the “vandalism/destruction” rationale as speculative and unsupported by substantial evidence in the record.
- The court rejected the “no benefit on private lands” rationale as unreasonably discounting the effects of designation on federal planning, funding, permitting, and future federal involvement.
- The case was remanded with instructions that FWS designate critical habitat consistent with ESA § 4.

## Legal Principles

- Critical habitat designation concurrent with listing is the statutory default; the “not prudent” exception is narrow.
- An agency declining to designate critical habitat must provide a reasoned explanation grounded in record evidence and consistent with the ESA’s conservation purposes.
- Speculation about third-party reactions, without evidentiary support, cannot justify noncompliance with a statutory duty.
- Critical habitat designation may confer regulatory and practical benefits beyond direct effects on private land, including effects on federal actions and decisionmaking that intersect with private development.

## Conclusion

The Ninth Circuit required FWS to designate critical habitat for the coastal California gnatcatcher, holding that the agency could not avoid ESA § 4’s default duty based on unsupported predictions of landowner behavior or an unduly narrow view of the benefits of designation where habitat is largely privately owned.


Nat. Res. Def. Council v. U.S. Dep’t of the Interior, 113 F.3d 1121 (9th Cir. 1997)