Conservation Groups Sue Trump Administration Over Delayed Pygmy Rabbit Listing Decision
Why It Matters
The pygmy rabbit, the world’s smallest rabbit species and a recognized indicator of sagebrush-steppe ecosystem health, faces an uncertain federal future in Wyoming and seven other western states. Two conservation organizations have now turned to the courts to force a federal decision that has remained unresolved for more than a year, arguing that further delay could put the species at greater risk before officials act.
What Happened
Western Watersheds Project and WildEarth Guardians filed a lawsuit on May 13 against the U.S. Fish and Wildlife Service, targeting what they describe as a missed statutory deadline. The Endangered Species Act requires the agency to issue a formal determination — known as a “12-month finding” — within one year of concluding that a listing petition presents substantial information warranting further review.
The Fish and Wildlife Service, during the final months of the Biden administration in early 2024, issued a preliminary “90-day finding” concluding there was substantial information suggesting that ESA protections for pygmy rabbits “may be warranted.” That preliminary finding triggered the one-year clock for a follow-up decision. More than a year later, no such determination has been issued.
Fish and Wildlife Service Director Brian Nesvik is named as the defendant in the groups’ 15-page complaint. The suit asks a federal judge to order the agency to issue the overdue determination by a court-set deadline. A spokesperson for the agency said it does not comment on active litigation.
The agency now has 60 days to respond to the legal filing, according to Greta Anderson, deputy director of the Western Watersheds Project. “With deadline lawsuits, you either met the deadline or you didn’t,” Anderson said in public remarks. “Hopefully, our lawsuit will compel them to address pygmy rabbit populations sooner rather than later.”
By the Numbers
- The agency’s internal listing workplan places a pygmy rabbit decision in fiscal year 2028 — roughly four years after the initial 90-day finding.
- Nearly 100 other species are ahead of the pygmy rabbit in the agency’s prioritization queue for fiscal years 2026 and 2027.
- Wyoming biologists surveyed 108 sites earlier this year and found evidence of pygmy rabbits at approximately half of them.
- The species has been documented across seven Wyoming counties, including Uinta, Lincoln, Sublette, Sweetwater, Fremont, Carbon, and Natrona.
- Environmental groups first petitioned for ESA listing of pygmy rabbits in 2003 — more than two decades ago.
Zoom Out
The lawsuit is part of a broader pattern of conservation organizations using ESA deadline litigation to compel federal action on species reviews that have stalled in the agency’s workplan backlog. The Fish and Wildlife Service manages listing decisions for hundreds of candidate species simultaneously, and resource constraints frequently push timelines beyond what the statute requires.
Pygmy rabbits share their habitat pressures with the sage grouse, another sagebrush-dependent species whose federal listing status has been contested for years. Both species face compounding threats from wildfire, the spread of invasive cheatgrass, and energy development across the interior West. The Fish and Wildlife Service’s own 2024 preliminary finding cited “compound effects of fire, cheatgrass, and climate change” as the primary drivers of concern for pygmy rabbits.
A newly documented threat adds urgency to the advocates’ position: rabbit hemorrhagic disease has been detected in Nevada, where populations near the town of Jiggs experienced a rapid decline. Anderson cited that disease outbreak as a reason federal wildlife managers need to assess current population status without further delay.
Wyoming’s pygmy rabbit numbers are considered relatively stable compared to other parts of the species’ range, and the state classifies the animal as a “species of greatest conservation need.” Researchers note, however, that the species is thermally sensitive and could lose portions of its habitat as temperatures rise. For context on Wyoming’s broader natural resource and energy landscape, see our recent coverage of Wyoming lawmakers mulling regulatory changes to meet growing electrical demand.
What’s Next
The Fish and Wildlife Service has 60 days to respond formally to the complaint. If a judge rules in the plaintiffs’ favor, the court would set a new deadline by which the agency must issue its 12-month finding — either proposing the pygmy rabbit for ESA listing or concluding that listing is not warranted. The agency’s current internal workplan does not anticipate that decision before fiscal year 2028, though court orders have historically accelerated similar reviews. A previous ESA petition for the broader pygmy rabbit species resulted in a denial, though the agency did grant “endangered” status to a genetically distinct, isolated population in Washington state.