On November 7, 2022, the U.S. Fish and Wildlife Service (Service) proposed to designate approximately 595,495 acres of critical habitat for the Southern Sierra Nevada distinct population segment (DPS) of fisher (Pekania pennanti) under the Endangered Species Act (ESA). The critical habitat designation would span six units in California’s Tuolumne, Mariposa, Madera, Fresno, and Tulare Counties. The majority of the land comprising these units is owned and/or managed by federal, state, or tribal governments.

The fisher is a small, carnivorous mammal native to North American boreal forests. It is closely related to the American marten (Martes americana) and Pacific marten (Martes caurina) and is a member of the weasel family. Fishers have few natural predators, but were historically prized for their pelts, and were nearly hunted to extinction in the early 20th century. Although conservation and protection measures have allowed some degree of rebound, fishers remain endangered under the ESA.

The Service had previously published a proposed rule on this same issue on October 19, 2021, and is now revising that proposal based on the information it received during the public comment period. The Service learned a new Fisher Reproductive Habitat Suitability Model (2021 Reproductive Model) had become available and made the determination that this model, along with the comments it received on site-specific habitat areas, had become the best available information upon which to base its critical habitat designation. The Service introduced a more inclusive definition of reproductive habitat in its updated proposal. It now defines suitable reproductive habitat as including intermixed denning, foraging and dispersal areas, and explains that such habitat provides structural features for parturition, raising kits, weather protection, foraging, and cover to reduce risk from predation. The updated critical habitat designation proposal sets aside an additional 41,041 acres of habitat when compared to the previous proposal.

The Federal Register notice states that the proposed rule will be open for comments until December 22, 2022. The Federal Register notice and supporting documents are available at regulations.gov, under Docket Number FWS-R8-ES-2021-0060.