# Endangered and Threatened Wildlife and Plants; 12-Month Not-Warranted Finding for the Northern California-Southern Oregon Distinct Population Segment of Fisher
**AGENCY:**
Fish and Wildlife Service, Interior.
**ACTION:**
Notification of findings.
**SUMMARY:**
We, the U.S. Fish and Wildlife Service (Service), announce a 12-month finding on the status of the Northern California-Southern Oregon distinct population segment (NCSO DPS) of fisher ( *Pekania pennanti* ) under the Endangered Species Act of 1973, as amended (Act). The fisher is a mammal species in the weasel family found primarily in mature conifer and mixed hardwood forests. After a thorough review of the best available scientific and commercial information, we find that listing the NCSO DPS of fisher as an endangered or threatened species is not warranted at this time. However, we ask the public to submit to us at any time any new information relevant to the status of the NCSO DPS of fisher or its habitat.
**DATES:**
The findings in this document were made on August 25, 2025.
**ADDRESSES:**
A detailed description of the basis for this finding is available on the internet at *https://www.regulations.gov* under Docket No. FWS-R1-ES-2023-0123. Supporting information used to prepare this finding is also available for public inspection, by appointment, during normal business hours at the Oregon Fish and Wildlife Office. Please submit any new information, materials, comments, or questions concerning this finding to the person listed under *FOR FURTHER INFORMATION CONTACT* .
**FOR FURTHER INFORMATION CONTACT:**
Kessina Lee, Oregon State Supervisor, Oregon Fish and Wildlife Office, 503-231-6179, *[email protected].* Individuals in the United States who are deaf, deafblind, hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or TeleBraille) to access telecommunications relay services. Individuals outside the United States should use the relay services offered within their country to make international calls to the point-of-contact in the United States.
**SUPPLEMENTARY INFORMATION:**
**Background**
Under section 4(b)(3)(B) of the Act (16 U.S.C. 1533(b)(3)(B)), we are required to make a finding on whether or not a petitioned action is warranted within 12 months after receiving any petition that we have determined contains substantial scientific or commercial information indicating that the petitioned action may be warranted (“12-month finding”). We must make a finding that the petitioned action is: (1) not warranted; (2) warranted; or (3) warranted, but precluded by other listing activity. We must publish a notification of these 12-month findings in the *Federal Register* .
**Summary of Information Pertaining to the Five Factors**
Section 4 of the Act (16 U.S.C. 1533) and the implementing regulations at part 424 of title 50 of the Code of Federal Regulations (50 CFR part 424) set forth procedures for adding species to, removing species from, or reclassifying species on the Lists of Endangered and Threatened Wildlife and Plants (Lists). The Act defines “species” as including any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature. The Act defines an “endangered species” as a species that is in danger of extinction throughout all or a significant portion of its range (16 U.S.C. 1532(6)) and a “threatened species” as a species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range (16 U.S.C. 1532(20)). Under section 4(a)(1) of the Act, the Secretary of the Interior (Secretary) may determine whether any species is an endangered species or a threatened species because of any of the following five factors:
(A) The present or threatened destruction, modification, or curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued existence.
These factors represent broad categories of natural or human-caused actions or conditions that could have an effect on a species' continued existence. In evaluating these actions and conditions, we look for those that may have a negative effect on individuals of the species, as well as other actions or conditions that may ameliorate any negative effects or may have positive effects.
We use the term “threat” to refer in general to actions or conditions that are known to or are reasonably likely to negatively affect individuals of a species. The term “threat” includes actions or conditions that have a direct impact on individuals (direct impacts), as well as those that affect individuals through alteration of their habitat or required resources (stressors). The term “threat” may encompass—either together or separately—the source of the action or condition or the action or condition itself.
However, the mere identification of any threat(s) does not necessarily mean that the species meets the statutory definition of an “endangered species” or a “threatened species.” In determining whether a species meets either definition, we must evaluate all identified threats by considering the species' expected response and the effects of the threats—in light of those actions and conditions that will ameliorate the threats—on an individual, population, and species level. We evaluate each threat and its expected effects on the species, then analyze the cumulative effect of all of the threats on the species as a whole. We also consider the cumulative effect of the threats in light of those actions and conditions that will have positive effects on the species, such as any existing regulatory mechanisms or conservation efforts. The Secretary determines whether the species meets the definition of an “endangered species” or a “threatened species” only after conducting this cumulative analysis and describing the expected effect on the species.
The Act does not define the term “foreseeable future,” which appears in the statutory definition of “threatened species.” Our implementing regulations at 50 CFR 424.11(d) set forth a framework for evaluating the foreseeable future on a case-by-case basis, which is further described in the 2009 Memorandum Opinion on the foreseeable future from the Department of the Interior, Office of the Solicitor (M-37021, January 16, 2009; “M-Opinion,” available online at *https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf* ). The foreseeable future extends as far into the future as we can make reasonably reliable predictions about the threats to the species and the species' responses to those threats. We need not identify the foreseeable future in terms of a specific period of time. We will describe the foreseeable future on a case-by-case basis, using the best available data and taking into account considerations such as the species' life-history characteristics, threat projection timeframes, and environmental variability. In other words, the foreseeable future is the period of time over which we can make reasonably reliable predictions. “Reliable” does not mean “certain;” it means sufficient to provide a reasonable degree of confidence in the prediction, in light of the conservation purposes of the Act.
In conducting our evaluation of the five factors provided in section 4(a)(1) of the Act to determine whether the NCSO DPS of fisher meets the Act's definition of an “endangered species” or a “threatened species,” we considered and thoroughly evaluated the best scientific and commercial information available regarding the past, present, and future stressors and threats. We reviewed the petition, information available in our files, and other available published and unpublished information for the species. Our evaluation may include information from recognized experts; Federal, State, and Tribal governments; academic institutions; foreign governments; private entities; and other members of the public.
In accordance with 50 CFR 424.14(h)(2)(i), this document announces a not-warranted finding on the petition to list the NCSO DPS of fisher. We have also elected to include a brief summary of the analysis on which this finding is based. We provide the full analysis, including the reasons and data on which the finding is based, in the decisional file for the action included in this document.
The species assessment form for the NCSO DPS of fisher contains more detailed biological information, a thorough analysis of the listing factors, a list of literature cited, and an explanation of why we determined that this species does not meet the Act's definition of an “endangered species” or a “threatened species.” To inform our status review, we completed a species status assessment (SSA) report for the NCSO DPS of fisher. The SSA report contains a thorough review of the taxonomy, life history, ecology, current status, and projected future status for the NCSO DPS of fisher. This supporting information can be found on the internet at *https://www.regulations.gov* under Docket No. FWS-R1-ES-2023-0123 (see *ADDRESSES* , above).
**Previous Federal Actions**
On April 8, 2004, we first found the West Coast DPS of fisher (previously delineated as a contiguous area encompassing parts of Washington, Oregon, and California) to be warranted for listing (69 FR 18770). We continued to do so each subsequent year through 2013 in the annual candidate notice of review. On October 7, 2014, we proposed to list the West Coast DPS of fisher as a threatened species under the Act (79 FR 60419). On April 18, 2016, we withdrew that proposed rule, concluding that the potential threats (stressors) acting upon the DPS were not of sufficient imminence, intensity, or magnitude to indicate that they were singly or cumulatively resulting in significant impacts at either the population or rangewide scales (81 FR 22710 at 22713).
On October 19, 2016, the Center for Biological Diversity, the Environmental Protection Information Center, the Klamath-Siskiyou Wildlands Center, and Sierra Forest Legacy filed a complaint for declaratory and injunctive relief, alleging that our determination on the West Coast DPS of fisher violated the Act.
On September 21, 2018, the District Court for the Northern District of California vacated the listing withdrawal and remanded our final determination for reconsideration by March 22, 2019. In subsequent amending orders, the court directed us to prepare a new determination or notice of a revised proposed rule by October 26, 2019, and in the event of publishing a revised proposed rule, submit for publication a final listing determination by April 25, 2020.
We published a revised proposed listing rule on November 7, 2019, based on new information and a reevaluation of the best available information, including reconfiguration of multiple DPSs within the area previously described as a single DPS called the West Coast DPS of fisher (84 FR 60278). The new delineation of DPSs included two original native populations (the NCSO and Southern Sierra Nevada (SSN) DPSs) and three reintroduced populations (Northern Sierra Nevada, Southern Oregon Cascades, and the Olympic Peninsula). On May 15, 2020, in the final rule listing the SSN DPS of fisher as endangered, we also concluded that listing the NCSO DPS of fisher was not warranted (85 FR 29532).
On September 13, 2022, the Center for Biological Diversity, the Environmental Protection Information Center, and the Klamath-Siskiyou Wildlands Center filed a complaint in the District Court for the Northern District of California challenging the 2020 Final Rule. On June 7, 2023, in light of new information, we entered into a stipulated settlement agreement to submit to the *Federal Register* by August 21, 2025, a new 12-month finding as to whether the listing of the NCSO DPS of fisher is warranted. On September 26, 2023, we also published a request for new information since 2019 to inform our SSA on the NCSO DPS of fisher (88 FR 65939).
Additional information on Federal actions concerning the West Coast DPS of fisher prior to October 7, 2014, is outlined in the species assessment form (Service 2025a, pp. 1-2) and the October 7, 2014, proposed listing rule (79 FR 60419).
**Summary of Finding**
The fisher is a medium-sized mammal belonging to the weasel family, Mustelidae, which also includes mink, martens, and otters. Characterized by its elongated body, short legs, and bushy tail, the fisher weighs between 3 and 13 pounds (1.4 and 5.9 kilograms) and measures about 29 to 47 inches (74 to 119 centimeters) with males typically being larger than females and size varying depending on the region. Fishers have a light brown to black fur coat, with white patches on their chest. They have a broad head, pointy snout, bushy tail and small ears. The fisher is found primarily in mature conifer and mixed hardwood forests, with populations distributed across parts of California, Oregon, and Washington; the Rocky Mountains; the northeastern United States; and Canada. For the SSA report and this evaluation, we consider the NCSO DPS as one population that is comprised of three subpopulations: the native Northern California-Southern Oregon (native NCSO) subpopulation, the Southern Oregon Cascades (SOC) reintroduced subpopulation, and the Northern Sierra Nevada (NSN) reintroduced subpopulation. For our analysis, we consider these three subpopulations as three analysis units.
At the individual level, fishers need an adequate amount of quality denning, resting, foraging, and dispersal habitat with abundant diversity and availability of prey, and the availability of mates to allow fishers to reproduce and successfully raise progeny to complete their life cycle. At the species level, fishers require a sufficient number of individuals distributed across the analysis area to ensure that the species can withstand annual environmental and demographic variation (resiliency), catastrophes (redundancy), and novel or extraordinary changes in its environment (representation).
For the NCSO DPS, we assessed resiliency using measures of abundance, density, connectivity of suitable habitat, and habitat quality. We assessed redundancy based on the number and distribution of subpopulations within the DPS relative to the scale and frequency of anticipated species-relevant catastrophic events. We assessed representation based on the distribution of fisher subpopulations across multiple ecosystems and the ability of those subpopulations to maintain adequate amounts of genetic diversity, including the adaptive capacity attributes that may allow for fishers to adapt to changes in either their physical ( *e.g.,* climate or habitat conditions) or biological ( *e.g.,* pathogens or predators) environments.
We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the NCSO DPS of fisher. We evaluated all relevant factors under the five listing factors, including any regulatory mechanisms and conservation measures addressing these threats. The primary threats affecting the DPS's biological status include ongoing habitat changes from climate conditions ( *i.e.,* increasing temperature and changing precipitation patterns, including reduced snowfall accumulation), increased severity and frequency of wildfires, and vegetation management (Factor A). We analyzed these threats, conservation measures addressing these threats, and the individual and cumulative effects of all other potential threats in this assessment. Additional threats to fishers that could play a role in cumulative or synergistic effects are impacts to forest health (droughts, forest insects, and tree disease (Factor A)), toxicants (including anticoagulant rodenticides (Factor E)), development (including vehicle collisions (Factors A and E)), and predation (Factor C). The SSA report also describes impacts from disease, trapping, and overutilization due to research activity; however, we determined that these threats are likely to have only low-level impacts to the DPS.
We found that the NCSO DPS of fisher is not in danger of extinction currently, nor in the near-term, throughout all or a significant portion of its range. We found that the abundance and distribution of the species, as well as important habitat needs that include connectivity between core areas, are adequate to maintain genetic diversity. There have been several approaches to estimate fisher population size across the DPS, and collectively, we estimate the DPS consists of an estimated 2,500-4,000 fishers, which includes approximately 78 fishers in the small SOC subpopulation and approximately 180 fishers in the NSN subpopulation. The best available information at this time suggests that abundance of fishers across the DPS is overall stable as evidenced by continued observations throughout the native NCSO/NSN analysis area over time. Additional fisher observations in some new areas not previously detected have also been reported (albeit some low recruitment rates evident in only two small study areas not suitable for extrapolating across the expansive range). We also project insignificant changes will occur to forest cover type in the near-term future (2010-2039) (see Figure 20 in the SSA report, Service 2025b, p. 95). Thus, the amount and configuration of suitable habitat is expected to remain relatively stable and is likely to continue providing resource needs for each fisher life stage.
Of the various negative influences on fishers within the NCSO DPS, the presence of anticoagulant rodenticides (AR) within select areas has been an ongoing concern given the prevalence of illegal cannabis cultivation operations that use poisons to kill rodents that damage their crops. The best available information appears reliable to conclude an overall insignificant effect on the native NCSO/NSN populations as a whole given the amount of rodenticide exposure found for individuals testing positive to toxicants, currently or projected for the future. Fisher occupancy across the NCSO DPS has, on the whole, remained largely stable over time despite the level of AR exposure in the living population of fishers. To some degree, the fisher's widespread distribution and relative commonness within the analysis area diffuses the potential for a significant percentage of the population to be exposed to these toxicants. Additionally, the best available information suggests that the exposure prevalence of ARs is likely biased high and not reliably extrapolated to the living population for both current or future condition projections.
Although various factors are influencing fishers and their habitat within the three analysis units, the best available information suggests that the species' response to the negative influences is not manifesting at a level such that the NCSO DPS of fishers meet the definition of an endangered species. Fishers in the NCSO DPS demonstrate a moderate ability to adapt to changing conditions such as shifts in forest composition and prey availability, ability to persist in fire-prone landscapes, and tolerance of landscape changes from silviculture. Many attributes of fishers, including their distribution across multiple ecosystems, dispersal distance, physiological tolerances, and a generalist life history as an opportunistic predator, are positively correlated with adaptive capacity.
After we determined the NCSO DPS of fisher is not in danger of extinction in the foreseeable future throughout all of its range, we then evaluated whether the DPS may be in danger of extinction in the foreseeable future in a significant portion of its range by examining the combined native NCSO/NSN analysis unit and the SOC analysis unit.
For the combined native NCSO/NSN analysis unit, some core areas could possibly be lost in the future from wildfire effects ( *i.e.,* some small core areas within the native subpopulation and possibly the core area within the NSN subpopulation). If that scenario occurred, it could reduce connectivity within this analysis unit. However, there is adequate representation across the combined native NCSO/NSN analysis unit that is anticipated to continue into the future (given likelihood of persistence of multiple other core areas and suitable habitat). Fisher distribution across the native NCSO/NSN analysis unit includes a wide variety of ecological subregions, forest zones, and topography across a large geographic area that is likely to provide refugia areas for the species into the future. Also, the western extent of the native subpopulation is projected to be more moist ( *i.e.,* more resistant to large, high-severity wildfires) in the future, and is therefore likely to provide refugia for fisher as temperatures continue to increase and precipitation patterns potentially change, thus contributing to drought conditions in some years.
Fisher abundance and suitable habitat in the combined native NCSO/NSN analysis unit is likely to decrease in the future given ongoing threats, including increasing temperatures and changing precipitation patterns that influence drought, degrading forest health ( *e.g.,* due to droughts, forest insects, tree disease), and wildfires, all of which can negatively affect the fisher's prey availability, reduce connectivity between core areas, and limit necessary habitat structures for fisher. However, the best available information suggests that pockets of suitable habitat will continue to persist between core areas even as connectivity diminishes in fire prone areas, thus likely resulting in enough connectivity and gene flow between the large core areas to allow maintenance of demographic viability and genetic diversity despite some loss of suitable habitat and some potential decrease in habitat connectivity.
In the native NCSO/NSN analysis unit, wildfire is a significant threat to fishers. Most core areas (8 of 14; 57 percent) exhibit a low to moderate risk for large, high-severity fire, and only one (the NSN subpopulation area; 7 percent) exhibits a high risk for large, high severity fire into the future. The increase in frequency, extent, and severity of wildfire within the native NCSO/NSN analysis area is expected to lead to more frequent displacement of fishers and increasing impacts to habitat suitability and connectivity, which in turn would reduce fishers' ability to withstand stochastic and catastrophic events and to adapt to future environmental change. Regardless of these increasing impacts, fuel reduction has been shown to effectively moderate fire behavior by reducing fire severity. This is an important consideration given that fishers appear to tolerate or favor some level of fuel reduction treatments in their home ranges, and fishers (so far within the Southern Sierras but it is reasonable to assume this could occur elsewhere, including within the NCSO DPS) have shown they continue to occupy landscapes disturbed by management activities, particularly those areas where fuels reduction activities have benefited fisher habitat. Together, fuel reduction and forest regeneration have already helped, and will continue to help, buffer some of the worst impacts of an intensifying fire regime in the future. Overall, while primary threats (predominantly wildfire) and other less significant threats are influencing fishers to varying degrees within the native NCSO/NSN analysis unit, they are not of a magnitude to increase the risk of extinction to the point where the species is likely to become in danger of extinction within the foreseeable future.
We also evaluated whether a portion of the range—the SOC analysis area—may be likely to become an endangered species in the foreseeable future ( *i.e.,* threatened). The SOC analysis unit portion of the range contains a much smaller population within a small geographic area that is also experiencing range contraction, and thus, it *may* be in danger of extinction within the foreseeable future. For this portion of the range where the species may be threatened, we first addressed whether it is “significant.” For the purposes of this analysis when considering whether a portion is “significant,” we considered factors such as size of the portion, habitat characteristics, and its conservation value for the species. The SOC analysis unit contains a significantly smaller population (estimated to be approximately 78 individuals (Moriarty 2024, in litt., p. 3) and 1 core area) compared to the combined native NCSO/NSN analysis unit, and it comprises only 10.3 percent (2 million ac (809,371 ha)) of the entire DPS.
The distribution of the population in the SOC could shift outside of the SOC over time if wildfires affect the single core area. However, it is unlikely that wildfire will cause fisher to shift outside of the SOC because approximately 10 percent of the core area is at risk for high-severity fire (Service 2025b, table 9, p. 112). Population trends for the SOC analysis unit are also unknown. Further, fishers in this population are isolated from the native NCSO subpopulation as a result of a significant barrier to movement ( *i.e.,* the subpopulation is isolated from the remainder of the DPS due to the Interstate 5 corridor). Finally, previous research has documented a 26 percent reduction of the SOC analysis unit compared to its 2016 overestimated historical distribution boundary (Service 2025b, pp. 20-24; Barry 2018, p. 22). For these reasons, the SOC analysis unit is at a greater risk of extinction in the foreseeable future than the remainder of the DPS.
The SOC analysis unit is a small geographic area that has always been comprised of a small number of fishers, and those fishers descended from reintroduced individuals from British Columbia and Minnesota (Service 2025b, pp. 4, 22); thus, the fishers within the SOC analysis unit do not contain the unique genetic characteristics of native fishers to this region nor meaningfully contribute to the gene pool of the remainder of this DPS. The overall population size has remained relatively small over time with no expectation that these fishers are likely to contribute meaningfully to the viability of the DPS as a whole. Additionally, the SOC analysis unit provides no unique or especially important habitat for the NCSO DPS of fisher that is not found in the rest of the range. Therefore, the native fisher range is not dependent upon the SOC gene pool for viability due to the SOC's size and genetic diversity, and the entire area does not provide unique or especially important habitat for the NCSO DPS that is not found in the rest of the range.
As a result of our finding that the SOC analysis unit is not “significant,” we do not need to determine whether fishers are likely to become in danger of extinction within the foreseeable future throughout this portion of the range. Therefore, there are no portions of the species' range that provide a basis for determining that the species is likely to become in danger of extinction within the foreseeable future throughout a significant portion of its range.
After assessing the best available information, we concluded that the NCSO DPS of fisher is not in danger of extinction now or likely to become in danger of extinction within the foreseeable future throughout all of its range nor in any significant portion of its range. Therefore, we find that listing the NCSO DPS of fisher as an endangered species or threatened species under the Act is not warranted. A detailed discussion of the basis for this finding can be found in the NCSO DPS of fisher species assessment form and other supporting documents on *https://www.regulations.gov* under Docket No. FWS-R1-ES-2023-0123 (see *ADDRESSES* , above).
**Peer Review**
In accordance with our joint policy on peer review published in the *Federal Register* on July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and clarifying the role of peer review in listing actions under the Act, we solicited independent scientific reviews of the information contained in the SSA report for the NCSO DPS of fisher. We sent the SSA report to seven independent peer reviewers and received four responses. Results of this structured peer review process can be found at *https://www.regulations.gov* under Docket No. FWS-R1-ES-2023-0123. We incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for this finding.
**New Information**
We request that you submit any new information concerning the taxonomy of, biology of, ecology of, status of, or stressors to the NCSO DPS of fisher, as specified under *FOR FURTHER INFORMATION CONTACT* , whenever it becomes available. New information will help us monitor these species and make appropriate decisions about their conservation and status. We encourage local agencies and stakeholders to continue cooperative monitoring and conservation efforts.
**References**
A complete list of the references used in this petition finding is available in the species assessment form, which is available on the internet at *https://www.regulations.gov* under Docket No. FWS-R1-ES-2023-0123 (see *ADDRESSES* , above) and upon request from the appropriate person (see *FOR FURTHER INFORMATION CONTACT* , above).
**Authority**
The authority for this action is section 4 of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 *et seq.* ).
Brian Nesvik,
Director, U.S. Fish and Wildlife Service.