Fisher (pekania penanti) historically occupied much of western oregon in the coast range and cascade mountains, but by the mid-20TH century they had been largely extirpated from the state

Their present distribution in the state is limited to a native population in the siskiyou mountains and a reintroduced population in the southern cascades. The odfw western wildlife research lab, in collaboration with partners at federal agencies and in academia, have been monitoring the distribution and demographic structure of native fisher in the siskiyou mountains using non-invasive genetic sampling since 2017. Through six years of non-invasive population monitoring we have seen limited variation in estimated population density between years, and consistently male biased SEX ratios. The factors influencing these demographic patterns, however, remain unknown, but could be caused by habitat, interspecific dynamics (e.g., predation, competition), pathogens and disease, or issues associated with current sampling methods such as poor detectability. In 2023 we initiated a GPS-telemetry study to better understand survival and mortality, spatial ecology, and habitat associations of fisher. Fisher prefer habitats characterized by a complex understory structure that provides opportunities to rest, DEN, and hunt. This sort of habitat, however, poses a significant wildfire risk, and efforts to thin forests and reduce fuel loads in high-risk firesheds is a top priority for federal and local land management agencies. We will use GPS-telemetry data from collared fisher to describe habitat use patterns in areas where thinning and fuel reduction projects are planned or in progress. We will also track locations of collared female fisher to identify locations of DEN sites used for kit rearing. Obtaining a better understanding of site and stand characteristics at denning locations in SW oregon will help to ensure that thinning and fuels reduction projects do not alter or destroy habitat that is critical for reproduction. We also captured and collared sympatric competitors to evaluate the extent to which they may be limited by resource competition and predation from the gray FOX (urocyon cinereoargenteus) and bobcat (lynx rufus). This effort will provide critical insight into realized and potential connectivity between these populations. The outcomes of this multifaceted project will odfw and federal agencies to better assess limits to fisher population recovery and expansion into unoccupied habitat in southern oregon.