Northern Sierra Fisher Reintroduction Project

Northern Sierra Fisher Reintroduction Project

Understanding if fishers can persist in forests that are managed for timber production is an important area of research. Evaluations of fisher population viability on managed landscapes, however, have received surprisingly little attention, even though they may play an important role in fisher recovery. Forests in the western United States available for fisher recolonization include extensive landscapes managed for timber production. Though fishers can occupy and reproduce in these forests, large-scale harvest of late-successional forests were also some of the primary causes for fisher population decreases across North America. Thus, understanding whether fisher populations can persist in systems used for timber production is imperative to their conservation.

We used a reintroduction of fishers to a privately-owned forest managed for timber production in northern California to experimentally evaluate the viability of a fisher population on a landscape managed for timber production. We studied this reintroduced population of fishers for 8 years using annual live-captures and year-round tracking with radio telemetry. Using population modeling with spatial capture-recapture methods, we estimated this population of fishers to be growing during the study period. The density of the reintroduced fisher population in 2017 (10.8 fishers/100 km2) was within the reported range of fisher densities across the western United States. The reintroduction of fishers to previously occupied portions of their range is an important component of fisher conservation and will play a role in the recovery of the species in western portions of the fisher’s range. Our results suggest that forests managed for timber production with landscape conditions similar to our study area may be important for future fisher reintroductions and species recovery (Green et al. 2022).

Hoopa Fisher Project

Female fisher emerging from a den cavity (Kerry Rennie / Hoopa Tribal Forestry)

The fisher, or ’ista:ngq’eh-k’itiqowh in the Hupa language, is culturally significant to many native communities of the Pacific Northwest, including the Na:tinaxwe or Hupa people. The Hupa name exemplifies the fisher’s agility, translated as ‘log-along-it scampers’. INR staff are collaborating with Hoopa Tribal Forestry biologists and foresters to develop a more complete understanding of fisher habitat selection patterns and recommendations for the protection, retention, and recruitment of fisher den sites.

The Hoopa Tribe's economy is almost entirely based on income generated from timber harvested on the Hoopa Valley Indian Reservation. Fishers depends on forests with old growth characteristics. So it is critical to determine fisher habitat components that can be maintained or enhanced while implementing the Tribe’s forest management plan.

Klamath-Siskiyou Carnivore Project

Fisher photographed at sampling device (David Green / INR-OSU)

The Klamath-Siskiyou Carnivore Project offers a unique opportunity in the Klamath-Siskiyou Ecoregion to address the effects of ecological processes and anthropogenic activities on fishers (Pekania pennanti) and other meso-carnivores. We have surveyed meso-carnivores on approximately 510 km2 in the Klamath National Forest and neighboring private-timber lands using non-invasive methods since 2006.

In the summer of 2013, the Beaver Creek Fire burned approximately 30% of the study area. Thus, we have 7 years of data before the burn occurred, and 3 years following the burning event. This represents an unprecedented dataset to investigate the effects of wildfire and salvage practices on carnivore populations.

Medford-Klamath Falls BLM Fisher Project

Female fisher (Katie Moriarty / USFS PNW)


Southern Sierra Carnivore Monitoring

Two fishers, likely a mother and her kit, at a survey station (Jody Tucker/U.S. Forest Service Region 5).

Dead trees along a forest road on the Sequoia National Forest in May 2016 (U.S. Forest Service).

A diverse array of carnivores lives in the forests of the southern Sierra Nevada Mountains in California. Biologists with the U.S. Forest Service Region 5 Carnivore Monitoring Program  conduct annual, systematic surveys to determine the presence of different carnivore species and the impacts of changes in environmental conditions. The program began in 2002 and uses remote cameras, sooted track plates, and genetics to survey over 12,240 km2, an area the size of Connecticut.

Drought and subsequent tree mortality are profoundly changing the forests of the southern and central Sierra Nevada. The U.S. Forest Service estimates there are 100 million dead trees, representing a major disturbance that will profoundly affect both human and biological communities. INR is collaborating with U.S. Forest Service colleagues to determine how these environmental changes are affecting occupancy patterns of fisher and other forest-dwelling species.