Density and Distribution of an Endangered Mustelid (Fisher: Pekania pennanti) Population Relative to Current Forest Structure and Simulated Prescribed Fire and Wildfire
Martin ME, Matthews SM, McGregor E, Green R, Townsend A, Mackey HL, Stock SL, Smith TR, Anderson C, Anderson J. 2026. Density and Distribution of an Endangered Mustelid (Fisher: Pekania pennanti) Population Relative to Current Forest Structure and Simulated Prescribed Fire and Wildfire. Science Report. NPS/SR—2026/520. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/2319314
Many forest-dependent species evolved in disturbance-prone landscapes, with intermittent, low-severity disturbances producing heterogeneous conditions to support their persistence. However, fire suppression and shifting climate conditions have altered disturbance regimes and drought cycles, resulting in larger, higher-severity wildfires and extensive drought-induced tree mortality. The fisher (Pekania pennanti) is a forest-dwelling species often associated with late-seral, complex forests and sensitive to losses in canopy and forest cover resulting from landscape disturbance. In the southern Sierra Nevada, fishers occur within a federally endangered distinct population segment and recent landscape-scale tree mortality and increasing risk of high-severity wildfire are persistent threats to their recovery. Here, we estimated the contemporary abundance, density, and distribution of fishers in the southern and central Sierra Nevada, in the area encompassing Sequoia, Kings Canyon, and Yosemite National Parks. We incorporated live capture, remote camera, and telemetry data into integrated spatial capture-recapture models to estimate fisher abundance and density and simulated the effects of 1) prescribed fire intended to restore ecosystem function and 2) stochastic wildfires at varying severities and spatial extents. We further incorporated these data and detection-nondetection monitoring data into an integrated species distribution model to estimate structural and landscape features that shape the contemporary distribution of fishers. Through this work, we identify forest structure and landscape conditions associated with the distribution of imperiled fishers, and elucidate the putative, differential effects of prescribed and stochastic fire on their persistence.
- Type
- Published Report
- Authors
- Martin, Marie; Matthews, Sean; McGregor, Eric; Green, Rebecca; Townsend, Andria; Mackey, Heather; Stock, Sarah; Smith, Tessa; Anderson, Chad; Anderson, Jenn
- Date of Issue
- 2026-10
- Publisher
- National Park Service
- DOI
- 10.36967/2319314
- Units
- SEKI , YOSE
- Keywords
- GPS collar, hierarchical modeling, integrated occupancy model, integrated spatial capture-recapture, noninvasive sampling, Pekania pennanti, prescribed fire, remote camera, wildfire