Project Details

Name:	2011-2012 - Fisher - Bridge River - Thompson Region - BC Hydro
ID:	4989
Coordinator:	Larry Davis
Funding Agency:	BCH: 12.W.BRG.01
Region:	Thompson
Security:	Normal

Surveys (1 records)

Survey Name	Survey Intensity	Inventory Method	Target Taxa (Species Code / Scientific Name / English Name)  * = Primary Focus
2012 - Fisher - Hair Snare DNA - Bridge River Watershed

Documents (8 records)

Report	Publish Year	Description	Filename
Inventory of Fisher Populations and Reproductive Dens in the Bridge River Watershed 2011	2011	Flooding of the Bridge River Valley by the Carpenter and Downton reservoirs likely removed many of the large, cavity-bearing trees that fishers (Martes pennanti) may have used for reproductive dens. This affected the supply of critical denning structures and the sustainability of fisher populations in this watershed. To assess and potentially mitigate the footprint impacts of these reservoirs on fishers and their reproductive habitat, baseline information on the fisher population and the abundance and distribution of cavity-bearing trees is needed. We conducted winter track count transects in 48-20 km² grid cells spread throughout the assessment area to determine if fishers are sufficiently widespread to warrant future habitat restoration efforts. We conducted 1415 km-days of track transects in the Gun, Tyaughton, and Yalakom watersheds over 4 survey sessions between December 2010 and March 2011. We encountered 72 fisher, 92 American marten (Martes americana), and 14 wolverine (Gulo gulo) tracks along 680 km of transects. Fishers were well distributed across the assessment area, with detections in 50% of the cells surveyed. Fisher tracks were generally more frequent along riparian areas in lower elevation Interior Douglas-fir habitats and in southern portions of the assessment area above Carpenter Lake. Fishers may be more common in these areas because shallower snow depths lower the cost of locomotion and large diameter cottonwood in riparian areas provide potential reproductive denning habitat. Based on the cell size used for this study, we estimate that 10 - 20 fishers may occur within the assessment area, which is in the range of other fisher populations studied in BC. These results suggest that the density of fishers is sufficiently high to warrant further population and habitat inventory. We recommend that a more rigorous mark-recapture inventory of fishers be conducted during winter 2011-12, which will build on the solid foundation that was achieve ...	wsi_4989_rpt_2011.pdf (3.3 MB)
Inventory of Fisher Populations and Reproductive Dens in the Bridge River Watershed	2013	The final year of this project focused calculating a population estimate for fisher (Pekania pennanti), proposing five Wildlife Habitat Areas, producing an article on the project for the BC Trappers Magazine, and developing a brochure on fisher habitat needs for private landowners. This information will provide resource managers with data to set sustainable harvest levels for fisher; focal areas for the application of strategies to retain and augment fisher reproductive habitat; and may help sustain fisher habitat values on locations outside of direct government control, such as private lands. We used DNA-based capture-mark-recapture methods to estimate the number of fishers in 38-20.3 km² cells at the southwest edge of the species' range in the Bridge River watershed of British Columbia. Genetic samples of fishers were collected at 16 hair-snag sites and we used 7 microsatellite markers and sex-specific markers to identify 8 individual fishers (5 male, 3 female) in our 771.4 km² study area. We used the two-innate rates model of program CAPWIRE to estimate the local population size to be 14 individuals (95% CI: 8 - 26 animals), giving us an estimated density of 18.1 fishers/1000 km². This density is higher than reported elsewhere in British Columbia in part because our estimate included all age classes and not just adult resident animals. In addition, other studies in British Columbia based density on the number of animals known alive at the end of the study, whereas we did not account for animals that may have died or dispersed. Despite these differences, the cost-effectiveness and expediency of non-invasive sampling techniques used with the program CAPWIRE hold promise for estimating the population size of low-density species such as fishers. In addition to the population estimate generated in this year, work completed in past years of this project has provided data on the abundance of potential den trees for fisher and the locations of another blue-li ...	wsi_4989_rpt_Final.pdf (1.2 MB)
Map	Publish Year	Description	Filename
Map of Fisher Populations and Dens inventoried		Map of Fisher Populations and Dens inventoried	wsi_4989_img_Map_PopDens.pdf (4.2 MB)
Map of proposed Wildlife Habitat Area for Fisher in the Gun Lake area		Map of proposed Wildlife Habitat Area for Fisher in the Gun Lake area	wsi_4989_img_WHA_GunLk_Map.pdf (428 KB)
Map of proposed Wildlife Habitat Area for Fisher in the Lajoie Lake area		Map of proposed Wildlife Habitat Area for Fisher in the Lajoie Lake area	wsi_4989_img_WHA_LajoieLk_Map.pdf (437 KB)
Map of proposed Wildlife Habitat Area for Fisher in the Liza Lake area		Map of proposed Wildlife Habitat Area for Fisher in the Liza Lake area	wsi_4989_img_WHA_LizaLk_Map.pdf (442 KB)
Map of proposed Wildlife Habitat Area for Fisher in the Marshal Lake area		Map of proposed Wildlife Habitat Area for Fisher in the Marshal Lake area	wsi_4989_img_WHA_MarshalLk_Map.pdf (436 KB)
Map of proposed Wildlife Habitat Area for Fisher in the Yalakom area		Map of proposed Wildlife Habitat Area for Fisher in the Yalakom area	wsi_4989_img_WHA_Yalakom_Map.pdf (432 KB)