Fisher

Tolko Industries Ltd Fisher Habitat Evaluation in Mountain Pine Beetle affected areas

http://www.env.gov.bc.ca/wildlife/wsi/reports/4128_WSI_4128_RPT1.PDF

The conservation status of fisher changed from S2 to S2S3 indicating concern for the success of the species population. There is not an extensive amount of research or information on fishers and their habitats. Therefore, this project monitors fishers and denning locations in the Sub-boreal Pine Spruce (SBPS) Biogeoclimatic Zone of British Columbia to better understand and assess prime habitats for the species to reproduce and inhabit.

Between the 2005 and 2006 fiscal year after receiving certification, traps, radios and establishing project goals, fishers were captured and monitored. The three goals for this projects were to capture and place implants in up to 12 fishers to track behavior and habitat range patterns with radio transmitters, use radio-telemetry so important habitats can be identified and recorded, and identify natal denning sites in SBPS. Ten fisher (3 males and 7 females) were  captured, implanted with radio transmitters, and monitored between Chantslar Lake and Chezacut. One male fisher was not successfully monitored. Researching and monitoring fishers show that majority of sites used by the species are in the Riparian Spruce (WR) Broad Ecosystem Unit (BEU) in mature stands.

Collecting data on fisher habitats and denning ecology in the Chilcotin Plateau can help guide management and conservation plans. Results from the study between 2005 and 2006 cannot be completed until further study and analysis occurs in April 2007. By this time, more denning locations can be located and monitored. Once an estimated 30 locations per animal are reached, the research will be more statistically relevant to produce data. Monitoring will continue by radio and aerial surveys during summer and fall. Research of fisher habitat will be monitored during maternal care period (spring-early summer) 2007 to record more data for analysis. Ongoing study will provide information to develop a forest management plan to ensure protection of fisher habitat.

Fishers are forest-dependent carnivores in the weasel family that are an important component of healthy ecosystems. Several aspects of the ecology of fishers, including their use of rare structural elements found primarily in late-successional forests, make them susceptible to changes to the forested landbase resulting from hydro-electric development, forest-harvest activities, and oil and gas development. As such, fishers are considered a species at risk under the Identified Wildlife Management Strategy and are blue-listed in British Columbia. Fishers are a high priority for conservation efforts, as they are considered rank 2 under Goal 3 of the provincial Conservation Framework: Maintain the diversity of native species and ecosystems. The Fisher has been historically important for First Nations for clothing and as a trading commodity after Europeans settled in the area. Currently they are protected from hunting but are a popular and abundant commodity for trappers.

Fishers bodies are long with short legs and a pointy face and their diet includes snowshoe hares, mice, squirrels, voles, grouse and porcupines. They inhabit forested areas with home ranges of 25 km2 for females and 100 km2 for males.

Fishers require specific and rare habitat structures such as cavity holes in trees for reproduction and resting. If the temperature drops below -10ºC then they need shelter with thermal protection such as log piles or burrows dug by other animals.

In order for forestry to not impact fisher populations it is necessary to consider different aspects and methods into the planning of a cutblock area. First of all, the harvest cannot cover too large of an area over too little time, for example 250 ha in a 50 km2 area over12 years, for it will decrease the chances of the area to support a fisher population in the future by 50%. This is very important to be considered into management planning. Leaving areas of coarse woody debris, shrub-layer cover for forage and secondary structures with live overstory trees in a cutblock can greatly enhance the chances of fishers using the area afterwards. The inclusion of Wildlife Tree Patches of at least 2 ha and within 200 m of the edge of the cutblock is another important step to ensure a connection to unharvested forests around the cutblock. Fishers need large trees with cavities, however, the suppression of diseases and decay is diminishing the numbers of suitable trees for reproduction dens and resting. Therefore, it is crucial to leave several large trees scattered around in the cutblocks which might form a heart-rot and later also cavities. In the regeneration phase of a cutblock it is important to consider planting several different species of tree to keep a diverse environment to maintain a variety of prey for the fisher and to leave at least 25% of the cutblock unthinned. Prescribed burning will result in the destruction of all suitable structures for fisher habitat and should be avoided in critical areas.

Monitoring populations and evaluating the use of large trees and cutblock areas is importnat to determine effective methods for conservation.

In conclusion, to maintain suitable fisher habitats in cutblocks it is critical to leave important structures scattered around the area and leave large trees that might develop cavities for reproduction dens and resting. When regenerating, planting several different plant species should be considered to maintain prey diversity for fishers. With proper management planning, fisher habitats can be maintained while forestry is ongoing.

Source: Fisher Wildlife Habitat Decision Aid

General issues across the Sub Region will be addressed below, followed by management plans specific to individual populations.

Issues:

  • This species is blue-listed
  • Commercial activities may be reducing suitable habitat available to the fisher

Goals:

  • Determine the availability of prime habitat for fishers in the Sub Region
  • Restore ecosystems to states that provide ample habitat for fishers

Objectives Management Direction/Strategies Measures of Success/Targets Intent