1.0 SPECIES-HABITAT MODEL FOR FISHER (MARTES PENNANTI) Martes Pennanti

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1 1.0 SPECIES-HABITAT MODEL FOR FISHER (MARTES PENNANTI) Species Data Species Name: Scientific Name: Species Code: Status: Identified Wildlife Status: COSEWIC: Fisher Martes Pennanti M-MAPE Blue-Listed No Not At Risk Project Data Ecoprovinces: Northern Boreal Mountains, Sub-Boreal Interior, Taiga Plains Ecoregions: Northern Canadian Rocky Mountains, Central Canadian Rocky Mountains, Muskwa Plateau Ecosections: EMR, HYH, MUF, MUP, PEF BGC Units: AT, BWBSdk2, BWBSmw1, BWBSmw2, BWBSwk2, ESSFmv4, ESSFmvp4, SWBmk, SWBmks Map Scale: 1:50, Introduction There are no specific published fisher habitat studies for the study area. However, some aspects of fisher habitat use are reasonably well understood by regional experts and some of this knowledge exists in the grey literature (unpublished reports etc ). In order to document unpublished expert opinion on fisher habitat use in the study area, a regional workshop was held and was documented in EBA (2001). Information on habitat requirements for other areas in the Rocky Mountains (particularly the eastern slopes) and elsewhere in British Columbia is also drawn upon. 1.2 Ecology and Habitat Requirements Fishers are distributed throughout the forested areas of North America and most of British Columbia. Optimal habitats are considered mature coniferous forests and mixed conifer/hardwood stands, mostly in areas of continuous overhead cover (Allen, 1983; Powell, 1992). Fishers may forage in different habitats from the ones they use for resting and denning therefore, a complete description of fisher habitat requirements must consider both foraging and resting and denning needs. Throughout their range, fishers exhibit a strong preference for forests with high canopy closure and avoid areas with low overhead cover. In the Pacific States and the Rocky Mountains, fisher appear to prefer late-successional coniferous forests (Krohn et al., 1996) and use riparian areas disproportionately more than their occurrence (Powell and

2 Zielinski, 1994). Forest structure is likely more important to fisher than specific forest types. Vertical and horizontal complexity, created by a diversity of tree sizes and shapes, light gaps, dead and downed wood and layers of overhead cover, provide good prey habitat, dens and resting sites (Powell and Zielinski, 1994). Fishers infrequently use large forest openings, open hardwood forests, recent clear-cuts, grasslands, areas above timberline and other non-forested areas (Powell and Zielinski, 1994). In fact, Powell (1992) states that fisher have avoided open areas 25m across or less in the American Midwest. Fishers are opportunistic feeders (Banci, 1989) and their prey may occur in a variety of forest types and seral stages (Powell and Zielinski, 1994). Snowshoe hares and rodents form the bulk of their diet but they will eat virtually any vertebrate that they are capable of killing (Forsyth, 1985). Other common prey items include birds, fish, snakes, toads, insects, fruit, seeds, berries, fern tips and carrion (Forsyth, 1985). Habitats with high small mammal diversity, such as riparian areas, wetlands and mixed conifer-hardwood forest types, are most preferred (Kelly 1977 as cited in Powell, 1992). Resting and denning sites tend to occur in structures associated with late-successional forests (Powell and Zielinski, 1994; Jones and Garton, 1994). This includes large trees, snags and logs greater than 55 cm dbh on average (Powell and Zielinski, 1994). Natal dens are located most often in cavities of large, dead trees situated 7 to 12 m above the ground (Banci, 1989). In most studies done in eastern North America, den sites were in hardwoods and over half were in aspens (Populus spp.). According to Powell and Zielinski (1994), only two natal dens and one maternal den have been recorded in western North America and these three dens were not in hardwoods. Maternal den site requisites are believed to be more stringent than those used for resting (Weir, 1995). For rest sites they will choose the largest diameter trees available and those with the most rust brooms (Weir, 1995). Some authors have shown differences in fisher winter and summer habitat. Jones and Garton (1994), studying in the Rocky Mountains of north-central Idaho, found that fishers preferred mature and old-growth forests during summer but additionally selected young forests in winter. They hypothesized that the shift to younger stages may be due to a shift in prey use, specializing more towards snowshoe hare. Kelly (1977, as cited in Powell, 1992) also found changes in seasonal habitat use. Regenerating clear-cuts were avoided during winter but used during the summer (presumably for feeding) and concluded that fisher perceive the dense cover from saplings as adequate overhead cover. Banci (1989) reports that seasonal elevational changes in fisher habitat use does not occur. Fisher have been found to be confined to or have greater density in areas with low snow accumulation (Powell, 1992). Travel in deep snow is energetically costly and, compared to marten, they are less able to access the sub-nivean spaces because of their large body size. Where snow is deep and frequent, fishers should be expected to be either absent or occur where dense overhead cover intercepts snowfall (Krohn et al., 1996).

3 Riparian forests appear to be very important for fisher, especially in the west (Jones and Garton, 1994; Powell, 1992; MOF and BCE, 1997). These areas likely provide several functions including high prey abundance, abundant snags for dens/resting sites and high canopy closure which provides snow interception. Fishers can travel long distances during short periods of time, about 5-6 km per day (reviewed by Powell and Zielinski, 1994). Males generally have larger territories than females an adult male s home range may be from 20 to 34 km 2 and may overlap those of several females. A female s home range is from 15 to 19 km 2. Home range within each sex are generally exclusive. Landscape-scale fisher habitat requirements are not well understood, however their preference for diverse habitats created by multi-aged stands containing wetland or riparian habitat and their requirement for continuous overhead cover is well documented (Banci, 1989; Powell and Zielinski, 1994; MOF and BCE, 1997). Small forest openings created by fire and wind-throw are a natural component of fisher habitat although large, non-forested areas, such as those created by clear-cut logging, are beyond the scale of natural disturbances. Other important landscape attributes, such as stand size and shape and use of corridors, are not known (Krohn et al., 1996). 1.3 Distribution Provincial Range Fisher are found throughout mainland British Columbia although they are rare in coastal ecosystems (Nagorsen, 1990; MOF and BCE, 1997) Distribution in Project Area Table 13 show the expected distribution of fisher according to Ecosection and BGC unit. Fisher are not present in the AT and only very low use in the growing season in the parkland and scrub variants. 1.4 Food/Cover Life Requisites and Habitat Uses For this project, fisher habitat use has been divided into two seasons: growing and winter. Since food and security are generally found in the same habitats and given the scale of mapping, habitat ratings are for general living, which includes requirements for both food and security (Table 14). It is assumed that suitable denning habitat is provided in habitat with good security and is not limiting. It is therefore not rated.

4 Table 1. Distribution of fisher in the project area. Ecoprovince Ecoregion Ecosection BGC Unit PTP Area 1 PTP Area 2 PTP Area 3 Northern Boreal Northern EMR AT Mountains Canadian BWBSdk2 Rocky BWBSmw2 Mountains SWBmk SWBmks MUF AT BWBSdk2 BWBSmw2 BWBSwk2 ESSFmv4 ESSFmvp4 SWBmk SWBmks Hyland Highland HYH BEBSdk2 Sub-Boreal Central PEF AT Interior Canadian BWBSmw1 Rocky BWBSwk2 Mountains ESSFmv4 ESSFmvp4 Taiga Plains Muskwa MUP BWBSmw2 Plateau SWBmk Note: Shaded cells indicate a BGC unit that is not present in a PTP Area. PTP Area 4 Table 2. Food/cover life requisites rated for fisher in the M-KMA project area. Food/Cover Life Requisite Food and Security Habitat Food and Security Habitat Habitat-Use General living during growing season Months June September Rating Column Title MMAPE_LIG General living during winter October May MMAPE_LIW

5 1.4.1 General Living in Growing Season Habitat that provides living (LI) contains security and food in close proximity. These life requisites are often provided in the same habitat, however, fisher will feed in areas with sub-optimal security if there is adequate security nearby. Security Habitat Security is provided by continuous overhead forest cover and in structures associated with late-successional forests. Estimates of crown closures that provide suitable cover vary. Kelly (1997, as cited in Powell, 1992) and Allen (1983) agree that fisher avoid forests with less than 50% canopy closure however MOF and BCE (1997) suggests that canopies with greater than 30% are adequate. In summer they may avoid stands with no deciduous component and show a preference for stand types with deciduous canopy closures of 20-40% (Weir, 1995). Spruce trees with rust brooms are favoured for resting sites. Food Optimum foraging habitat for fishers is provided by a mosaic of different forest types in various structural stages, together with forest floor structural complexity, which provide habitat niches for a diversity of prey species. Fishers will hunt hares (their preferred prey) and other mammal and bird species in conifer-dominated habitats, deciduous riparian forests, birch-willow scrub/parkland and shrub fens/carrs. Summer foraging is strongly associated with coarse woody debris (CWD). Primary prey species are associated with abundant CWD and understory shrub cover. However, fishers will also feed in areas that do not provide good year-round cover, such as younger forests and regenerating clear-cuts General Living In Winter Habitat that provides living (LI) in winter contains security and food in close proximity. These life requisites are often provided in the same habitat, however, fisher will feed in areas with sub-optimal security if there is adequate security nearby. Security Habitat Security habitat conceals fishers from larger predators and modifies extremes in climate thus assisting them in maintaining a constant body temperature. Thermal habitat is more critical for fishers in winter when they may be nutritionally stressed and need to minimize energy expenditures. Security is provided by continuous overhead forest cover (greater than 30% crown closure) and in structures associated with late-successional forests. Fisher will rest in ground dens among coarse woody debris and slash piles during periods of low temperatures (below 20 C). Weir (1995) found a greater-than-expected winter use by fishers of habitats with >50 m³/ha of large debris (more than 20 cm diameter).

6 Branch nests and tree cavities may offer adequate thermal environments in winter when temperatures are above 20 C (Taylor, 1993; Weir, 1995). Spruce trees with rust brooms are favoured for resting sites (Arthur, 1987; Jones, 1991). If adequate winter cover is available, habitat requirements during other seasons may also be satisfied. For example, an area that provides suitable winter cover will also provide suitable summer cover, and suitable habitat for feeding, denning etc Food Foraging habitat for fishers in winter is much the same as in summer. However, in winter fishers, because of their large body size, are restricted to hunting on the snow surface (Powell, 1982). Therefore, structurally complex debris (CWD), which provides subnivean access, may not be required as foraging habitat. Deep winter snow may limit the distribution of fishers (Aubry and Houston, 1992). 1.5 Ratings Habitat ratings were generated using the six-class rating scheme. Table 3. Habitat capability/suitability 6-Class rating scheme used for final fisher ratings. % of Provincial Best Rating Code 100% - 76% High 1 75% - 51% Moderately High 2 50% - 26% Moderate 3 25% - 6% Low 4 5% - 1% Very Low 5 0% Nil Provincial Benchmark A provincial benchmark for fisher has not been formally established. We assumed, that at an ecosection level, the study area provides up to moderate (class 3) fisher habitat and therefore expect to give a lot of moderate habitat ratings.

7 1.5.2 Assumptions Table 16 lists the assumptions for habitat use by fisher for each season and life requisite. For some attributes, the listed assumptions represent broad patterns only and detailed ratings are contained in the RRM. Table 4. Assumptions for habitat use by fisher in the M-KMA project area. SSn and Use LIG Attribute Biogeoclimatic Zone Site Series Structural Stage Coarse Woody Debris Assumptions The BWBS zone has the potential to be rated highest because of the greater occurrence of riparian areas. This zone is rated up to 50% relative to the best in the Province. The ESSFmv4 and SWBmk are rated up to 20%. The ESSFmvp4, SWBmks and AT are rated up to 5%. In general, moister site series (soil moisture regimes from mesic to subhygric) provide better fisher habitat than drier site series (very xeric to sub-mesic) and very wet site series (hygric to hydric) and are therefore rated up to 100%. Moister sites typically have higher canopy closure and denser shrub and herb layers (MOF, 1996), providing better prey habitat. Very xeric to submesic sites are rated up to 60%. Structural stages 06 (mature forest) and 07 (old forest) represent the best year-round fisher habitat as they provide the greatest vertical and horizontal structural complexity and have the greatest likelihood of high coarse woody debris. These stages are rated up to 100%. Structural stage 05 (young forest) lacks some of the complexity associated with mature and old forest and is considered to provide lower quality yearround habitat and is rated up to 70%. Structural stage 4 (pole/sapling) is rated up to 50%. Structural stages 3a (low shrub) and 3b (tall shrub) provide low-level feeding habitat and are rated up to 10 and 30% respectively. Structural stages 01 (non-vegetated/sparse), 02 (herb) and are not considered to provide significant fisher habitat and rated 5%. Late successional forests are most likely to contain the highest CWD. As well, productive, mesic site series are likely to have higher CWD than both drier and wetter site series. The effect of CWD is therefore incorporated into the sites series and structural stage assumptions described above. LIW Ecosection The EMR has higher typical snowdepth and is rated up to 70%. All other Ecosections are rated up to 100%. Biogeoclimatic Zone The BWBS zone has the potential to be rated highest because of the greater occurrence of riparian areas. This zone is rated up to 50% relative to the best in the Province. The ESSFmv4 and SWBmk are rated up to 20%. The ESSFmvp4, SWBmks and AT are rated up to 5%.

8 SSn and Use Attribute Assumptions Site Series Moister sites typically have higher canopy closure and denser shrub and herb layers (MOF, 1996), providing better cover habitat and are therefore rated up to class 100%. Very wet sites (sub-hydric to hygric) typically have a lower canopy closure, thus providing poorer security habitat and are therefore rated down 25%. Mesic and moister sites are also likely to have higher coarse woody debris than both very wet and very dry sites. Structural Stage Structural stages 06 (mature forest) and 07 (old forest) represent the best year-round fisher habitat as they provide the greatest vertical and horizontal structural complexity and have the greatest likelihood of high coarse woody debris. These stages are rated up to 100%. Structural stage 05 (young forest) lacks some of the complexity associated with mature and old forest and is considered to provide lower quality yearround habitat and is rated up to 70%. Structural stage 4 (pole/sapling) is rated up to 50%. Structural stage 3b (tall shrub) provides low-level feeding habitat and is rated up to 20%. Structural stages 01 (non-vegetated/sparse), 02 (herb) and 3a (low shrub) are not considered to provide significant fisher habitat and rated up to 5%. Stand Association Coniferous stands provide optimal security. Broadleaf stands are rated up to 20% Ratings Model The habitat ratings were generated using Resource Ratings Models (RRMs). (see Section 2.3 for a full description of the modelling approach). The variables included in the models are the ecosystem map attributes described in Table 12. The assumptions for each of the variables are more precisely defined in the accompanying MS Excel workbook for fisher. 1.6 Map Themes and Ratings Adjustments Habitat Use Maps Habitat use maps of living in the growing season and living in winter can be produced. For complex polygons, the polygon rating should be the weighted average of all deciles. 1.7 References Allen, A.W Habitat Suitability Index Models: Fisher. U.S.D.I. Fish and Wildlife Service. FWS/OBS-82/ pp. Arthur, S.M Ecology of fishers in southcentral Maine. Ph.D. Thesis, Univ. Maine, Orono. 112pp.

9 Aubry, K.B., and D.B. Houstin Distribution and status of the fisher in Washington. Northwest naturalist. 73: Banci, V A Fisher Management Strategy for British Columbia. Wildlife Bulletin No. B-63. BC Ministry of Environment, Wildlife Branch, Victoria BC. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) Internet web site: Canadian Wildlife Service, Environment Canada. Douglas, C.W. and Strickland, M.A Fisher. In M. Novak, J.A. Baker, M.E. Obbard and B. Malloch (eds.). Wild Furbearer Management and Conservation in North America. Ontario Ministry of Natural Resources, Queen s Printer for Ontario. EBA Proceedings of a workshop on wildlife habitat use of selected species in the Muskwa-Ketchika Management Area. EBA Engineering Consultants Ltd. Forsyth, A Mammals of the Canadian Wild. Camden House Publishing Ltd. 351 pp. Jones, J.L Habitat use of fisher in northcentral Idaho. M.Sc. Thesis, University of Idaho, Moscow. 146pp. Jones, J.L. and E.O. Garton Selection of successional stages by fishers in northcentral Idaho. In Buskirk, S.W., A.S. Harestad, M.G. Raphael and R.A Powell (Eds.). Marten, Sables and Fisher: Biology and Conservation. Cornell University Press, Ithaca, NY. Kelly, G.M Fisher (Martes pennanti) biology in the White Mountain National Forest and adjacent areas. Ph.D. Thesis. University of Massachusetts, Amherst, MA. Krohn, W.B., K.D. Elowe, R.B. Boone Relations among fishers, snow, and martens: development and evaluation of two hypotheses. For. Chron. 71(1): Ministry of Environment, Lands and Parks (MELP) B.C. Conservation Data Centre: Rare Vertebrate Animal Tracking List. Internet web site: Ministry of Forests (MOF) Draft Field Guide Insert for Site Identification and Interpretation for the Rocky Mountain Trench. Victoria, BC. Ministry of Forests and BC Environment (MOF and BCE) Species and Plant Community Accounts for Identified Wildlife. Forest Practices Code of British Columbia. Province of British Columbia, Victoria.

10 Nagorsen, D The Mammals of British Columbia. Royal British Columbia Museum Memoir No. 4. Royal British Columbia Museum and Wildlife Branch, Victoria. Powell, R.A The Fisher: Life History, Ecology, and Behavior. Minneapolis, University of Minneapolis Press. Powell, R.A. and W.Z. Zielinski Fisher. In Ruggiero, L.F., K.B. Aubrey, S.W. Buskirk, L.J. Lyon and W.J. Zielinski (tech. eds.). The Scientific Basis for Conserving Forest Carnivores: American Marten, Fisher, Lynx and Wolverine in the Western United States. Gen. Tech. Report RM-254. U.S. Dept. of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 184 p. Resources Inventory Committee (RIC) Standards for Wildlife Habitat Capability and Suitability Ratings in British Columbia. Review Draft. Wildlife Interpretations Subcommittee, Ministry of Environment, Lands and Parks, Victoria, B.C.. 22 pp. Stephens, V. and S. Lofts Species Notes for Mammals. Volume 1 in A.P. Harcombe (tech. ed.). Wildlife Habitat Handbooks for the Southern Interior Ecoprovince. Ministry of Environment and Ministry of Forests. Taylor, S.L Thermodynamics and energetics of resting site use by the American marten (Martes americana). M.Sc. Thesis, Unuversity of Wyoming, Laramie. 89pp Weir, R.D Diet, spatial organisation, and habitat relationships of fishers in southcentral British Columbia. M.Sc. Thesis. Simon Fraser University, Burnaby, British Columbia.