1.0 SPECIES-HABITAT MODEL FOR AMERICAN MARTEN (MARTES AMERICANA) Martes americana

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1 1.0 SPECIES-HABITAT MODEL FOR AMERICAN MARTEN (MARTES AMERICANA) Species Data Species Name: Scientific Name: Species Code: BC Status: Identified Wildlife Status: COSEWIC Status: American marten Martes americana M-MAAM Not at risk 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 marten habitat studies for the study area, although studies have recently been completed near Chetwynd in the BWBS zone (Grindal et al., 2000). Some aspects of marten habitat use are also reasonably well understood by regional experts and some of this knowledge exists in the grey literature (unpublished reports etc ). In order to document unpublished expert opinion on marten habitat use in the study area, a regional workshop was held and was documented in EBA (2001).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 British Columbia, Alberta, and western USA, including Marten Habitat Suitability Index Models (Allen, 1982; Takats et al. 1999) is also drawn upon. 1.2 Ecology and Habitat Requirements Marten are generally associated with late-successional stands of mesic conifers, especially those with complex physical structure near the ground (Buskirk and Ruggiero, 1994). They may use younger forests and even open areas in the snow free seasons if good cover is provided nearby. The complex physical structure near the ground provides escape space/refuge sites; access to subnivean space where most prey are captured in winter; and protective thermal environments, especially in winter (Buskirk and Ruggiero, 1994). They require well insulated resting dens when not active. Dens are almost always

2 subnivean and typically associated with coarse woody debris such as squirrel middens, stumps, snags, and the root masses of large trees (Lofroth and Steventon, 1990). Marten diet varies by season. In summer, their diet includes bird s eggs and nestlings, insects, fish, fruit and young mammals. In winter, voles, mice, hares and squirrels dominate (Buskirk and Ruggiero, 1994). Marten hunt mostly on the ground, though they are good climbers and may chase squirrels or reach bird nests by climbing. Hunting is often done beneath the snow and fallen logs or rocks are used to access the subnivean spaces (Stevens and Lofts, 1988). Food is a significant factor limiting marten presence and distribution, especially in winter. Fluctuations in small mammal densities in Montana were believed to directly affect the carrying capacity for marten (Weckwerth and Hawley, 1962). However, large quantities of snow in winter with limited access routes to get at prey below deep snow may be more restrictive on marten winter densities than the actual density of prey present (Clark and Campbell, 1976). Thompson and Harested (1994) suggest that although marten have been reported to show some diet preferences, it is unlikely that the presence of individual prey species influences habitat selection. Resting sites are very important to marten and include fallen trees, dense vegetation, natural cavities between rocks or stumps and in trees. The resting sites provide thermal shelter during inclement weather to reduce energy expenditure. Resting sites are often located near recent kills (Stevens and Lofts, 1988). In Wyoming, Clark and Campbell (1976) report that marten frequently select large (35 to cm dbh), rotten Engelman spruce or sub-alpine fir snags as refuge sites. Marten prefer coniferous stands with a closed canopy. Recorded canopy closure preferences vary widely; from as low as 20% to as high as 100%. Koehler and Hornocker (1977) report that habitat with less than 30% cover is utilised but movement about these areas may be restricted to edges. However, in the Foothills Model Forest, Alberta, some marten were found using stands with a 6-30% canopy closure (Takats et al., 1999). In Colorado, marten have been recorded searching for prey 0.8 to 3.2 km from forest cover from May to November (Streeter and Braun, 1968). In these cases, they were most commonly found in boulder fields looking for prey such as pikas (Ochotona princeps). Lofroth (1994) suggests that differences in canopy closure preferences must be interpreted in the context of the range of canopy closures that are available in the area. There is little documentation on the requirements of natal den sites however logs, trees, rocks and snags account for the greatest number of reported dens (Buskirk and Ruggiero, 1994). The availability of natal sites may be related to structural complexity, often associated with old-growth forests. Males generally have larger territories than females. A male s territory ranges from 0.9 km 2 to 17.9 km 2 and may overlap those of several females. The female home range may be from 0.5 km 2 to 8.5 km 2 (Stordeur, 1985). Home range size depends upon prey and habitat.

3 Marten home range does not shift among seasons although they do specialise in the higher quality portion of their range during winter (Buskirk and Ruggiero, 1994). Winter is considered the most critical season for marten when habitat requirements are most restrictive (Allen, 1982; Buskirk and Ruggiero, 1994; Lofroth and Steventon, 1990). Little is known about landscape-scale marten habitat use. Attributes such as stand size, stand shape, area of interior, amount of edge, use of corridors and connectivity may be important in marten habitat selection but are almost completely unknown (Buskirk, 1992). Reports of minimum habitat size have been estimated in the western US to be approximately 2.59 km² for males. Based on this information, it is assumed that at least 2.59 km² of suitable habitat must be available before an area will be occupied by this species (Allen, 1982). Marten are adversely affected by logging and by forest fires, both of which may remove overhead cover and coarse woody debris (Buskirk and Ruggiero, 1994; Strickland and Douglas, 1987; Thompson and Harested, 1994). 1.3 Distribution Provincial Range American marten are found throughout mainland British Columbia, on Vancouver Island and on the Queen Charlotte Islands in addition to several smaller coastal islands (Nagorsen, 1990). They are generally split into two different forms: interior and coastal (Lofroth and Stevens, 1990) Distribution in Project Area Table 9 show the expected distribution of marten according to Ecosection and BGC unit. Since marten are associated with forested ecosystems, they do not normally occur in AT and ther eis low use in parkland/scrub variants Elevation Range From valley bottoms (420 m ASL) to the limit of continuous tree cover (around 1500 m ASL). Highest quality habitat is predominantly found at lower elevations. 1.4 Food/Cover Life Requisites and Habitat Uses For this project, marten 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 10). 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 American marten 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 American marten in the M-KMA project area. Food/Cover Life Requisite Food, Security Habitat Food, Security Habitat Habitat-Use General living during growing season Months June September Rating Column Title MMAAM_LIG General living during winter October May MMAAM_LIW

5 1.4.1 General Living in the Growing Season Habitat that provides living in the growing season contains both security and food. These requisites are often provided in the same habitat, however, marten will feed in areas with sub-optimal security if there is adequate security nearby in summer. Food Food is provided in habitats that support abundant small mammal prey. These are mesic sites with high herbaceous and shrub cover. Since berries can also be a significant diet item in summer, sites with high berry producing shrubs are also rated high. During the growing season, marten may also use areas for feeding that are not suitable for winter cover. Security Habitat Security Habitat habitat (which provides cover) is required in all seasons, however, winter cover is considered the single most important factor determining habitat selection for marten (Allen, 1982; Buskirk and Ruggiero, 1994). 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.. Habitat characteristics that relate to the provision of cover are therefore emphasised. Good security habitat is characterised by a coniferous canopy with canopy closure greater than 30% and high coarse woody debris. Allen (1982) considers that early successional forests provide no marten habitat, midsuccessional forests provide moderate marten habitat and mature or old growth forests provide optimum value. Lofroth (1994) found marten in the Sub-Boreal Spruce zone avoided young seral stages. However, Grindal et al. (2000) reported extensive use by marten of an area dominated by year old regenerating aspen. The presence of coarse woody debris (CWD) piles, remnant from recent clearings, was considered likely to have contributed to the value of these young aspen stands as marten habitat General Living in Winter Habitat that provides living in the winter contains both security and food. In winter, these requisites are provided in the same habitat. Food In winter, food availability is closely linked to security those areas that provide good security provide access to subnivean spaces where prey are captured. Thus, habitats that support small mammals and provide security provides adequate feeding.

6 Security Habitat See discussion under living in the growing season. 1.5 Ratings Habitat ratings were generated using the six-class rating scheme (Table 11). Table 3. Habitat capability and suitability 6-Class rating scheme used for final marten 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 marten has not been formally established. We assumed, that at an ecosection level, the study area provides up to high (class 1) marten habitat and therefore expect to give a lot of high habitat ratings Assumptions Table 12 lists the assumptions for habitat use by American marten for each season and life requisite. For some attributes, assumptions represent broad patterns only and detailed ratings are contained in the RRM.

7 Table 4. Assumptions for habitat use by American marten in the M-KMA project area. SSn and Attribute Assumptions Use LIG BGC Unit The BWBS subzones, with their higher canopy closure and denser undergrowth, provide the highest quality food habitat and are rated up to 100%. ESSF and SWB subzones also provide food in the growing season. These are rated up to 70%. Because of its predominantly low canopy cover, parkland and scrub variants provide very low food. They are therefore rated up to 20%. Food is not provided in the AT because of the lack of canopy cover. AT is rated 5%. Site Series In general, moister site series (sub-mesic to sub-hygric) provide better food than drier site series (very xeric to sub-xeric). Moister sites typically have higher canopy closure and denser shrub and herb layers, providing better prey habitat. These sites also provide better berry production. Sub-mesic to sub-hygric are generally rated 100% to 50% Very xeric to sub-xeric are rated up to 40%. Site series with poor and very poor soil nutrient regimes have less herb and shrub cover/production and provide lower levels of food than medium and rich sites. Therefore, they are rated up to 60%. Structural Stage Structural stages mature forest (06) to old growth (07) provide optimal habitat in the growing season and are rated up to 100%. Structural stages pole sapling (04) and young forest (05) are rated up to 50% and 70% respectively. Low shrub (3a) and tall shrub (3b) provide low-level food and are rated up to 20 and 30% respectively. Non-vegetated and herbaceous structural stages (01 and 02) provide almost no food and are rated 5%. Stand Association Broadleaf stands are rated down 30%. Canopy Closure Sites with high canopy closure provide optimal security and are rated up to 100%. Typical canopy closure is generally related to Site Series and Structural Stage. Coarse Woody Debris 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 BGC Unit The BWBSmw2 zone, with its higher canopy closure and denser undergrowth, provides the highest quality habitat in the project area and is rated up to 100%. The relatively open canopy of the SWBmk and ESSFmv4 zones provides up to 40%. The low or absent forest cover in the ESSFmvp4, SWBmks and AT are rated 5%. Site Series In general, moister site series (sub-mesic to sub-hygric) provide better food than drier site series (very xeric to sub-xeric). Sub-mesic to sub-hygric are generally rated up to 100%. Very xeric to sub-xeric are rated up to 40%. Site series with poor and very poor soil nutrient regimes are rated up to 60%.

8 SSn and Use Attribute Assumptions Structural Stage Structural stages mature forest (06) to old growth (07) provide optimal habitat and are rated up to 100%. Structural stages pole sapling (04) and young forest (05) are rated up to 50% and 70% respectively. Low shrub (3a) and tall shrub (3b) provide low-level food and are rated up to 5 and 20% respectively. Non-vegetated and herbaceous structural stages (01 and 02) provide almost no food and are rated 5%. Stand Association Coniferous stands provide optimal security for marten. Broadleaf have open canopies in winter are rated up to 20%. Canopy Closure Sites with high canopy closure provide optimal security and are up to 100%. For the most part, effect of canopy closure has been incorporated into the site series and Stand Association assumptions described above. Coarse Woody Debris 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 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 American marten. 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: Marten. U.S.D.I. Fish and Wildlife Service. FWS/OBS-92/ pp. Buskirk, S. W. and R. A. Powell Habitat ecology of fishers and American martens. Comstock Publishing Assoc. Cornell Univ. Press. Buskirk, S.W Conserving circumboreal forests for martens and fishers. Conservation Biology 6:

9 Buskirk, S.W. and L.F. Ruggiero American Marten. 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. Clark, T. W., and T. M. Campbell, III Population organisation and regulatory mechanisms of martens in Grand Teton National Park, Wyoming. Proc. Of the first Conf. On Sci. Research in the National Parks, U. S. D. I. Nat. Park Serv., Trans. Proc. Series 5. Vol. 1. EBA Proceedings of a workshop on wildlife habitat use of selected species in the Muskwa-Ketchika Management Area. EBA Engineering Consultants Ltd. Grindal, S.D., R.D. Weir, and A. De Vries Winter habitat use by martens in young aspen stands in British Columbia. AXYS Environmental Consulting, Calgary, AB. Takats, L., Stewart, R., Todd, M., Bonar, R., Beck, J., Beck, B., and R. Quinlan American marten winter habitat. Habitat Suitability Index Model, Version 5. Koehler, G. M. and M. G. Hornocker Fire effects on marten habitat in the Selway- Bitterroot Wilderness. J. Wildl. Manage. 41(3): Lofroth, E.C Scale dependent analyses of habitat selection by marten in the Sub- Boreal Spruce Biogeoclimatic Zone, British Columbia. M.Sc. Thesis, Department of Biological Sciences, Simon Fraser University. Lofroth, E.C. and J.D. Steventon Managing for Marten Winter Habitat in Interior Forests of British Columbia. Ministry of Environment, Wildlife Branch. Nagorsen, D The Mammals of British Columbia. Royal British Columbia Museum Memoir No. 4. Royal British Columbia Museum and Wildlife Branch, Victoria. 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. Steventon, J.D. and J.T. Major Marten use of habitat in a commercially clear-cut forest. J. Wildl. Manage. 46(1): Stordeur, L Marten in British Columbia with Implications for Forest Management. Res. Branch, BC Ministry of Forests, Victoria. Streeter, R. G., and C. E. Braun Occurrence of marten in Colorado alpine areas. Southwest Nat. 13(4):

10 Thompson, I.D. and A.S. Harested Effects of Logging on American Marten With Models for Habitat Management. Pages in Buskirk, S.W., A.S. Harested, M.G. Raphael (eds.). Martens, Sables and Fishers: Biology and Conservation. Cornell University Press, Ithaca, N.Y. Weckwerth, R. P. and V. D. Hawley Marten food habitat and population fluctuations in Montana. J. Wildl. Manage. 26(1): Ministry of Environment, Lands and Parks (MELP) B.C. Conservation Data Centre: Rare Vertebrate Animal Tracking List. Internet web site: Committee on the Status of Endangered Wildlife in Canada (COSEWIC) Internet web site: Canadian Wildlife Service, Environment Canada.