SPECIES ACCOUNT MARTEN (m-maam)

Transcription

1 SPECIES ACCOUNT MARTEN (m-maam) General Marten (Martes americana; MAPE) are found across North America in a circumpolar distribution and are usually confined to forested biomes (Allen 198; Stordeur 1986). The marten is a member of the weasel family and is found throughout BC, where the species is yellow- listed. Economically, they are the most important furbearer harvested. Marten require old growth forests with high levels of coarse woody debris (CWD). Martens are good climbers and often venture into the trees. They avoid dry areas, open forests, extensive stands of aspen or lodgepole pine and sub-alpine shrub lands with only scattered stands of trees (Blood (no date)). Primary predators of marten are Great Horned Owls, lynx, coyote and fisher. Marten are scarce in settled areas, farmland, grassland and alpine zones. Their economic importance and dependence on late successional stands make marten a good indicator species for old, structurally complex forests. Critical Seasons The critical time period for marten is when snow is present on the ground. At this time their mobility is limited by deep snow and the number and species of prey are limited. The limiting requisite for marten populations is the presence of large CWD in the understory. For the purposes of the model two seasons, growing (the snow free season) and dormant (the snow present season) will be used. The snow free season is defined as May-October while the snow present season is defined as November to April. Marten require coarse woody debris (CWD) and large diameter (DBH) snags to provide access to subnivean sites which are used for foraging and resting sites in winter. Migration Martens do not undergo seasonal shifts in home ranges, and only rarely do they migrate in the face of environmental unpredictability (Buskirk and Ruggiero 199). Densities Archibald and Jessup (198) estimated that fall density of resident adult marten in their Yukon study area to be 0.6/km 2. High quality marten habitat in the BC interior may support a maximum late winter density of 2.0 marten/km 2 (Lofroth and Steventon 1990). Diets Key prey species in the Morrison area include snowshoe hare, voles, mice and red squirrels. During the dormant season larger prey is captured (snowshoe hares, squirrels, grouse) which provide marten with multiple meals, but voles (especially red-backed voles) remain of primary importance (Buskirk and Ruggiero 199). Primary food species vary with geographical area but include: Microtus spp., birds, squirrels, snowshoe hares and beaver ( Lensink et al 1995; Douglas et al. 1983). Additional prey available during snowfree months includes bird eggs and nestlings, insects and fish (Buskirk and Ruggiero 199). During the growing season, fruits (raspberries, blueberries), when abundant and available to marten, are eaten in large amounts (Buskirk and MacDonald 198; Lensink et al. 1955). Natal Dens There is little information on natal dens used by marten in BC. Because kits are born in mid-march to early April, wet weather conditions and residual snow probably greatly influence den site selection (Lofroth and Banci 1991). Natal den sites have been suggested by some authors to limit marten populations (Bergerud 1969; Wynne and Sherburne 198). The literature records marten whelping den sites in tree cavities, hollow logs or log piles, old stumps or root masses of large trees, in cavities in piles of rocks, or in squirrel middens (numerous authors cited in Buskirk and Ruggiero 199). It is unclear whether females select den sites that differ from male resting sites (Buskirk and Ruggiero 199). Territoriality Marten are solitary except during the breeding season (July and August). Males are pugnacious and polygamous. Home ranges are exclusive within but not between sexes (Katnik et al. 199). Reported home range size of males varies from 0.8 to 15.7 km 2, and that of females is about one half the size of males' (Buskirk and Ruggiero 199). In the SBSmc, Lofroth (1993) found average male home ranges of 5.25 km 2 while female home ranges averaged 3.16 km 2 Home range size of martens varies with geographical area as well as with prey abundance and habitat type (Buskirk and Ruggiero 199).

2 CALIBRATION AND STANDARDIZATION IN BC Provincial Distribution Marten are resident in BC and are found throughout BC. They range from sea level to timberline but are generally found at higher elevations in the snow-free season (Cowan and Guiget 1978). Best Habitats Best habitats for marten are those that provide coniferous forests, particularly those dominated by spruce and balsam fir with large amounts of CWD that support healthy populations of small mammals and or snowshoe hares. The provincial benchmark is unknown. Information Sources Information from the SBSmc2 is available and has been used to develop the model. Information from other studies in central BC, Alaska, the Yukon, and the US was also used. Information Gaps There is little information on characteristics of natal dens used by female marten in BC. Knowledge is almost completely lacking regarding behavioural or population responses of martens to such landscape attributes as stand size, stand shape, area of stand interior, amount of edge, stand insularity, use of corridors, and connectivity (Buskirk 1992). SEASONAL HABITAT REQUIREMENTS Assumptions Iit is assumed that recorded habitat preferences reflect habitat requirements, and that habitat preferences are reflected in changes in individual fitness Limiting Habitat The limiting life requisite for marten is the availability of high quality dormant season habitat. Of particular importance is the presence of large diameter CWD and snags which are used for thermal and security cover and access to the subnivean layer. Growing Season Habitat Use/requirements Marten prefer forests with 30-80% coniferous canopy cover and generally avoid areas with little to no cover (various authors). In the interior of BC, marten preferred habitats with abundant CWD (21-0 pieces/ha), little deciduous canopy cover (0-20%), low to moderate high shrub and low shrub closure, high basal area of trees and snags, high stocking of trees > 20 cm DBH and large DBH snags (1-20 m 2 /ha basal area) ( Lofroth 1993). In south-central Alaska, microtine rodents preferred by marten were those that were generally restricted to meadow habitats (Buskirk and MacDonald 198). Marten avoid xeric forests, young seral stages, lakes and wetland habitats (Lofroth 1993), although they may select riparian areas for resting and foraging. Breeding females require natal dens (see Natal Dens) for giving birth and raising kits. Dormant Season Habitat use/requirements The dormant season is critical for marten due to restricted mobility, increased thermoregulatory costs (Lofroth and Banci 1991) and decreased prey abundance. Seral stages 1a/b, 2 and 3a/b are not used by marten in the dormant season. Koehler et al. (1975) reported that during winter, marten avoid stands with less than 30% canopy closure. They also believed that marten avoided dense stands that suppressed herbaceous cover. Takats et al. (1995) reported that in south-central Alberta optimal canopy closure for winter cover is between 31 and 71%. During the dormant season, there is more selective use of late-successional coniferous stands (various authors cited in Buskirk and Ruggiero 199). Most resting sites of marten in south-central Alaska were red squirrel middens (both active and inactive) located in old-growth stands of white spruce or white spruce-paper birch with canopy cover >60% (Buskirk 198). Aspects between 135 and were selected, and selection of resting sites reflected preferences for red squirrel habitat. Resting sites were selected for their thermoregulatory advantages and for their protection from predators. During cold weather marten in the Central Rocky Mountains used subnivean sites and remained in them for longer periods than in warmer weather when they sometimes rested above the snow (Buskirk et al. 1989). Marten save approximately 25% of their energy expenditure by resting in subnivean sites instead of above the snow (Sherburne and

3 Bissonette 199). Spruce-fir forests provided marten with higher levels of subnivean CWD (Buskirk et al. 1989), and only older forests with accumulated CWD provide the forest floor structure necessary to enable marten to forage efficiently in winter (Sherburne and Bissonette 199). Old growth spruce-fir stands were used more than expected and even-aged, regenerating lodgepole pine stands were used less than expected. Resting sites were closer than expected to streams and lakes. Marten are able to determine where high levels of prey are found under the snow (Sherburne and Bissonette 199). In south-central Alaska, Buskirk and MacDonald (198) found herbaceous and low shrub meadow habitats supported the most diverse and abundant small mammal populations, followed by coniferous-dominated forests. Tall shrub thickets and deciduous-dominated forests supported the lowest small mammal populations. Food habits are affected by availability, preference and availability of alternate prey. In the SBS zone small mammals are most abundant in habitats that have % cover of low shrubs and 100 m 3 /ha of dead and down woody material (Lofroth and Banci 1991). Confounding Factors Populations experience frequent fluctuations in density (Stordeur 1996). Ther is evidence of avoidance by juveniles of high-quality habitat occupied by adults (Buskirk and Ruggiero 199). Juveniles occupy a wider range of habitat types than adults. Seasonal variation in habitat selection has been reported by most authors who have analysed their data for it. There is little evidence of shifts of home range boundaries to encompass different habitat types, but martens seasonally adjust their selection of stands within stable home ranges (Buskirk and Ruggiero 199). Summary of Key Seasonal Habitat Attributes (Table M1, M2) High value habitats for marten, in both seasons, have the following attributes: mature to old structural stage, especially those with complex physical structure near the ground conifer dominated tree canopy (0-20% deciduous in canopy), canopy closure >30%, CWD > 100m 3 /ha, CWD in a range of sizes with some > 0 cm DBH, presence of large DBH snags, presence of dense conifer regen, forest moisture regime mesic to hydric. Sites that are avoided include: xeric areas, young structural stages, open areas (some use may occur in the no snow season only), areas with little CWD and snags, areas with primarily deciduous canopies.

4 Table M1. Summary of growing season (May-October) habitat requirements for marten in the study area. Habitat Attributes Required Structural Stage Thermal cover and Security cover (ST) Food (FD) large conifers >0 cm DBH with broom rusts, conifer dominated stands with > 30 % canopy closure, wetter than mesic site series, deciduous <20%, presence of snags >0 cm DBH. wetter than mesic sites, abundant CWD (>100m 3 /ha), well developed herb layer, dense conifer regen. 6 or 7 6 or 7 Table M2. Summary of dormant season (November-April) habitat requirements for marten in the study area. Habitat Attributes Required Structural Stage Thermal and Security cover (ST) Food (FD) CWD to provide access to subnivean layer (some should be off ground and sticking up), conifer dominated stands with > 30 % canopy closure, wetter than mesic site series, deciduous <20%, presence of snags >0 cm DBH. wetter than mesic sites, abundant CWD (>100m 3 /ha), well developed herb layer, dense conifer regen. 6 or 7 6 or 7

5 ECOSYSTEM UNIT (EU) VALUES AND ASSUMPTIONS The following assumptions were made when constructing the species model and assigning ratings to each habitat: Marten requirements for security and thermal cover in the growing and dormant seasons are reflected in their choice and use of resting sites. The stand level attributes identified and used in this model accurately reflect high value marten habitats. The regional field guide (Banner et al. 1993) accurately predicts characteristics of ecosystems in the study area. Predation, disease, intra/interspecific competition and trapping have been excluded from the model. Habitat requirements and use are similar to that found in studies conducted in other parts of Canada and the US. Using information available on the site series occurring in the study area (ie moisture regime, canopy closure, tree species composition, shrub density) site series SB (01), TC (05), SO (06), BF (07), SD (09), SH (10) in the SBSmc2 and FB (01), FT (05), FO (06), FD (07) and FH (10) in the ESSFmc are expected to provide high and moderate value marten habitats in the Morrison area. Mature and oldgrowth structural stages (6 and 7) will provide the highest value habitats for marten in both the growing and dormant seasons. Structural stages 3a and 3b may be used by marten during the growing season for feeding on berries. Structural stages 1-2 and -5 are expected to be of low value to marten. Table 3 lists the expected key marten habitats, their important attributes and expected season of use. While habitats in Table M1 may be limiting, sufficient amounts of large CWD and snags must be present if marten are to use them.

6 Table M3. Predicted high value marten habitats in the Morrison River study area. Expected use Habitat Attributes important to marten Site series name Code SBScm2 feeding, thermal and security cover thermal and security cover mesic, > 30% tree canopy closure, dense shrub layer, no to small deciduous tree component very moist to wet forest, >50% tree canopy closure, minor deciduous component ESSFmc Sxw-Huckleberry SB (01) Sxw-Twinberry-Coltsfoot TC (05) Sxw-Oak fern SO (06) Sxw-Devil=s club SD (09) Sxw-Horsetail SH (10) Sxw-Scrub birch-feathermoss BF (07) feeding, thermal and security cover fresh to moist forest, trees have good growth, shrub layer well developed, Bl-Huckleberry-Leafy liverwort FB (01) fresh to moist forest, large Bl and Sxw, lush shrub layer Bl-Huckleberry-Timbleberry FT (05) fresh to moist forest, large Bl Bl-Oak fern-heron=s-bill FO (06) Bl-Devil=s club-lady fern FD (07) very wet to wet forest, large Bl and Sxw, lush shrub layer Bl-Horsetail-Leafy moss FH (10) DRAFT ECOSYSTEM UNIT RATINGS Ratings Scheme -six class rating scheme (1=very high; 2=high; 3=moderate; =low; 5=very low; 6=nil) Ratings will be assigned for thermal cover (TH); security cover (SH); denning (DE) and feeding (FD); when TH and SH values can not be separated, the habitat will be rated for both and the code ST will be used. These codes correspond to the codes on the new Wildlife Habitat Assessment Form which will be used to assign ratings to habitats visited during field surveys. Appendix 1 lists draft ratings for the site series and structural stages expected in the study area. Amounts and sizes of CWD and snags will be quantified for each site series during field sampling. The preliminary ratings scheme will be adjusted to take into account these factors.

7 Map Adjustments If a forested polygon is adjacent to a wetland, fen or carr, increase rating for foraging in the growing season by 1 (ie 3 increases to 2). This will reflect the possible increase in use of this site by marten to feed on the diverse small mammal population. If a clear cut contains Aislands= of uncut conifers increase the rating of the polygon for foraging in the growing season by 1 (ie 3 increases to 2). This will account for the fact that marten will use these Aislands@ for resting sites. If the continuous forest surrounding the polygon is < 1.5 km2, then decrease rating for forage and cover to. It is believed that this much forest is required to maintain resident marten in logged landscapes. Field Sampling Scheme In order to qualitatively rate habitats for marten the following information must be collected (Table M) at all sites visited during field sampling. Track counts during the winter months should be conducted as they will help to verify high and low use habitats during the dormant season. Table M. Attributes to be recorded during field sampling for marten. Attribute Structural stage Canopy closure Moisture regime Density of conifer regen Snag presence Coarse woody debris Presence of red squirrel middens* Use of habitat Sample Method Recorded on the Ecosystem Field Form Recorded on the Ecosystem Field Form Recorded on the Ecosystem Field Form Recorded on the Ecosystem Field Form Complete Wildlife Tree Form; as there is no place to specify snags write the tree number corresponding to snags in the mensuration portion of the form Complete a Coarse Woody Debris Form Record the number in the plot on the Wildlife Tree form in the comments section; note the number of active and inactive middens. Complete winter track transects *non-standard data to be recorded in addition to regular plot data. REFERENCES Allen, A.W Habitat suitability index models: Marten. U.S. Dep. Interior, Fish and Wildl. Ser. FWS/OBS-82/ p. Banner, A., W. MacKenzie, S. Haeussler, S. Thomson, J. Pojar and R. Trowbridge A field guide to site identification and interpretation for the Prince Rupert Forest Region. BC Ministry of Forests. Bergerud, A. T The status of pine marten in Newfoundland. Can. Field-Nat. 3(2): Blood, D.A. (No date). Marten: Management guidelines for British Columbia. Ministry of Environment,Lands and Parks. 6 pp. Buskirk, S.W Seasonal use of resting sites by marten in south-central Alaska. J. Wildl. Manage. 8(3): Buskirk, S. W Conserving circumboreal forests for martens and fishers. Cons. Biol. 6:

8 Buskirk, S.W. and L.L. McDonald Analysis of variability in home-range size of the American marten. J. Wildl. Manage. 53(): Buskirk, S.W., S.C. Forrest, M.G. Raphael and H.J. Harlow Winter resting site ecology of marten in the central Rocky Mountains. J. Wildl. Manage. 53(1): Buskirk, S.W. and S.O. MacDonald Seasonal food habits of marten in south-central Alaska. Can. J. Zool. 62: Buskirk, S., and L. Ruggiero American Marten. Ch. 2 in American Marten, Fisher, Lynx and Wolverine in the Western United States: The scientific basis for conserving forest carnivores. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station. Gen. Tech. Report RM-25. Corn, J.G. and M.G. Raphael Habitat characteristics at marten subnivean access sites. J. Wildl. Manage. 56(3):2-8. Cowan, I. Mct., and C. J. Guiguet The Mammals of British Columbia. BC Provincial Museum, Victora, BC. Douglas, R.J, L.G. Fisher and M. Mair Habitat selection and food habits of marten, Martes americana, in the Northwest Territories. Can. Field. Nat. 97:71-7. Hargis, C.D and D.R. McCullough Winter diets and habitat selection of marten in Yosemite National Park. J. Wildl. Manage. 8(1): Katnik, D. D., D. J. Harrison, and T. P. Hodgman Spatial relations in a harvested population of marten in Maine. J. Wildl. Manage. 58: Koehler, G.M., W.R. Moore and A.R. Taylor Preserving the pine marten: management guidelines for western forests. Western Wildlands. 2:31-36 Lensink, C.J., R.O. Skoog and J.L. Buckley Food habits of marten in interior Alaska and their significance. J. Wildl. Manage. 19(3): Lofroth, E. and V. Banci Marten habitat suitability research project: working plan. Lofroth, E Scale dependent analyses of habitat selection by marten in the Sub-Boreal Spruce Biogeoclimatic zone, British Columbia. Masters Thesis. Simon Fraser University, Burnaby BC. 109pp Ministry of Environment, Wildlife Branch. Wildlife Working Report No. WR pp. Masters, R.D Daytime resting sites of two Adirondack pine martens. J. Mammal. 61:157. Sherburne, S.S. and J.A. Bissonette Marten subnivean access point use: response to subnivean prey levels. J. Wildl. Manage. 58(3): Spencer, W.D Seasonal rest-site preferences of pine martens in the northern Sierra Nevada. J. Wildl. Manage. 51(3): Stordeur, L.A Marten in British Columbia with implications for forest management. Research Branch, B.C. Ministry of Forests and Lands. WHR-25. Victoria BC. Takats, L., R. Stewart, M. Todd, R. Bonar, J. Beck, B. Beck and R. Quinlan Draft habitat suitability index (HSI) model for marten (winter habitat). Foothills Model Forest, Hinton, AB. Wynne, K. M., and J. A. Sherburne Summer home range use by adult marten in northwestern Maine. Can. J. Zool. 62:91-93.

9 Appendix M1. Preliminary Habitat Capability Ratings For Marten in the Morrison Study Area. Habitat unit Dormant season (October-April) Growing season SBSmc2 SB (01) D;S T 3FD; 3SH 3FD; SH 6 D; D; PF (02) FD; 5FD; 5FD;5 ST 6 D;S T D; BM (03) D; SH D; SH D; SH 6 D; D; TC (05) D; SH 1FD; 1SH 1FD; 1SH 6 D; D; SO (06) D; SH 1FD; 1SH 1FD; 1SH 6 D; D; BF (07) D; SH 1FD;1S H 1FD;1SH 6 D; D; SD (09) D; SH 1FD; 1SH 1FD;1 SH 6 D; D; SH (10) D; SH 1FD;1 SH 1FD; 1SH 6 D; D; ST SS (12) CF (31) 6 6 CA FD; 3FD; 3FD; WT FD; 3FD; ESSFmc FB (01) FD; ST 3FD; ST 3FD; ST 6 D; ST D; ST LC (02) FC (03) 6 6 D; ST 5FD; ST 5FD; ST 3ST; D HH (0) 6 6 D; ST 5FD; ST 5FD; ST 3ST; D FT (05) 6 6 D; ST 5FD; ST 5FD; ST 3ST; D FO (06) 6 6 D; ST 5FD; ST 5FD; ST 3ST; D 3ST; D 6 5FD; ST 5FD; ST 5F 3ST; D ST; D S 3ST; D S FD(07) 6 6 D; ST 5FD; ST 5FD; ST 3ST; FD 3ST; FD S FV (08) 6 6 D; ST 5FD; ST 5FD; ST 3ST; FD 3ST; FD 6 D; ST D; ST HG (09) 6 6 D; ST 5FD; ST 5FD; ST 3ST; FD 3ST; FD FH (10) ; FD ; FD 3ST; FD 3ST; FD 6 6 D 1F S

10 Habitat unit Dormant season (October-April) Growing season CF (31) 6 6 AF (33) 6 6 AC (35) 6 6 SL(51) 6 6