MONTANE

Scientific Name: montanus Species Code: M-MIMO

Status: Yellow-listed

Distribution • Provincial Range In Montane are at the northern limit of their range. They occur in the southern interior of British Columbia in the Okanagan, Kettle and Thompson valleys north to the Cariboo.

• Elevational Range: 300 to 1200m

• Provincial Context The abundance of Montane Voles in the province is not known.

• Project Area: Ecoprovince: Central Interior Ecoregions: Fraser Plateau Ecosections: Central Chilcotin Ranges (CCR), Chilcotin Plateau (CHP) and Fraser River Basin (FRB) Biogeoclimatic Zones: BGxh3, BGxw2, IDFxm; IDFdk3; IDFdk4; MSxk; MSxv; ESSFxv2, ESSFxvp2; SBPSxc The ecosections and biogeoclimatic zones that have been italicized indicate areas within the project area, that have suitable habitat for the species under consideration, and have therefore been rated.

Ecology and Key Habitat Requirements In British Columbia the Montane Vole is found only in the valleys and seems to prefer arid short grassland (Banfield 1974). They occur in well-vegetated (>60% cover) grassland where burrowing is fairly easy. In the Chilcotin, Montane Voles are more common in the middle and higher elevation grasslands rather than the lower elevation grasslands. In the lower grassland areas they usually occur near hayfields where the grass cover is higher. Montane Voles occur in wide open, short-grass prairie, where the vegetation may be dense, but close to the ground.

Habitat Use and Life Requisites The life requisite that will be rated for Montane Voles is living, which is satisfied by the presence of suitable feeding and security/reproducing habitats, as described in detail below.

• Living The life requisite that will be rated for Montane Vole is Living. The Montane Vole occupies the same habitat year round, with foraging, underground breeding habitat and cover being provided by the same small area. They inhabit upland semi-arid grasslands for all life requisites. Their preferred grassland habitats have 60-70% grass-sedge cover, with total vegetative cover being much higher. The Montane Vole is a weak burrower, and requires soft soils for easy digging. They tunnel in the grassland to the extent that there is no longer much vegetation left growing on the surface.

Seasons of Use Feeding and security habitats are required throughout the year. Table 1 summarizes the life requisites required for each month of the year.

Table 1. Monthly Life Requisites for Montane Voles.

Life Requisite Month Season Living January All Living February All Living March All Living April All Living May All Living June All Living July All Living August All Living September All Living October All Living November All Living December All

Habitat Use and Ecosystem Attributes Table 2 outlines how each life requisite relates to specific ecosystem attributes (e.g., site series/ecosystem unit, plant species, canopy closure, age structure, slope, aspect, terrain characteristics).

Table 2. Terrestrial Ecosystem Mapping (TEM) Relationships for each Life Requisite for Montane Voles.

Life Requisite TEM Attribute Living - site: site disturbance, structural stage, slope - soil/terrain: terrain texture, flooding regime - vegetation: % cover by layer, species composition

Ratings There is an intermediate level of knowledge on the habitat requirements of Montane Voles in British Columbia and thus, a 4-class rating scheme will be used.

• Provincial Benchmark Ecosection: Fraser River Basin (FRB) Biogeoclimatic Zone: BGxw2 Habitats: Grasslands with dense-grass sedge cover

• Ratings Assumptions 1. Open grassland habitats with a dense cover of grass or sedges will be rated up to high. 2. Grasslands that have been heavily grazed will be rated lower. 3. Disturbed / agricultural habitats rated up to high (i.e. cultivated fields).

Table 3. Summary of habitat requirements for Montane Voles in the study area.

Season Life Requisite Structural Stage Requirements All Seasons Living (LI) 2 open grasslands with a dense cover of grasses and sedges

• Ratings Adjustment Considerations Final capability and suitability map products may incorporate 1) landscape heterogeneity and connectivity; 2) habitats adjacent to significant anthropogenic disturbance regimes (e.g. settlements); 3) interspersion of different structural stages within the landscape.

Please note that eventhough structural stage substage or modifiers and stand composition modifiers were employed in the original mapping, these units (other than structural stage modifier 3a and 3b) have not been included in the final ratings tables. This is because the ratings for the modified and unmodified ecosystem units are the same and including these units in the final ratings table would in turn make the ratings table too cumbersome. In instances where the modified ecosystem unit (either structural stage substage or modifiers and stand composition modifiers) is mapped, please use the wildlife habitat rating for the same unmodified ecosystem unit.

References

Banfield, A. 1974. The of Canada, University of Toronto Press.

Roberts, G. 1994. Comparison of Populations of Ungrazed and Grazed Areas in the Chilcotin Grassland subzone BGxw2. unpublished report submitted to Ministry of Environment Lands and Parks. 30pp.

Stevens, V. and S. Lofts. 1988. Wildlife Habitat Handbooks for the Southern Interior Ecoprovince. Volume 1: Species Notes for Mammals. Wildlife Report No. R-15. Ministry of Environment, Wildlife Branch. Victoria, B.C.