Sorex hoyi in Idaho: a new state record

Publication Type:

Journal Article

Authors:

Foresman, Kerry R.

Source:

Murrelet, Pacific Northwest Bird and Mammal Society, Volume 67, Issue 3, p.81-82 (1986)

Call Number:

A86FOR01IDUS

Keywords:

pygmy shrew, Sorex hoyi

Abstract:

The pygmy shrew (Sorex hoyi) ranges throughout most of Canada to Alaska and south into the United States. Specimens have been collected from two localities in Washington and four in Montana. Distribution maps for this species include the northern panhandle of Idaho in the probable range between Washington and Montana localities although no specimens collected from Idaho. On 19 June and 2 September 1985, single individuals were collected in pitfall traps along the South Fork of Spruce Creek in Idaho County, Idaho (T38N R6E Sect 25) at an elevation of 1603 m. The trapline consisted of 36 (later 50) No. 10 cans placed flush with the ground surface in a non-random, selective manner depending upon the habitat characteristics deemed most suitable for shrews. These were the only specimens of S. hoyi caught in two trapping periods of 12 and eight days duration (957 total trap nights) although the masked shrew (Sorex cinereus) and the vagrant Shrew (S. vagrans) were commonly taken. Additionally, specimens of the montane vole (Microtus montanus) and the northern pocket gopher (Thomomys talpoides) were taken in the pitfall traps while the northern red-backed vole (Cethrionomys gapperi) was commonly taken in museum special traps. Dominant overstory consisted of subalpine fir (Abies lasiocarpa), grand fir (Abies grandis) and lesser amounts of Engelmann spruce (Picea engelmannii), with an understory of mountain gooseberry (Ribes spp.), huckleberry (Vaccinium spp.), and extensive horsetail (Equisetum spp.), interspersed with sedges (Carex spp.). The immediate area surrounding the collection sites was mesic with free-flowing rivulets. This wet-dry boreal habitat preference is consistent with that described for Sorex hoyi by many authors. Specimens from Montana and Washington, however, have been collected in a somewhat different habitat dominated by Douglas fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), and/or lodgepole pine (Pinus contorta) and western larch (Larix occidentalis). It is apparent that the pygmy shrew can inhabit a fairly wide variety of habitats.