Small Mammals and Other Vertebrates 



Small mammal populations were sampled in September of 1978 using a combination 

 of snap and pitfall traps. September was chosen as the trapping period in an 

 effort to sample populations near the peak of their annual cycle. The locations 

 of all trapping sites and their code numbers are shown in Figure 8. Four snap 

 trap lines, each consisting of 25 stations (2 traps/station, for a total of 50 

 traps per line) located at 15 m (45 ft.) intervals, were operated for three con- 

 secutive nights (September 3-5, 1978). Two of these trap lines (Nos. 1 and 2) were 

 set in typical riparian grassland habitats in an area likely to be inundated should 

 the project be implemented. The two remaining lines (Nos. 3 and 4) were set in 

 typical nonriparian larch-cedar coniferous forest habitats adjacent to the grass- 

 land. Total trapping effort for these lines was 600 trap-nights (200 traps x 3 

 nights). In addition to snap trap lines, four additional lines, each consisting 

 of 4 sunken-can ("pitfall") traps at 15 m (45 ft.) intervals, were run during the 

 same period. These lines sampled typical forest-edge shrub (no. 5), streamside 

 within larch-cedar forest (no. 5), shrubby Douglas fir-dominated forest (no. 7), and 

 rockslide habitats (no. 8). All traps were removed at the end of the trapping period. 

 Animals captured were weighed, measured, sexed, and identified to species. Standard 

 study skins and skulls were prepared of all species except the deer mouse. 



Observations of large mammals other than ungulates, all canivores, rodents, 

 amphibians, and reptiles were collected incidental to other activities. Data recorded 

 for the three latter groups included: date, location, habitat type, elevation, and 

 aspect. 



RESULTS 



Habitat 



The area south of the river in the vicinity of Kootenai Falls is heavily 

 timbered and falls within the relatively moist western red cedar/queencup 

 beadlily and western hemlock/queencup beadlily types, while the area to the 

 north falls primarily within the much drier Douglas fir/ninebark, Douglas fir/ 

 bluebunch wheatgrass and Douglas fir/snowberry habitat types. Rocky outcrops, 

 grassy meadows, and scree slopes are much more prevalent north of the river. A 

 map of terrain types is shown in Figure 7. A detailed description of the vegeta- 

 tion of the primary study area, including the results of the quantitative survey, 

 are presented in Appendix A. 



Summary of Fauna Observed 



Inventory data for 66 species of birds and 24 of mammals encountered during 

 this study are summarized in Tables 1 and 2, respectively. The only reptiles 

 observed were a group of nine western garter snakes {Thcamophis elegans vagrans) 

 found beneath discarded sheet metal in riparian grassland near the head of Kootenai 

 Falls. Stebbins (1966) however indicates that at least 14 other species of reptiles 

 and amphibians occur in this region of the state. 



Small mammal trapping conducted by DNRC personnel 



14 



