Small Mammal Response to Clearings 131 



important to capture of all six species, but abiotic factors (rocks, slope, 

 water) were also important to capture of S. fumeus, B. brevicauda, P. 

 leucopus, and O. nuttalli. Habitat characteristics selected by most spe- 

 cies were similar to those reported by previous investigators, but there 

 were a few notable exceptions. The similar relative abundance of S. 

 fumeus and B. brevicauda on southfacing and northfacing slopes would 

 be unexpected based on the findings of Manville (1949), Pruitt (1953), 

 Wetzel (1958), Getz (1961), and Barbour and Davis (1974) who reported 

 moisture as important to the occurrence of shrews. Contrary to Getz 

 (1961), we did not find leaf cover correlated with soricid capture. Gott- 

 schalk and Shure (1979) and Bormann and Likens (1979) reported that 

 herbicides and clearcutting, respectively, will increase leaf litter decom- 

 position rates and increase microarthropod populations; microarthro- 

 pods are important food items in soricid diets. Log cover was important 

 to capture of both species; logs may serve as moisture-maintaining cover 

 and/ or feeding sites for shrews. Several authors have reported B. brevi- 

 cauda to be tolerant of a wide range of habitats (Getz 1961; Briese and 

 Smith 1974; Geier and Best 1980), but no similar estimate of tolerance is 

 available for S. fumeus. We found S. fumeus not as tolerant of site 

 differences as B. brevicauda, but it was relatively tolerant of site change 

 within the small mammal community we sampled. Sorex fumeus and B. 

 brevicauda were similar in abundance on each aspect and treatment, 

 and both selected similar microhabitats. The number of logs per 4 m 2 

 was the most useful variable in predicting captures of both species, and 

 log cover was also important to both species. Occurrence of S. fumeus 

 was positively associated (r = +0.31; SPRC = +0.26) with understory 

 species richness on northfacing slopes, while B. brevicauda occurrence 

 was associated negatively (SPRC = -0.12) with understory species rich- 

 ness in the habitat-wide regression model. Geier and Best (1980) also 

 reported low plant species richness as important to occurrence of B. 

 brevicauda. Coexistence of these shrews seems to be allowed by subtle 

 differences in vegetative structure. Additional research is needed to 

 determine differences in foods, microhabitats, and microclimates of 

 these two sympatric soricids. 



Dueser and Shugart (1978) compared microhabitat characteristics 

 among P. leucopus, O. nuttalli, and T. striatus. Our results support 

 their findings: P. leucopus and T. striatus are more tolerant of a wide 

 range of habitat characteristics than are O. nuttalli. We found O. nut- 

 talli associated (r>0.40) with high log cover and canopy openings 

 (+DST, +DSS, and -BA) on ridges and north slopes. Peromyscus leu- 

 copus was associated to that degree (r>0.40) with low crown cover on 

 ridges, but otherwise was not strongly associated with any particular 

 habitat characteristics, and T. striatus occurrence was not correlated 



