Water Shrew 125 



AQUATIC MACROINVERTEBRATES 



Aquatic macroinvertebrate communities were sampled in June 1995 at 

 each stream to provide information on the species composition and relative abun- 

 dance of the shrew's primary food source. A D-frame dip net was used to collect 

 organisms along a 100-m stretch. All primary habitats were sampled, including 

 riffles, pools, bank areas, and woody debris; the material collected was compos- 

 ited into one sample per stream. 



Invertebrates were removed from the samples in the laboratory under a 

 stereo-microscope after addition of rose bengal to facilitate the sorting process. 

 A minimum of 200 organisms was randomly picked from the samples; picking 

 ending when no new taxa were observed. Organisms were identified with the 

 taxonomic keys in Merritt and Cummins (1996) and Pennak (1989). 



RESULTS 

 DISTRIBUTION 



Sorex palustris was collected along four streams of the Potomac River 

 drainage in Highland County. Along with the original Little Back Creek site 

 (Pagels and Tate 1976, Pagels 1987) in the James River drainage in Bath Coun- 

 ty, it is now known from five Virginia localities, all on Allegheny Mountain. 

 Three of the new sites are in the George Washington and Jefferson National 

 Forests in the Laurel Fork area of northwestern Highland County. The other site 

 is on private property just west of Hightown, Virginia, and is the site since tim- 

 bered by the land owner. The continued existence of the water shrew at this site 

 after timbering has not been confirmed. General locations of the sites where S. 

 palustris has been captured in Virginia are given in Figure 1 . 



Four other species of shrews, the short-tailed shrew {Blarina brevicau- 

 da), masked shrew (Sorex cinereus), smoky shrew (S. fumeus), and rock shrew 

 (S. dispar), were captured on traplines with S. palustris at all Highland County 

 sites except the private property site where no S. dispar was taken. Sorex fumeus 

 represented 66.5%, S. cinereus 17.9%, S. dispar 6.9%, B. brevicauda 4.6%, and 

 S. palustris 4.0% of the 173 shrews taken at the four Highland County sites 

 where S. palustris was captured. A summary of all S. palustris captured in Vir- 

 ginia, including records in Pagels and Tate (1976), and Pagels (1987), is given in 

 Table 3. 



HABITAT 



Habitat characteristics of all streams were typical of relatively pristine 

 headwater streams of the Virginia mountains (Table 4). Streamwater was cool, 

 had a circum-neutral pH, and low to moderate conductivity. All streams were 

 either first or second order and hence had a narrow channel and wetted width. 

 Channel gradients were a relatively steep 7-14%. A variety of flow regimes 

 Table 4. Means, standard errors, and ranges of geomorphic, hydrologic, and 



