and granivores — deer mice, western jumping mice, 

 and Great Basin pocket mice — were caught in the 

 nonponded habitat. Each of the herbivorous and 

 insectivorous species trapped in the beaver pond 

 habitat at Summit Creek has been shown to prefer 

 or characterize areas with substantial herbaceous 

 ground cover (Clark 1973; Hooven and others 1975; 

 Feldhamer 1979; Smolen and Keller 1987). 



In sum, we found clearly marked differences in 

 small mammal populations and community compo- 

 sition between a willow-dominated beaver pond 

 ecosystem and an adjacent nonponded riparian 

 habitat. Relative small mammal density and 

 standing crop biomass were two to three times 

 higher in the moist, densely vegetated beaver pond 

 habitat when compared to the drier, more sparsely 

 vegetated adjacent riparian habitat. Among four 

 foraging guilds represented on the Summit Creek 

 site, herbivores and insectivores were numerically 

 dominant in the beaver pond complex. We suggest 

 that the dense and structurally more complex 

 vegetation of the beaver pond ecosystem produced 

 the food and cover resources needed to support 

 higher relative populations of small mammals. 



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