tiger beeties, grasshoppers, butterflies) throughout 

 the entire Centennial Valley. This survey work 

 would help place the significance of the Sandhills- 

 associated fauna in the larger landscape context. 

 In conjunction with habitat modeling, valley- wide 

 surveys could further inform management regard- 

 ing patch size requirements and distribution across 

 the landscape. Because the Centennial Valley is 

 an integrated system, management of special 

 concern species should be conducted across the 

 entire valley rather than at specific sites within the 

 valley. Species such as early-succession sandhills 

 obligate plants and invertebrates, restricted to 

 unique sites and requiring special management 

 attention, are the exceptions. 



Finally, we also recommend additional survey 

 work be conducted in the Sandhills themselves for 

 two reasons. First, Sandhills distribution and 

 status for vertebrate species of special concern or 

 high conservation interest including Preble's 

 Shrew, Pygmy Rabbit, Black-tailed Jackrabbit, 

 Great Basin Pocket Mouse, Sage Thrasher, and 

 Grasshopper Sparrow are still uncertain, and 

 microhabitat relationships remain largely unknown. 

 To understand how these species will respond to 

 prescribed disturbance in the Sandhills requires 

 better information about their habitat requirements 

 and distributions. Second, there are groups of 

 invertebrates that were not tiioroughly surveyed 

 but which are known to contain sandhills-obligate 

 species (spiders, ground beetles, grasshoppers) 

 closely tied to early stages of succession (Rust 

 1986), or species with specific food plant require- 

 ments (butterflies) that serve as indicators of the 

 spectrum of sandhills habitats. These groups 

 probably are the best animal indicators of the 

 overall health of the Centennial Sandhills because 

 their requirements are quite specific. 



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