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• adjacent mountain shrub community. A measure of community similarity calculated <br />between all habitat types (Table 2.7-I) shows its highest value (.401) between the <br />mountain shrub and sagebrush. Of the 48 species seen in the sagebrush community <br />32 were also seen in the mountain shrub. Of the remaining 16 species, 12 were also <br />seen in the adjacent riparian vegetation. This leaves four species seen in the <br />sagebrush: eastern kingbird (Tyrannus t ry annul) (only a few seen), sage thrasher <br />(OreoscopTes montanus), black-throated sparrow (Amphispiza bilineata), and sage <br />sparrow (A. Belli), the latter two seen only as transients. <br />In the winter, the sagebrush is less important, supporting only a low abundance <br />of birds (I per km). The fairly high winter diversity is at least somewhat due to the <br />higher diversities in adjacent riparian and mountain shrub communities (Figure 2.7- <br />4). <br />Unreclaimed -Summer bird abundance in the pre-law mining area is <br />substantially lower than the areas of natural vegetation, although diversity and <br />species richness (57 species) is similar to that in mountain shrub and sagebrush <br />(Exhibit 2.7-3). The importance of the unreclaimed area To birds on the mine <br />complex occurs primarily in the winter when this area supports over 20 birds per km, <br />• higher than any other vegetation type (Exhibit 2.7-4). IT should be noted, however, <br />that 78 percent of this winter abundance is due to common crows (Corvus <br />brachyrhynchos). Their presence is at least partially influenced by the location of <br />a refuse dump within 2 km of the transect. <br />There is only one species Thar was observed exclusively in the unreclaimed <br />area: the black-chinned-hummingbird (Archilochus alexandri). This single ob- <br />servation is regarded as accidental and does not reflect a dependence on the <br />unreclaimed area. The lack of uniqueness of bird species in this area is not <br />surprising, as its vegetation consists of aspen, grass and sagebrush, all of which were <br />sampled in other areas. A measure of community similarity (Table 2.7-I) shows that <br />the unreclaimed area is most simior (0.341) to the aspen. Also of interest is the very <br />low similarity (.037) between the unreclaimed and the other disturbed site, the <br />reclaimed grass. This can be partially explained by The fact that the unreclaimed <br />area has been available to invading species for about 30 years, but the diverse <br />topography in the unreclaimed area is obviously also an important factor. <br />Reclaimed Grass -The reclaimed grass area does not support a very <br />diverse or abundant bird community. Summer abundance, summer diversity, and <br />• winter diversity are lower than all other habitat types and winter abundance, <br />although slightly higher than abundance in the sagebrush, is still very low (I.5 per <br />2.7 - I I <br />