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4 - 27 <br />• 4.3.5 BIRD STUDIES <br />The results of bird studies conducted during summer, fall, winter and spring are presented <br />on Table 4.3.5. Quantitative counts of bird species observed in various habitats were <br />conducted during the summer and fall periods (fable 4.3-6) and in spring (fable 4.3.7). The <br />counts were made by walking an 800 meter transect or for a one•hour period in each habitat <br />sampled and counting all the individuals of each species observed. Only unstructured <br />observations were made during winter because of the extreme scarcity of birds during this <br />season. Results of quantitative studies are useful for evaluating habitat affinities and seasonal <br />changes in diversity and abundance, and these results will tie closely with spring census <br />information. Ffty•six species of birds were identified within a one mile zone surrounding the <br />lease property. This species list includes notes on seasonal occurrence, abundance, and <br />habitat affinity that are based on the field observations of this study. <br />The results of the spring bird counts given in Tables 4.3-7 and 4.3-8 can be compared with <br />Table 4.3.6 to obtain an understanding of seasonal changes in avian abundance and diversity <br />among the major habitat types. <br />• There is a basic similarity among the results of the spring, summer, and fall data. Namely, <br />in all three seasons bird diversity is greatest in the riparian areas. <br />Within the lease area the distinction between riparian and upland habitats is less clear than <br />is seen downstream, south of the site, beyond the front of the Book Cliffs. This is largely due to <br />the canyon topography, which creates many microhabitat situations associated with lateral <br />draws and the slopes adjacent to drainages. Consequently, the separation of riparian and <br />upland habitats shown on Table 4.3.8 is somewhat arbitrary. The upland site listed in Table <br />4.3-8 is predominantly located on the valley floors of tributaries of East Salt Creek, but these <br />tributaries represent ephemeral drainages that are usually dry. There tends to be denser <br />vegetation here; however, than occurs on the upper slopes. These sites therefore, are <br />somewhat intermediate between the moist habitats near East Salt Creek and the dry habitats <br />higher on the slopes. Avian diversity undoubtedly bears some correlation to this habitat <br />gradient, as is suggested in Table 4.3.8 which shows the fewest bird species for the driest site, <br />the mixed mountain shrub. <br /> <br />Ivlo Volume 1 4 - 29 - 96 <br />