Year-to-year changes in bird species richness, logarithmic standard 

 deviation (sigma), and number of species (excluding visitors, migrants, and 

 water birds) for June runs of the five roadside survey routes are shown in 

 Figures 16-18. Note that the relative positions of the routes on these graphs 

 remain fairly constant from year to year. Figure 19 shows the species curve 

 obtained by pooling 1977-1980 May-June data for the five routes combined; also 

 note that this species curve is remarkably similar to those based on earlier 

 data, and that the mode of the curve advances almost exactly one octave to the 

 right with each doubling of sample size. 



No new breeding species were observed in 1980 (Table 14). When all May-July 

 data for the period 1977-1980 are pooled, the number of breeding species 

 actually observed is 101 (Table 14), and the theoretical number of species 

 present in the sampling universe is 104. Sampling of the habitats along the 

 five routes, therefore, appears to be 97% complete. For individual routes, 

 sampling completeness based on pooled May-July 1977-1980 data ranges from 83°o to 

 93°o. Even though less than 2°o of the Reconnaissance Study Area was sampled by 

 the roadside survey method, the method appears to be very effective for 

 determining bird species composition. May-July 1977-1980 runs (a total of 60) 

 recorded 90?o of all breeding species and 89°o of all permanent residents observed 

 during the four-year study period (Tables 3, 14). 



For the Circle Route, similarity between 1979 and 1980 runs was 86% (Figure 

 20). 



SMALL MAMMAL COMMUNITY PARAMETERS 



Small mammal capture data for 1980 are summarized in Table 16. 



Figure 21 shows year-to-year changes in small mammal biomass for six 

 habitats (biomass estimates obtained for control and experimental sites were 

 averaged for combined spring and fall data). It should be noted that 1977 data 

 are not strictly comparable, since a spring-fall trapping regime was not used 

 that year. Nonetheless, it is clear from this figure that tall coulee shrub 

 habitats consistently yielded the greatest biomass during all four years. An 

 overall decrease in small mammal biomass between 1979 and 1980 is apparent. 



Figure 22 shows year-to-year changes in the spring-fall small mammal biomass 

 increase (which is related to production) for the same four habitats. 

 Surprisingly, small mammal biomass in tall coulee shrub habitats decreased 

 sharply over the summer of 1980. This is in contrast to a remarkable increase 

 in biomass during the summer of 1979. 



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