Table 5.7. Correlation coefficients for regressions of antler 

 characteristics of yearling male mule deer against forb 

 production and per capita forb production, 1976-1986, Missouri 

 River Breaks, Montana. 



Dependent Variables 



Independent Variables 



Forb Production 

 (kg /ha ) 



Per Capita Forb Production 

 (kg/ha/deer) 



Number of antler 0.793 <0.01 11 



points per side. 



Percentage antlers 0.789 <0.01 11 

 2x2 points per 

 side or more. 



0.703 



0.751 



<0.05 



<0.01 



11 



11 



Beam diameter 

 (mm) 



0.799 



<0.01 



10 



0.603 



0.06 



10 



Product of beam 

 diameter and 

 percentage antlers 

 2x2 points per 

 side or greater. 



0.825 



<0.01 



10 



0.792 



<0.01 



10 



survival during 1965 was much below expectation based on 

 current forage conditions . Both number of antler points per 

 side and % 2X2 point antlers of yearling males, however, 

 increased in 1965 over that of 1964 (Fig. 5.7), as expected, 

 based on forage conditions. That information verified our 

 projections that forage conditions were good during summer 

 1965, and that fawn survival was probably poor because of lag 

 effects in female condition following the preceding severe 

 winter. 



Forage conditions were apparently sufficient to result in 

 average or better antler size of yearling males during 

 1973-1977, when fawn survival was lower than average (Fig. 

 5.7). Although forage conditions were excellent during 1975, 

 the 2 measurements of antler size displayed in Figure 5.7 

 declined. However, another measure of antler size (beam 

 diameter) was near the highest recorded (Table 4.7). Antler 

 size that year, regardless of the measure used, was at least 

 near average, and certainly greater than in 1961, 1984, and 

 1985, when deer were in extremely poor condition and antlers 

 were extremely small. 



137 



