radio-collared fawns during 1976-1986 (Fig. 5.2). Mortality 

 rates were highest ( r>0 . 10/month) during June, July, August, 

 and February. Mortality was moderate during September, 

 October, January, and March, and very light during November, 

 December, April, and May. 



0.25 -i 



0.00 



i 1 1 1 1 1 1 1 1 1 r 



Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May 



Month 



N 168 151 129 106 95 86 82 116 110 109 107 106 



Figure 5.2 



Instantaneous monthly mortality rate for radio- 

 collared mule deer fawns, 1976-1986. 



1960-1974 



Early winter classifications were made during most years 

 of this period (Table 4.2), but autumn (Table 4.1) and spring 

 (Table 4.3) classifications were made during few years prior 

 to 1975. Assuming average fawn production each year, annual 

 first-year mortality rates were 43%, 69%, 62%, and 53% for the 

 1960-1963 cohorts. Annual mortality was 89% for the 1971 

 cohort and 77% for the 1972 cohort. Because spring 

 classifications were not made during other years, annual 

 mortality could not be calculated directly. 



Observed fawn mortality rates were 12%, 24%, <1%, and 14% 

 during autumn; and 4%, <1%, <1%, and 17% during winter for the 

 1960-1963 cohorts, respectively. Observed winter fawn 

 mortality rate was approximately 77% for the 1971 cohort. 



119 



