Adult Males 



Information on the age structure of adult male 

 populations was provided by deer killed by hunters during 

 1960-1964 and 1976-1986 (Table 4.5). Male age structure and 

 changes were also estimated using the model that added in each 

 recruited cohort, starting with 1960, and reduced its numbers 

 on the basis of annual and average estimates of hunting and 

 winter losses (Fig. 4.11). Age-specific differences in 

 mortality were applied to 3 age classes: yearlings, 2-year- 

 olds, and 3-year-old and older males, based on mortality data 

 from 1976-1986 (Chapter 6). Data were also available to age 

 males as either yearlings or older adults from aerial 

 classifications during 1976-1986 (Table 4.6). 



The 3 estimates of male age structure generally followed 

 the same trend, though some differences were apparent (Table 

 4.6). Aerial classifications usually over-estimated yearling 

 males as compared to estimates based on fawn recruitment. 

 That probably occurred because, from the air, some small- 

 antlered, 2-year-old males were misclassif ied as yearlings. 

 The proportion of yearling males in the harvested sample was 

 lower than estimates based on fawn recruitment. That was also 

 expected because age-specific mortality data indicated that 

 yearling males were harvested at a lower rate than older and 

 larger males. Because those 2 estimates deviated as expected 

 from the estimate based on fawn recruitment, we considered the 

 estimates based on fawn recruitment to be the most accurate. 



Although age structures for harvested males, 1960-1964 

 and 1976-1986 (Table 4.5), probably underestimated proportions 

 of yearling males and overestimated older males in the 

 population, they did indicate the numerical importance of 

 yearling males to the total harvest, even during years 

 following poor fawn recruitment. The modeled age structure 

 (Fig. 4.11) also indicated the importance of yearling males to 

 the surviving male population. Because the total male 

 population after the hunting season was usually one-third or 

 less that of the female population, the size of each annual 

 cohort had a proportionately greater effect on numbers of 

 males in the population than on female numbers (Figs. 4.9 and 

 4.11). As a result of hunter selection for older, larger- 

 antlered males, the male age structure generally retained a 

 more pyramidal shape than that for females, even at low 

 population levels following poor fawn recruitment (Figs. 4.9 

 and 4.11). Harvest rates of males that averaged over 40% 

 reduced the influence of strong year classes much sooner than 

 occurred among the female population. 



Only 3.4% of 739 adult males aged during 1960-1986 were 

 7 years or older. Seventy percent (70%) were yearlings or 2 

 years old. The oldest male was 11 1/2 years-old. 



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