Table 5.4. Age-specific fawn recruitment to late autumn for 



female mule deer during 1984 and 1985, compared to 

 the average for 1976-1983. 



a Age at conception -- age at parturition. 

 b Female sample size. 



greatest decline in recruitment of fawns. First year breeders 

 experienced an equally great decline in recruitment, probably 

 because more than for other age groups, nutritional demands of 

 body growth competed with reproductive demands. 



Based upon estimated age structure, 3-year-old and 7- 

 year-old-and-older females produced 54% of fawns surviving 

 through late autumn in 1984 and 1985. If recruitment had been 

 equivalent to the average for 1976-1983, those age classes 

 would have produced 32% of surviving fawns. However, the 

 difference in survival by female age class had no measurable 

 impact on the population because few fawns of the 1984 and 

 1985 cohorts survived to 1 year of age regardless of the age 

 of their mother. 



Population Effects of Age-Specific Recruitment 



We hypothesized that age-specific variation in 

 recruitment of fawns, in conjunction with changes in age 

 structure of the female population, might explain declines in 

 fawn survival on the area during the early-mid 1970s. 

 However, analyses using several different models did not 

 support that hypothesis. Numbers of fawns produced and 

 fawn: 100 female ratios generated by the models are presented 

 in Table 5.5. Calculations were based on female age structure 

 (Fig. 4.9) and the recruitment by age class observed during 



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