M.A. Theses: Gerald A. Oetelaar, 1981

Deer Remains in Archaeology With Special Reference to the Mandible of Mature Rocky Mountain Mule Deer.

This study is concerned with the estimation of a deer's absolute age, sex, weight and season of death from a single anatomical element. The value of these population parameters in zooarchaeological research is discussed and former methods for their derivation are reviewed. The results of an osteometric and histological analysis of the mandible in a modern sample of mature Rocky Mountain mule deer from the Cache la Poudre reserve, Colorado are then presented and discussed. From this analysis, more accurate approaches to the assessment of a deer's age, sex, weight and season of death are derived.

By means of simple regression analysis, significant correlations are shown to exist between various dimensions of the mandible and the bled carcass weight of mule deer. The strength of these associations increases substantially when seasonal fluctuations in weight are incorporated in the analysis. Significant correlations are also shown to exist between mandibular measurements and the skinned and eviscerated carcass weights of mature mule deer. The resultant regression equations are valuable predictive tools in the estimation of meat weights for prehistoric mule deer.

From the mandibular measurements, linear discriminant functions are also derived to segregate the sex of mature deer. The resultant linear functions identify and classify the sex of an unknown with an accuracy of 88 percent or more. The accuracy of the functions in the analysis of prehistoric fauna, however, requires further testing.

Decalcified and stained longitudinal thin sections of the first mandibular molars are shown to be the most reliable for establishing the absolute age of prehistoric fauna. In the present study, ninety-one deer were aged independently from incremental growth lines of the central incisor and the first mandibular molar. There is perfect agreement between the age estimates for 80 of the deer. For the remaining 11 specimens, the disagreements in the age estimates do not exceed plus or minus one year. Possible explanations for these discrepancies are presented.

Incremental growth lines, as seen in decalcified and stained thin sections, are also shown to be reliable for inferences on a deer's season of death. This study presents a methodology for the derivation of a ratio of outer increment width over expected increment width. As shown, this ratio increases linearly from March until the end of December. Thereafter, there is no demonstrable increase in the outer increment until the succeeding March. The resultant annual growth curve for the cementum deposit of the first mandibular molar permits accurate assessments of a month of death for mature mule deer. Greater precision in the seasonality estimates, however, requires further research.