The formulation and application of a technique, based on phalanges, for discriminating the sex of plains bison (Bison bison bison)
Roberts, Linda J.
This thesis develops a new technique for sexing plains bison (bison bison bison) based on a large collection of front, first phalanges from known sex bison. It includes an evaluation of previous sexing techniques developed on Old World Artiodactyl phalanges and New World bison elements. It remedies the shortcomings of many other techniques which are not based on a large known sex sample. The new sexing technique is developed on the known sex plains bison population from Elk Island National Park, Alberta. The technique is tested on a known sex Museum collection of plains bison from several areas of Central North America. It is applied to bison remains from the Stott Site, an archaeological site near Brandon, Manitoba circa A.D. 800 to A.D. 1400. The sexing technique utilizes a discriminant function analysis. Three measurements rounded to 0.1 millimeter are required per phalanx. The measurements are as follows: Length (L), Greatest Length (GL), and Distal Height (DH). Complete separation (100%) of male from female bison is demonstrated by the histogram of the discriminant function (GL X 0.52067) + (DH X 0.54678) - (L X 0.29469) with the separation area at slot 29.16 for the EINP and Museum samples. A value below slot 29.16 indicates a female and above slot 29.16 indicates a male. When the value of the discriminant function is plotted in a bivariate fashion against either the L,GL or DH measurement a clear patterned separation is possible. This patterned separation becomes the important separating tool for prehistoric bison phalanges. The values of separation for the Stott Site are from slot 30.96 to 30.14. It is concluded that the front first phalanges can be used to establish the sex of plains bison. The phalanges can be used to trace evolutionary changes and to calculate minimum numbers of bison. Sex ratios in turn may be used to determine hunting selection, weight of useable meat and seasonality in special instances at catastrophic kill sites. The main importance of this thesis lies in the fact that it: a) explores a new area of research in North American studies b) demonstrates the formulation, testing and application of a new sexing technique based on known sex samples c) adds to the interpretation of archaeological sites.