Were bison predictable prey? Using stable isotopes to examine early Holocene bison mobility on the Central Great Plains

Plains Paleoindians are synonymous with bison due to the frequency with which bison remains are found at archaeological sites. However, the nature of the relationship between bison, humans, and the Plains environment remains unclear. Past and current Paleoindian land-use models incorporate aspects of bison behavior that are largely based on historic records and modern observations of extant bison, both problematic datasets. A better understanding of bison is required in order to evaluate the role bison played in past human groups and how that relationship changed over time.;To answer these questions, this study uses stable isotopes to examine the mobility behavior of bison during the Holocene. Bison mobility was a key aspect of prey behavior, and would have influenced human land-use and hunting strategies. This study sampled 29 bison from seven Paleoindian sites from the western Central Great Plains (i.e., Burntwood Creek, Clary Ranch, Norton, O. V. Clary, Scottsbluff, Slim Arrow, and Winger). I collected 217 delta 13C and delta18O values and 78 87Sr/ 86Sr values to evaluate the predictability of bison mobility in the Early Holocene. In addition, I compiled isotopic data from 119 sites to evaluate the long-term impact of humans on bison over a 15,000-year period, from the arrival of humans in the Late Pleistocene through the historic period.;Results of this study indicate that current datasets do not contain the needed samples to analyze changes in bison mobility behavior over the Holocene. The results from Early Holocene sites indicate that herds were predictable at the local level, due to low variability in stable isotope values. There is no evidence of any long-distance, seasonal movements or migratory behavior. There is also no indication of seasonal aggregation; however, the resolution of the data may not reflect smaller aggregations. Regional-scale analysis indicates that western Nebraska herds exhibited lower mobility than western Kansas herds. Stable isotope values from individual bison at different sites overlap in western Kansas, which suggest that bison were moving between herds, similarly to modern herds. This movement of individuals may have provided opportunities for Paleoindians to target individuals as they moved between local areas.;These patterns of locally predictable bison suggest that herds were available to humans during all times of the year. The resolution in the data is not able to determine if herds were available at specific locations in space, such as alluvial valleys. Together, these data indicate that the Central Great Plains contained predictably available bison during all times of the year to human hunters.