Some aspects of bison ecology and behavior in a tallgrass prairie

Scope and method of study. In study 1 seeds were collected and identified from both bison hair samples (n = 111) and dung (n = 144) to determine the importance of bison as seed dispersers in a tallgrass prairie ecosystem. In study 2 bison and cattle behaviors were compared across seasons and the effects of ambient temperature on behaviors of the two species were studied. In study 3 the diet quality of bison bulls, cows, and juveniles were determined by carbon isotope analysis of bison hair samples. In the study 4 body weight and calving rates data from the bison herd of the Tallgrass Prairie Preserve were analyzed and compared with data published in the literature from other similarly managed bison herds in the Great Plains in order to evaluate the hypothesis that bison numbers were historically scarce on tallgrass prairie due to nutritional deficiencies.; Findings and conclusions. Study 1: 2,779 and 7,407 seeds from at least 76 and 71 species were found in bison wool and dung, respectively, indicating that bison are seed dispersal agents on tallgrass prairie. Study 2: bison and cattle activity behaviors were affected similarly by ambient temperature across seasons. Study 3: diets differed among bulls, cows and juveniles in tallgrass prairie and skewed sex ratios favoring females were found in about half of the herds. Because adult male and female bison probably impact differently on vegetation due to segregation, it was suggested that herds should adopt sex ratios close to those found in bison wild populations. Study 4: male and female bison weights differed at all ages, except at 6 months old. Calving rates and bison mean weights at tallgrass prairie were within the range found in other Great Plains' herds with similar management, indicating that nutritional inadequacy was not the main cause for bison scarcity on tallgrass prairie regions. (Abstract shortened by UMI.)...