Haugen, Arnold O. and Shult, Milo J. 1968. Breeding Biology and Behavior of American Bison. pp. 25-44.
Field work began on June 1, 1968 in Wind Cave National Park located 6 miles north of Hot Springs, South Dakota. The park, approximately 44 square miles in size, is in the southern Black Hills in the ecotone between the coniferous forest and grasslands of South Dakota. The park itself consists of hills, valleys, canyons, ridges, and mesas with interspersed stands of Ponderosa pine (Pinus ponderosa) forest and grassland. A herd of approximately 350 bison (Bison bison bison) range "freely" over the entire expanse of the park. Observations on these animals were made from June 1 to the present (Sept. 1968) and will continue until the end of November, 1968.
Daily activities of the bison were recorded throughout the study period. Most observations were made from a particular vehicle whenever the bison could be located along fire trails. Other observations were made on foot when the animals were in more remote areas. Observations were made during all hours of the day and night. When it was impossible to approach the bison closely, observations were made with the aid of 7x50 binoculars or a 20x spotting scope. Behavior patterns were recorded on 35 mm. slides and on 8 mm. motion picture film. These films and slides will be studied in detail at a later date.