The social environment and the role of an individual in that environment are often overlooked. This is unfortunate because social interactions help explain how animals of the same species survive in very different environments, live on radically different diets, and behave differently even in the same environment.

In herd animals such as bison, social groups are often composed of closely related females. Such social organization leads to culture that can be passed from one generation to the next. A culture develops when habits contribute to the group’s success in solving problems, and cultures can change as individuals in groups discover new ways of behaving – such as finding new foods or habitats or better ways to select a nutritionally balanced diet.

Importantly, social organization and culture may affect foraging behavior, lead to short-duration grazing without fences and have management implications for domestic livestock. This notion is based on three assumptions: (1) social herbivores live in extended families, (2) maintaining the cohesiveness of families and their home ranges influences food and habitat selection, and (3) individuals within families differ in their preferences for foods and habitats. If so, social interactions within families may encourage animals to eat a broader diversity of plants and to forage in a greater variety of locations as individuals maintain the cohesiveness of the group and respond to different preferences of individuals within the group. Interactions among families may further increase movements about landscapes as families avoid prolonged contact with one another by selecting different foraging locations.

USU graduate student, Ryan Shaw and professor, Fred Provenza, are conducting a study on the social organization of bison on a 1,000 head herd that ranges over 250 sq. km. at the Armendaris Ranch near Truth or Consequences, NM. Another smaller 60 head herd ranging over 28 sq. km. is also being studied at the ranch. His objectives are to determine 1) the degree to which bison with and without weaned calves live in stable groups or extended families; 2) whether or not interactions within and among bison groups with and without weaned calves influence habitat selection and patterns of landscape use, and 3) if habitat quality and landscape structure influence bison social organization.