Disease and Behavioral Dynamics for Brucellosis in Elk and Cattle in the Greater Yellowstone Area

We investigate private responses to policies that have been proposed to confront a human-wildlife conflict that likely emerged as a result of a management regime designed to address an earlier human-wildlife conflict: specifically, brucellosis in elk that has spread to cattle in Wyoming. We examine population and disease dynamics under several different management options for the Jackson elk herd, where each option involves a combination of changes in elk feeding and population levels. Farmer responses to these dynamics, when vaccination is not required, are modeled along with the associated impacts to livestock dynamics. We also examine livestock management when there is little-to-no consideration given to the risk posed by elk. In practice, the policies and proposals to address elk have been considered separately of the behavioral responses of farmers, with many livestock advocacy groups are pushing for an elimination of the feeding grounds. Overall, our results contradict the conventional wisdom that farmers would benefit from more stringent disease controls in the elk sector. We find that farmers do experience lower herd-level infection rates when more stringent elk controls are implemented. But this is primarily due to increased vaccination by farmers in response to increased risks to cattle that result from elk spending more time on public grazing areas and farmlands as feedgrounds are closed.