Abstract
Chronic Wasting Disease (CWD) is of increasing concern for management of wild cervid populations in many western states. In Utah, CWD was first detected in Mule Deer (Odocoileus hemionus) in 2002, and 188 cases have been confirmed as of 2023. Disease transmission patterns emerge from host movements, which determine the occurrence of direct and indirect contacts between individuals. In turn, host movements are shaped by the environmental context. Migratory movements are of particular interest to predict CWD spread, because they span long distances and many individuals are likely to use overlapping routes, which increases opportunities for pathogen exposure. Our goal is to build a model that describes spatial spread of CWD in Utah's Mule Deer populations. We used a two-part modeling approach. First, we developed a predictive model of migratory movements parameterized from GPS-tracking data from 107 Mule Deer. Second, we will combine this movement model with a disease-transmission model. Here, we present results from the first component of this modeling framework. Elevation gain, distance to roads, and population of origin were the strongest predictors of Mule Deer migratory routes. Individuals from a population tended to migrate to the same general area in summer and winter, and several populations that are segregated during winter migrated to a common summer range. We developed a predictive map of migration routes, identifying likely hotspots of contacts among hosts. Ultimately, we will use the integrated model to inform and optimize the Utah Division of Wildlife Resources" surveillance scheme to detect spread of CWD.