Cooperative Fish and Wildlife Research Units Program: Wyoming
Education, Research and Technical Assistance for Managing Our Natural Resources

While environmental variables like weather and plant phenology are thought to be the main drivers of migration, new evidence suggests that anthropogenic disturbances, such as hunting, as well as intrinsic factors like age and sex can also influence ungulate migrations. However, critical gaps in understanding of the influence of both the intrinsic and extrinsic factors that affect migratory behaviors abound. We used three years (2016 – 2018) of GPS-collar data for a herd of migratory mule deer (Odocoileus hemionus) in south-central Wyoming to compare key migratory behaviors between sexes, identify factors that influence the potential and timing of migration, and evaluate habitat selection in and around the autumn hunting season. We found that during hunting season, males found security by using habitats far from roads, while females used habitats through the hunting season that retained higher forage quality longer. This collaborative study with the Wyoming Game and Fish Department suggests that mule deer mitigate disturbance from hunting season by moving to roadless security habitats. Overall, our findings contribute to a broader understanding of migration ecology and the factors that influence migration and habitat selection of wild ungulates in western landscapes.