Chronic wasting disease reduces mule deer survival and hunter success in the Wind River Basin of Wyoming
Chronic wasting disease (CWD) is a fatal prion disease of cervids that has spread across much of North America and has recently become a global concern. Although CWD typically emerges gradually in new geographic regions, some areas experience rapid increases in prevalence for reasons that remain unclear. Herein, we describe the establishment of CWD in a mule deer (Odocoileus hemionus) population in the eastern portion of the Wind River Basin, WY, USA, where CWD prevalence in adult males (n=249) increased from 0% to 63% within a decade. We provide historical context, including a description of regional anthropogenic changes, and examine the epizootic’s impact on deer survival and hunting. From 2023 to 2025, we captured and monitored 96 adult mule deer. Annual survival was low: 0.38 for adult males (n=21) and 0.53 for adult females (n=75). Before CWD detection in 2012, mean hunter success was 72% (2000 to 2011). After detection, hunter success declined to 30% in 2022. We propose three hypotheses to explain the rapid rise in CWD prevalence, including food hotspots created by agriculture, increased agricultural dependency due to habitat degradation, and declining migratory behavior. Our case study highlights the potential effects of CWD and provides insights into possible drivers of transmission, to support more targeted management.