Effects of population density on prevalence of chronic wasting disease, physical condition, and vital rates of elk at Wind Cave National Park, South Dakota

CWD is a degenerative neurological disease caused by infectious proteins called prions.  Although documented cases are invariably fatal, infected elk commonly survive for several months or longer, passing prions directly to other individuals and into the environment, where they bind to surfaces or soils and can persist for years.  CWD reached Wind Cave National Park about 1997 and rapidly became the leading cause of mortality for adult elk.  By 2016, prevalence reached ~24% in eastern WICA, an unsustainable level that threatens persistence of the population.  Although CWD at WICA constitutes a crisis for park management, it also presents an unprecedented opportunity for studying effects of population density on CWD prevalence, physical condition, and vital rates of elk.  During 2016-2017, the National Park Service removed 262 elk from WICA, reducing the population by about half.  We are working with NPS partners to evaluate effects of the reduction and develop guidance for management of CWD and high-density elk populations not only at WICA, but in other parks and preserves.