Paul Cross' Research Projects

Current

• Brucellosis
  Brucellosis, a bacterial disease caused by B. abortus, affects bison, cattle and elk in the Greater Yellowstone Ecosystem (GYE), and the GYE is the last reservoir of infection in the United States. Roughly 40% of the Yellowstone NP bison population was permanently removed in 2008 for disease control purposes. Despite the extensive management of bison, cattle herds in Wyoming, Idaho and Montana have all been infected, presumably from elk, since 2004. As a result, there is an intense focus upon the management of both bison and elk. My research program provides science based on a multi-pronged interdisciplinary approach to several key aspects: the Wyoming supplemental feedgrounds, estimating and modeling the source-sink disease dynamics within and among species and populations, identifying areas of cattle risk, and assessing the effectiveness of different management interventions. My current research projects in this area include:
  • Supplemental feeding grounds of Wyoming. l Project Page l
  • Free-ranging elk populations of Wyoming. l Project Page l
  • Modeling the effectiveness of bison management actions on reducing seroprevalence
  • Potential eradication in the wildlife and livestock of Spain. l Project Page l

  
  
  View animation of elk movement and snow pack:

  • Soda Lake
  • Dell Creek

  
  

• Chronic Wasting Disease
  Chronic wasting disease (CWD) is a type of spongiform encephalopathy which is a transmissible disease that affects the brain and nervous system of of cervids such as deer and caused by an infectious, irregular form of cellular prion protein. Similar to the degenerative scrapie disease in sheep, bovine spongiform encephalopathy (“mad cow”) in cattle, and Creutzfeldt-Jakob’s disease in humans, normal cellular prion protein, found throughout the body, change their conformation to that of CWD prions and accumulate in lymphoid tissue and the central nervous system causing tissue damage and eventually host death. Although originally assumed to be primarily directly transmitted, CWD has been shown to be both directly and indirectly transmitted through the contact with saliva, urine, feces, and infected carcasses, or CWD contaminated environmental surfaces. CWD affects North American cervids such as mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus), elk (Cervus elaphus), and moose (Alces alces). The origin of CWD is unknown, but following its discovery among a captive population of mule deer in 1967, it has since been found to infect several wild cervid populations throughout North America (for map of current distribution, see: www.cwd-info.org). My current research projects in this area include:
  • Viral tracking: discovering new pathogens of mule deer and elk to determine population connectivity. l Project Page l Information Sheet l
    
  • Modeling the implications of prion persistence in the environment on disease dynamics and deer populations. l Project Page l
  • Estimating the force of infection from current-status data. l Project Page l
  • Impact of fragmented habitats on persistence of wildlife diseases. l Project Page l

  
  

• Effects of Sarcoptic Mange on Gray Wolves in Yellowstone National Park l Project Page l
  
  
• Effects of Climate Change on Ungulates l Project Page l Information Sheet l

Historic

• General disease ecology. l Project Page l
• Canine distemper in the wolves of Yellowstone National Park. l Project Page l
• Bovine tuberculosis in the African buffalo of Kruger National Park. l Project Page l
• Alternative methods of analyzing GPS data. l Project Page l