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CWD Simulation App

April 14, 2020
Mule deer investigating a game camera in Madison Valley, Montana.
Mule deer investigating a game camera in Madison Valley, Montana.

Chronic wasting disease (CWD) is a fatal disease of deer, elk, and moose transmitted through direct contact and via environmental contamination (Williams and Young 1980, Williams and Miller 2002, Miller et al. 2004). CWD has transitioned from an obscure prion disease with limited geographical distribution to a disease that poses substantial risks to the future vitality of free-ranging cervids in North America. CWD has been reported in captive or free-ranging cervid populations in 24 States and 2 Canadian provinces map. The prevalence of CWD appears to be increasing in many areas, and in some locations this had been associated with coincident population declines (Edmunds et al 2016, DeVivo et al 2017). Effective vaccines are not currently available. One of the primary management tools is altering harvest management. Modeling and some field observations suggest that increased harvest could help control the spread of CWD (Jenelle et al. 2014, Manjerovic et al 2014, Potopov et al. 2016).

CWD Application image
CWD Application image. (Public domain.)

On this website we provide some tools to simulate CWD and harvest management scenarios. The intention is to provide decision-support tools for natural resource managers interested in investigating different scenarios associated with CWD over the 5-10 year time horizon given a set of assumptions about how the disease works. The applications allow the user to enter parameters for deer or elk vital rates, hunting mortality, and disease transmission and the model will plot the total number of individuals, prevalence, age and sex distribution, and how many deaths were natural, hunting or CWD-related. The user can tailor the model to their species and region of interest by modifying the parameters and starting conditions. In many cases, the parameters used in these models are unkown, but reasonable guesses can be made some cases. These models were developed by the U.S. Geological Survey (USGS) in collaboration with Montana Fish, Wildlife, and Parks.

To download the R package and run the models on your own computer, go to the following link:

To access the application page: