Developing Tools to Evaluate Chronic Wasting Disease Transmission Risk
Aerial view of elk after being provided supplemental feed
Chronic Wasting Disease (CWD) infects and kills ungulates (deer, elk, moose), and has been spreading across North America for the past 20 years. Some ungulate populations have declined because of CWD and there are no viable vaccines or treatments for this disease. Therefore, tools that assist wildlife managers in preventing and mitigating CWD can be powerful assets in protecting our nation’s big game species. Transmission can occur between individuals, so USGS NOROCK scientists are developing tools that will assist partners in preventing and mitigating CWD by quantifying ungulate densities and ranking relative disease risk across management units.
Background
Chronic Wasting Disease (CWD) has spread across much of North America over the last two decades leading to declining populations of deer, elk, and moose. Infected animals suffer neurological degeneration resulting in behavioral changes like decreased social interaction, weight loss, and eventually, death. CWD is caused by improperly folded, infectious proteins found in ungulate brain and central nervous system tissue called prions. There are no effective vaccines or treatments for CWD. Tools and technical support that measure CWD risk, evaluate factors that may influence disease transmission, and help managers reduce and evaluate the effectiveness of their response to CWD threats to ungulate herds are valuable for wildlife managers.
Animal Movement and Disease Transmission
CWD can be transmitted both directly from infected to uninfected individuals and indirectly through contaminated sites, so understanding the factors that influence animal congregation and how animals interact within a herd can assist with disease mitigation. Recent USGS research indicates that certain activities, like supplemental winter feeding, can be a stronger driver than weather variables in determining how close together elk are, and the length of time pairs of elk can spend in proximity to each other. Using information like this, wildlife managers may be able to reduce disease risk through adaptive management of population densities. This approach dominates CWD response plans for most wildlife agencies.
Tools For Wildlife Managers
First among several new tools, we created an analysis platform that more easily measures ungulate densities and concentrations using animal locations such as those obtained with GPS collars or satellite imagery. We developed a method to evaluate the success of adaptive management attempting to reduce densities. We designed an approach to identify focal areas of high density to better find and address wildlife-human conflict locations. Current tool development includes evaluating the use of advanced machine learning methods to assess normal and atypical movements.
These tools and associated training support federal, state, and Tribal units. Focal projects include supporting the National Elk Refuge and Fossil Butte National Monument in Wyoming, Glacier National Park, and the Blackfeet Nation in Montana, and the Navajo Nation in Arizona.
Based on these data, we will rank the relative disease risk for multiple management units, evaluate the success of adaptive management efforts in areas with appropriate data, and identify collaborators to co-design a multi-population study to better quantify the connections among ungulate density, management, and CWD ecology. Although there are currently no approaches to treat CWD, we will provide wildlife managers valuable information they can use to develop disease prevention and mitigation programs.
For more information on NOROCK chronic wasting disease research, click here.
Chronic Wasting Disease (CWD) infects and kills ungulates (deer, elk, moose), and has been spreading across North America for the past 20 years. Some ungulate populations have declined because of CWD and there are no viable vaccines or treatments for this disease. Therefore, tools that assist wildlife managers in preventing and mitigating CWD can be powerful assets in protecting our nation’s big game species. Transmission can occur between individuals, so USGS NOROCK scientists are developing tools that will assist partners in preventing and mitigating CWD by quantifying ungulate densities and ranking relative disease risk across management units.
Background
Chronic Wasting Disease (CWD) has spread across much of North America over the last two decades leading to declining populations of deer, elk, and moose. Infected animals suffer neurological degeneration resulting in behavioral changes like decreased social interaction, weight loss, and eventually, death. CWD is caused by improperly folded, infectious proteins found in ungulate brain and central nervous system tissue called prions. There are no effective vaccines or treatments for CWD. Tools and technical support that measure CWD risk, evaluate factors that may influence disease transmission, and help managers reduce and evaluate the effectiveness of their response to CWD threats to ungulate herds are valuable for wildlife managers.
Animal Movement and Disease Transmission
CWD can be transmitted both directly from infected to uninfected individuals and indirectly through contaminated sites, so understanding the factors that influence animal congregation and how animals interact within a herd can assist with disease mitigation. Recent USGS research indicates that certain activities, like supplemental winter feeding, can be a stronger driver than weather variables in determining how close together elk are, and the length of time pairs of elk can spend in proximity to each other. Using information like this, wildlife managers may be able to reduce disease risk through adaptive management of population densities. This approach dominates CWD response plans for most wildlife agencies.
Tools For Wildlife Managers
First among several new tools, we created an analysis platform that more easily measures ungulate densities and concentrations using animal locations such as those obtained with GPS collars or satellite imagery. We developed a method to evaluate the success of adaptive management attempting to reduce densities. We designed an approach to identify focal areas of high density to better find and address wildlife-human conflict locations. Current tool development includes evaluating the use of advanced machine learning methods to assess normal and atypical movements.
These tools and associated training support federal, state, and Tribal units. Focal projects include supporting the National Elk Refuge and Fossil Butte National Monument in Wyoming, Glacier National Park, and the Blackfeet Nation in Montana, and the Navajo Nation in Arizona.
Based on these data, we will rank the relative disease risk for multiple management units, evaluate the success of adaptive management efforts in areas with appropriate data, and identify collaborators to co-design a multi-population study to better quantify the connections among ungulate density, management, and CWD ecology. Although there are currently no approaches to treat CWD, we will provide wildlife managers valuable information they can use to develop disease prevention and mitigation programs.
For more information on NOROCK chronic wasting disease research, click here.