Researchers at the USGS Northern Rocky Mountain Science Center and their partners place thermal remote cameras near deer and elk carcasses in Yellowstone National Park to capture images of wolves with mange feeding in the wild.
Paul Cross, Ph.D.
My research focuses on applied wildlife disease, conservation and management issues around the Greater Yellowstone Ecosystem.
Research Interests
I try to integrate multiple different scientific fields, but my specific background is in field ecology, behavior and mathematical modeling. There are two central themes in my research: (1) the integration of empirical data and mathematical modeling, and (2) the effects of host behavior on disease dynamics. Currently, my research focuses on brucellosis, chronic wasting disease, canine distemper and sarcoptic mange.
Science and Products
Filter Total Items: 13
USGS Chronic Wasting Disease Research at NOROCK
Chronic wasting disease (CWD) is a growing management issue in the U.S. and has been detected in 36 states as of April 2025, including many western states. There is no cure or vaccine for CWD, and the disease threatens economically important animals like elk and deer. NOROCK scientists have taken a multi-pronged approach to develop actionable science including 1) evaluating CWD management options...
USGS Chronic Wasting Disease Research at the National Elk Refuge
Over the past 20 years, chronic wasting disease (CWD) in Wyoming has been spreading slowly outward from the southeastern corner of the state into the Greater Yellowstone Area and Wyoming's elk feed grounds. CWD detections have been getting closer to the National Elk Refuge, which provides supplemental feeding to approximately 8,000 elk and 500 bison each winter. NOROCK scientists have been...
Predicting the effects of supplemental feeding and chronic wasting disease in Greater Yellowstone Ecosystem elk
To support management decisions concerning 500 bison and 8,000 elk in Jackson, Wyoming, USGS scientists assessed how alternative U.S. Fish and Wildlife Service plans for providing supplemental food would influence: 1) chronic wasting disease prevalence, 2) elk and bison numbers, 3) wildlife movement and human-wildlife conflict 4) multiple use opportunities for the public, like hunting, and 5)...
Brucellosis
Brucellosis is a nationally and internationally regulated disease of livestock with significant consequences for animal health, public health, and international trade. NOROCK provides science based on an interdisciplinary approach to several key aspects: 1) estimating and modeling disease dynamics within and among wildlife species and populations, 2) identifying risks to cattle, and 3) assessing...
Climate-Informed Disease Threat Assessment for Montana’s Species of Greatest Conservation Need
Project Overview Infectious disease poses a growing threat to wildlife and human health, and managing disease threats is complicated by climatic changes that can change levels of disease risk. Researchers supported by this North Central CASC project will co-develop a method to rank wildlife disease threats under climate change, providing critical useable information to Montana’s wildlife...
COVID-19 Pathways and Wildlife Dynamics
Below are the USGS 2020 Coronavirus Aid, Relief and Economic Security Act (CARES Act) research projects related to COVID-19 pathways and wildlife dynamics. Select tabs above for related items.
Evaluating Transmission of Chronic Wasting Disease in the Environment
Chronic wasting disease (CWD) is a fatal disease of deer, elk, and moose and has been spreading in North America for the past two decades. The disease is spread by infected body fluids. Animals can become infected by coming into direct contact with a CWD-infected animal, or an infected animal can leave behind fluids (e.g., saliva, urine) that an uninfected animal will come into contact later...
Quantitative Disease Ecology
Researchers at the USGS are working on developing new quantitative methods to study disease dynamics in wildlife systems as well as systems at the wildlife-domestic-human interface. Much of our work focuses on how host population structure affects disease invasion, persistence and control in wildlife disease systems. We tackle these issues with a combination of simulation and statistical modeling...
Moose and Winter Ticks in Western Wyoming
Moose are an important game species in Montana, Idaho and Wyoming but hunter opportunities have been reduced in many areas over the last two decades as populations have declined at this southern limit of the species’ geographic range. In the Jackson, Wyoming area moose populations have declined by an estimated 80% since the early 1990s. Rising temperatures, pathogens, and parasites...
Impacts of Disease on Wolves in Yellowstone National Park
In 1995 and 1996, wolves were reintroduced into the Northern Rockies where they have since established and spread. Within Yellowstone National Park, one of the core protected release sites, the unmanaged population steadily increased to high densities, producing a large wolf population susceptible to infections such as canine parvovirus (CPV), canine distemper virus (CDV) and sarcoptic mange.
Pneumonia in Bighorn Sheep
Bighorn sheep populations are often impacted by outbreaks of pneumonia that are suspected to come from domestic sheep and goats.
NOROCK Large Carnivore Research Program
NOROCK has substantial expertise in large carnivore research, primarily involving species listed as Threatened or Endangered. NOROCK’s Large Carnivore Research Program includes scientists from NOROCK’s Headquarters, West Glacier Field Station, and the Southern Appalachian Field Station. Studies are conducted in a wide variety of landscapes throughout the U.S., as well as international research...
Wild Wolf Afflicted with Mange
Researchers at the USGS Northern Rocky Mountain Science Center and their partners place thermal remote cameras near deer and elk carcasses in Yellowstone National Park to capture images of wolves with mange feeding in the wild.
Elk in Northwestern Wyoming
Elk congregate on the Camp Creek Feed Ground in northwestern Wyoming.
Elk congregate on the Camp Creek Feed Ground in northwestern Wyoming.
Close Encounters, Yellowstone National Park.
In the Rocky Mountain West, people and wildlife inhabit many of the same areas and USGS scientists are studying wildlife diseases, such as brucellosis in elk and bison, and how these diseases are transmitted between domestic and non-domestic hosts.
In the Rocky Mountain West, people and wildlife inhabit many of the same areas and USGS scientists are studying wildlife diseases, such as brucellosis in elk and bison, and how these diseases are transmitted between domestic and non-domestic hosts.
Science and Products
Filter Total Items: 13
USGS Chronic Wasting Disease Research at NOROCK
Chronic wasting disease (CWD) is a growing management issue in the U.S. and has been detected in 36 states as of April 2025, including many western states. There is no cure or vaccine for CWD, and the disease threatens economically important animals like elk and deer. NOROCK scientists have taken a multi-pronged approach to develop actionable science including 1) evaluating CWD management options...
USGS Chronic Wasting Disease Research at the National Elk Refuge
Over the past 20 years, chronic wasting disease (CWD) in Wyoming has been spreading slowly outward from the southeastern corner of the state into the Greater Yellowstone Area and Wyoming's elk feed grounds. CWD detections have been getting closer to the National Elk Refuge, which provides supplemental feeding to approximately 8,000 elk and 500 bison each winter. NOROCK scientists have been...
Predicting the effects of supplemental feeding and chronic wasting disease in Greater Yellowstone Ecosystem elk
To support management decisions concerning 500 bison and 8,000 elk in Jackson, Wyoming, USGS scientists assessed how alternative U.S. Fish and Wildlife Service plans for providing supplemental food would influence: 1) chronic wasting disease prevalence, 2) elk and bison numbers, 3) wildlife movement and human-wildlife conflict 4) multiple use opportunities for the public, like hunting, and 5)...
Brucellosis
Brucellosis is a nationally and internationally regulated disease of livestock with significant consequences for animal health, public health, and international trade. NOROCK provides science based on an interdisciplinary approach to several key aspects: 1) estimating and modeling disease dynamics within and among wildlife species and populations, 2) identifying risks to cattle, and 3) assessing...
Climate-Informed Disease Threat Assessment for Montana’s Species of Greatest Conservation Need
Project Overview Infectious disease poses a growing threat to wildlife and human health, and managing disease threats is complicated by climatic changes that can change levels of disease risk. Researchers supported by this North Central CASC project will co-develop a method to rank wildlife disease threats under climate change, providing critical useable information to Montana’s wildlife...
COVID-19 Pathways and Wildlife Dynamics
Below are the USGS 2020 Coronavirus Aid, Relief and Economic Security Act (CARES Act) research projects related to COVID-19 pathways and wildlife dynamics. Select tabs above for related items.
Evaluating Transmission of Chronic Wasting Disease in the Environment
Chronic wasting disease (CWD) is a fatal disease of deer, elk, and moose and has been spreading in North America for the past two decades. The disease is spread by infected body fluids. Animals can become infected by coming into direct contact with a CWD-infected animal, or an infected animal can leave behind fluids (e.g., saliva, urine) that an uninfected animal will come into contact later...
Quantitative Disease Ecology
Researchers at the USGS are working on developing new quantitative methods to study disease dynamics in wildlife systems as well as systems at the wildlife-domestic-human interface. Much of our work focuses on how host population structure affects disease invasion, persistence and control in wildlife disease systems. We tackle these issues with a combination of simulation and statistical modeling...
Moose and Winter Ticks in Western Wyoming
Moose are an important game species in Montana, Idaho and Wyoming but hunter opportunities have been reduced in many areas over the last two decades as populations have declined at this southern limit of the species’ geographic range. In the Jackson, Wyoming area moose populations have declined by an estimated 80% since the early 1990s. Rising temperatures, pathogens, and parasites...
Impacts of Disease on Wolves in Yellowstone National Park
In 1995 and 1996, wolves were reintroduced into the Northern Rockies where they have since established and spread. Within Yellowstone National Park, one of the core protected release sites, the unmanaged population steadily increased to high densities, producing a large wolf population susceptible to infections such as canine parvovirus (CPV), canine distemper virus (CDV) and sarcoptic mange.
Pneumonia in Bighorn Sheep
Bighorn sheep populations are often impacted by outbreaks of pneumonia that are suspected to come from domestic sheep and goats.
NOROCK Large Carnivore Research Program
NOROCK has substantial expertise in large carnivore research, primarily involving species listed as Threatened or Endangered. NOROCK’s Large Carnivore Research Program includes scientists from NOROCK’s Headquarters, West Glacier Field Station, and the Southern Appalachian Field Station. Studies are conducted in a wide variety of landscapes throughout the U.S., as well as international research...
Wild Wolf Afflicted with Mange
Researchers at the USGS Northern Rocky Mountain Science Center and their partners place thermal remote cameras near deer and elk carcasses in Yellowstone National Park to capture images of wolves with mange feeding in the wild.
Researchers at the USGS Northern Rocky Mountain Science Center and their partners place thermal remote cameras near deer and elk carcasses in Yellowstone National Park to capture images of wolves with mange feeding in the wild.
Elk in Northwestern Wyoming
Elk congregate on the Camp Creek Feed Ground in northwestern Wyoming.
Elk congregate on the Camp Creek Feed Ground in northwestern Wyoming.
Close Encounters, Yellowstone National Park.
In the Rocky Mountain West, people and wildlife inhabit many of the same areas and USGS scientists are studying wildlife diseases, such as brucellosis in elk and bison, and how these diseases are transmitted between domestic and non-domestic hosts.
In the Rocky Mountain West, people and wildlife inhabit many of the same areas and USGS scientists are studying wildlife diseases, such as brucellosis in elk and bison, and how these diseases are transmitted between domestic and non-domestic hosts.