Paul Cross, Ph.D.
Biography
Education
Ph.D. Environmental Science, Policy, and Management. 2005. University of California, Berkeley
B.A. Environmental Science. 1998. University of Virginia, Charlottesville
Research Interests
My research focuses on applied wildlife disease, conservation and management issues around the Greater Yellowstone Ecosystem. 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
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....
Chronic Wasting Disease
Over the past 20 years, chronic wasting disease (CWD) in Wyoming has been spreading slowly outward from the southeastern corner of the state toward the Greater Yellowstone Area and Wyoming's elk feed grounds, where more than 24,000 elk are supplementally fed each winter.
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...
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 represent...
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.
Brucellosis
Brucellosis is a nationally and internationally regulated disease of livestock with significant consequences for animal health, public health, and international trade.
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...
COMPLETED: Using thermal imagery to assess wolf hairloss from sarcoptic mange
Researchers at NOROCK and their partners used thermal cameras at the Grizzly and Wolf Discovery Center in Montana to assess the amount of heat lost under a range of environmental conditions with and without hair. These methods help scientists better understand how mange operates in wild wolves throughout the Greater...
Scavengers reduce potential brucellosis transmission risk in the Greater Yellowstone Ecosystem
Scavengers likely play an important role in ecosystem energy flow as well as disease transmission, but whether they facilitate or reduce disease transmission is often unknown. In the Greater Yellowstone Ecosystem, scavengers are likely to reduce the transmission and subsequent spread of brucellosis within and between livestock and elk by consuming...
Szcodronski, Kimberly E; Cross, Paul Natural history of a bighorn sheep pneumonia epizootic: Source of infection, course of disease, and pathogen clearance
A respiratory disease epizootic at the National Bison Range (NBR) in Montana in 2016–2017 caused an 85% decline in the bighorn sheep population, documented by observations of its unmarked but individually identifiable members, the subjects of an ongoing long-term study. The index case was likely one of a small group of young bighorn sheep on a...
Besser, T. E.; Cassirer, E. Frances; Lisk, Amy; Nelson, Danielle; Manlove, Kezia R.; Cross, Paul; Hogg, John T. Effects of supplemental feeding on the fecal bacterial communities of Rocky Mountain elk in the Greater Yellowstone Ecosystem
Supplemental feeding of wildlife is a common practice often undertaken for recreational or management purposes, but it may have unintended consequences for animal health. Understanding cryptic effects of diet supplementation on the gut microbiomes of wild mammals is important to inform conservation and management strategies. Multiple laboratory...
Couch, Claire E; Wise, Benjamin; Scurlock, Brandon M.; Rogerson, Jared D.; Fuda, Rebecca K.; Cole, Eric K; Szcodronski, Kimberly E; Sepulveda, Adam J.; Hutchins, Patrick R.; Cross, Paul Sarcoptic mange: An emerging panzootic in wildlife
Sarcoptic mange, a skin infestation caused by the mite Sarcoptes scabiei, is an emerging disease for some species of wildlife, potentially jeopardizing their welfare and conservation. Sarcoptes scabiei has a near-global distribution facilitated by its forms of transmission and use of a large diversity of host species (many of those...
Escobar, L. E.; Carver, Scott; Cross, Paul; Rossi, Luca; Almberg, E. S.; Yabsley, M. J.; Niedringhaus, K D; Van Wick, Peach; Dominguez-Villegas, Ernesto; Gakuya, F.F.; Xie, Yue; Angelone, Samer; Gortázar, Christian; Astorga, Francisca Elk migration influences the risk of disease spillover in the Greater Yellowstone Ecosystem
Wildlife migrations provide important ecosystem services, but they are declining. Within the Greater Yellowstone Ecosystem (GYE) some elk (Cervus canadensis) herds are losing migratory tendencies, which may increase spatiotemporal overlap between elk and livestock (domestic bison [Bison bison] and cattle [Bos taurus]), potentially exacerbating...
Rayl, Nathaniel D.; Merkle, J. A.; Proffitt, Kelly M.; Almberg, E. S.; Jones, Jennifer D.; Gude, Justin; Cross, Paul Patterns and processes of pathogen exposure in gray wolves across North America
The presence of many pathogens varies in a predictable manner with latitude, with infections decreasing from the equator towards the poles. We investigated the geographic trends of pathogens infecting a widely distributed carnivore: the gray wolf (Canis lupus). Specifically, we investigated which variables best explain and predict geographic...
Brandell, E. E.; Cross, Paul; Craft, Meggan E.; Smith, Douglas W.; Dubovi, E. J.; Gilbertson, Marie L. J.; Wheeldon, Tyler; Stephenson, John A.; Barber-Meyer, Shannon; Borg, B. L.; Sorum, Mathew; Stahler, Daniel R.; Kelly, Allicia P; Anderson, Morgan; Cluff, H. D.; MacNulty, Daniel R.; Watts, David L.; Roffler, G.; Schwantje, Helen M.; Hebblewhite, Mark; Beckman, K.; Hudson, P. J. Human activities and weather drive contact rates of wintering elk
Wildlife aggregation patterns can influence disease transmission. However, limited research evaluates the influence of anthropogenic and natural factors on aggregation. Many managers would like to reduce wildlife contact rates, driven by aggregation, to limit disease transmission. We develop a novel analytical framework to quantify how management...
Janousek, William Michael; Graves, Tabitha; Berman, Ethan; Chong, Geneva W.; Cole, Eric K; Dewey, Sarah; Johnston, Aaron; Cross, Paul A metapopulation model of social group dynamics and disease applied to Yellowstone wolves
The population structure of social species has important consequences for both their demography and transmission of their pathogens. We develop a metapopulation model that tracks two key components of a species’ social system: average group size and number of groups within a population. While the model is general, we parameterize it to mimic the...
Brandell, E E; Dobson, A P; Hudson, PJ; Cross, Paul; Smith, Douglas W. Group density, disease, and season shape territory size and overlap of social carnivores
1. The spatial organization of a population can influence the spread of information, behaviour, and pathogens. Territory size and territory overlap, components of spatial organization, provide key information as these metrics may be indicators of habitat quality, resource dispersion, contact rates, and environmental risk (e.g., indirectly...
Brandell, E. E.; Fountain-Jones, Nicholas M.; Gilbertson, Marie L. J.; Cross, Paul; Hudson, P. J.; Smith, Douglas W.; Stahler, Daniel R.; Packer, Craig; Craft, Meggan E. Infectious diseases in Yellowstone’s wolves
No abstract available.
Brandell, Ellen E.; Almberg, Emily S.; Cross, Paul; Dobson, Andrew P; Smith, Douglas W.; Hudson, Peter J.
Ecological forecasting—21st century science for 21st century management
Natural resource managers are coping with rapid changes in both environmental conditions and ecosystems. Enabled by recent advances in data collection and assimilation, short-term ecological forecasting may be a powerful tool to help resource managers anticipate impending near-term changes in ecosystem conditions or dynamics. Managers may use the...
Bradford, John B.; Weltzin, Jake; Mccormick, Molly; Baron, Jill; Bowen, Zack; Bristol, Sky; Carlisle, Daren; Crimmins, Theresa; Cross, Paul; DeVivo, Joe; Dietze, Mike; Freeman, Mary; Goldberg, Jason; Hooten, Mevin; Hsu, Leslie; Jenni, Karen; Keisman, Jennifer L.; Kennen, Jonathan; Lee, Kathy; Lesmes, David; Loftin, Keith; Miller, Brian W.; Murdoch, Peter S.; Newman, Jana; Prentice, Karen L.; Rangwala, Imtiaz; Read, Jordan; Sieracki, Jennifer; Sofaer, Helen; Thur, Steve; Toevs, Gordon; Werner, Francisco; White, C. LeAnn; White, Timothy; Wiltermuth, Mark Parsing the effects of demography, climate, and management on recurrent brucellosis outbreaks in elk
1. Zoonotic pathogens can harm human health and well-being directly or by impacting livestock. Pathogens that spillover from wildlife can also impair conservation efforts if humans perceive wildlife as pests. Brucellosis, caused by the bacterium Brucella abortus, circulates in elk and bison herds of the Greater Yellowstone Ecosystem and poses a...
Cotterill, Gavin G.; Cross, Paul; Merkle, J. A.; Rogerson, JD; Scurlock, BM; Du Toit, Johan T.
CWD Simulation App
Chronic wasting disease (CWD) is a fatal disease of deer, elk, and moose transmitted through direct contact and via environmental contamination. This software provide tools to simulate CWD and harvest management scenarios. These models were developed by the U.S. Geological Survey (USGS) in collaboration with Montana Fish, Wildlife, and Parks.
Friday's Findings - August 7 2020
Using Models and Web Applications for Chronic Wasting Disease Scenario Planning
Date: August 7, 2020 from 2-2:30 p.m. eastern time
Speaker: Paul Cross, Research Wildlife Biologist, U.S. Geological Survey, Northern Rocky Mountain Science Center
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Study Shows Pathways of Disease Transmission Between Elk, Bison and Cattle in the Greater Yellowstone Area
The U.S. Geological Survey and its partners have shown how brucellosis has impacted cattle, bison and elk in the greater Yellowstone area.
Study Shows Cold and Windy Nights Physically Drain Mangy Wolves
During winter, wolves infected with mange can suffer a substantial amount of heat loss compared to those without the disease, according to a study by the U.S. Geological Survey and its partners.