Assistant Unit Leader - Montana Cooperative Wildlife Research Unit
Since joining the USGS in 2011, his research has focused on developing and applying quantitative approaches to understanding and managing wildlife disease processes. He has conducted applied research on a wide array of diseases including bighorn sheep respiratory disease, chronic wasting disease, Newcastle Disease, and Avian Influenza. He also conducts capacity building in wildlife disease management for countries throughout the world in collaboration with the World Organisation for Animal Health (OIE).
Professional Experience
2011 – Present Quantitative Ecologist, U.S. Geological Survey, National Wildlife Health Center, Madison WI
2007 – 2011 Disease Researcher, Colorado Division of Wildlife
2003 – 2007 Research Assistant-Michigan State University
2000 – 2002 Research Assistant-Colorado State University
Education and Certifications
Ph. D. Fisheries and Wildlife, Michigan State University, 2007
M. S. Statistics Michigan State University, 2007
M. S. Fish and Wildlife Biology, Colorado State University, 2002
B. S. Fisheries and Wildlife, Michigan State University, 1999
Affiliations and Memberships*
Honorary Fellow, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison
Affiliate Faculty, South Dakota State University
Member of the Wildlife Disease Association
Member of the Wildlife Society
Member of the North Central Section of the Wildlife Society
Member of Wisconsin Chapter of the Wildlife Society
Science and Products
Research in response to Florida’s emerging coral disease
Application of a Systems Approach for Management of Chronic Wasting Disease in Wisconsin
Assessing the Ability of Incineration to Inactivate CWD Prions from Carcasses
Advancing the Use of RT-QuIC for Applications in CWD Management
Chronic Wasting Disease
Avian Influenza
Disease Ecology and Modeling
White-tailed deer and sharp-tailed grouse data used in constrained generalized additive models to enhance survival analyses and incorporate ecological theory
Expert assessments of hypotheses concerning the etiological agent(s) of Stony Coral Tissue Loss Disease collected during a rapid prototyping project
Pseudogymnoascus destructans detections by US county (2008-2012)
Pseudogymnoascus destructans survival at elevated temperatures - Artificial media count data
Recovering individual-level spatial inference from aggregated binary data
Efficacy of fenbendazole and ivermectin against Trichuris spp. in African green monkeys (Chlorocebus sabaeus) in Barbados West Indies
Space matters: Host spatial structure and the dynamics of plague transmission
An ecological and conservation perspective
Improving the accessibility and transferability of machine learning algorithms for identification of animals in camera trap images: MLWIC2
Assessing the risks posed by SARS-CoV-2 in and via North American bats — Decision framing and rapid risk assessment
Removal of chronic Mycoplasma ovipneumoniae carrier ewes eliminates pneumonia in a bighorn sheep population
Chronic wasting disease—Research by the U.S. Geological Survey and partners
Artificial intelligence and avian influenza: Using machine learning to enhance active surveillance for avian influenza viruses
Predicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl
Challenges and opportunities developing mathematical models of shared pathogens of domestic and wild animals
Applying a Bayesian weighted surveillance approach to detect chronic wasting disease in white‐tailed deer
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Code for Assimilating ecological theory with empiricism: Using constrained generalized additive models to enhance survival analyses
Code for Rapid prototyping for quantifying belief weights of competing hypotheses about emergent diseases
Science and Products
- Science
Research in response to Florida’s emerging coral disease
Coral reefs are both ecologically and economically important, serving as nurseries for fisheries, protecting the coastline from storm surges, and generating income from tourism. Since 2014, a wide variety of corals have been dying from unexplained causes throughout South Florida with mortalities ranging from North Miami to the Florida Keys.Application of a Systems Approach for Management of Chronic Wasting Disease in Wisconsin
Chronic wasting disease (CWD), a fatal neurologic disease of cervids that causes population declines and is increasing in intensity and spatial extent, has proven extremely difficult to manage despite intensive control efforts that have spanned several decades.Assessing the Ability of Incineration to Inactivate CWD Prions from Carcasses
Chronic wasting disease (CWD), a fatal neurologic disease of cervids, presents a monumental management challenge, in part because the etiological agent, an infectious prion, is extremely difficult to inactivate and can be transmitted directly or indirectly to hosts. Due to these attributes of prions, proper disposal of CWD-infected carcasses is an important consideration for management agencies to...Advancing the Use of RT-QuIC for Applications in CWD Management
Chronic wasting disease (CWD) is an emerging infectious disease that is fatal to free-ranging and captive animals in Cervidae, the deer family. The development of the real-time quaking-induced conversion (RT-QuIC) assay has the potential to transform laboratory research of prions and provide new opportunities for improved surveillance and management.Chronic Wasting Disease
Chronic wasting disease (CWD) is an emerging infectious disease that is fatal to free-ranging and captive animals in Cervidae, the deer family. CWD is one member of a family of diseases called transmissible spongiform encephalopathies (TSEs), and is thought to be caused by prions. CWD is the only TSE known to affect free-ranging wildlife.Avian Influenza
Avian influenza is a viral disease caused by various strains of avian influenza viruses that can be classified as low pathogenic avian influenza (LPAI) or highly pathogenic avian influenza (HPAI). It remains a global disease with potential high consequence with the potential to threaten wildlife, agriculture, and human health.Disease Ecology and Modeling
The USGS National Wildlife Health Center (NWHC) provides quantitative support and technical assistance to state and federal wildlife managers and partners to better understand or predict the impact of disease on wildlife populations. - Data
White-tailed deer and sharp-tailed grouse data used in constrained generalized additive models to enhance survival analyses and incorporate ecological theory
Grouse: These data on sharp-tailed grouse survival times are provided for individuals wanting to run an age-period survival analysis. Entry and exit times are expressed in integer days from the start of the study. Entry age and exit age expressed in integer days are also included. Data are structured to implement survival analysis. White-tailed Deer: These data on white-tailed deer survival timesExpert assessments of hypotheses concerning the etiological agent(s) of Stony Coral Tissue Loss Disease collected during a rapid prototyping project
This dataset is from expert elicitation of a panel of 15 experts with knowledge of stony coral tissue loss disease (SCTLD) and its impacts on coral reefs. We gathered this group of 15 participants with diverse expertise who had previously studied SCTLD including at universities and various government agencies as microbiologists, pathologists, disease ecologists, population ecologists, and coral exPseudogymnoascus destructans detections by US county (2008-2012)
This data represents the number of positive and negative Pd (Pseudogymnoascus destructans) detections by county over the sampling period 2008-2012. Pd is the fungus that is the causative agent of white-nose syndrome.Pseudogymnoascus destructans survival at elevated temperatures - Artificial media count data
The survival of Pseudogymnoascus destructans (Pd) was evaluated at temperatures outside of its thermal range of growth on three different artificial growth media; Sabouraud dextrose agar (SD), brain-heart infusion agar (BHI), and brain-heart infusion agar supplemented with 10% sheep red blood cells (BHI+B). Pd was harvested from starting cultures grown of MEA agar at 7?C for 60 days. Harvested con - Multimedia
- Publications
Filter Total Items: 30
Recovering individual-level spatial inference from aggregated binary data
Binary regression models are commonly used in disciplines such as epidemiology and ecology to determine how spatial covariates influence individuals. In many studies, binary data are shared in a spatially aggregated form to protect privacy. For example, rather than reporting the location and result for each individual that was tested for a disease, researchers may report that a disease was detecteEfficacy of fenbendazole and ivermectin against Trichuris spp. in African green monkeys (Chlorocebus sabaeus) in Barbados West Indies
Trichuris spp. are common helminths in NHP, and benzimidazoles and avermectins have both been used to treat these intestinal parasites. The current study compared the efficacy of fenbendazole and ivermectin against natural infection of Trichuris spp. in African green monkeys (Chlorocebus sabaeus). Anthelmintic-naive animals (n = 65) were randomly assigned to 4 groups: an untreated control group, aSpace matters: Host spatial structure and the dynamics of plague transmission
The development of models to elucidate the transmission pathways and dynamics of wildlife diseases remains challenging. Sylvatic plague, caused by the bacterium Yersinia pestis (Yp), is an infectious zoonotic disease that primarily affects wild rodents, including prairie dogs (Cynomys spp.) in North America. Proposed transmission pathways for Yp include flea bites, direct contacts between hosts, aAn ecological and conservation perspective
Natural ecosystems are facing unprecedented threats which directly threaten human well-being through decreases in critical ecosystem services (IPBES 2019). The top five drivers causing the largest global impacts to biodiversity and ecosystem services include: 1) changes in land and sea use; 2) direct exploitation of organisms; 3) climate change; 4) pollution, and 5) invasive alien species (IPBES 2Improving the accessibility and transferability of machine learning algorithms for identification of animals in camera trap images: MLWIC2
Motion‐activated wildlife cameras (or “camera traps”) are frequently used to remotely and noninvasively observe animals. The vast number of images collected from camera trap projects has prompted some biologists to employ machine learning algorithms to automatically recognize species in these images, or at least filter‐out images that do not contain animals. These approaches are often limited by mAssessing the risks posed by SARS-CoV-2 in and via North American bats — Decision framing and rapid risk assessment
The novel β-coronavirus, SARS-CoV-2, may pose a threat to North American bat populations if bats are exposed to the virus through interaction with humans, if the virus can subsequently infect bats and be transmitted among them, and if the virus causes morbidity or mortality in bats. Further, if SARS-CoV-2 became established in bat populations, it could possibly serve as a source for new infectionRemoval of chronic Mycoplasma ovipneumoniae carrier ewes eliminates pneumonia in a bighorn sheep population
Chronic pathogen carriage is one mechanism that allows diseases to persist in populations. We hypothesized that persistent or recurrent pneumonia in bighorn sheep (Ovis canadensis ) populations may be caused by chronic carriers of Mycoplasma ovipneumoniae (Mo ). Our experimental approach allowed us to address a conservation need while investigating the role of chronic carriage in disease persistenChronic wasting disease—Research by the U.S. Geological Survey and partners
IntroductionChronic wasting disease (CWD) is the only transmissible spongiform encephalopathy, a class of invariably fatal neurodegenerative mammalian diseases associated with a misfolded cellular prion protein found in wild free-ranging animals. Because it has a long incubation period, affected animals in Cervidae (the deer family; referred to as “cervids”) may not show signs of disease for severArtificial intelligence and avian influenza: Using machine learning to enhance active surveillance for avian influenza viruses
Influenza A viruses are one of the most significant viral groups globally with substantial impacts on human, domestic animal and wildlife health. Wild birds are the natural reservoirs for these viruses, and active surveillance within wild bird populations provides critical information about viral evolution forming the basis of risk assessments and countermeasure development. Unfortunately, activePredicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for cChallenges and opportunities developing mathematical models of shared pathogens of domestic and wild animals
Diseases that affect both wild and domestic animals can be particularly difficult to prevent, predict, mitigate, and control. Such multi-host diseases can have devastating economic impacts on domestic animal producers and can present significant challenges to wildlife populations, particularly for populations of conservation concern. Few mathematical models exist that capture the complexities of pApplying a Bayesian weighted surveillance approach to detect chronic wasting disease in white‐tailed deer
Surveillance is critical for early detection of emerging and re‐emerging infectious diseases. Weighted surveillance leverages heterogeneity in infection risk to increase sampling efficiency.Here, we apply a Bayesian approach to estimate weights for 16 surveillance classes of white‐tailed deer in Wisconsin, USA, relative to hunter‐harvested yearling males. We used these weights to conduct a surveilNon-USGS Publications**
Alldredge, M. W., D. P. Walsh, L. L. Sweanor, R. B. Davies, A. Trujillo. 2015. Evaluation of translocation of black bears involved in human–bear conflicts in South-central Colorado. Wildlife Society Bulletin 39: 334–340. doi:10.1002/wsb.526.Smith, J. B., D. P. Walsh, E. J. Goldstein, Z. D. Parsons, R. C. Karsch, J. R. Stiver, J. W. Cain III, K. J. Raedeke, and J. A. Jenks. 2014. Techniques for capturing bighorn sheep lambs. Wildlife Society Bulletin 38: 165–174. doi: 10.1002/wsb.360.Davis, M. J., S. Thokala, X. Xing, N. T. Hobbs, D. P. Walsh, R. Y. Han, and S. Mishra. 2012. Developing a data-transfer model for a novel Wildlife-tracking network. Wildlife Society Bulletin 36:820–827.Walsh, D. P., L. L. Wolfe, M. E. P. Vieira, and M. W. Miller. 2012. Detection probability and Pasteurellaceae surveillance in bighorn sheep. Journal of Wildlife Diseases 48: 593–602.Sirochman, M. A., K. J. Woodruff, J. L. Grigg, D. P. Walsh, K. P. Huyvaert, M. W. Miller, and L. L. Wolfe. 2012. Evaluation of management treatments intended to increase lamb recruitment in a bighorn sheep herd. Journal of Wildlife Diseases 48:781–784.Walsh, D. P., H. Campa III, D. E. Beyer Jr., and S. R. Winterstein. 2011. Measurement error and survey design in sightability model development. Journal of Wildlife Management 75: 1228–1235.Bishop, C. J., C. R. Anderson, D. P. Walsh, E. J. Bergman, P. Kuechle, and J. Roth. 2011. Effectiveness of a redesigned vaginal implant transmitter in mule deer. Journal of Wildlife Management 75: 1797–1806.Walter, W. D., D. P. Walsh, M. L. Farnsworth, D. L. Winkleman, and M. W. Miller. 2011. Soil clay content underlies prion infection odds. Nature Communications 2:200 doi: 10.1038/ncomms1203.Walsh, D. P., and M. W. Miller. 2010. A weighted surveillance approach for detecting chronic wasting disease foci. Journal of Wildlife Diseases 46: 118–135.Walsh, D. P., J. R. Stiver, G. C. White, T. E. Remington, and A. D. Apa. 2010. Population estimation techniques for lekking species. Journal of Wildlife Management 74: 1607–1613.Griffin, K. A., D. J. Martin, L. E. Rosen, M. A. Sirochman, D. P. Walsh, L. L. Wolfe, and M. W. Miller. 2010. Detection of Yersinia pestis DNA in prairie dog-associated fleas by polymerase chain reaction assay of purified DNA. Journal of Wildlife Diseases 46: 636–643.Martin, D. J., B. R. McMillan, J. D. Erb, T. A. Gorman, and D. P. Walsh. 2010. Diel activity patterns of river otters (Lontra canadensis) in southeastern Minnesota. Journal of Mammalogy 91: 1213–1224.Wolfe, L. L., B. Diamond, T. R. Spraker, M. A. Sirochman, D. P. Walsh, C. M. Machin, D. J. Bade, and M. W. Miller. 2010. A bighorn sheep die-off in southern Colorado involving a Pasteurellaceae strain that may have originated from syntopic Cattle. Journal of Wildlife Diseases 46: 1262–1269.Rosen, L. E., D. P. Walsh, L. L. Wolfe, C. L. Bedwell, and M. W. Miller. 2009. Effects of selenium supplementation and sample storage time on blood indices of selenium status in bighorn sheep. Journal of Wildlife Diseases 45: 795–801.Walsh, D. P., C. F. Page, H. Campa III, S. R. Winterstein, and D. E. Beyer Jr. 2009. Incorporating estimates of group size in sightability models for wildlife. Journal of Wildlife Management 73: 136–143.Walsh, D.P. 2007. Population estimation and fixed kernel analyses of elk in Michigan. Michigan State University, East Lansing, Michigan. Ph.D. Dissertation, 238pp.Felix, A. B., D. P. Walsh, B. D. Hughey, H. Campa III, and S. R. Winterstein. 2006. Applying landscape-scale habitat-potential models to understand deer spatial structure and movement patterns. Journal of Wildlife Management 71: 804–810.Walsh, D. P., G. C. White, T. E. Remington, and D. C. Bowden. 2004. Evaluation of the lek-count index for greater-sage grouse. Wildlife Society Bulletin 32: 56–68.Walsh, D. P. 2002. Population estimation techniques for Greater-Sage Grouse. Colorado State University, Fort Collins, Colorado. M.S. Thesis, 139 pp.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- Software
Code for Assimilating ecological theory with empiricism: Using constrained generalized additive models to enhance survival analyses
Code will be submitted to the Dryad repository upon acceptance of the manuscript. These R code are used for simulations and case studies. Simulations include data for generating age-period survival data. We have provided code for each of the 10 models that were fit using NIMBLE, where each model has four R scripts including: 1) A script to execute and run all the additional R scripts for each simuCode for Rapid prototyping for quantifying belief weights of competing hypotheses about emergent diseases
Code submitted to Journal of Environmental Management and ScienceBase for running Bayesian hierarchical models on a dataset that was collected using expert elicitation of a panel of 15 experts on the etiology of stony coral tissue loss disease and its impacts on coral reefs. The code is for a rapid prototyping method for quantifying belief weights for competing hypotheses about the etiology of dis
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government