Daniel A Grear
Dan Grear is a Wildlife Disease Ecologist at the National Wildlife Health Center.
I am interested in mechanisms that cause heterogeneities in pathogen transmission in wild animal disease systems and at the interface of wildlife, domestic animal, and human health. I lead investigations into wildlife mortality events and research that incorporates field studies with theoretical modeling of disease systems to identify key mechanisms that drive transmission dynamic.
Professional Experience
2015 - Present Wildlife Disease Ecologist, U.S. Geological Survey, National Wildlife Health Center, Madison, WI
2013 - 2015 Ecologist, U.S. Department of Agriculture, Veterinary Services, Center for Epidemiology and Animal Health, Fort Collins, CO
2011 - 2014 Post-Doctoral Researcher, Colorado State University
Education and Certifications
2011 Ph.D. Ecology, Pennsylvania State University
2006 M.S. Wildlife Ecology, University of Wisconsin
2002 B.S. Wildlife Ecology, University of Wisconsin
Affiliations and Memberships*
Member of the Ecological Society of America
Member of the Wildlife Society
Bsal Task Force Working Group Member
Science and Products
Cross-species transmission potential between wild pigs, livestock, poultry, wildlife, and humans: Implications for disease risk management in North America
Early action to address an emerging wildlife disease
Quarterly wildlife mortality report January 2017
Quarterly wildlife mortality report January 2016 to March 2016
No evidence of infection or exposure to Highly Pathogenic Avian Influenzas in peridomestic wildlife on an affected poultry facility
Surveillance for highly pathogenic avian influenza virus in wild birds during outbreaks in domestic poultry, Minnesota, 2015
USGS National Wildlife Health Center quarterly wildlife mortality report July 2015 to September 2015
USGS National Wildlife Health Center quarterly wildlife mortality report April 2015 to June 2015
USGS National Wildlife Health Center quarterly mortality report January 2015 to March 2015
Effects of chronic wasting disease on reproduction and fawn harvest vulnerability in Wisconsin white-tailed deer
Diversity and distribution of white-tailed deer mtDNA lineages in chronic wasting disease (CWD) outbreak areas in southern Wisconsin, USA
Chronic wasting disease infection patterns in female white-tailed deer related to demographics, genetic relationships, and spatial proximity of infected deer in southern Wisconsin
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.
Science and Products
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Filter Total Items: 37
Cross-species transmission potential between wild pigs, livestock, poultry, wildlife, and humans: Implications for disease risk management in North America
Cross-species disease transmission between wildlife, domestic animals and humans is an increasing threat to public and veterinary health. Wild pigs are increasingly a potential veterinary and public health threat. Here we investigate 84 pathogens and the host species most at risk for transmission with wild pigs using a network approach. We assess the risk to agricultural and human health by evaluaAuthorsRyan S. Miller, Steven J. Sweeney, Chris Slootmaker, Daniel A. Grear, Paul A. DiSalvo, Deborah Kiser, Stephanie A. ShwiffEarly action to address an emerging wildlife disease
A deadly fungal pathogen, Batrachochytrium salamandrivorans (Bsal) that affects amphibian skin was discovered during a die-off of European fire salamanders (Salamandra salamandra) in 2014. This pathogen has the potential to worsen already severe worldwide amphibian declines. Bsal is a close relative to another fungal disease known as Batrachochytrium dendrobatidis (Bd). Many scientists consider BdAuthorsM. J. Adams, M. Camille Harris, Daniel A. GrearQuarterly wildlife mortality report January 2017
No abstract available.AuthorsBryan J. Richards, Daniel A. Grear, Anne Ballmann, Robert J. Dusek, Barbara BodensteinQuarterly wildlife mortality report January 2016 to March 2016
No abstract availableAuthorsAnne E. Ballmann, Barbara L. Bodenstein, Robert J. Dusek, Daniel R. Grear, Jennifer ChipaultNo evidence of infection or exposure to Highly Pathogenic Avian Influenzas in peridomestic wildlife on an affected poultry facility
We evaluated the potential transmission of avian influenza viruses (AIV) in wildlife species in three settings in association with an outbreak at a poultry facility: 1) small birds and small mammals on a poultry facility that was affected with highly pathogenic AIV (HPAIV) in April 2015; 2) small birds and small mammals on a nearby poultry facility that was unaffected by HPAIV; and 3) small birds,AuthorsDaniel A. Grear, Robert J. Dusek, Daniel P. Walsh, Jeffrey S. HallSurveillance for highly pathogenic avian influenza virus in wild birds during outbreaks in domestic poultry, Minnesota, 2015
In 2015, a major outbreak of highly pathogenic avian influenza virus (HPAIV) infection devastated poultry facilities in Minnesota, USA. To clarify the role of wild birds, we tested 3,139 waterfowl fecal samples and 104 sick and dead birds during March 9–June 4, 2015. HPAIV was isolated from a Cooper’s hawk but not from waterfowl.AuthorsChristopher S. Jennelle, Michelle Carstensen, Erik C. Hildebrand, Louis Cornicelli, Paul C. Wolf, Daniel A. Grear, Hon S. Ip, Kaci K. VanDalen, Larissa A. MinicucciUSGS National Wildlife Health Center quarterly wildlife mortality report July 2015 to September 2015
No abstract available.AuthorsAnne Ballmann, Barbara L. Bodenstein, Robert J. Dusek, Daniel A. Grear, Jennifer G. Chipault, Michelle MagagnaUSGS National Wildlife Health Center quarterly wildlife mortality report April 2015 to June 2015
No abstract available.AuthorsAnne Ballmann, Barbara L. Bodenstein, Robert J. Dusek, Daniel A. Grear, Jennifer G. ChipaultUSGS National Wildlife Health Center quarterly mortality report January 2015 to March 2015
No abstract available.AuthorsAnne Ballmann, Barbara L. Bodenstein, Robert J. Dusek, Daniel A. Grear, Jennifer G. ChipaultEffects of chronic wasting disease on reproduction and fawn harvest vulnerability in Wisconsin white-tailed deer
Chronic wasting disease (CWD) is a fatal, transmissible spongiform encephalopathy that affects free-ranging and captive North American cervids. Although the impacts of CWD on cervid survival have been documented, little is known about the disease impacts on reproduction and recruitment. We used genetic methods and harvest data (2002–04) to reconstruct parentage for a cohort of white-tailed deer (OAuthorsJulie A. Blanchong, Daniel A. Grear, Byron V. Weckworth, Delwyn P. Keane, Kim T. Scribner, Michael D. SamuelDiversity and distribution of white-tailed deer mtDNA lineages in chronic wasting disease (CWD) outbreak areas in southern Wisconsin, USA
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting North American cervids. Because it is uniformly fatal, the disease is a major concern in the management of white-tailed deer populations. Management programs to control CWD require improved knowledge of deer interaction, movement, and population connectivity that could influence disease transmission and spread. GeAuthorsK.G. Rogers, S.J. Robinson, M. D. Samuel, D.A. GrearChronic wasting disease infection patterns in female white-tailed deer related to demographics, genetic relationships, and spatial proximity of infected deer in southern Wisconsin
Chronic wasting disease (CWD) is a fatal disease of white-tailed deer (Odocoileus virginianus) caused by transmissible protease resistant prions. Since the discovery of CWD in southern Wisconsin in 2001, more than 20,000 deer have been removed from a >2,500 km2 disease eradication zone surrounding the three initial cases. Nearly all deer removed were tested for CWD infection and sex, age, and harvAuthorsDaniel A. GrearNon-USGS Publications**
Gorsich EE, Luis AD, Buhnerkempe MG, Grear DA, Portacci K, Miller RS, Webb CT. 2016. Mapping US cattle shipment networks: Spatial and temporal patterns of trade communities from 2009 to 2011. Preventive Veterinary Medicine, 134, 82-91.Lavelle MJ, Kay SL, Pepin KM, Grear DA, Campa H, VerCauteren K. 2016. Evaluating wildlife-cattle contact rates to improve the understanding of dynamics of bovine tuberculosis transmission in Michigan, USA. Preventive Veterinary Medicine, 135, 28-36.Scott A, B McCluskey, M Brown-Reid, DA Grear, P Pitcher, G Ramos, D Spencer. 2016. Porcine epidemic diarrhea virus introduction into the United States: Root cause investigation. Preventive Veterinary Medicine, 123, 192-201. doi: 10.1016/j.prevetmed.2015.11.013Glaser L, M Carstensen, S Shaw, S Robbe-Austerman, A Wunschmann, DA Grear, T Stuber, B Thomsen. 2016. Descpriptive epidemiology and whole genome sequencing analysis for an outbreak of bovine tuberculosis in beef cattle and white-tailed deer in Northwestern Minnesota. PLoS ONE, e0145735.McClure RSM, CL Burdett, ML Farnsworth, MW Lutman, DM Theobold, PD Riggs, DA Grear, RS Miller. 2015. Modeling and mapping the probability of occurrence of invasive wild pigs across the contiguous United States. PLoS ONE 10(8): e0133771. doi:10.1371/journal.pone.0133771Pepin KM, CB Leach, C Marques-Toledo, KH Laass, KS Paixao, AD Luis, DTS Hayman, NG Johnson, MG Buhnerkempe, S Carver, DA Grear, K Tsao, AE Eiras, and CT Webb. 2015. Utility of mosquito surveillance data for spatial prioritization of vector control against dengue viruses in three Brazilian cities. Parasites and Vectors, 8, 98.Tsao K, S Robbe-Austerman, RS Miller, K Portacci, DA Grear, and CT Webb. 2014. Sources of bovine tuberculosis in the United States. Infection, Genetics, and Evolution. 114, 201-212.Luong LT, DA Grear, and PJ Hudson. 2014. Manipulation of host-resource dynamics impacts transmission of trophically transmitted parasites. International Journal for Parasitology, 44, 737-742.Grear DA, J Kaneene, J Averill, and CT Webb. 2014. Local cattle movements in response to ongoing bovine TB zonation and regulations. Preventive Veterinary Medicine, 114, 201-212.Buhnerkempe MG, MJ Tildesley, T Lindström, DA Grear, RS Miller, K Portacci, M Keeling, U Wennergren, and CT Webb. 2014. The impact of movements and animal density on continental scale cattle disease outbreaks in the United States. PLoS one, e91724.Grear DA, LT Luong, and PJ Hudson. 2013. Network transmission inference: host behavior and parasite life-cycle make social networks meaningful in disease ecology, Ecological Applications, 23, 1906-1914.Buhnerkempe, MG, DA Grear, RS Miller, K Portacci, J Lombard, and CT Webb. 2013. A national-scale picture of U.S. cattle movements obtained from Interstate Certificates of Veterinary Inspection data. Prev. Vet. Med., 112, 318-329.Lindström T, DA Grear, MG Buhnerkempe, CT Webb, RS Miller, K Portacci, and U Wennergren. 2013. Bayesian approach for modeling cattle movements in the United States: scaling up a partially observed network. PLoS ONE,8, e53432. doi:10.1371/journal.pone.0053432Grear DA, LT Luong, and PJ Hudson. 2012. Sex-biased transmission of a complex life-cycle parasite: why males matter. Oikos, 121, 1446-1453. doi: 10.1111/j.1600-0706.2012.20358.xBlanchong, JA, DA Grear, BV Weckworth, DP Keane, KT Scribner, and MD Samuel. 2012. Effects of chronic wasting disease on reproduction and fawn harvest vulnerability in Wisconsin white-tailed deer. Journal of Wildlife Diseases, 48, 361-370.Rogers K, S Robinson, MD Samuel, and DA Grear. 2011. Diversity and distribution of white-tailed deer mtDNA lineages in CWD outbreak areas in southern Wisconsin, USA. Journal of Toxicology and Environmental Health, 74, 1521-1535. doi: 10.1080/15287394.2011.618980Grear DA and PJ Hudson. 2011. The dynamics of macroparasite host-self-infection: a study of the patterns and processes of pinworm (Oxyuridae) aggregation. Parasitology, 138, 619-617. doi: 10.1017/S0031182011000096.Grear DA, MD Samuel, K Scribner, BV Weckworth, and JA Langenberg. 2010. Influence of genetic relatedness and spatial proximity on CWD transmission among female white-tailed deer. Journal of Applied Ecology, 47, 532-540.Luong, LT, SE Perkins, DA Grear, A Rizzoli, and PJ Hudson. 2010. The relative importance of host characteristics and co-infection in generating variation in Heligmosomoides polygyrus fecundity. Parasitology, 137, 1003-1012.Grear DA, SE Perkins, and PJ Hudson. 2009. Does elevated testosterone result in increased exposure and transmission of parasites? Ecology Letters, 12, 528-537.Luong, LT, DA Grear, and PJ Hudson. 2009. Male hosts are responsible for the transmission of a trophically transmitted parasite, Pterygodermatites peromysci to the intermediate host in the absence of sex-biased infection. International Journal for Parasitology, 39, 1263-1268.Grear DA, MD Samuel, JA Langenberg, and D Keane. 2006. Demographic patterns and harvest vulnerability of chronic wasting disease infected white-tailed deer in Wisconsin. Journal of Wildlife Management, 70, 546-553.**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.
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*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