Daniel A Grear
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.
- 2002 B.S. Wildlife Ecology, University of Wisconsin
- 2006 M.S. Wildlife Ecology, University of Wisconsin
- 2011 Ph.D. Ecology, Pennsylvania State University
- 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
- Member of the Ecological Society of America
- Member of the Wildlife Society
- Bsal Task Force Working Group Member
Science and Products
Pathology and case definition of Severe Perkinsea Infections of frogs
Severe Perkinsea infection (SPI) is an emerging disease of frogs responsible for mass mortalities of tadpoles across the United States. It is caused by protozoa belonging to the phylum Perkinsozoa that form a distinct group referred to as the Pathogenic Perkinsea Clade of frogs. In this work, we provide detailed description of gross and histologic...Isidoro Ayza, Marcos; Grear, Daniel A.; Chambouvet, Aurélie
Identifying management-relevant research priorities for responding to disease-associated amphibian declines
A research priority can be defined as a knowledge gap that, if resolved, identifies the optimal course of conservation action. We (a group of geographically distributed and multidisciplinary research scientists) used tools from nominal group theory and decision analysis to collaboratively identify and prioritize information...Campbell Grant, Evan H.; Adams, M.J.; Fisher, Robert N.; Grear, Daniel A.; Halstead, Brian J.; Hossack, Blake R.; Muths, Erin L.; Richgels, Katherine L. D.; Russell, Robin E.; Smalling, Kelly L.; Waddle, J. Hardin; Walls, Susan C.; White, C. LeAnn
Chlamydia psittaci in feral Rosy-faced Lovebirds (Agapornis roseicollis) and other backyard birds in Maricopa County, Arizona
In 2013, a mortality event of nonnative, feral Rosy-faced Lovebirds (Agapornis roseicollis) in residential backyards in Maricopa County, Arizona, US was attributed to infection with Chlamydia psittaci. In June 2014, additional mortality occurred in the same region. Accordingly, in August 2014 we sampled live lovebirds and sympatric bird...Dusek, Robert J.; Justice-Allen, Anne; Bodenstein, Barbara; Knowles, Susan N.; Grear, Daniel A.; Adams, Laura; Levy, Craig; Yaglom, Haley D.; Shearn-Bochsler, Valerie I.; Ciembor, Paula; Gregory, Christopher R.; Pesti, Denise; Ritchie, Branson W.
Quarterly wildlife mortality report - January 2018
No abstract available.Richards, Bryan J.; Grear, Daniel A.; Ballmann, Anne; Dusek, Robert J.; Kaler, Robert; Kuletz, Kathy
Inferring epidemiologic dynamics from viral evolution: 2014–2015 Eurasian/North American highly pathogenic avian influenza viruses exceed transmission threshold, R0 = 1, in wild birds and poultry in North America
Highly pathogenic avian influenza virus (HPAIV) is a multihost pathogen with lineages that pose health risks for domestic birds, wild birds, and humans. One mechanism of intercontinental HPAIV spread is through wild bird reservoirs, and wild birds were the likely sources of a Eurasian (EA) lineage HPAIV into North America in 2014. The introduction...Grear, Daniel R.; Hall, Jeffrey S.; Dusek, Robert J.; Ip, Hon S.
Novel dermatophilosis and concurrent amyloidosis in Sanderlings (Calidris alba) from Louisiana, USA
We observed Sanderlings (Calidris alba) with facial growths in coastal Louisiana, US during summer of 2016. Severe lesions were associated with lethargy and lack of a flight response. We determined that the skin growth etiology was a bacterium of the genus Dermatophilus, rarely reported infecting birds. Sanderlings also exhibited severe...Shearn-Bochsler, Valerie I.; Schulz, Jessica L.; Dobbs, Robert C.; Lorch, Jeffrey M.; Waddle, J. Hardin; Grear, Daniel A.
Pathogenic lineage of Perkinsea associated with mass mortality of frogs across the United States
Emerging infectious diseases such as chytridiomycosis and ranavirus infections are important contributors to the worldwide decline of amphibian populations. We reviewed data on 247 anuran mortality events in 43 States of the United States from 1999–2015. Our findings suggest that a severe infectious disease of tadpoles caused by a protist...Isidoro Ayza, Marcos; Lorch, Jeffrey M.; Grear, Daniel A.; Winzeler, Megan; Calhoun, Daniel L.; Barichivich, William J.
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...Miller, Ryan S.; Sweeney, Steven J.; Slootmaker, Chris; Grear, Daniel A.; DiSalvo, Paul A.; Kiser, Deborah; Shwiff, Stephanie A.
Early 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...Adams, M.J.; Harris, M. Camille; Grear, Daniel A.
USGS-NWHC Quarterly Wildlife Mortality Report- January 2017
No abstract available.Richards, Bryan J.; Grear, Daniel A.; Ballmann, Anne; Dusek, Robert J.; Bodenstein, Barbara
No 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...Grear, Daniel A.; Dusek, Robert J.; Walsh, Daniel P.; Hall, Jeffrey S.
USGS National Wildlife Health Center quarterly wildlife mortality report: January 2016 to March 2016
No abstract availableBallmann, Anne E.; Bodenstein, Barbara L.; Dusek, Robert J.; Grear, Daniel R.; Chipault, Jennifer
As wildlife diseases increase globally, an understanding of host-pathogen relationships can elucidate avenues for management and improve conservation efficacy. Amphibians are among the most threatened groups of wildlife, and disease is a major factor in global amphibian declines.