Meet Our Scientists

Browse a list of our scientists and their expertise, and connect to their detailed staff profiles. Alternatively, please use our Staff Directory for a complete listing of all of our scientific and support teams.

For our complete listing of our scientific and support staff at Patuxent, please use our Staff Directory, or search all USGS staff profiles.  Below we’ve compiled a browsable list to help you learn about our scientists and their expertise; each name links to the scientist’s full profile and publications.

Alicia Berlin

Relationship between foraging energetics, benthic distribution, and seaduck distribution. Habitat utilization and potential climate change impacts on seaduck migration. Potential impacts of oyster restoration on wintering seaducks in the Chesapeake Bay. Use of two large dive tanks for controlled energetic and/or behavioral research (i.e. underwater hearing, electrosensitivity, foraging energetics). Maintaining a captive colony of diving ducks and seaducks consisting of surf scoters, white-winged scoters, long-tailed ducks, harlequin ducks, and lesser scaup.

Terry Chesser

Carrying out original field and collection-based research on mammals, curation and oversight of the national research collection of mammals, serving as authority on mammals for public institutions and agencies.  Expertise: North American bird taxonomy and classification, phylogenetic systematics, Neotropical phylogeography, and South American austral migration.

Sam Droege

Exploration and development of monitoring techniques and programs for plants and animals.  Current research activities include work on developing native bee survey techniques and monitoring programs, surveys of saltmarsh birds and surveys of Rusty Blackbirds..  Expertise in birds, identify native bees to species, take high resolution stacked macros insects and plants, and develop and design monitoring programs.

Mary Freeman

Research Ecologist, studies effects of environmental change on freshwater biodiversity.  Projects include estimating stream fish responses to changes in climate, water availability, and land use in the southeast US.  Mary provides technical assistance concerning management and conservation of freshwater species to Federal and State agencies, and other stakeholders.  Areas of expertise are stream ecology, freshwater fishes, and ecological flows and river management.

Howard Ginsberg

Published widely on the ecology of vector-borne diseases, especially tick-transmitted infections such as Lyme disease, and on mosquito ecology. His emphasis is on understanding transmission dynamics and factors that influence human exposure to vector-borne zoonotic pathogens. This knowledge is used to develop efficient approaches to surveillance and management of vector-borne diseases that protect public health while minimizing negative effects on sensitive natural systems. Other interests include conservation of invertebrates and bee foraging ecology, especially the interactions between native and introduced species.

Evan Grant

A principle investigator of the US Geological Survey’s Amphibian Research and Monitoring Initiative (ARMI), northeast region, and stationed at the Patuxent Wildlife Research Center in Laurel, MD.  My research focuses on questions relating to amphibian populations, specifically with respect to their landscape-scale ecology and conservation.  My work is focused on monitoring and research questions which can aid resource managers.  Current Projects: movement ecology of stream salamanders, dendritic network ecology, dynamics of vernal pool breeding amphibian populations, management of amphibian populations in the National Capital Region Network of National Parks, planning a management response to population change in the endangered Shenandoah salamander

Glenn Guntenspergen

Paula Henry

A research physiologist at the USGS Patuxent Wildlife Research Center. She received her B.A. from Reed College and her M.S.(Zoology) and Ph.D. (Marine Estuarine Environmental Science interdisciplinary program) from the University of Maryland. With a background in endocrinology and wildlife toxicology, her research interests include identifying physiologically and behaviorally relevant markers for evaluating sublethal effects of exposure to environmental contaminants and stressors on wildlife. Her work is focused on population and relative species responses of birds, amphibians, and reptiles. Her current research projects include a series of field studies on turtles in the Maryland Chesapeake Bay and controlled pen studies assessing effects of multigenerational exposure to endocrine disrupting contaminants on avian embryonic development, sexual differentiation, and reproduction.

Jim Hines

Analysis, modeling, and software development for capture-recapture, presence-absence, and other types of wildlife data.  Also, administration and content-development of WWW server (hardware and software).

Natalie Karouna-Renier

As a molecular toxicologist, my expertise includes the application of toxicogenomic and biochemical tools for understanding, detecting, and predicting the effects of environmental stressors on wildlife. Work in my lab includes development and application of molecular biomarkers, gene expression and genetic analysis, DNA damage assessment, and hormone analysis for characterizing adverse biological responses in wildlife and identifying toxicity pathways or modes of action. 

William Link

Mathematical Statistician, Biometrics Group. Duties include development of mathematical models and analytical tools for investigation of ecological questions and for monitoring of wildlife populations, serves as consultant to quantitative ecologists and biologists. Current research includes application of Bayesian methods to hierarchical models. 

Jeff Marion

Recreation ecology:  research and monitoring to evaluate environmental impacts resulting from recreational activity in protected natural areas.  Research to: 1) identify, measure, and manage recreation resource impacts, 2) model and understand the influence of use-related, environmental, and managerial factors, 3) evaluate the efficacy of educational, site management and, regulatory actions designed to avoid or minimize recreation impacts, and 4) support and improve carrying capacity planning and decision-making.

Dan McAuley

Primary responsibility is to conduct field research on migratory bird issues identified by the US Fish and Wildlife Service and other Department of Interior agencies.  Current research includes a large scale woodcock productivity study in Maine and NY, a study of migratory woodcock in Cape May, NJ, and a banding study to determine survival and recruitment of common eiders using mark-recapture methods and band recovery analyses.  I have also done an analysis of habitat along Woodcock Singing Ground survey routes in ME, VT, NH, MA, and NY, survival of American woodcock during fall migration using radio telemetry, and evaluating the effects of habitat management on American woodcock and neo-tropical birds.  Recently completed a study on the effects of hunting on survival and habitat use of American woodcock in the Northeast

Hilary Neckles

My research focuses on understanding and predicting responses of estuarine and wetland ecosystems to various human and natural stressors, with the ultimate goal of informing conservation and management decisions in coastal environments. Recent areas of emphasis include developing appropriate indicators and approaches for monitoring and assessing seagrass, estuarine, and salt marsh ecosystems at local and regional scales; determining the impacts of some common commercial fishing practices on New England eelgrass habitats; identifying the role of invasive European green crabs in eelgrass habitat destruction; and quantifying relationships between nutrient loading and the integrity of seagrass ecosystems.

Glenn Olsen

My areas of study include sea ducks and cranes. Captive breeding of cranes, diseases of cranes and sea ducks. Satellite radio telemetry or just radio telemetry in general, release techniques for cranes. crane biology and ecology, sea duck ecology, veterinary medicine of sea ducks, cranes, waterfowl in general, raptors, and other avian species. 

Keith Pardieck

Avian monitoring and sampling techniques; avian conservation; development and management of biological monitoring programs; citizen science; North American Breeding Bird Survey program

Suzanne Peurach

As a Collections Manager at the Smithsonian Institution, National Museum of Natural History, Suzy is responsible for curation and conservation of North American mammalian voucher specimens, identification and cataloging of incoming collections, and answering information requests. Duties also include the preparation, shipment, and documentation of specimen loans; the collecting of mammals in the field; and maintaining, updating, and adding records to the electronic database. Suzy also provides identification of mammal hair, primarily from wildlife strikes with aircraft worldwide, but also as needed for other investigations.

James Poindexter

As a Collections Manager at the Smithsonian Institution, National Museum of Natural History, James is responsible for duties the care, management, and curation of the National Museum of Natural History North American Amphibian and Reptile Collections and associated data.  James takes the lead for all things related to digital photography in his division.  He regularly takes digital photographs of preserved museum specimens at the request of both division staff and researchers around the world.  In addition to his regular photography duties, James has taken on the project of photographing all of the primary type specimens in his division that presently have no photographs, or that need better quality photographs.    

Diann Prosser

Diann Prosser is a Wildlife Research Biologist with a background in wetland ecology and ornithology.  Her research interests include using spatial modeling techniques to help answer questions related to wildlife stressors such as climate change and disease.  Some of her recent projects include using satellite telemetry and spatial modeling to investigate the role of wild birds in the spread of avian influenza viruses; exploring the effects of shoreline hardening on waterbird communities; and using mark-resight techniques to improve waterbird population estimates on a large restoration project in the Chesapeake Bay.

Barnett Rattner

Conducts hypothesis-driven laboratory and field investigations, risk assessments and scholarly evaluations of the hazard and toxicity of legacy and contemporary pollutants (industrial contaminants, metals, pesticides, petroleum crude oil) to wildlife and the environment.  His current focus is on exposure and adverse effects of flame retardants and pharmaceuticals, comparative toxicology, non-target secondary poisoning associated with rodenticides, alternative testing methods, and screening-level risk assessments.  Dr. Rattner actively represents the DOI as a member of the Interagency Testing Committee of the Toxic Substances Control Act and the Interagency Coordinating Committee for the Validation of Alternative Methods, and serves as a special consultant to the Fish and Wildlife Service on issues related to nontoxic shot used in hunting. He has published over 100 articles, co-edited three reference texts, and serves on several journal editorial boards

Andy Royle

Research Statistician engaged in the development of statistical methods and analytic tools for animal demographic modeling, statistical inference and sampling wildlife populations and communities. His current research is focused on hierarchical models of animal abundance and occurrence, Bayesian analysis in ecology, spatial modeling, and especially the development of spatially explicit capture-recapture models for the study of spatial structure and dynamics of animal populations.

Michael Runge

Research ecologist with the U.S. Geological Survey, Patuxent Wildlife Research Center, where he was worked since 1999.  His research focuses on the use of decision theory and population modeling to inform wildlife management, with particular emphasis on the formal application of adaptive management.  Most of his research involves collaboration with Federal management agencies (U.S. Fish and Wildlife Service, Bureau of Reclamation, National Park Service, National Marine Fisheries Service, and others).  He has worked on projects with migratory birds, National Wildlife Refuges, endangered species, and marine mammals (including manatees and polar bears).  He co-designed the “Introduction to Structured Decision Making” and “Adaptive Management” courses for the National Conservation Training Center, and co-leads the joint USGS/FWS Structured Decision Making Workshops.

John Sauer

Research involves analysis of survey data.  Designing surveys and estimating status and trends in bird populations are components of this work, but the primary goal of the research is to better integrate surveys with management activities and scientific studies.

Daniel Twedt

His research has focused on avian ecology within bottomland hardwood forests, including bird response to forest restoration and silvicultural management, and assessment of alternative restoration and management techniques. Ongoing projects address forest structure and bird response to silvicultural prescriptions targeting wildlife in bottomland hardwoods, survival and productivity of birds in bottomland forests, and landscape scale integration of national land cover and forest inventory databases for assessment of bird distribution and abundance.

H. Brian Underwood

A Research Wildlife Biologist studying biology and management of wild herbivores, measuring and interpreting impacts of herbivores on vegetation establishment, growth and development, population monitoring, ecology, dynamics, community ecology, distance sampling for abundance estimation of biological populations, wildlife fertility control, stochastic population modeling, sampling and survey design

Nimish Vyas

Duties include exotoxicology, field and laboratory studies to evaluate contaminant exposure and effects to wildlife, review study plans and manuscripts, serve on graduate committees.

Neal Woodman

Phylogenetic systematics of mammals, with particular expertise in Soricidae, Tupaiidae, Chiroptera, Rodentia.  Short- and long-term biodiversity surveys of mammalian faunas.  Identification of mammal remains, with particular experience with Native American medicine bundles and Egyptian animal mummies.  Use of digital x-rays to reveal otherwise hidden skeletal characteristics, with particular expertise characterizing bones of the manus and pes of small mammals and classifying natural fracture patterns in mammal skeletons.  History of science, with particular expertise in early 19th history and some experience with medieval concepts of mammals.  Application of taxonomic nomenclature (former secretary for the American Association for Zoological Nomenclature).  Curation of systematic natural history collections.  Preparation of museum-quality study specimens and field records. Critical evaluation of scientific research proposals and manuscripts. Editorial work (former associate editor for Journal of Mammalogy).

David Ziolkowski, Jr.

Program Biologist for the North American Breeding Bird Survey. Duties involve technical, public relations, and field work relating to the advancement and maintenance of the multinational North American Breeding Bird Survey. Technical aspects span the development and integration of web-based data management tools, annual review of ornithological data, and generation of program manuscripts. Expertise includes: Development and management of biological monitoring programs, Citizen science, Avian conservation, Aural and visual bird identification, Bird banding, Science education and public outreach, Data management, Avian specimen collection and preparation, Ecology Evolution, biogeography, and systematics, Ecotoxicology, Behavioral ecology, Natural History, Diverse taxonomic field methods