About Our NHFS Instructors

Rick Borchelt

Rick Borchelt is the Director for Communications at the Department of Energy’s Office of Science. He has led many field trips in bird and butterfly identification and conservation and participates in national butterfly counts. B.A., Biology, Southeast Missouri State University. Graduate hours in entomology and science writing.

Joel Cohen

Joel Cohen teaches STEM courses, including life sciences, chemistry, and ecosystem studies, at Parkland Middle Magnet School in the Gifted and Talented program. Previously Senior Research Fellow at International Food Policy Institute; research specialist at the US Agency for International Development. Ph.D. in Plant and Soil Sciences, University of Massachusetts.

Jai Cole

Jai Cole leads the Aquatic Ecology Unit for the Montgomery County MD Department of Parks. She manages the stewardship of streams, lakes, ponds and stormwater management facilities and devices in the park system. She plans, coordinates and supervises biological monitoring studies for resource management, stream restoration, and park development projects. B.A., Biology, University of North Carolina, Greensboro.

Mark England

Mark England is Senior Project Manager/Estimator at Can-Am Contractors. He leads birding trips and forays for ANS and for the Montgomery Bird Club, and participates in breeding bird atlases and surveys.

Rachel Gauza

Rachel Gauza is an aquatic biologist with the D.C. Department of Energy & Environment. Previously she served as education outreach coordinator at the Association for Zoos and Aquariums. As National Coordinator for FrogWatch USA, she leads acoustical studies, develops curricula, and runs workshops to train volunteers. B.A., Biology, Hood College.

Margareta (Gogi) Kalka

Margareta (Gogi) Kalka has researched the climate footprint of global and local food systems, studied bat ecology, and surveyed threats to tropical biodiversity. She has taught courses and led seminars in ecology and biology in the U.S., the U.K, and Germany. M.S. Energy and Resources, University of California Berkeley; M.S. Biology, University of Berlin, Germany.

Tovi Lehmann

Tovi Lehmann is a research biologist and facility head in the laboratory of malaria and vector research, National Institute of Allergies and Infectious Diseases, National Institute of Health. He has experience leading multidisciplinary studies on diverse organisms, especially malarial mosquitoes. He also conducts courses and leads seminars on fungi. Ph.D. Entomology, University of Arizona.

Serenella Linares

Serenella Linares is the Director of Adult Education and Co-Chair of Naturally Latinos Conference at Audubon Naturalist Society. In addition to her graduate training in Mycology from University of Maryland, she holds a Bachelor’s degree in biology from Universidad Metropolitana de Puerto Rico, and a Master’s degree in Atmospheric Science from Howard University. When Ms. Linares is not teaching, she explores natural areas, photographs nature around her, and participates in community science projects.Serenella Linares is the Director of Adult Education and Co-Chair of Naturally Latinos Conference at Audubon Naturalist Society. In addition to her graduate training in Mycology from the University of Maryland, she holds a Bachelor’s degree in biology from Universidad Metropolitana de Puerto Rico, and a Master’s degree in Atmospheric Science from Howard University. When Ms. Linares is not teaching, she explores natural areas, photographs nature around her, and participates in community science projects.

Jean Mansavage

Jean Mansavage is a senior historian in the U.S. Air Force Historical Studies Office. She performs primary historical research, conducts oral histories, and writes responses to inquiries from Congress, the military, and the public. She is the author of several works about conservation on military lands, military land acquisition, and conscientious objectors to war. Ph.D., History, Texas A&M University.

Joe Marx

Joe Marx teaches physical and historical geology at Northern Virginia Community College, and leads geological field trips for ANS. M.S., Geochemistry, California Institute of Technology. B.S., Chemistry, Georgetown University.Joe Marx teaches physical and historical geology at Northern Virginia Community College, and leads geological field trips for ANS. M.S., Geochemistry, California Institute of Technology. B.S., Chemistry, Georgetown University.

Stephanie Mason

Stephanie Mason is the Senior Naturalist for the Audubon Naturalist Society. She teaches classes and leads field trips for ANS both in the mid-Atlantic and much farther afield. B.A., Goshen College.Stephanie Mason is the Senior Naturalist for the Audubon Naturalist Society. She teaches classes and leads field trips for ANS both in the mid-Atlantic and much farther afield. B.A., Goshen College.

Liam McGranaghan

Liam McGranaghan teaches biology at Northern Virginia Community College and Loudon Valley High School. He bands raptors, and has authored several articles and one book on raptors. Winner of Presidential Innovation Award for Environmental Educators. M.S., Biology, George Mason University.

Teresa McTigue

Teresa McTigue is an ecologist with NOAA’s National Centers for Coastal Ocean Science, located in Silver Spring, MD. Her science portfolio is diverse, ranging from coastal ecology and restoration to the restoration of mesophotic and deep sea coral communities to work in the forecasting of harmful algal blooms. Ph.D., Wildlife and Fisheries Sciences, Texas A&M University.

Katherine Nelson

Katherine Nelson is a Planner-Coordinator with the Montgomery County Department of Park and Planning. She is a recipient of the Outstanding Award in Physical Planning. She is a certified Arborist. B.S., Soil and Crop Environmental Science. M.S. in Planning, University of Virginia.

Sean Potter

Sean Potter is a NASA media relations specialist supporting the agency’s Science Mission Directorate. Previously was a meteorologist and communications specialist for NOAA’s National Weather Service, executive producer of online news and weather-related news briefs. Earlier, he created weather segments for several national network-level news broadcasts and monitored hydrometeorological data from national data collection sites. M.S., Atmospheric Science, Indiana University.

Gemma Radko

Gemma Radko is the Communications/Media Manager for the American Bird Conservancy. She completed MAPS (Monitoring Avian Productivity and Survivorship) training through the Institute for Bird Populations in1998. A licensed bird bander, she operated the MAPS station at Adventure in Potomac, MD. B.A., Allegheny College.Gemma Radko is the Communications/Media Manager for the American Bird Conservancy. She completed MAPS (Monitoring Avian Productivity and Survivorship) training through the Institute for Bird Populations in1998. A licensed bird bander, she operated the MAPS station at Adventure in Potomac, MD. B.A., Allegheny College.

Sujata Roy

Sujata Roy is a Volunteer Naturalist with Montgomery Parks, leading programs for all ages at Black Hill Regional Park and Little Bennett Regional Park. She is an avid wildflower enthusiast, an active birder, and all-around nature lover. B.A., University of Chicago.

Lynn Rust

Lynn Rust is a Scientific Review Officer for the National Institute of Allergies and Infectious Diseases at the National Institutes of Health. Previously a research professor at the Center of Excellence for Vaccine Research, University of Connecticut. She is a volunteer team lead for the ANS Water Quality Monitoring Program. Ph.D., Microbiology and Immunology, University of Rochester.

Bradley Simpson

Bradley Simpson is the Restoration Manager for the Audubon Naturalist Society, working to improve habitat quality at Woodend Nature Sanctuary. He has led the effort to survey the trees of Woodend's forest, tagging over 4,000 trees. B.S., Environmental Science and Policy with a concentration in Wildlife Ecology and Habitat Management, University of Maryland.Bradley Simpson is the Restoration Manager for the Audubon Naturalist Society, working to improve habitat quality at Woodend Nature Sanctuary. He has led the effort to survey the trees of Woodend's forest, tagging over 4,000 trees. B.S., Environmental Science and Policy with a concentration in Wildlife Ecology and Habitat Management, University of Maryland.

Cathy Stragar

Cathy Stragar manages the Plant Protection and Weed Management’s bio control program for the Maryland Department of Agriculture. She has a Masters in Entomology from the University of Delaware and is a lifelong naturalist and educator, regularly leading programs with the Audubon Naturalist Society.Cathy Stragar manages the Plant Protection and Weed Management’s bio control program for the Maryland Department of Agriculture. She has a Masters in Entomology from the University of Delaware and is a lifelong naturalist and educator, regularly leading programs with the Audubon Naturalist Society.

Carl Taylor

Carl Taylor is a retired Research Associate from the Smithsonian National Museum of Natural History. He currently lectures on ferns of the mid-Atlantic, leads field trips in northern Virginia for the Beltway Naturalists group, and regularly teaches classes in plant taxonomy and identification for the Master Naturalists and Master Gardeners groups. Ph.D. in Botany, Southern Illinois University.

Sally Valdes

Sally Valdes is a retired Environmental Protection Specialist/Fishery Biologist, Division of Environmental Assessment, Bureau of Ocean Energy Management (BOEM), Department of the Interior. Worked with BOEM's Environmental Studies Program; wrote sections of environmental impact statements. Subject matter included fish and fisheries, birds and bats, invasive species, impacts of climate change on wildlife. M.A. in Biology, University of Michigan. Ph.D. in Aquatic Ecology, Cornell University.

Clare Walker

Clare Walker is an environmental educator at Irvine Nature Center where she manages the woodland gardens. She previously worked as an education specialist at the Maryland Department of Natural Resources developing programs and guides about pollinators and other wildlife concerns. She is currently assisting the USGS Bee Lab in creating pollinator gardens for specialist bees. Ms. Walker did her Ph.D. work studying Peatlands, at Huddersfield University.Clare Walker is an environmental educator at Irvine Nature Center where she manages the woodland gardens. She previously worked as an education specialist at the Maryland Department of Natural Resources developing programs and guides about pollinators and other wildlife concerns. She is currently assisting the USGS Bee Lab in creating pollinator gardens for specialist bees. Ms. Walker did her Ph.D. work studying Peatlands, at Huddersfield University.

Paula Wang

Paula Wang retired from teaching biology at Sidwell Friends School and Holton Arms School. Adjunct Faculty, School of Education, American University. As a Maryland Master Naturalist, she leads environmental and natural history programs. M.S. in Microbiology, Medical College of Virginia. M.S.S.E. in Science Education, Montana State University.

Cathy Wiss

Cathy Wiss is a team leader in the ANS Water Quality Monitoring Program at two monitoring sites on Ten Mile Creek in Montgomery County, MD. From March 2008 through August 2020, she served as the ANS Water Quality Monitoring Program Coordinator. In addition, Cathy has worked to preserve streams, trees, and a wetland in her neighborhood and to encourage developers to incorporate Low Impact Development techniques into their projects. She holds a Juris Doctor degree from Catholic University Law School, a Bachelor of Arts degree from Smith College, and a certificate in Natural History Field Studies.Cathy Wiss is a team leader in the ANS Water Quality Monitoring Program at two monitoring sites on Ten Mile Creek in Montgomery County, MD. From March 2008 through August 2020, she served as the ANS Water Quality Monitoring Program Coordinator. In addition, Cathy has worked to preserve streams, trees, and a wetland in her neighborhood and to encourage developers to incorporate Low Impact Development techniques into their projects. She holds a Juris Doctor degree from Catholic University Law School, a Bachelor of Arts degree from Smith College, and a certificate in Natural History Field Studies.

Kerry Wixted

Kerry Wixted is an Education and Outreach Specialist for Maryland’s Department of Natural Resources. She coordinates projects, develops wildlife resource material involving rare/threatened/endangered species, and conducts workshops on invasive species. She’s taught courses in biology, physiology, and ecology. M.S., Biology, West Virginia University.Kerry Wixted is an Education and Outreach Specialist for Maryland’s Department of Natural Resources. She coordinates projects, develops wildlife resource material involving rare/threatened/endangered species, and conducts workshops on invasive species. She’s taught courses in biology, physiology, and ecology. M.S., Biology, West Virginia University.