Chad Seewagen, Ph.D.
Executive Director

Chad joined Great Hollow as the organization’s first Executive Director in May of 2016. He leads Great Hollow’s conservation science program, the planning of educational programs and community events, fundraising, and all other aspects of the administration and operation of Great Hollow. Prior to joining Great Hollow, Dr. Seewagen was a Senior Wildlife Biologist and Technical Director at a New York City-based environmental consulting firm, and before that, worked as a Research Scientist in the Department of Ornithology at the Wildlife Conservation Society’s Bronx Zoo.  He has a B.S. in Wildlife & Fisheries Conservation from the University of Massachusetts-Amherst, an M.A. in Conservation Biology from Columbia University, and a Ph.D. in Biology from the University of Western Ontario. He holds faculty appointments as an Adjunct Research Scientist in the University of Connecticut’s Department of Natural Resources & the Environment (faculty webpage) and Wildlife & Fisheries Conservation Center.  Dr. Seewagen’s primary research interests include the physiological ecology of bird migration, the impacts of mercury pollution on birds, and the effects of non-native, invasive plants on wildlife habitat quality.


John Foley
Naturalist & Preserve Steward

John is a self-taught naturalist who has spent years working in and around Great Hollow, studying the local plants and animals that make the area so special. He is a Connecticut-certified Master Wildlife Conservationist and has worked as a field technician for multiple agencies and organizations, such as the Connecticut Bureau of Natural Resources and Bureau of Outdoor Recreation. He sits on the Board of Directors of the Friends of the Great Swamp and the Naromi Land Trust. John’s passion is turtles, and he has spent the past several years collecting valuable data on the movement patterns and survivorship of turtles inhabiting Great Hollow and neighboring natural areas. At Great Hollow, John works hard to maintain the trails that so many people enjoy hiking while also managing the land to optimize habitat for native plants and wildlife. John also maintains Great Hollow’s many facilities and coordinates and leads many of our events and outreach initiatives.

Maggie Cozens, M.S.
Education Coordinator

Maggie develops and instructs all of Great Hollow’s environmental education programming for children and young adults, and is the director of our summer camp. She emphasizes field research techniques and exploratory learning in all her lessons, and brings to Great Hollow a variety of prior experience teaching environmental and STEM education to students ranging from Pre-K all the way up to college. Prior to joining Great Hollow, she most recently worked for the Living Classrooms Foundation in Baltimore, where she developed and instructed marine and coastal science curricula for middle-school students. Before that, Maggie led the graduate teaching assistant program for the University of North Carolina-Wilmington’s Environmental Science Department, which involved teaching various introductory and advanced environmental science classes and labs to undergraduates. She holds an M.S. in Environmental Science from the University of North Carolina-Wilmington and a B.A. in International Sustainable Development, with minors in Spanish and Geography from Appalachian State University.

Sena Rasun-Mahendra, M.Ed.
Environmental Educator

Sena is a part-time instructor of Great Hollow’s environmental education programs and camps, and previously served as our Education Coordinator for three years. She holds a Master of Education degree from Antioch University-New England, is a certified Wilderness First Responder, and has more than 15 years of outdoor and environmental education experience in addition to her time at Great Hollow. Outside of Great Hollow, Sena is currently an elementary school teacher at an environmentally focused charter school in northern New Jersey.


2019 Seasonal Staff:

Cassidy Barshinger
Camp Instructor

Cassidy recently earned her B.S. in Recreation Management, with concentrations in Therapeutic and Outdoor Recreation, and minors in Environmental Studies and Psychology from Lock Haven University in her home state of Pennsylvania. She has previously worked with children and adults, often with developmental disabilities, at a variety of outdoor recreation camps and other organizations in Pennsylvania and Colorado, where she led whitewater rafting, rock climbing, horseback riding, canoeing, and camping programs.  She is an avid climber, hiker, mountain-biker, and kayaker, and is Wilderness First Aid certified.

Megan Hart
Field Technician

Megan joins us from Tennessee where she recently completed an M.S. in Biology from the Center of Excellence for Field Biology at Austin Peay State University. She conducts standardized bird surveys all over western Connecticut as part of Great Hollow’s contribution to the Connecticut Bird Atlas Project that is led by UConn and the Connecticut Department of Energy & Environmental Protection. She has a great amount of previous field experience studying birds, including her thesis research on the effects of the Deepwater Horizon oil spill on Seaside Sparrows. This is her second season working on the Connecticut Bird Atlas Project while based at Great Hollow.

Heidi Faulkner
Research Assistant

Heidi is an experienced bird bander and assists with Great Hollow’s field research projects on the effects of Japanese barberry on habitat quality and the ecology of forest songbirds, and the role of birds as a dispersal mechanism for the newly introduced Asian long-horned tick. She comes to us from Wisconsin where she most recently worked for the La Crosse Department of Parks & Recreation. She has previously worked as a field technician in Wisconsin and Pennsylvania, where she assisted with studies of golden-winged warblers that involved  banding, visual surveys, and vegetation surveys. Heidi graduated with a B.S. in Conservation Biology from the SUNY College of Environmental Science & Forestry in 2017 and was the president of the university’s Birding Club.

Hannah Miller
Research Assistant

Hannah assists with Great Hollow’s field research projects on the effects of Japanese barberry on habitat quality and the ecology of forest songbirds, and the role of birds as a dispersal mechanism for the newly introduced Asian long-horned tick. Before coming to Great Hollow, she worked as a field assistant for the University of Southern Mississippi, banding and conducting point-counts of migrating birds along the Gulf Coast. Prior to that, Hannah conducted bird and vegetation surveys, assisted with habitat restoration efforts, and led children’s education programs for Audubon New York and the New York State Office of Parks, Recreation, and Historic Preservation. She graduated with a B.S. in Biology from SUNY-New Paltz in 2015 and is an avid birder.