Current Projects


Biological research is at the core of what we do at Great Hollow. Our researchers and collaborators conduct conservation-driven studies of biodiversity in Connecticut and beyond to better understand human impacts to the environment and provide science that can help guide management decisions and public policy. We specialize in integrating the fields of animal ecology, physiology, and toxicology to investigate the effects of introduced species, land use change, and pollution on wildlife and habitats.  We take a highly collaborative approach to research, pooling and leveraging the skills and resources of multiple partners across academia, government, and non-governmental organizations to most effectively and efficiently approach scientific studies of common interest. Our current projects include:


Effects of Japanese Barberry on Forest Songbird Breeding Habitat Quality

Japanese barberry has quickly become one of the most widespread non-native invasive plants in Northeastern forests, and like most other non-native invasive plants, is assumed to diminish habitat quality for forest wildlife. Yet, surprisingly few studies have actually investigated the effects of Japanese barberry on the wildlife that inhabits invaded areas. Great Hollow is conducting an integrative assessment of the effects of Japanese barberry on breeding habitat quality for forest songbirds, using the ovenbird as a model. The study is comparing three indicators of habitat quality between ovenbird breeding territories that either have extensive or little to no Japanese barberry coverage: territory size, male physiological condition, and food abundance. The results of this study will allow for more science-based decision making among land managers and conservation practitioners who are grappling with Japanese barberry invasions.

Effects of Japanese Barberry on Invertebrate Food Webs

The effects that non-native plants may have on the abundance and diversity of foliage-dwelling and leaf litter invertebrates are surprisingly poorly understood. Invertebrates play an important role in forest nutrient cycling and are a critical food source for birds and other wildlife higher up in the food web. We are working to compare invertebrate biomass, diversity, and community composition on Japanese barberry to that of native plants in the forest understory and leaf litter. This will provide important information with consequences for the management of highly invasive plant species of Connecticut’s forests.

Impacts of Light Pollution on Foraging Bats

Populations of many bat species are in dramatic decline due to the outbreak of a disease known as White-nose Syndrome. Bats are also facing a series of other threats from habitat loss, wind turbine collisions, chemical pollution, and light pollution. As nocturnal creatures, bats may be adversely affected by the abundance of artificial lighting in our cities and towns, along our roads, and around our homes, but this has not been well-studied in North America. In collaboration with Dr. Amanda Adams at Texas A&M University, Great Hollow is conducting an experiment on the effects of L.E.D. lighting on bat activity at our preserve. Using an array of lights erected along the edge of the wetland at the southern end of the preserve and an acoustic bat recorder that detects the echolocation calls of bats and identifies them to species, we are able to compare bat activity levels on nights with and without the lights turned on. The findings of this experiment will help natural resources managers to evaluate potential impacts to bats from new development projects that involve nighttime lighting.

Home Ranges and Movement Patterns of Wood Turtles

Great Hollow’s naturalist, John Foley has been consistently radio tracking numerous wood turtles throughout Fairfield and Putnam Counties for the past few years. In collaboration with Dr. Suzanne Macey at the American Museum of Natural History and Columbia University graduate student, Jason Hagani, we are using these data to determine the home range sizes and area requirements of wood turtles in our region, and examine differences between age groups and sexes. Continued monitoring of these turtles will also provide long-term data needed to determine their survivorship in the face of threats from vehicles, water pollution, and an abundance of synanthropic predators like raccoons

Effects of Mercury Pollution on the Migratory Behaviors of Songbirds

Mercury is a global pollutant and a powerful neurotoxin that has become increasingly widespread in the environment as a result of a two- to three-fold increase in atmospheric emissions over the past 200 years. The threats of mercury pollution to fish-eating wildlife and other top predators have been well-documented, but it has recently become apparent that animals at lower positions in food webs, like songbirds, can also accumulate harmful levels of mercury. However, it is largely unknown at what level mercury begins to cause adverse effects in songbird species. We also know next to nothing about how mercury exposure might affect the ability of birds to migrate long distances. In collaboration with Drs. Chris Guglielmo, Yolanda Morbey, and Yanju Ma at the University of Western Ontario, Great Hollow is radio-tagging and tracking (see yellow-rumped warblers of differing blood mercury levels during their spring migration in Ontario to investigate the effect of mercury on migration behavior and orientation. Great Hollow is also conducting a similar study on ovenbirds here in Connecticut. These are the first studies to investigate the potential impacts of mercury pollution on the migration performance of birds.

Additional Projects

In addition to the above projects that are being lead by Great Hollow, our staff also frequently collects data for, or otherwise supports projects that are lead by researchers at other institutions. Such projects to which Great Hollow is currently contributing include:


Black Bear Distribution in the Lower Hudson Valley (Project Lead: Budd Veverka, Mianus River Gorge)

Black-legged Tick Population Monitoring in Western Connecticut (Project Lead: Dr. Neeta Connely, Western Connecticut State University Tick Lab)

Connecticut Bird Atlas Project (Project Leads: Dr. Chis Elphick, UConn and Dr. Min Huang, CT Department of Energy & Environmental Conservation)

Bobcat Occupancy and Diet in Connecticut (Project Leads: Dr. Tracy Rittenhouse and Kristen Beattie, UConn)

Motus Wildlife Tracking System