Current Projects

Floral Inventory and Forest Characterization

Little information on the plant species occurring at Great Hollow Nature Preserve is available, and the forested areas of the preserve have never been formally characterized. We are currently conducting a floral inventory of the property, building a reference collection of specimens, and quantitatively characterizing the structure and composition of the upland forests. This will provide important baseline data to which future changes in the plant communities at Great Hollow can be related to habitat and wildlife management practices, climate change, non-native species invasions, natural processes, or other factors.

Effects of Non-native Invasive Plants on Invertebrate Communities

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 abundance and community composition on non-native host plants to that of native plants in the forest understory and ground layer. This will provide important information with consequences for the management of highly invasive plant species of Connecticut’s forests.

Effects of Nighttime Lighting on Bat Activity

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, noise 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 a bat biologist 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 Steward & Outreach Coordinator, John Foley, has been consistently radio tracking numerous wood turtles throughout Fairfield and Putnam Counties for the past few years. In collaboration with the American Museum of Natural History, 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 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 mercury pollution on the speed and orientation of migrating 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. In collaboration with the University of Western Ontario, Great Hollow is radio-tagging and tracking (see www.motus.org) yellow-rumped warblers of differing blood mercury levels during their spring migration to investigate the relationship between mercury and migration speed and orientation.