Connecticut Summary

Although a small state, Connecticut’s geological history has resulted in one of the more varied topographies of any state, east or west. Tectonic and glacial activity produced several geological and ecological regions and distinctive features such as the glacial moraines in Long Island Sound and the basalt ridges of the Central Valley. Long Island Sound is one of the region’s largest estuaries, unique in that it flushes to the Atlantic Ocean via two waterways—to the east, through Rhode Island’s Block Island Sound, and to the west through the East River and New York Harbor.

Connecticut’s landscape has also been sculpted by human settlement. European settlers cleared three fourths of the state’s forests for agriculture, causing significant declines in furbearers and other forest-dependent species. Since the 1800s Connecticut’s forest cover has expanded once again, but recent population growth and development is causing fragmentation of forest habitats.

Connecticut has several areas of regional, national and international importance. The Connecticut River watershed is part of the Silvio O. Conte National Fish and Wildlife Refuge, and the tidal marshes of the lower Connecticut River are designated as Wetlands of International Importance under the Ramsar Convention. In eastern Connecticut, the Quinebaug-Shetucket River Valley is part of a National Heritage Corridor that has been called the “Last Green Valley,” a relatively undeveloped rural gem in this densely populated region.

Rare Species and Characteristic Habitats

Connecticut’s rare and specialized habitats like sand plains, tidal wetlands and calcareous spring fens support many unique specialists, while extensive upland forests and large rivers and waterbodies support healthy populations of commonly recognized wildlife species, including a recent resurgence in bear, bobcat, fisher and moose populations. Connecticut is the southern range limit for many northern species including the Three-toothed cinquefoil, northern saw-whet owl, yellow-rumped warbler, rainbow smelt, and lobsters. At the other end of the spectrum, Connecticut is the northern range limit for more southern species such as king rail, least shrew, green milkweed, and Torrey’s mountain-mint. This makes Connecticut an interesting area for biologists as species at the edge of their range may utilize different habitats and show different adaptations.

Connecticut’s basalt cliffs feature a wide range of habitats, from open rocky summits and cliffs to dense forests, and varying microclimates from warm west-facing slopes to the cooler talus base. Locally referred to as traprock ridges, they provide habitat for a number of rare species including timber rattlesnakes, northern metalmark, Columbine duskywing, Jefferson salamanders, yellow corydalis, and narrow-leaved glade fern. Because they are mostly unsuitable for agriculture and development, these ridges appear as large undeveloped islands in this heavily populated landscape.

Pitch pine/scrub oak woodlands and sandplain grasslands are two of Connecticut’s most imperiled habitat types, with 95 percent of the pre-settlement acreage either developed or otherwise degraded. The scattered remnants still support a high diversity of species including several rare noctuid moths, the state endangered eastern spadefoot toad, and the federally endangered sandplain gerardia.

Connecticut’s offshore islands provide critically important breeding grounds for many shorebirds, loafing sites for marine mammals, and important stopover sites for migratory species. Falkner Island hosts common tern and roseate tern colonies of national significance. These islands are being impacted by development and recreational use and are potentially vulnerable to rising sea levels.

Public and Private Conservation Efforts

The Connecticut Department of Environmental Protection (DEP) has many important conservation initiatives including open space protection, the Statewide Forest Resource Plan, Landscape Stewardship (which provides guidance to municipalities as part of the Governor’s Responsible Growth initiative), and a Comprehensive Wildlife Conservation Strategy. The State Geological and Natural History Survey has been documenting the state’s natural resources for over 100 years. Recent publications include The Connecticut Butterfly Atlas and The Vegetation of Connecticut, a preliminary classification. One program of the Survey is the state’s natural heritage program, the Natural Diversity Data Base (NDDB), which compiles information on rare species and significant natural communities. The NDDB works with many partner organizations such as the New England Wild Flower Society, the Connecticut Ornithological Association, Connecticut Entomological Society, the Appalachian Trail Monitors, The Nature Conservancy and many other volunteers, landowners, students and scientists, all of whom contribute to species inventories, site management and conservation efforts.

Two recent studies in the state serve as important examples of private and public partnerships where intensive natural resources inventories were conducted and valuable information was gathered for the use of local decision makers for conservation and development planning. The Farmington Valley Biodiversity Project covered a seven-town region and created maps of priority conservation areas. The Eightmile River Wild and Scenic Study was a twelve-year project leading up to the final federal Wild and Scenic designation in 2008. The study described the watershed, highlighting this exceptional area of largely undeveloped, unfragmented forest land and natural flowing, high-quality streams.


Many of the challenges facing Connecticut are a result of our high population density and development patterns. Current land use patterns are a direct result of having a multitude of local-level decision-making bodies, rather than a more regional approach. In many areas residential and commercial developments find resistance from neighbors who wish to preserve the rural character of their towns. There is also increased pressure to create new transportation and energy transmission corridors. Existing open space managers have to balance multiple passive and active recreational uses as well as maintaining the environmental integrity of their properties. State wildlife managers find that they are increasingly responding to human-wildlife interactions with species like bear, coyotes and moose.

Regionally, many states are joining together to respond to issues related to invasive species and wildlife diseases. Of note is the recent effort to unravel the mysterious white-nose syndrome that is decimating the region’s bat populations. Other regional hot issues include controlling the spread of the invasive Asian longhorned beetle and the aquatic plant, hydrilla. Our challenge is to provide guidance and outreach to towns and individuals so we can all share and enjoy the resources of this great state.

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