Important Bird Areas


Greenwich Audubon Center

Greenwich (Fairfield County)

Status: Recognized IBA

Ownership: Audubon Connecticut

Nominator: Ted Gilman, Greenwich Audubon Center

Size: 522 Acres

Location: 41° 06’ N, 73° 41’ W

Habitats: Primarily deciduous forest with some mixed conifer forest and some areas of riparian or floodplain forest, shrubland, field, swamp, a river, and a pond

Land Use:
Primary—nature and wildlife conservation
Secondary—water supply, ~2% suburban/residential

Minor-Serious—Invasive or non-native plants
Potential—Cowbird parasitism, pollution, habitat conversion (on adjacent property), encroachment by development, and large deer population

Thousands of raptors pass over Greenwich Audubon Center each year, making it one of the two best HawkWatch locations in Connecticut. Photo of an immature Cooper's Hawk by AJ Hand, courtesy of the Connecticut Ornithological Association, the COA Electronic Committee, and webmaster Dave Provencher.

Site Description: Greenwich Audubon Center is located in the coastal ridge and valley system of southwestern Fairfield County. The 522 acres include five parcels of land. The geology is Paleozoic, including both gneiss/schist and marble areas. The latter areas host a variety of calcareous-loving plants. Habitats include mixed deciduous forest; red maple/alder/willow/sumac shrub swamp; a small cattail/red maple marsh; mature hemlock/oak forest, old fields, wet meadow, river corridors, lake, ponds, and vernal pools. The middle branch of the Byram River runs the length of the main property parcel and borders the eastern edge of the Fairchild Wildflower Audubon Sanctuary. The west branch of the Byram River forms the eastern boundary of the hemlock gorge property east of Bedford Road. The southwestern corner of the property, at 500 feet, is one of the two highest points in Greenwich and serves as the site of the Quaker Ridge Hawk Watch.

IBA Criteria: High Conservation Priority Species of Birds; Rare, Unique, or Representative Habitat; 5,000+ Raptors (seasonal); Long-term Research and/or Monitoring; Exceptional Concentrations of Migratory Landbirds.

Birds: Greenwich Audubon Center is one of the two top HawkWatch locations in Connecticut, with an average of over 20,000 raptors counted annually. It has been providing important data on the populations of migrant raptors for over 20 years. In addition to serving the important purpose of a location where data can be obtained to assist biologists with trend analysis for raptor populations, this site serves as an important stopover and hunting area for the migrant hawks. The large size of the property and the variety of habitats create quality nesting habitat for many species of birds including Worm-eating Warbler, Wood Thrush, Scarlet Tanager, Rose-breasted Grosbeak, Eastern Wood Pewee, Great-crested Flycatcher, Louisiana Waterthrush, Blue-winged Warbler, Black-and-white Warbler, and Baltimore Oriole. The site also is an important migratory stopover for migratory landbirds and the state species of special concern Saw-whet Owl, with as many as 20 recorded in some years.

Existing Conservation Measures: Center staff and volunteers, including GE Elfun Volunteers, control invasive plants such as Oriental bittersweet, Tartarian honeysuckle, multiflora rose, and winged euonymus. Many trees badly covered with Oriental bittersweet. First recorded site of the invasive mile-a-minute weed in Connecticut. Deer population 1-2 dozen on the property, concern with heavy browsing of forbs, saplings, and shrub layer for bird habitat and plant diversity. The deer management program was initiated in the fall of 2003. Local chapter monitors, habitat conversion, and development on adjacent upstream land.

State-listed Species:






Sharp-shinned Hawk



'98 – '99

Cooper’s Hawk T

2 pairs



'85 – '98

Saw-whet Owl SC



Fall, 20

'97 – '98

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