Important Bird Areas


Menunketesuck/Duck Islands Area

Westbrook (Middlesex County)

Status: Recognized IBA

Ownership: Private/State of Connecticut/Public Trust

Nominator: Patrick Comins, Connecticut Audubon Society and U.S. Fish and Wildlife Service

Size: 15.1/5.6 Terrestrial acres + aquatic and intertidal acreage

Location: 41° 15’ N, 72° 27’ W

Primary—Island, tidal flats/marine
Secondary—Sandy shore, rocky shore, shrub, maritime forest

Land Use:
Primary—Hunting/fishing, nature and wildlife conservation, other recreation or tourism, undeveloped

Serious—Disturbance to birds or habitat (by boaters, general recreation, and dogs), predators
Potential—Invasive or non-native plants, pollution, habitat conversion (succession), hydrologic changes (changes in sea level), erosion, development

Site Description: The site is composed of two small, undeveloped islands off the coast of Westbrook with approximately 200 acres of intertidal flats, intertidal sandbars and shell-bars situated to the east of the islands. Menunketesuck Island is a privately owned 15.1-acre island with low scrubby vegetation and rocky and sandy shoreline. It is nearly connected to the mainland via a gravel and shell-bar at low tide. Duck Island Natural Area Preserve is a 5.6-acre state-owned island located to the west of Menunketesuck, across the outflow of the Menunketesuck River. Its vegetation is more mature, consisting of small trees with dense shrub/scrub understory and a rocky shoreline.

IBA Criteria: Connecticut (and Federally) Endangered and Threatened Species; High Conservation Priority Species; Rare, Unique, or Representative Habitat; 500+ Waterfowl (winter)/1,000+(staging/migration); 100 Terns/500+ Gulls (staging and migration); 500+ Shorebirds; 25+ Breeding Pairs of Wading Birds/100+ Individual Staging/Feeding; Single-species Concentrations (>1%). 

Birds: Menunketesuck Island has 1 nesting pair of the federally threatened Piping Plovers, up to 4 pairs of American Oystercatchers, and a small colony of Least and Common Terns. The extensive intertidal area is a significant foraging area for migratory shorebirds, which roost on the island at higher tides. The area is a wintering area for Dunlin, Sanderling, Purple Sandpipers, and Ruddy Turnstones. Red Knots are regular in small numbers in migration. The island has been the location of Manomet International Shorebird Surveys since 1998. Egrets forage in the intertidal zone (max # of Snowy Egrets 100). Up to several hundred Common Terns loaf on the exposed sandbars at lower tidal levels. Small numbers of the federally endangered Roseate Tern (max #20) are regular in the Common Tern flocks. The island is a historical nesting area for Roseate Tern, but predators and human disturbance make this unlikely to happen again. Both Common and Roseate Terns forage in the waters south of the island and between Menunketesuck and Duck. Over 10,000 gulls have been observed feeding around the two islands in the late winter, and large flocks of Atlantic Brant, Green-winged Teal, and Greater Scaup have been observed using the waters. 

Duck Island Natural Area Preserve is the largest egret rookery in eastern Connecticut, with as many as 50-100 pairs of Snowy Egret, over 25 pairs of Great Egret, plus nesting Glossy Ibis, Black-crowned Night-Heron, and Little Blue Heron.

Non-avian Resources: Undeveloped coastal islands are a rare resource in Connecticut. There appears to be healthy populations of small fish and mollusks and other invertebrates in the intertidal zone, as evidenced by large numbers of birds feeding in the area and direct observations. The area is a popular recreational zone.

Existing Conservation Measures: Educational signage has been placed on Duck Island by the CT DEEP Wildlife Division.

State-listed Species: 






Great Egret, T

10 to 20 pairs, Duck Island



Snowy Egret, T

10-50 pairs, Duck Island, up to 100 foraging on flats



Little Blue Heron, SC

1-2 pairs, up to 10 seen feeding on flats



Glossy Ibis, SC

10 pairs



Piping Plover, T, Federally T

1 pair



American Oystercatcher, SC

5-7 pairs in area


Roseate Tern, E, Federally E

Roost on sandbars in late summer



Common Tern, SC

~20 pairs nest, 100-500 regularly staging



Least Tern, T

~20 pairs nest



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