Important Bird Areas

Constitution Marsh Sanctuary

New York

This site consists of a 4,000-5,000 year old fresh and brackish (depending
on the time of year) tidal marsh (270 acres) and forested uplands (80
acres) located on the east shore of the Hudson River, directly opposite
West Point Military Academy, and 52 miles north of New York City.
There are a series of human-made dikes and channels that were
constructed in the 1830s for wild rice farming within the marsh. The
site is administered by the New York State Office of Parks, Recreation
and Historic Preservation (NYS OPRHP) and managed by Audubon
New York.

Ornithological Summary

This important wetland site hosts a diversity of birds (more than 200
species have been identified). Characteristic wetland breeders at the
site include Least Bitterns (2-4 pairs each year), Virginia Rails, Marsh
Wrens, and Swamp Sparrows. Large numbers of waterfowl use the
area during winter and migration, with average fall concentrations
of 1,500 individuals and occasional peak counts of 2,000 that can
include 700 Wood Ducks and several hundred American Black Ducks
and Mallards. Mixed flocks of blackbirds (Bobolinks, Red-winged
Blackbirds, and Common Grackles) numbering in the thousands,
use the site as a staging area and migratory stopover in the fall. Other
at-risk species using the site include Pied-billed Grebes (occasional
migrants), American Bitterns (uncommon but regular migrants),
Ospreys (regular migrants, non-breeding visitors), Bald Eagles
(averaging 2-5 in winter, with a maximum of 30), Northern Harriers
(regular migrants), Sharp-shinned Hawks (fairly common foragers),
Cooper?s Hawks (probable breeders), Red-shouldered Hawks (rare
migrants), Merlins (regular migrants), Peregrine Falcons (occasional
foragers), Willow Flycatchers (estimated 3-5 breeding pairs), Wood Thrushes (breed in adjacent woodlands), Blue-winged Warblers
(possible breeders), Cerulean Warblers (regular migrants), Wormeating
Warblers (breed in adjacent woodlands), and Canada Warblers
(regular migrants). Until mid-1990s, fall swallow concentrations at the
site typically numbered about 20,000 individuals, but reached as high
as 100,000. Today, swallow concentrations number in the thousands.

Conservation Issues

This site is listed in the 2002 Open Space Conservation Plan as a
priority site under the project name Hudson River Corridor Estuary/
Greenway Trail. The site is part of the Hudson Highlands State Park
and is managed by Audubon New York as a wildlife conservation
area. Portions have been designated as a state Bird Conservation Area.
There is an Audubon Center on site that provides education programs
to thousands of people each year. Non-native invasive plants and
animals that require monitoring include common reed (Phragmites
australis), purple loosestrife (Lythrum salicaria), European water
chestnut (Trapa natans), zebra mussels (Dreissena polymorpha), and
Mute Swans. The sanctuary is part of a federal Superfund Site and
cadmium and nickel contamination have been remediated. Regular
monitoring of contaminant levels is ongoing.