Best known for its wintering bald eagles, but also good for a variety of upland, marsh and riverine species.
Eagles may be present from December through March. The Island is closed during this period, however, the eagles can be seen from the pull-out along Rt. 6/202 on the east side of the river (see Directions). May through June is best for other species.
Iona Island is one of the four National Estuarine Research Reserves on the Hudson River (including Piermont Marsh, Tivoli Bay, and Stockport Flats). This approximately 120-acre site is located at the southern gate of the Hudson Highlands. Much of the Island was used by the US Navy during WWII. Now the Palisades Interstate Park Commission has several construction and storage buildings on the island. Iona Island and adjacent Salisbury Marsh encompass several distinct habitats, including deciduous forest, freshwater and brackish tidal wetlands and riverine habitats. Food, water, and restrooms are available at the Bear Mountain Inn at nearby Bear Mountain State Park.
For viewing birds and wildlife other than bald eagle, the marsh edge along the road and the railroad causeway is best. The steep sloped knolls and Iona Island east of the railroad are off limits.
Special permission is needed from the Palisades Interstate Park Commission to enter the main portion of the Island.
The Island and adjoining Doodletown were designated as New York State Important Bird Areas in 1997. In September 2000, the New York State Biodiversity Research Institute sponsored a survey of biodiversity of the area. (See BioBlitz 2000).
From 2 to 5 or more bald eagles typically overwinter on Iona Island. In recent years, 35 to 40 eagles have been spotted along the river in the vicinity of Iona Island. The waters and marsh surrounding the Island support migratory pied-billed grebe, American bittern, osprey, and Northern harrier. During the spring, wood duck, Canada goose, mute swan, marsh wren, Virginia rail, least bittern, belted kingfisher, red-tailed hawk, barn swallow, tree swallow, cliff swallow, Eastern bluebird, warbling vireo, red-wing blackbird, song sparrow, among others, can be seen. The grassy field and trees of the main portion of the Island support American kestrel, Eastern bluebird, field sparrow, Eastern kingbird, prairie warbler, and, on occasion, bobolink.