| Tivoli Bays Wildlife Management Area Red Hook, New York |
THE HUDSON RIVER ESTUARYThe Hudson River Estuary extends from New York Harbor 150 miles north to the Federal Dam at Troy. Oceanic tides ranging between three and six feet rise and fall twice a day throughout the estuary. In the lower Hudson fresh water from the surrounding countryside mixes with salt water from the Atlantic Ocean, but at Tivoli Bays the river's tidewaters are entirely fresh.THE TIVOLI BAYSThe Tivoli Bays is part of the Hudson River National Estuarine Research Reserve, managed as a field laboratory for research and education about the Hudson River Estuary. The New York State Department Of Environmental Conservation also operates the site as a wildlife management area.
LIFE IN THE TIVOLI BAYSNarrow-leaved cattail is the most common plant of the freshwater tidal marsh in Tivoli North Bay. Muskrats build their lodges out of cattail and feed on its roots and young shoots. Birds such as Virginia rails, red-winged blackbirds, marsh wrens and least bitterns nest in the wetlands. Spatterdock, wild rice and invasive plants such as purple loosestrife and common reed also grow in North Bay and provide food and nesting opportunities for other species.In the winter ice scours the wetlands and shorelines. The dead cattail stalks, wild rice, spatterdock, pockerel weed and other marsh plants are swept under water where they decay and add nutrients to the Hudson River food web. Occasionally bald eagles scavenge water around the bays. As soon as the ice is out, kingfish and megansers return to fish in the open waters. Spring brings new life to the bays. Migrating ducks, shorebirds, and ospreys feed and rest in the bays before continuing their flight north. American toads, spotted salamanders, and green frogs breed in shallow pools on Cruger Island. Bright yellow blossoms of marsh marigolds brighten the swampy areas. In early summer snapping turtles leave tidal creeks to lay eggs in dry soils adjacent to the marsh. Noisy splashes signal carp spawning in the bays. Male fourspine stickleback fish build cup shaped nests of plant material amidst the underwater plant life. During the summer Tivoli South Bay is covered by Eurasian water chestnut, a floating plant introduced from Asia that shelters a rich aquatic insect community. Hard black seed pods with sharp spikes that wash up along the Hudson's shore are evidence of this plant's invasion of the estuary. Like zebra mussels, another recently introduced species, water chestnut has profoundly changed the estuarine ecosystem. Fall brings sky-darkening flocks of red-winged blackbirds, starlings, grackles and cowbirds that arrive at dusk to roost in the cattail marsh and the wooded tidal swamps between the bays. Rafts of migrating waterfowl signal a temporary lull in the cycle of life at the Tivoli Bays.
Page Updated February 2000 |
