Kearny Marsh supports breeding state-endangered Pied-billed Grebes and Northern Harriers as well as several wading birds including state-threatened Black-crowned and Yellow-crowned Night-Herons, Snowy Egrets, Great Egrets, and Great Blue Herons. The tidal salt marsh also supports the breeding of Least Bitterns, Saltmarsh Sharp-tailed Sparrows, Marsh Wrens, American Black Ducks, Mallards, and Canvasbacks. The Meadowlands provide a resting and foraging habitat for spring and fall migrants. Migratory shorebirds such as Greater and Lesser Yellowlegs and Semipalmated Plovers utilize the tidal mudflats during spring and especially fall migration. Other fall migrants include wading birds, waterfowl, raptors, and warblers. The Sawmill Creek WMA, Merhof Pond, and the freshwater and brackish water impoundments at Kingsland support a wide variety of wintering waterfowl species: Common and Hooded Mergansers, American Black Ducks, Canvasbacks, Green-winged Teal, Northern Pintails, Buffleheads, Northern Shovelers, Gadwalls, and Ruddy Ducks. Northern Harriers, Red-tailed, Rough-legged, and Cooper’s Hawks are also winter visitors.

Just seven miles west of New York City and four miles north of Newark, this estuarine complex sits in the middle of one of the most highly urbanized areas in the United States. The Meadowlands District intersects several municipalities across Bergen and Hudson Counties and includes the Kingsland Impoundments, Kearny Marsh, Skeethill Marsh, Sawmill Creek Wildlife Management Area, Richard W. Dekorte Park, Mill Creek, Schmidt’s Woods, Merhof Pond, and Losen Slote. A majority of the site is privately owned and partly regulated by the Hackensack Meadowlands Development Commission (HMDC), a State land-use regulatory agency. One of the priority habitat areas in the Meadowlands is Kearny Marsh, a tidal wetlands complex west of the Hackensack River in the southern part of the site. Other important habitat areas include tidal mudflats, nontidal wetlands and grassland, shrubland, and early successional forest on the landfills and scattered around the edge of the Meadowlands. Centuries ago, the area was a large, freshwater Atlantic white cedar (Chamaecyparis thyoides) swamp that has since been transformed by intense development and its associated landfills.