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Three Mile Bay Bird Conservation Area

General Site Information: Three Mile Bay BCA, located on the northwestern shore of Oneida Lake, encompasses 3,697 acres and consists mostly of wooded swamp land with small amounts of marsh. It is the site of Audubon's Toad Harbor Swamp Important Bird Area. The site also includes areas of upland forest, successional old field, and shrubland habitats. The DEC holds jurisdiction over 132 acres of underwater lands in Oneida Lake adjacent to the Wildlife Management Area extending 500-1000 feet offshore from about 1/2 mile west of Phillips Point to about 3/4 mile east of the point.

Flooded hardwood swamps provide habitat for red-shouldered hawk (special concern), cerulean warbler (special concern), prothonotary warbler, as well as a large great blue heron rookery. The area supports large numbers of migrating waterfowl during the spring, and lake waters adjacent to the property harbor thousands of waterfowl throughout the year. Grassland habitats have historically supported Henslow's sparrow (threatened), grasshopper sparrow (special concern) and sedge wren (threatened). Marsh areas support pied-billed grebe (threatened), least bittern (threatened), and American bittern (special concern).

Three Mile Bay BCA Management Guidance Summary

Site Name: Three Mile Bay

State Ownership and Managing Agency: Department of Environmental Conservation

Location: Three Mile Bay Wildlife Management Area; Oswego County, Towns of West Monroe and Constantia.

Size of Area: 3,697 acres

DEC Region: 7

Vision Statement: Maintain swampland to maximize bird use throughout the year. Monitor breeding populations of species at risk and individual species such as prothonotary warbler and cerulean warbler. Restore grassland habitat for at risk species like grasshopper sparrow and Henslow's sparrow.

Key BCA Criteria: Waterfowl concentration site, wading bird concentration site, individual species concentration site, and species at risk site (ECL §11-2001, 3.e, f, g, and h). The site is a regular hot spot for spring migrating waterfowl. Examples include 5,000 scaup in 2000 and 2,600 scaup in 2003. Wood ducks are also reported to use the site in fall in numbers from 2,000 in the past to 400 in 2005. Several pairs of pied-billed grebes also breed here. Breeding prothonotary warbler and cerulean warbler numbers are locally high. At least 90 great blue heron nests are found in a flooded hardwood swamp. American bittern and least bittern are probable breeders and black-crowned night-heron is a possible breeder. Species of concern include: pied-billed grebe (threatened), least bittern (threatened), northern harrier (threatened), American bittern (special concern), osprey (special concern), Cooper's hawk (special concern), red-shouldered hawk (special concern), and cerulean warbler (special concern). Sedge wren (threatened) was recently recorded singing in the breeding season but nesting has not been confirmed. Henslow's sparrow (threatened) historically bred here in 1980s-90s.

Critical Habitat Types: Extensive wetland communities consisting of red maple-hardwood swamp, silver maple-ash swamp, northern white-cedar swamp and marsh communities. Lake waters adjacent to the property harbor thousands of waterfowl throughout the year. Grasslands are found that could provide habitat if properly managed.

Operation and Management Considerations:

  • Identify habitat management activities needed to maintain the site as a BCA.
    Manage the grasslands to keep them in grass. Shrub encroachment is occurring and the suitability for grassland birds is being reduced.

    Portions of the marsh and adjacent lands have been overrun by Phragmites. Efforts to control this invasive species would be highly beneficial.
  • Identify seasonal sensitivities; adjust routine operations accordingly.
    Mowing should occur outside the normal breeding season of May 1 through July 31.
  • Identify state activities or operations which may pose a threat to the critical habitat types identified above; recommend alternatives to existing and future operations which may pose threats to those habitats.
    Lack of mowing will result in loss of grasslands over time. Phragmites control is needed for marsh communities.
  • Identify any existing or potential use impacts; recommend new management strategies to address those impacts.
    None identified.

Education, Outreach, and Research Considerations:

  • Assess current access; recommend enhanced access, if feasible.
    Access is limited but that is largely due to the amount of swampland.
  • Determine education and outreach needs; recommend strategies and materials.
    Education about the importance of grassland communities, and wetland communities is needed. Importance of the site to breeding cerulean warbler and prothonotary warbler, and the habitat of these species needs to be presented.
  • Identify research needs; prioritize and recommend specific projects or studies.
    Monitoring and population assessment of the cerulean warbler and prothonotary warbler populations is needed.

Other Issues:
None identified.

DEC Region 7 Wildlife Manager, 607-753-3095


NYS DEC. 1996. Three Mile Bay Wildlife Management Area Biodiversity Inventory Report. NY Natural Heritage Program. Albany, NY.

Date Designated: 9/25/06

Date Prepared: 5/9/06