Important Bird and Birding Areas
Duke Farms

IBBA Site Guide

Somerset County
Coordinates: N 40.54248
W 74.65771
Site Map
Piedmont Plains: Piedmont

Area: 4,620 Acres     

Habitat: Agricultural land interspersed with floodplain and upland forest

Site Description: Duke Farms, an estate located in Hillsborough, was initially developed by tobacco and hydropower businessman James Buchanan Duke in 1893. Upon inheriting the property in 1935, his daughter, Doris Duke, began purchasing and restoring adjacent farms. Today, the property is owned by the Doris Duke Charitable Foundation and managed for its diverse wildlife and as a public resource. Duke Farms contains approximately 1100 acres of grasslands and agricultural lands, 950 acres of woodlands, 400 acres of floodplain habitat and 72 acres of open water spread across 10 lakes. This mix of habitat types provides an oasis for wildlife in a highly developed region of New Jersey. This mix of habitat types provides an oasis for wildlife in a highly developed region of New Jersey. This IBA also contains the Orchard Drive Grasslands Natural Heritage Priority Site. Designated by New Jersey Department of Environmental Protection (NJDEP), Natural Heritage Priority Sites are considered the state’s most significant natural areas.

IBA Criteria:
Conservation Concern – State-endangered (B)Bald Eagle
Conservation Concern – State-threatened (B)Bobolink, Grasshopper Sparrow, Savannah Sparrow
Significant Congregations (W)Waterfowl
Significant Migrant Stopover/Flyover (FM)Raptors
Long-term Research/Monitoring
Henslow's Sparrow
Henslow's SparrowMatt Sileo
Birds: Extensive native meadows and grasslands at Duke Farms support impressive numbers of state-threatened Grasshopper Sparrows, Savannah Sparrows and Bobolinks. Additional breeding birds include Pine Warblers and Wild Turkeys. Over 3500 raptors are recorded flying or stopping over during fall migration. Ring-necked Ducks, Common Mergansers, American Black Ducks, Green-winged Teal and Canada Geese regularly winter within the many acres of lakes.

Conservation: Like most natural areas in central and northern NJ, Duke Farms is plagued by invasive species such as Japanese stilt grass (Microstegium vimineum) and an overabundant deer population. Recently developed management and restoration programs have begun to address these issues. Duke Farms partners with a variety of organizations, officials and experts to restore, conserve and learn from the property’s diverse resources. Many restoration projects are in progress on the farm, including restoration of upland and riparian forests as well as native meadows and grasslands. Approximately 430 acres are designated for beneficial management of breeding grassland birds in cooperation with Rutgers, the State University of NJ. Duke Farms is also at the heart of the Raritan Piedmont Wildlife Habitat Partnership, involving several organizations, including NJ Audubon Society. This partnership focuses on the protection and management of critical wildlife habitats within three closely associated landscape regions in central NJ. Staff biologists also coordinate fall migration counts of raptors, bats and butterflies.

Additional Information: Site Report
Grassland Field at Duke Farm
Grassland Field at Duke FarmThom Almendinger