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Maryland-Virginia Barrier Islands

Site Facts

Country, State, Province/Region:

United States, Maryland and Virginia

Relative Location:

Barrier islands extending along the Atlantic coast of Maryland and Virginia, USA.  It includes the Chincoteague NWR and the Assateague National Seashore.


37 54' N, 75 54' W



Basis for Designation:

More than 100,000 shorebirds annually


20725 hectares (51212 acres)


September 1990

Site Owner/Steward:

U.S. Fish and Wildlife Service, National Park Service, 

Site Partners:


Human Population within 100 km:



Barry Truitt
Chief Conservation Scientist
Virginia Coast Reserve Program
The Nature Conservancy
Virginia Coast Reserve


A series of primarily sandy barrier islands, mostly unwooded, with varying amounts of dunes and low shrubs. Habitats include fresh water impoundments, beach, dune, marsh, maritime forest, and mud flats. Exposure to the sea is mostly unregulated and storms alter the coastline frequently. During migration, the outer islands are frequented by sanderling and peeps, and the inner side are often used by plovers and larger shorebirds.

While detailed information is not yet available for the entire area, it is evident that the Barrier Islands are extremely important to migratory shorebirds during both spring and fall migrations. Further investigation may likely reveal that the area hosts numbers of shorebirds well exceeding 500,000 annually. 

Results obtained from the International Shorebird Surveys (surveys conducted since 1974) show that of all 600 sites surveyed to the east of the Rocky mountains, Chincoteague ranks second in species diversity during both spring and fall migrations, and is among the top ten for sites with greatest maximum counts. 

The 1987 Wildlife Report prepared by the U.S. Fish and Wild life Service quoted 120,348 shorebirds for a single count at Chincoteague NWR alone, suggesting far greater numbers for the extended Barrier Islands. 

Data compiled by the International Shorebird Surveys from 1976-1987 counts at Chincoteague report single maximum counts of 54,335 shorebirds in the spring, and 32,522 shorebirds in the fall, totaling 86,857 shorebirds (single maximum count) annually. When these data are extrapolated to consider turnover rates of migrants as well, numbers well exceed 170,000 for Chincoteague alone.

Chincoteague, Wachapreague, and Cape Charles support over 1100 American Oystercatchers during the winter -- one of the largest known wintering concentrations in the U.S.. (Christmas Bird Count, 1986). A significant percentage of American Oyster catchers and Piping Plovers also breed on the Barrier Islands, as well as Wilson's Plovers, and numerous terns and gulls. Production counts for 1994 are as follows:

Assateague - 25 pairs 53 chicks fledged

Wallops Is - 3 prs. 2 chicks fledged

Assawam Is. - 12 prs 13 chicks fledged

Metompkin Is. - 4prs 5 chicks fledged

Ecology & Conservation


Special Information



Barry Truitt
Chief Conservation Scientist
Virginia Coast Reserve Program
The Nature Conservancy
Virginia Coast Reserve

Additional Resouces