Bird Key Stono Seabird Sanctuary was established to protect significant nesting habitat of sea and shorebirds. Bird Key Stono Seabird Sanctuary encompasses approximately 35 acres in the Stono Inlet which drains the Stono, Kiawah and Folly Rivers in Charleston County. The size of this sanctuary varies from year to year. From the late 1980's to 1994, the island supported the largest number of nesting eastern brown pelicans in the range of the species. The Seabird Sanctuaries are sandspit islands formed by deposits from their associated river systems. The islands are dynamic and shift in position and structure due to erosion and deposition of sand. Two plant communities exist on the preserves: intertidal beach and maritime grasslands. The intertidal beach community consists of shifting sand beaches and regularly-flooded mud flats. If present, vegetation is sparse and consists of smooth cord grass, glasswort, marsh hay and sea purslane. Bird Key supports colonies of nesting waterbirds because of its isolated nature and lack of mammalian predators. Although all species may not nest on the island each year, examples of species that have used the island include: brown pelican, least tern, royal tern, black skimmer, gull-billed tern, sandwich tern, common tern, laughing gull, Wilson's plover, American oystercatcher, willet, great egret, snowy egret, tricolored heron and ibis. Besides providing nesting habitat, the sanctuary provides winter loafing and feeding areas for numerous species. The colonial nesting behavior of these birds makes them very susceptible to disturbance. Birds are densely packed into breeding sites during the nesting season, rendering the entire colony susceptible to disruption or destruction. Therefore, the sanctuary is closed to public use from March 15 thru October 15. The area may be viewed from boats during these months and is accessible to the public below the high water tidal line from October 16 thru March 14. Dogs are prohibited year round and camping is not allowed.