Dredge islands are an important but relatively unstudied habitat for seabirds on the northern coast of the Gulf of Mexico. We characterized nest sites of Forster's terns (Sterna forsteri), least terns (S. antillarum), gull-billed terns (S. nilotica) and black skimmers (Rynchops niger) on dredge islands in the Atchafalaya Delta Wildlife Management Area in Louisiana. With the exception of the least tern, seabird use of the islands has increased over the last 5 years. Generally, dredge islands were used only during the first nesting season following their creation. Forster's terns nested on clumps of dead water hycacinth (Eichornia crassipes); nest sites of the other 3 species were relatively devoid of dead vegetation. Both least and gull-billed terns nested on substrates that contained shell while avoiding nearby patches of sand. The nest sites of black skimmers were very similar to surrounding habitat, and nest location may have been more influenced by the presence of gull-billed terns than by substrate composition.
