Natural and Dredged Material Nesting Habitats of Gull-Billed Terns, Common Terns and Black Skimmers in North Carolina

摘要

In North Carolina all colonies of Gull-billed Terns (Gelochelidon nilotica), Common Terns (Sterna hirundo), and Black Skimmers (Rynchops niger) were visited during the 1976 and 1977 nesting seasons. The majority of the nests of all three species were placed on dredged material sites. The habitats of natural and dredged material sites were characterized as to: distance to open areas, water, grass and shrubs; height and percent cover of vegetation; plant species present; substrate; general and microtopography; and elevation and shape. It appeared that dredged material sites were similar to natural habitat, except that dredged material sites were usually more elevated. Possible reasons for the historical shift from traditional natural colony sites to dredged material sites by these species are presented and discussed.