Sandwich terns are distinguishable by their bicolored bills 



prefer sandy nesting habitats, the 

 islands quickly become useless. 



Parnell says there could be problems 

 in the future for the sandy nesters if 

 too many diked, dredged islands 

 became heavily vegetated or if the 

 corps continues to deposit more and 

 more of its dredge material on 

 beachfront or mainland areas. A 1983 

 census of all nesting colonial water- 

 birds in North Carolina, conducted by 

 Parnell, showed a decline in the pop- 

 ulations of least terns, common terns, 

 gull-billed terns and black skimmers — 

 all bare-sand nesters. 



Parnell points out that new deposits 

 of dredge material or other manage- 



ment tools such as tilling, applying 

 plant retardants or burning could be 

 used to keep vegetation at a minimum. 

 Scientists are just beginning to study 

 methods of altering or creating nesting 

 habitats for colonial waterbirds. 



In the 1983 census, sponsored by 

 UNC Sea Grant and U.S. Army 

 Corps of Engineers, Parnell found that 

 four percent of the colonial-waterbird 

 nests occurred on barrier-island sites; 

 18 percent on natural estuarine 

 islands; 27 percent on diked, dredge- 

 material islands; and 51 percent on un- 

 diked, dredge-material islands. He also 

 learned that populations of brown 



pelicans, white ibises, laughing gulls 

 and royal terns had increased since his 

 1977 census. 



After comparing the 1977 and 1983 

 censuses, Parnell found that the water- 

 birds were nesting at fewer sites, but 

 that the sites in use were supporting 

 larger colonies. This trend has Parnell 

 worried because dense aggregations of 

 birds at relatively few breeding sites 

 might mean a single catastrophic 

 event, such as an epidemic, could spell 

 disaster for a large percentage of birds. 



But it's not only habitat degrada- 

 tion that has ornithologists wor- 

 ried about the waterbirds' future. Sci- 

 entists are also concerned about the 

 encroachment of man. 



"There's a recognition on the part of 

 Audubon that the human population 

 in this country is shifting to the 

 southeast," says Donald McCrimmon, 

 a research biologist with the National 

 Audubon Society. "That's potentially 

 a problem for colonially nesting water- 

 birds. 



"In North Carolina, the greatest 

 threat is from recreational interests 

 that are only going to increase with 

 more and more people using the 

 waterways. More birds are going to be 

 subject to impact. We need to learn 

 more about the resource requirements 

 of birds to permit them to coexist with 

 the surge of populations." 



Parnell says human disturbance of 

 colonies during nesting may leave the 

 eggs or newly born chicks vulnerable 

 to weather conditions or predation 

 from other birds and animals. During 

 spring and early summer, he warns 

 people to avoid the islands where the 

 birds are nesting and to leave the nests 

 and young chicks of beach nesters 

 alone. 



— Kathy Hart 



Baby common tern and egg 



Fresh dredge material being deposited on an island 



