Attractiveness of Shredded Garbage to Gulls and Other Avian Species Potentially Hazardous to Aircraft

摘要

Bird activities were studied during January - December 1976 at the solid waste shredder at Romney Stree, Charleston, South Carolina. At least 84 bird species were observed; Herring Gulls, Ring-billed Gulls, Laughing Gulls, Common Crows, Fish Crows, Boat-tailed Grackles, and Cattle Egrets were the major species. Up to 1,000 Herring Gulls, 300 Ring-bills, and 800 Crows were present in winter. Greater proportions of immature Herring and Ring-billed Gulls were found at the shredder than in the greater study area; the reverse was true for laughing Gulls. Gull and crow daily movement patterns showed peaks of abundance during midmorning and midafternoon. Similar peaks but reduced numbers were noted on weekends and at other times when refuse was not being processed. Daily movement patterns were not influenced by tidal or seasonal variations. All species by Ring-billed Gulls showed a preference for feeding on newly-dumped piles of shredded refuse on the landfill; Ring-bills fed primarily on unprocessed refuse at the mill. All gull species fed on shredded refuse, Cattle Egrets on insects obtained from the refuse, and crows and grackles on invertebrates in the nearby salt marshes as well as on some shredded garbage. GulI numbers and habits were monitored in the 500 square mile greater Charleston area during 1976. Herring, Ring-billed, and Laughing GulIs were the main species present. Numbers ot Herring and Ring-billed, but not Laughing gulIs were significantly reduced from those of 1971-72; however, variations in weather between the years obscured this difference. Gull movement patterns and food sources also changed with the reduction in number of solid waste disposal sites in 1976. Most gulIs remained along the coast, with few inland flights; and most birds fed on natural food sources. These habits were reflected in an 86 percent reduction in the number of bird strikes at Charleston Air Force Base for 1976 (only two strikes) when compared with 1971- 72 (14 strikes).