Quantitative and qualitative changes in habitat and avifauna at Sydney airport

Abstract

From January 1964 to June 1968 counts were made of the birds seen during the middle of the day at Sydney Airport. Numbers and varieties of birds declined after the following measures were taken: exposure of household refuse near the airport was stopped; airfield drainage was improved; frequency of mowing the airfield was increased; and the airfield was treated with insecticide. There was also a corresponding decrease in reports of bird strikes, and of bird strike damage to aircraft. The numbers of five bird species of about equal size which were killed by aircraft during this period were found to be positively related to the cube roots of their average numbers on the airfield. The implication of this relationship is that bird control measures may be able to produce significant reductions in the incidences of bird strikes only if bird numbers on the airfield are reduced by at least 80%.