STUDIES ON EFFECTS OF SONIC STIMULI ON FLYING ALBATROSSES AT MIDWAY ISLAND.

The objectives were 1 to study aspects of the behavior of flying albatrosses Gooney Birds that might be used to develop an acoustic barrier to prevent their crossing the runways, and 2 to set up, on the basis of these fundamental studies, a pilot scale installation to test the practicality of this type of control. Extensive observations were made on flight activity and responses of flying birds to a variety of sounds broadcast at high intensities about 120 db. at a meter from the speaker. Among sounds which caused up to 50 of flying albatrosses to veer away at distances up to 700 feet were distress call of black-footed albatross, helicopter auto-rotation noise, and other aircraft noises. The first two proved most effective in turning back flying birds, and were used for the pilot scale installation. The installation was set up at the runway intersection, broadcasting sound southward across one runway. Sound was applied during aircraft take-offs and landings on 40 randomly selected days out of 90 in February, March, and April, 1964. Comparisons were made between numbers of birds crossing before and during sound applications, and of numbers of bird strikes by planes on days which sound was applied and on days with no sound. Crossings and strikes were both reduced about 36 during sound application, the reduction being statistically very highly significant. High intensity, low frequency noises, therefore, seem to have promise for alleviating the Gooney Bird problem at Midway. Author