was reported to be partially successful. 

 Investigations of herring gull populations 

 and movements by the Massachusetts Audu- 

 bon Society under contract with the Bureau 

 of Sport Fisheries and Wildlife indicated 

 that a majority of the gulls creating the 

 problem live year-round within 10 miles 

 of the airport. Recorded distress cries of 

 herring gulls are being tested as a method 

 of frightening gulls from airfields. Pre- 



Birds damage many types of crops. Here are some 

 samples: First column, from top, corn, grapes, 

 grapefruit; second column, grain sorghum, rice in 

 shock. (Photos by Denver Wildlife Research Center.) 



liminary tests were sufficiently promising 

 that the technique is being explored further 

 with the aid of mobile electronic equip- 

 ment. 



An ultrasonic siren, tested as a possible 

 albatross scaring device at Midway, proved 

 ineffective. Such devices would seen-i to be 

 of possible use in some situations, how- 

 ever, and an electrical sound laboratory 

 has been established at the Denver Wildlife 

 Research Center. Much of the equipment 

 necessary for further field studies has been 

 obtained. Recordings have been made of the 

 distress calls of the starling, redwinged 

 blackbird, yellow-headed blackbird, cow- 

 bird, common grackle, ring-billed gull, 

 magpie, and sparrow hawk. Recordings have 

 been made of many of the common noise- 

 nnaking devices and of sounds made by jet 



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