The Performance Evalution Of Acoustic Bird Repeller And Methods Of Sound Modification

With the development of civil aviation transportation industry,bird strike has became a worldwide problem.At present,bird strike prevention is mainly carried out within the area of the airport,which makes the research on the current bird repellent equipment of the airport become particularly important.The airport mainly uses the sound bird repeller to expel the birds,but there are few studies on the effect of different sound bird repellers and related different sound sources.This study was carried out in Taoxian International Airport in Shenyang.The common danger birds,Pigeon(Columba Livia domestica),Oriental turtle dove(Streptopelia orientalis)and Kestrel(Falco tinnunculus),were chosen as the study species,the research contents include the effective distance of the gas gun and the directional acoustic bird repeller,the effectiveness evaluation of the current sound source of the directional acoustic bird repeller,as well as the influence of different methods to modify the sound source of bird repeller on its bird repellent effect,The results are as follows:(1)In the range of 30 m from the gas gun bird repeller,the frequencys of alarm and escape behavior of pigeons and kestrels was significantly higher than that of the control group.In the range of 100 m,the frequencys of alarm and escape behavior of pigeons and kestrels were significantly higher than that of the control group,and the frequenncy of alarm behavior of kestrels was still higher at 300 m from the directional acoustic bird repeller.There was significant difference between the two groups.As for the effect of the two devices,the effectiveness of the directional acoustic bird repeller is better than that of the gas gun bird repeller.(2)Bird alarm song,raptor song and mechanical noise all had significant bird repellent effects,and there were significant differences among the three sound sources.Among them,the effect of alarm song was the best,while the effect of raptor song and mechanical noise were almost similar.From the perspective of experimental subjects,compared with pigeon,turtle dove was more sensitive to the song of raptors,and there was no significant difference between other two sounds.(3)Under the effect of 0-10 kHz and 10-20 KHZ white noise,there was no significant difference in the proportion of alarm period time between domestic pigeons and the control,while the average pecking times of domestic pigeons under the effect of 0-10 kHz white noise was significantly higher than the control.The ratio of alert time and pecking times of pigeons under the action of 0.1s shortening syllableinterval were significantly higher than that of kestrel song,while the ratio of alert time and pecking times of pigeons under the action of combined repelling sound source of kestrel and magpie were significantly higher than that of kestrel song and magpie scream.As a whole,our results indicated that the effective distance of the gas gun is 30 m,which is lower than 100 m of the directional acoustic bird repeller,and the effect of the directional acoustic bird repeller is better.Among them,the three kinds of bird repellent sound sources currently used by directional acoustic bird repeller can play a better role in bird repellent,the effect of bird alarm sound is better than that of other bird repelling sound sources,and the song of raptors can enhance the driving effect on wild birds.Finally,we found that the simple frequency modulation can not significantly enhance the effect of bird repellent,but shorten the syllable interval time of raptor and the combination of raptor and bird alarm calls can significantly enhance the effect of bird repellent.In conclusion,we suggest that the airport should introduce more directional acoustic bird repellers,increase the proportion of raptor and alarming calls in the sound source and conduct more necessary works on the song modification.