Research On Animal Diversity Monitoring Method Based On Ecoacoustics

In recent years,as a non-invasive,low-disturbance,and low-cost method for biodiversity monitoring,ecoacoustic method has been deeply researched and widely applied in the world.As one of the most important analysis method under the framework of ecoacoustics,the acoustic index has been confirmed a positive effects according to many studies,but at the same time,there are also a few researches questioning its scope of application.At present,the domestic research and application of the ecoacoustics method are rarely reported.Whether the method is applicable to the domestic complex ecological environment is still unknown and needs to be tested and verified by field research.The Dalongtan Area of Shennongjia National Park in Hubei Province where was the key activity area for the snub nosed monkey was taken by this paper as the study area.The vegetation types and terrain conditions of the study area were analyzed on basis of field surveys,satellite remote sensing data and geography information system.Long-term time series sound recordings were collected with equipment in appropriate sampling points in this area.Then ecoacousticsrelated methods were applied and acoustic indices were extracted from those collected sound recordings to analyze the main composition and sound source of the soundscape,the diurnal and seasonal changes of birds songs,and the spatial difference of bird songs in the study area.Results shows that the ecoacoustics method through the long-term deployment of automatic sound collection device in the field is applicable as a bird diversity monitoring method in Shennongjia.Meanwhile,it was difficult for artifical to carry out the analysis and research of high spatialtemporal resolution of bird activities based on the continuous long-term monitoring data.The main research conclusions are as follows:1.The main sounds in the soundscape of the study area were mainly distributed in the range of 1-5k Hz,of which the sounds within 1-2k Hz mainly came from the interference noise of the recording equipment operation noise,sounds in the 2-4k Hz range was dominated by birdsong and supplemented by other animal sounds,and sounds in the 4-5k Hz range mainly appear at night,which may come from a few nocturnal birds or insects.2.The acoustic complexity index,bio-acoustic index and normalized difference soundscape index were significantly correlated with the avian species richness in study area.The acoustic activities of study area birds showed similar diurnal changes in spring,summer,and autumn,and both the intensity and duration of the acoustic activity in summer wre obviously stronger and longer compared with the other two seasons;while the acoustic activity of birds was much less in winter.3.Through the spatial difference analysis of the sound between different sampling sites,it was found that the difference in the birdsong between different sampling sites in the study area was more likely to be a phenomenon of niche differentiation in order to avoid resource competition.Due to the different placement positions of the sampling sites,there might be different natural sounds,leading to sound differences between the two sites.This study shows that the ecoacoustics method is one of the feasible methods to carry out the rapid assessment of the status of bird biodiversity.The has been proposed as a non-invasive,cost-effective way to collect data automatically.When passive acoustic monitoring is carried out in study area,care should be taken to exclude the influence of weather,human activities and the other species on the results of acoustic index analysis.In addition,this study can help in the establishment of a ecoacoustics monitoring system and the promotion of a soundscape monitoring network as well as a sound data management platform in the future.