Bird diversity monitoring at Beijing Xiaolongmen Forest with acoustic indices

Acoustic data collected through passive acoustic monitoring (PAM) were used for Spearman correlation analysis to examine indicative performance of six commonly used acoustic indices on avian species diversity at Xiaolongmen Forest, Baihua Mountain national nature reserve． Strong correlation was found between bird diversity and acoustic complexity index (ACI), bioacoustic index (BI), acoustic diversity index (ADI), and acoustic evenness index (AEI)． Coefficient of ρ > 0.3 was correlated with bird species number, ρ > 0.4 with song quantity, with significance level of P < 0.01． The diversity and intensity of sound were positively correlated with bird diversity． This study provides clear evidence that the acoustic indices as a method of quick assessment of bird diversity and demonstrates how they can reflect bird diversity at Xiaolongmen Forest． This study provides recommendations for the selection of recording locations and durations in similar acoustic research endeavors．