Table 2. The Spearman’s rank correlation coefficients between acoustic indices and bird species richness.

Site	nACI	ADI	1-AEI	BI	H	Ht	Hf	AR
Raw (unprocessed)
Pooled	-0.10 **	-0.02	-0.02	-0.01	-0.07 *	0.02	-0.07*	-0.001
A	-0.25 ***	-0.14 *	-0.15 *	-0.01	-0.19 **	0.02	-0.19 **	-0.09
B	-0.05	-0.01	-0.01	-0.16 **	-0.01	0.08	-0.02	0.01
C	-0.04	0.15 *	0.17 **	0.05	0.01	0.12	0.004	0.09
Pre-processed
Pooled	-0.15 ****	-0.09 **	-0.09 **	-0.01	0.02	-0.10 **	0.05	-0.11 **
A	-0.25 ****	-0.20 **	-0.20 ***	0.01	-0.08	-0.05	-0.05	-0.13 *
B	-0.05	-0.10	-0.10	-0.18 **	0.15 *	-0.03	0.16 **	-0.04
C	-0.20 ***	-0.05	-0.05	0.06	0.05	-0.20 ***	0.10	-0.16 **

Based on the pooled pre-processed data, the nACI, ADI, 1-AEI, Ht, and AR had significant but weak negative correlations with bird species richness. Asterisks and bold indicate significance levels

* p < 0.05

** p < 0.01

*** p < 0.001.