Sampling effort
A total of 123 breeding birds were recorded in our field surveys (Figure
2). All accumulation curves for each 100‐m elevational band reached a
plateau or an asymptote (Figure S1 in Appendix 2). Moreover, the
observed species richness was highly correlated with Chao2 value
(R =0.82). Both accumulation curves and correlation analysis
indicated that the sampling effort within 26 elevational bands was
adequate.