The effects of habitat (a) and patry (b) on call characters, NRR, ND and DF.

We performed a MANCOVA with predictor variables including barrier, locality, SVL, temperature and humidity (see Methods). One-way ANOVA was conducted on residuals of MANCOVA for three call characters. Habitat that was either rice paddy or non-rice paddy was a predictor variable in one-way ANOVA using all samples. Patry was either allopatry or sympatry. Localities only in the western group were included to test the effect of patry.