Abstract:Acoustic communication plays an important role in the survival and reproduction of anurans. In anurans, the calling activity has a circadian rhythm that is affected by environmental factors and social context. In this study, we recorded the calls of 57 males of Hylarana guentheri, from August to September in 2016, to analyze their acoustic characteristics. We investigated the temporal rhythm of the calling behavior and the relationship with the air temperature and relative humidity (17 d). The results showed that the calls of H. guentheri were composed of from a single note to four notes (Fig. 1), the notes from different call types of H. guentheri differed in dominant frequency and duration (P < 0.05) (Games-Howell test, Table 1). The calling activity occurred from day to night, with a peak at 13:00 - 14:00 (Fig. 2). Moreover, the number of call in single-note calls, two-note calls, three-note calls, total calls and total notes were greater during the day than at night (P < 0.01) (Mann-Whitney U test, Table 2). Furthermore, the calling activity of H. guentheri was affected by the air temperature (P < 0.01) (Spearman correlation analysis, Fig. 3). The results showed that the strategy of call was changed by changing the number of notes, dominant frequency of notes and duration of notes. The calling activity of H. guentheri followed circadian rhythm, and affected by air temperature.