Totally 12 records from two males were examined. The calling song consists of phrases (Figure 4B) with irregular intervals. Phrase durations vary between 0.93 and 1.07 s (1.01 ± 0.04), and each phrase contains 31–37 syllables (33.3 ± 1.5). The phrase generally begins with an isolated first hemisyllable and is followed by a gap which lasts for 8–19 ms (13.6± 3.6). After the gap, the phrase continues with 2–3 higher amplitude syllable group and a 2–4 lower amplitude syllable group (generally corresponds to 1/8 of phrase), then reaches the highest amplitude after this part and goes along with ordinary syllables which have a quite similar amplitude (Fig 4C). The oscillographic analyses show that the syllable periods duration varies between 21.20 and 38.21 ms (26.35 ± 1.98), and each syllable shows a standard structure, which is formulated as soft and long opening hemisyllable + loud and short closing hemisyllable (Figure 4D). The opening hemisyllables duration varies between 7.59–21.46 ms (16.39 ± 1.82), while the closing hemisyllable lasts for 6.80–17.53 ms (9.96 ± 1.46). [1]
