Calling song (Figs 7, 8). The calling song contains a set of repeated phrases. At the onset of calling, each phrase begins with a long echeme (0.646–1.702 s duration), followed by a 0.023–0.045 s gap, a short echeme or macrosyllable (0.02–0.097 s duration) and a 0.196–1.767 s gap (all statistics, n =8 recordings). Close inspection of the beginning of the long echemes in each phrase reveals a series of discrete syllables that coalesce and increase up to 3x in amplitude during production of the echeme. After production of several successive echemes, males typically start to lengthen the introduction of each phrase with the addition of a long sequence of syllables (each 0.005–0.013 s duration), separated by gaps of 0.042–0.092 s duration. The gaps between these syllables noticeably decrease towards the end of a sequence, shortening down to 0.011 s immediately prior the production of the long echeme. These introductory sequences range in duration between 1.204 and 2.277 s, with the longest examples shortening the gap at the end of the preceding phrase down to 0.030 s on occasion. Field observations indicate that the female responds during the gap following the short echeme or macrosyllable at the end of each phrase.
This species calls during the day and is not known to sing at dusk. The calling song maintains an even frequency distribution throughout, with a high amplitude plateau of 9.7–13.2 kHz and a dominant frequency between 10.2 and 12.0 kHz. [1]