Paraplangia sinespeculo

The male calling song consisted of song units, repeated in interval of many minutes as long as the female did not respond. Each song unit (163 recorded) contained two series of syllables, the first with 10.7±1.0 syllables (mean±SD; range 8-12; n = 21), the second only with 4.2±0.9 (range 3-5; Fig. 6). The second series started 9.3 ± 0.7 s (range 8.3-10.7 s) after the beginning of the first and both series were separated by a silent interval of 4.2±0.4 s (range 3.7-5.3 s). The intervals between the syllables ranged from 400 to 619 ms (487±66 ms), measured in the second half of the first series. In amplitude modulation, both series were decrescendo or without change in loudness. The syllables were very short, less than 5 ms (Fig. 7A), consisting of few, often hardly separable impulses.

Like in most phaneropterines (Heller et al. 2015), the female that was ready to mate reacted to the male song with its own acoustic signals. It always answered after or at the end of the second series. The first response syllable of its response was registered 2.7±0.6 s after the beginning of the second male series (range 1.7-4.2 s; n = 74) and 0.55±0.33 s after a male syllable (range 0.04-2.8 s; n = 73). The female response was quite variable; the simplest answer consisted of one impulse, but she could also make two impulses at relatively large intervals, long (about 8) series of impulses with short intervals or mixtures with many impulses at varying intervals (Fig. 6B–C; see Suppl. materials 1, 2: duets 1 and 2).

The carrier spectrum of male and female song is relatively narrow-banded with its maximum at about 8.4±0.7 kHz (n = 3; range 10 db below peak 7.3-10.2 kHz) in the male and 8.7±0.2 kHz (n = 3; range 10 db below peak 6.9-10.9 kHz; Fig. 7) in the female. [1]

References