Bioacoustics of Myopsalta parvula

Distribution, habitat and behaviour ( Fig. 17 ). Myopsalta parvula n. sp. is currently known only from a small area on the lower eastern slopes of Black Mountain in the Australian Capital Territory and from near Anglers Rest, approximately 20 km north of Omeo in north-eastern Victoria . Adults occur for a period of approximately one week from mid-November. The Australian Capital Territory specimens were found in low shrubs and grass on the edge of eucalypt woodland. Males call from the stems of grasses and shrubs during warm, sunny conditions. Calling song ( Fig. 26 ). Examination of the calling song of M. parvula n. sp. reveals the phrase durations to be quite variable, often prolonged. From a small sample of available recordings ( n =2), phrase durations ranged from 3.7 s to>47 s and this variation was a consequence of the number of smaller subphrases incorporated into each phrase. Each subphrase comprises a long macrosyllable (0.05– 0.08 s duration; sometimes preceded by a syllable and gap of 0.007– 0.008 s and 0.008– 0.017 s duration, respectively), a gap of 0.020– 0.025 s duration and a syllable sequence (0.12– 0.19 s duration, containing 5–7 syllables separated by gaps of 0.020– 0.025 s duration). Each phrase concludes with a drawn out syllable sequence (0.5– 1.0 s duration, containing 18–35 syllables), followed by a gap (0.039– 0.042 s duration), a short macrosyllable (0.017– 0.022 s duration) and a longer gap (0.10– 0.12 s duration). Based upon the observations of the calling behaviour in other Myopsalta species, it is considered likely that the female would respond with a wing-flick signal during the long gap at the end of each phrase. The calling song maintains an even frequency distribution throughout, with a high amplitude plateau of 12.9– 19.3 kHz and a dominant frequency between 13.1 and 17.7 kHz.

Calling song (Fig. 26). Examination of the calling song of M. parvula n. sp. reveals the phrase durations to be quite variable, often prolonged. From a small sample of available recordings ( n =2), phrase durations ranged from 3.7 s to >47 s and this variation was a consequence of the number of smaller subphrases incorporated into each phrase. Each subphrase comprises a long macrosyllable (0.05–0.08 s duration; sometimes preceded by a syllable and gap of 0.007–0.008 s and 0.008–0.017 s duration, respectively), a gap of 0.020–0.025 s duration and a syllable sequence (0.12–0.19 s duration, containing 5–7 syllables separated by gaps of 0.020–0.025 s duration). Each phrase concludes with a drawn out syllable sequence (0.5–1.0 s duration, containing 18–35 syllables), followed by a gap (0.039–0.042 s duration), a short macrosyllable (0.017–0.022 s duration) and a longer gap (0.10–0.12 s duration). Based upon the observations of the calling behaviour in other Myopsalta species, it is considered likely that the female would respond with a wing-flick signal during the long gap at the end of each phrase. The calling song maintains an even frequency distribution throughout, with a high amplitude plateau of 12.9– 19.3 kHz and a dominant frequency between 13.1 and 17.7 kHz.