BioAcoustica is a free, open repository of wildlife sound recordings from the Natural History Museum, London.
Taxonomic index of the BioAcoustica collection
Acoustic and biological measurements in the BioAcoustica collection
Recording annotations from ann-o-mate
The specimens that recordings are of, from the collections
Where the specimens that recordings are of were collected, not where the sound was recorded
(1 male recorded) We successfully recorded the singing of one specimen at 28°C. This male's duty cycle was extremely low: in making a succession of seven call he sang for about 1/3 of 1% of the time available. Each call was a zip lasting 106.7 ms (c.v. = 1.6%). One complete zip is shown in Fig. 31 A. Average down time between calls was 35.8 s (n=9). The amplitude modulation of the call is complex and a little variable; it incorporates trains of rapid-decay pulses of low amplitude as well as trains of higher amplitude prolonged pulses (Fig. 31B); within the trains these latter tend to increment in duration. The maximum prolonged pulse duration achieved was in the final train (Fig. 31B,C): 2.1 ms. The call always begins with a pair of low-amplitude rapid-decay pulse pulse trains. Then there are a few short sinusoidal pulses at higher amplitude and finally a short succession of the rather variable (presumed) phonatomes, each comprised of a minor low amplitude train preceding a major train of several maximally sustained pure tone pulses (Fig. 31 A,B). Though this insect's song includes so many low amplitude rapid-decay pulse trains, its spectrum is is nevertheless dominated by a single relatively high-Q peak of unusual symmetry (Fig. 31 D,E). At any signficant distance from a singer a female would only perceive this dominant carrier. The peak is the product of the higher intensity pulses which involve one dominant frequency: 29.3 kHz (c.v1.3%). Though not obvious in all spectra there are also very low harmonic peaks. There is a fundamental at 14.5 kHz >37 dB down. The principal carrier is thus the first harmonic of this suppressed fundamental. Other low harmonic peaks occur, 2'nd, 3'rd, 5th, all >30 dB below the dominant peak. One prolonged pulse is shown (Fig. 31C) at a resolution that reveals the pure-tone sinusoid; the power spectrum of this particular time sample is shown in Fig. 31 E.