Mimetica incisa (Stål, 1875)

Though several were taken on under story vegetation both at La Selva and Monte Verde, they did not survive transportation. Information on calling song is derived from a field recording made at Monte Verde with the Uher equip ment. This was on 30 August 1976 in the early part of the night. Because of the audio-limited equipment the possibility of sound energy beyond 20 kHz cannot be ruled out.

The song of a predominantly brown-winged male (Fig. 8) was a succession of prolonged high-Q pulses, each pulse about 31 ms in duration. These song bursts lasted about 3 s or so. The carrier fre quency of the sinusoidal wave calculated from an oscillogram is 13.6 kHz in mid-pulse. The spectrum analyser shows a principal peak centred on 14 kHz. The absence of energy between 15 and 20 kHz suggests that there is no ultrasonic component to this animal's emission. To the human ear at 16 C the song is a series of ethereal squeaks as if some tiny machine was running short of oil.
The pulses are paired in time and at 16 C, the recording temperature, this double-pulse is just resolvable with the unaided human ear. The pulses in a pair are separated by about 76 ms (up per trace Fig. 8) and the successive pairs by about 170 ms. Pulse pairs occurred in groupings of 4-8, with groups of 6 most common (n= 13 groups). [1]

References