Conocephalus (Conocephalus) conocephalus (Linnaeus, 1767)

In its simplest form the very faint calling song, produced both by day and night, is a series of single syllables repeated at rather irregular intervals, bbut more often it consists of a randommixture of single syllables and echemes. The number of syllables in teh echemes is very variable, usually within the range 3-9, but they are repeates within each echeme at a very constant rate, usually within the range 11-14/s. Each syllable is normally a closing hemisyllable lasting about 45-60ms, whether isolated or forming part of an echeme. In a song including echemes, teh brief pauses between successive echems or isolated syllables are usually less than a second (commonly 0.2-0.2 s), but there are sometimes longer pauses of up to 10 s or more.

In a common variant of this simple song there is a mixture of quieter and louder syllables; both the quieter and the louder ones may be isolated or in echems and, apart from amarked contrast in loudness, they are similar in structure and duration. In such songs there is usally a series of quiet echemes or ungrouped syllables followed immediately by a series of loud echemes or ungorued syllables; there is tehn an interval of several seconds before another such sequence begins. Sometimes the duration of a sequence of this kind is about equally divided between the quieter and louder parts, but in the most highly developed song studied (shown in Fig. 141) the quieter part of each song lasted about 13-15 s and the louder part less than 2 s. In this song, as the oscillograms show, the louder part was heralded by a pair of very quiet syllables, and at this point in the song some of the opening strokes of teh fore wings produced brief hemisyllables.

Sometimes soft and loud syllables are produced in pairs, as oft one being followed 1-3 s later by a loud one and then an interval of about 6-8 s before the next pair. Clealry this species has an interesting acoustic repertoire which merits a more comprehensive study. [1]

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