In warm sunshine the calling song consists of long sequences of echemes repeated fairly regularly at the rate of about 2-4/s and each usually consisting of 3-5 (very rarely 2 and occassionally 6) syllables. Oscillographic analysis shows that opening hemisyllables are often absent and that the closing hemisyllables usually last about 10-30 ms and are repeated within an echeme at the rate of about 25-35/s. The duration of a single echeme of four syllables is about 100-200 ms and the interval between two echemes is about 100-300 ms. In dull weather and at night the echeme repetition rate can drop to less than 1/s and the syllable repetetion rate to less than 10/s; in such conditions the closing hemisyllable sometimes lasts more than 100 ms and a four-syllable echeme more than 600 ms. The first syllable in an echeme is usually quieter than the remaining ones. Microsyllables are usually absent, but occassionally a few are added at the end of an echeme, especially the opening echeme of a sequence (see Figs 261, 267, 2730. [1]
參考文獻
- . The Songs of the Grasshoppers and Crickets of Western Europe. Colchester, Essex: Harley Books; 1998.