Bioacoustics of Isophya tosevski

Diagnosis : Colouration and other characters resembling I. andreevae . The recognition of this species from I. andreevae may be difficult and is based mainly on the shape of cerci, the stouter cercus tooth, the bigger excision between the tooth and the cercus apex, the larger number of stridulatory teeth—88 (in a specimen from Dojran Lake, Macedonia )–110 (95–110 after Heller 1988), and the song having a clearly differentiated group of afterclicks. The song after Heller (1988) consists of single syllables. Heller (1988) showed oscillograms of two types of songs of I. tosevski . We believe the oscillogram on Abbildung 30-C (p. 228) may represent the song of I. andreevae (see above) or at least a pattern unusual for I. tosevski . Supplement to the song description : The song of a typical male specimen from Macedonia (FYROM) (Kozhuf Mts, Moklishte Village) at 23.5°С consisted of syllables constantly repeating at an interval of 1–5 s (1323–4820 ms; mean 2016±651 ms; n=30) that may be regarded either as groups or single syllables. The syllables included main part of dense impulses and commonly an additional part of sparse after-clicks. Rarely (in the beginning of the song) the after-clicks were missing. The main syllable part lasted 169–216 ms (mean 191±10 ms; n=30) and included 25-36 impulses (mean 28±2; n=30) with impulse period of 3–15 (rarely up to 20 ms or more at the end of the part) (average of about 7 ms). The main part was usually followed at 80–150 ms by additional part of sparse impulses (after-clicks) lasting 55–230 ms with an impulse period of 110–60 ms. The total duration of the syllables (main part+after-clicks) was 380–530 ms (mean 466±36 ms; n=30).