Bioacoustics of Mantidactylus tricinctus

Calls .—The advertisement call of M. tricinctus , recorded on 23 February 2007 at Manombo, at an estimated air temperature of 25°C, consisted of a short, pulsed note, emitted in regular series at very fast succession ( Fig. 58 ). Amplitude modulation was present, with relative amplitude increasing from the beginning of the call, reaching its maximum with the terminal pulse. Numerical parameters of 64 analysed calls were as follows: call duration (= note duration) 45–113 ms (83.4 ± 19.0 ms); 8–19 pulses per note (15.5 ± 3.6); pulse duration 2–5 ms (2.8 ± 1.1); pulse repetition rate within notes 147.1–214.3 pulses/s (177.2 ± 27.7); dominant frequency 2787–2906 Hz (2851 ± 59 Hz), with a second peak of almost equal energy at ca 2100–2200 Hz; prevalent bandwidth 1400–5300 Hz; call repetition rate (= note repetition rate) within regular series ca 470– 580 calls/min. Call series consist of 35–42 calls (n = 3), but calls were also emitted isolated (possibly territorial function) or in short groups containing 2–3 calls. Tadpoles.— The tadpole of this species has not been described.

Diagnosis .—A member of the M. tricinctus clade as revealed by the phylogenomic analysis, and sister to M. grubenmanni sp. nov. described below. See Table 4 for a list of diagnostic morphological characters. The combination of very small body size (below 20 mm male SVL), connected lateral metatarsalia, reduced webbing, presence of a light (often yellowish) marking on snout tip, a yellow inguinal marking, and a short, pulsed advertisement call emitted in rapid succession in regular series, readily distinguishes M. tricinctus from all other nominal species of Brygoomantis . Most similar to its sister species M. grubenmanni sp. nov. and to a lesser degree, to M. gudrunae sp. nov. ; for comparisons, see the diagnoses of these species below. For detailed distinction from other new species described herein, see the respective species accounts. A full list of molecular diagnostic sites in the 16S gene of M. tricinctus in pairwise comparisons to all other Brygoomantis species is provided as Supplementary appendix.