Physalaemus evangelistai Bokermann, 1967

Hepp, Fábio & Pombal, José P., 2020, Review of bioacoustical traits in the genus Physalaemus Fitzinger, 1826 (Anura: Leptodactylidae: Leiuperinae), Zootaxa 4725 (1), pp. 1-106 : 83-84

Physalaemus evangelistai Bokermann, 1967

We found a single call type for the species, referred to as call A. The call is composed of a single harmonic note, with a general downward FM and an up-downward FM segment in the first sixth of the call duration. Calls usually have intermediate PAM (with no silence intervals between peaks) and PFM throughout their duration.

Call A ( Fig. 53 A–F and 52C). We examined eight recordings, a total of 27 minutes, with ca. 340 calls from 20 males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.976 to 1.358 s. Call rise duration is very short and similar to call fall duration; the call rise and fall shapes vary from logarithmic to almost linear or exponential. The sustain is flat or gradually ascending ( Fig. 53D, C ). There is a long shallow valley at the beginning of the sustain (Fig. A, C, D). The amplitude peak is usually at the end of the first seven tenths of the call duration. The envelope varies from rectangular ( Fig. 53A, D ) to triangular (pointed left; Fig. 53C ). More than 50 % of the call energy is concentrated in 36 % of the call duration around the amplitude peak. Some calls show an intermediate PAM only in the final two fourths of the call duration. This PAM yields emphasized cycles (with no silence intervals between peaks; Fig. 53A, C ). The rate of the PAM is ca. 9 Hz, forming ca. 10 cycles throughout the call. The cycle rise and fall are similar, with amplitude peak at the middle of the cycle. The call has a harmonic series ( Fig. 52C ). The fundamental frequency at ca. 540 Hz and approximately the first six harmonics are emphasized. The wave periods are regular and harmonics are clear throughout the call. The dominant frequency varies from ca. 670 to 2910 Hz ( Fig. 53B ). The dominant harmonic varies from the first to sixth (except the second), but it is usually the first or fourth ( Fig. 52C ). There is a clear shift in relative energy between the bands; the dominant frequency increases towards the end of the call, starting at the first harmonic, moving to the fourth and fifth, and ending at the sixth; thenceforth, it decreases, ending at the third ( Fig. 52C , 53E, F ). Most of the call energy is between 550 and 3100 Hz (three to four harmonics). The call has a general downward FM, with a short up-downward FM at the first sixth of the call duration, leading to slightly arc-shaped bands in this part of the call, and a short downward FM at the end ( Fig. 53B, E, F ). The general downward FM and the initial up-downward FM result in S-shaped harmonics when considering the entire call. Some calls have a PFM during the entire call independent of the PAM. Other calls have PFM inversely proportional and synchronic to the PAM.

Figures

FIGURE 52. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of four Physalaemus species. Each graph shows a single call A of P. gracilis (A), P. lisei (B), P. evangelistai (C), P. barrioi (D), P. jordanensis (E). Grid corresponds to the harmonic values (right y-axis). Red squares are the values of “instantaneous” dominant frequency; blue circles are the values of the reciprocal of w; green triangles are the factor values of the ratio “instantaneous” dominant frequency / w reciprocal per delta time. Delta time corresponds to the duration of one period of the measured acoustic oscillation. Note that factors around integer values suggest harmonic relationship between the frequency calculated (w reciprocal) and the dominant frequency.

FIGURE 53. Call A of Physalaemus evangelistai. Oscillograms (A, C, and D) and audiospectrograms (B, E, and F). A typical call (A–B). Variant calls with different envelopes (C–F). Note the absence of PAM in the call (D–F). Horizontal scale bars have 0.2 s; vertical scale bars have 1 kHz. Filter bandwidth (Hz): 110 (B); 69 (E); 42.3 (F).