Physalaemus fischeri (Boulenger, 1890)

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 : 66-67

Physalaemus fischeri (Boulenger, 1890)

We found a single call type for the species, referred to as call A. The call is composed of a single harmonic note with an envelope varying from elliptic to almost triangular, resembling an arrow-like shape. It has a general down- ward FM, with a slight up-downward FM segment in the first half of the call duration and a short upward FM at the end.

Call A ( Fig. 35 A–B and 33C). We examined three recordings, a total of five minutes, with ca. 60 calls from five males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.795 to 0.850 s. The call rise and fall are similar in duration and shape (exponential). The sustain is usually composed of a long and deep valley (i.e., with a concave shape). The envelope varies from elliptic to triangular (pointed right; Fig. 35A ). Due to the concave shape of the sustain, the triangular shape of some calls resembles an arrow. The amplitude peak is at around the end of the first two fifths of the call duration. More than 50 % of the call energy is concentrated in 18 % of the call duration around the amplitude peak. There is no PAM in the call. The call has a harmonic series ( Fig. 33C ). The fundamental frequency is ca. 410 Hz, and this band can be present with low energy or absent in the audiospectrograms. There are ca. six emphasized harmonics. The wave periods are regular and harmonics are clear throughout the call. However, jumps of the fundamental frequency, subharmonics and deterministic chaos can be present at the end of the call ( Fig. 35B ). The dominant frequency is ca. 850 Hz ( Fig. 35B ). The dominant harmonic is the second. There is a clear shift in the relative energy among bands, higher bands getting more energy toward the end of the call ( Fig. 33C , 35B ). Most of the call energy is between 650 and 1800 Hz (two to four harmonics). The call has a general downward FM ( Fig. 35B ). Additionally, calls have a slight up-downward FM in the first half of the call duration, yielding arc-shaped bands in this part of the call and a short upward FM at the end ( Fig. 35B ). The general downward FM and the initial up-downward FM result in S-shaped harmonics when considering the entire call. There is no PFM.

Figures

FIGURE 33. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of eight Physalaemus species. Each graph shows a single call A of P. cuvieri (A), P. ephippifer (B), P. fischeri (C), P. cicada (D), P. aguirrei (E), P. soaresi (F), P. maximus (G), P. feioi (H). 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. Factors multiple of ½ of the fundamental frequency correspond to subharmonics (see P. ephippifer; B).

FIGURE 35. Call A of Physalaemus fischeri. Oscillogram (A) and audiospectrogram (B). A single call (A and B). Filter bandwidth (Hz): 55.2 (B).