Physalaemus kroyeri (Reinhardt & Lütken, 1862)

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 : 62

Physalaemus kroyeri (Reinhardt & Lütken, 1862)

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 throughout the call and an up-downward FM segment in the first fifth of the call duration.

Call A ( Fig. 30 A–F and 24G). We examined four recordings, a total of six minutes, with ca. 190 calls from eight males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.673 to 0.759 s. In some calls the limits between the call rise, sustain and call fall is not very clear (mainly in calls with elliptic envelope, Fig. 30A ). The call rise and fall are similar in duration. Usually, the call rise has a short logarithmic-shaped section followed by an exponential shape, whereas call fall has an exponential shape only. The sustain is irregular, usually with short or long shallow valleys ( Fig. 30D ). The amplitude peak is usually before the middle of the call duration. The envelope varies from elliptic ( Fig. 30A, C ) to almost rectangular (when flat sustains are present; Fig. 30D ). More than 50 % of the call energy is concentrated in 34 % of the call duration around the amplitude peak. There is no PAM in the call. The call has a harmonic series ( Fig. 24G ). The fundamental frequency is ca. 480 Hz and approximately the first seven harmonics are emphasized. The wave periods are regular and harmonics are clear throughout the call. The dominant frequency varies from ca. 2060 to 2160 Hz ( Fig. 30B ). The dominant harmonic varies from the second to the sixth ( Fig. 24G , 30E, F ). There is a clear shift in the relative energy between the bands; the dominant frequency gets higher until three fourths of the call duration, starting at the second harmonic and ending at the sixth; thenceforth, it gets lower, ending at the third harmonic ( Fig. 24G , 30E, F ). Most of the call energy is between 450 and 2700 Hz (four to seven harmonics). The call has a general downward FM ( Fig. 30B, E, F ). Additionally, the calls have an up-downward FM in the first fifth of the call duration, yielding arc-shaped bands in this part of the call, and a short downward FM at the end ( Fig. 30B, E, F ). 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 24. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of eight Physalaemus species. Each graph shows a single call A of P. henselii (A), P. albonotatus (B), P. cuqui (C), P. atim (D), P. albifrons (E), P. erikae (F), P. kroyeri (G), P. centralis (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. The heterogeneity of the factors in P. henselii (A) suggests sidebands.

FIGURE 30. Call A of Physalaemus kroyeri. Oscillograms (A, C, and D) and audiospectrograms (B, E, and F). A single typical call with elliptic envelope (A–C). Variant calls A with different envelopes (C–F). Horizontal scale bars have 0.2 s; vertical scale bars have 1 kHz. Filter bandwidth (Hz): 78.9 (F); 55.2 (E); 110 (B).