Physalaemus erikae Cruz & Pimenta, 2004

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 : 61

Physalaemus erikae Cruz & Pimenta, 2004

We found a single call type for the species, referred to as call A. The call is composed of a single harmonic note. It has a general downward FM throughout the call but with an up-downward FM segment in the first sixth of the call duration.

Call A ( Fig. 29 A–H and 24F). We examined two recordings, a total of four minutes, with 37 calls from four males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.478 to 0.566 s. The limits between the call rise, sustain, and call fall are not clear (mainly in calls with elliptic envelope, see Fig. 29C, D ). When perceptible, the call rise and fall can be similar in duration, or fall shorter than rise. Usually, call rise has an exponential shape, whereas call fall has a logarithmic shape. When present, the sustain is irregular, usually with short and very shallow amplitude valleys ( Fig. 29A, E ). The amplitude peak is at around the middle of the call duration. The envelope of the call varies from elliptic ( Fig. 29C, D, E ) to slightly rectangular (when flat sustains are present; Fig. 29A ). More than 50 % of the call energy is concentrated in 30 % of the call duration around the amplitude peak. There is no PAM in the call. The call has a harmonic series ( Fig. 24F ). The fundamental frequency is ca. 420 Hz and approximately the first eight harmonics are emphasized. The wave periods are regular and harmonics are clear throughout the call. The dominant frequency varies from ca. 2840 to 2890 Hz ( Fig. 29B ). The dominant harmonic varies from the first to the seventh. There is a clear shift in the relative energy among bands; the dominant frequency gets higher toward the end of the call, starting at the first harmonic and ending at the seventh ( Fig. 24F , 29B, F, G, H ). Most of the call energy is between 650 and 3450 Hz (five to six harmonics). The call has a general downward FM ( Fig. 29B, F, G, H ). Additionally, the calls have an up-downward FM in the first sixth of the call duration, yielding arc-shaped bands in this part of the call, and a short downward FM at the end ( Fig. 29B, F, G, H ). 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 29. Call A of Physalaemus erikae. Oscillograms (A, C, D, and E) and audiospectrograms (B, F, G, and H). A single typical call (A and B). Variant calls A with differences in their envelopes (C–H). Horizontal scale bars have 0.1 s; vertical scale bars have 1 kHz. Filter bandwidth (Hz): 61.9 (B, F, and G); 67.4 (H).