Physalaemus albonotatus (Steindachner, 1864)

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 : 56

Physalaemus albonotatus (Steindachner, 1864)

We found a single call type for the species, referred to as call A. The call has a single harmonic note with a slight PAM without silence intervals. It has a gradual downward FM throughout the call.

Call A ( Fig. 25 A–H and 24B). We examined 14 recordings, a total of 24 minutes, with ca. 330 calls from 26 males. Only some of these calls were measured (see Table 2 ). Call duration varies from 1.333 to 1.429 s. In most calls the limits between the call rise, sustain, and call fall are not clear (for example, see elliptic envelope in Fig 25A ). In calls where they are perceptible, the call rise and fall can be similar in duration with variable shape (linear, exponential, or logarithmic) or call fall is shorter than the rise. In some calls, there is a long regular sustain ( Fig. 25E ). The amplitude peak of the calls measured is at around the end of the first three fourths of the call duration. The envelope varies from elliptic ( Fig. 25A, C, D ) to rectangular ( Fig. 25E ). More than 50 % of the call energy is concentrated in 42 % of the call duration around the amplitude peak. The call has a slight PAM (there is no silence interval between amplitude peaks; Fig. 25A, C, D, E ). The rate of the PAM is ca. 25 Hz, forming ca. 35 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. 24B ). The fundamental frequency is ca. 530 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. 1590 to 2440 Hz ( Fig. 25B ). The dominant harmonic varies from the first to the sixth, but it is usually the fifth. There is a clear shift in relative energy among the bands; the dominant frequency gets higher toward the end of the call, starting at first harmonic and ending in the fifth or sixth one ( Fig. 25B, F, G, H ). Most of the call energy is between 450 and 2950 Hz (five to six harmonics). The call has a general downward FM. Additionally the calls have a subtle up-downward FM at the beginning, yielding arc-shaped bands in this part of the call ( Fig. 25F, G, H ), and a short downward FM at the end ( Fig. 25B, F, G, H ). The general downward FM and the initial up-downward FM result in S-shaped harmonics when considering the entire call. The call also has a PFM, which is inversely proportional and synchronic to the PAM ( Fig. 25A, B, C, E, F, H ). In a few calls, the rate of the PAM is very low and so is the number of cycles ( Fig. 25D, G ). In those calls, the PFM is equally slow and weak ( Fig. 25D, G ).

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 25. Call A of Physalaemus albonotatus. Oscillograms (A, C, D, and E) and audiospectrograms (B, F, G, and H). A single typical call with elliptic envelope (A and B). Variant calls with different envelopes (C–H). Note the calls with clear PAM and PFM (A–C, E–F, and H) and that with irregular PAM and slight PFM (D and G). Horizontal scale bars have 0.1 s; vertical scale bars have 1 kHz. FFT (points): 3000 (B and G); 2500 (F); 2000 (H).