Physalaemus nattereri (Steindachner, 1863)

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 : 15

Physalaemus nattereri (Steindachner, 1863)

We found a single call type for the species, referred to as call A. The call is composed of a single harmonic note usually emitted in sequences of three or four calls ( Fig. 3A and B ), but longer sequences, with dozens of calls, can be sporadically emitted.

Call A ( Fig. 3 A–F and 4A). We examined 15 recordings, a total of 21 minutes, with ca. 5500 calls from 28 males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.057 to 0.074 s. The abrupt call rise is much shorter than the call fall, which is more gradual; the amplitude peak is within the first third of the call’s duration (usually at the very beginning of the call). The envelope of the call resembles a triangle pointed right. More than 50 % of the call energy is concentrated at the first 26 % of the call duration ( Fig. 3C, E ). The call has no PAM. The call is composed of clear harmonics ( Fig. 3D, F , 4A ). The fundamental frequency is around 330 Hz and it is usually present with low energy or absent in the audiospectrograms. The dominant frequency of the calls varies from 703 to 1031 Hz. Within each call, the dominant harmonic varies from the first to third, but it is usually the second or third. There is no clear shift in the relative energy among the bands throughout the call. Most of the call energy is between 700 and 1050 Hz (often, two harmonics). Frequency modulations are very subtle in this species. Nonetheless, the frequency bands have a general downward FM with a slight rapid up-downward FM at the beginning and a short down or upward FM at the end. There is no PFM ( Fig. 3D, F ).

Figures

FIGURE 3. Call A of Physalaemus nattereri. Oscillograms (A, C, and E) and audiospectrograms (B, D, and F). Sequence of groups of call (A and B). A single typical call (C and D). A single call with a variant envelope (E and F). Horizontal scale bars have 0.2 s; vertical scale bars have 1 kHz. Filter bandwidth (Hz): 92.1 (F); 67.4 (B); 92.1 (D).

FIGURE 4. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of seven Physalaemus species. Each graph shows a single call A of: P. nattereri (A), P. maculiventris (B), P. erythros (C), P. rupestris (D), P. camacan (E; F), P. obtectus (G), P. irroratus (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 w of the measured 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. irroratus; H).