Physalaemus lateristriga (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 : 73

Physalaemus lateristriga (Steindachner, 1864)

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 long duration and a slight PAM (no silence intervals between pulses). It has irregular and strong PFM throughout the call. The bands have no general FM or only slight general FM, which is usually upward.

Call A ( Fig. 43 A–F and 42B). We examined seven recordings, a total of 20 minutes, with ca. 160 calls from 16 males. Only some of these calls were measured (see Table 2 ). Call duration varies from 1.330 to 3.746 s. The call rise is restricted to the very beginning of the call, most of the call corresponding to the sustain ( Fig. 43C ). Call rise and fall are very short and similar to each other in duration. Sustain usually regular and almost flat ( Fig. 43C ), but some calls have convex or inclined segments, with amplitude gradually increasing towards its end ( Fig. 43A, D ). In some calls, there is a shallow valley at the beginning of the sustain ( Fig. 43A, C ). The amplitude peak is at around the middle or at the end of the call duration. The envelope of the call varies from rectangular ( Fig. 43C ) to triangular (pointed left; Fig. 43A, D ). More than 50 % of the call energy is concentrated in 39 % of the call duration around the amplitude peak. The call has a slight PAM (silence intervals absent between peaks; Fig. 43A, D ). The rate of the PAM is ca. 8 Hz, forming ca. 29 cycles throughout the call. The cycle rise and fall are similar and the amplitude peak is at the middle of the cycle duration. The call has a harmonic series ( Fig. 42B ). The fundamental frequency is ca. 170 Hz. The first five harmonics are usually absent in the audiospectrogram or with very low energy. There are ca. eight adjacent emphasized harmonics. The wave periods are regular and harmonics are clear throughout the call. Subharmonics (f 0 1/2) are present at the beginning of some calls ( Fig. 43B, F ). The dominant frequency varies from ca. 1590 to 1840 Hz ( Fig. 43B ). The dominant harmonic varies from the ninth to the 13 th, but it is usually the ninth or 10 th ( Fig. 42B ). There is no clear shift in the relative energy between bands throughout the call. Most of the call energy is between 1100 and 2150 Hz (seven harmonics). Calls usually lack a clear general FM ( Fig. 43B, E ). In some calls, a slight up or downward general FM is observed, usually upward. A short downward FM is frequently present at the end of the call ( Fig. 43E ). Additionally, there is a strong PFM throughout the call, which is usually independent ( Fig. 43C, E ), but it is directly proportional and synchronic to PAM when it is present ( Fig. 43A, B ).

Figures

FIGURE 42. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of eight Physalaemus species. Each graph shows a single call A of P. orophilus (A), P. lateristriga (B), P. olfersii (C), P. riograndensis (D), P. biligonigerus (E), P. marmoratus (F), P. santafecinus (G), P. carrizorum (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 call B of P. ephippifer).

FIGURE 43. Call A of Physalaemus lateristriga. Oscillograms (A, C, and D) and audiospectrograms (B, E, and F). A typical call (A–B). Variant calls with different envelopes and different spectral features (C–F). Horizontal scale bars have 0.5 s (C and E) and 0.1 s (D and F); vertical scale bars have 1 kHz. Filter bandwidth (Hz): 18.4 (E); 42.3 (B); 31.7 (F).