Physalaemus lisei Braun & Braun, 1977

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 : 82

Physalaemus lisei Braun & Braun, 1977

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, slight PAM (no silence intervals between peaks) and irregular PFM. The bands have a general downward FM and a short upward FM segment at the end. Calls usually have nonlinear regimes such as deterministic chaos and subharmonics.

Call A ( Fig. 51 A–N and 52B). We examined 19 recordings, a total of 89 minutes, with ca. 915 calls from 50 males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.967 to 1.997 s. The envelope of the call is variable; durations of call rise and fall are usually short and similar in duration, with a long sustain in between; the rise and fall shapes vary from logarithmic to almost linear or exponential. The sustain is flat ( Fig. 51E, F, H, I ) or gradually ascending ( Fig. 51C, G ). Some calls have a final part with higher amplitude ( Fig. 51C, G, I ). Shallow and short amplitude valleys can be present, mainly at the beginning and end of the call ( Fig. 51C, I ). The amplitude peak is usually at the very end of the call duration. Depending on the slope of the sustain, the envelope varies from rectangular ( Fig. 51E, F, H, I ) to triangular (pointed left; Fig. 51C, G ). More than 50 % of the call energy is concentrated in 47 % of the call duration around the amplitude peak. The call can have a slight PAM (there is no silence interval between peaks; Fig. 51E, G, H ). The rate of the PAM is ca. 26 Hz, forming ca. 25 cycles throughout the call. The call has a harmonic series ( Fig. 52B ). The fundamental frequency is ca. 480 Hz and this band can be present with low energy or absent in audiospectrograms. Six adjacent harmonics are emphasized (first seven except the fundamental). Usually, the wave periods are regular and harmonics are clear throughout the call. However, several calls show nonlinear regimes such as subharmonics (f 0 1/2, f 0 1/3, f 0 1/4, or f 0 1/5), biphonation, and deterministic chaos ( Fig. 51D, J, K, M ). These phenomena can occur over the entire call. The dominant frequency varies from ca. 2330 to 2460 Hz ( Fig. 51D ). The dominant harmonic varies from the first to the fifth (except the second), but it is usually the fourth or fifth along the first half of the call ( Fig. 52B ). There is a clear shift in relative energy between the bands. Although there is no shift in the dominant frequency, higher bands get more energy towards the end of the call ( Fig. 51D, L, N ). Most of the call energy is between 950 and 3350 Hz (five to six harmonics). The call has a slight general downward FM ( Fig. 51D, L, N ). Additionally, calls have a very short and slight up-downward FM at their outset, leading to slightly arc-shaped bands in this part of the call, and a short upward FM at the end ( Fig. 51L, N ). The general downward FM and the initial up-downward FM result in S-shaped harmonics when considering the entire call. Some calls show clear PFM ( Fig. 51L, N ). Calls are usually emitted in irregular sequences, with two or three calls ( Fig. 51 A–B).

Figures

FIGURE 51. Call A of Physalaemus lisei. Oscillograms (A, C, E–I) and audiospectrograms (B, D, J–N). Ten calls gathered in groups (A–B). A typical call (C–D). Variant calls with different envelopes and spectral features (E–N). Note PFM and the subharmonics in the calls (J, K, L, M, and N). Horizontal scale bars have 0.5 s; vertical scale bars have 1 kHz. Filter bandwidth (Hz): 61.9 (D and P); 46 (K, L, N, and O); 69 (B); 55.2 (M).

FIGURE 52. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of four Physalaemus species. Each graph shows a single call A of P. gracilis (A), P. lisei (B), P. evangelistai (C), P. barrioi (D), P. jordanensis (E). 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.