Physalaemus bokermanni Cardoso & Haddad, 1985

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 : 49-50

Physalaemus bokermanni Cardoso & Haddad, 1985

We found two different calls, referred to as call A and B. Calls B were common in recordings in which several males were active and calling at the same night. Calls A and B are composed of harmonics and pulses (i.e., pulse-PAM). Call B has two notes while Call A has only one. The first note of call B is similar to that of call A. The second note of call B is much longer than that of call A and has an envelope with a long and gradual rise.

Call A ( Fig. 18 A–D and 13E). We examined eight recordings, a total of 12 minutes, with ca. 650 calls from nine males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.177 to 0.197 s. The call rise is linear or logarithmic-shaped and longer than the fall, which is usually abrupt and logarithmic-shaped; the amplitude peak is at around the end of the first three fourths of the call duration ( Fig. 18A ). The envelope of the call is elliptic or triangular (pointed left; Fig. 18A, C ). More than 50 % of the energy is concentrated in 41 % of the call duration around the amplitude peak. This call has a strong PAM (with silence intervals present between pulses; Fig. 18 A–D). The rate of the PAM is ca. 35 Hz, forming ca. six pulses throughout the call. The pulse rise is abrupt and much shorter than the fall; the amplitude peak is at the beginning of the pulse ( Fig. 18C ). The first one or two pulses have much lower amplitude than the others ( Fig. 18A ). Often, the second and the last pulses are the longest ( Fig. 18A, B ). Silence intervals are present between pulses, ca. fivefold longer than pulse duration. The first interval is usually much shorter than the others ( Fig. 18 A–D). The call has a harmonic series ( Fig. 13E ). The fundamental frequency is ca. 780 Hz and this band can be present with low energy or absent in the audiospectrograms. The short duration of the pulses makes the bands broad with narrow intervals ( Fig. 18B, D ). Some pulses can have not very clear harmonics, with considerably deterministic chaos due to the irregularity of the wave periods ( Fig. 18B, D ). There are jumps of the fundamental frequency between pulses in some calls. The dominant frequency varies from ca. 2840 to 3660 Hz ( Fig. 18B ). The dominant harmonic varies from the second to the 10 th, but it is usually the fourth. There is no clear shift in the relative energy among the bands throughout the call. Most of the energy is concentrated between 2600 and 3900 Hz (ca. three harmonics). Usually, there is no clear general FM throughout the call, however, in some calls the first two pulses have their energy concentrated in lower frequency bands, making the general FM of the call upward ( Fig. 18B ).

Call B ( Fig. 18 E–H and 16C). We examined three recordings, a total of six minutes, with 35 calls from three males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.947 to 1.868 s and the call has two different notes. Duration of the second note is ca. 1.0 s. The amplitude, temporal and spectral traits of the first note resemble those of call A, although in call B the first note often has more abrupt rise and fall ( Fig. 18E ). Usually, there is a silence interval between the notes ( Fig. 18E, F ). However, in some calls, this interval is perceptible only as a decrease in amplitude. The rise of the second note is logarithmic-shaped and shorter than fall, which is gradual, almost linear; the amplitude peak of the note is at the end of the first tenth of the note duration ( Fig. 18E ). Due to the very short rise and the long and gradual fall, the envelope of the component B is triangular (pointed right; Fig. 18E ). More than 50 % of the energy of the compound call is concentrated in ca. 34 % of the duration around the amplitude peak. Both notes have a strong PAM (there are silence intervals present between pulses; Fig. 18 E–H). The rate of the PAM is similar to that of the call A, ca. 30 Hz, yielding 28 pulses throughout the call. The rate of the PAM is less regular in the second note than in the first one. The pulse rise is abrupt and much shorter than the fall; the amplitude peak is at the beginning of the pulse ( Fig. 18G ). Some pulses can be twofold longer than the others. At the beginning of the second note the ratio between the silence interpulse-interval and pulse duration is similar to that in component A. The interval becomes longer (pulse duration remains the same) towards the end of the call (i.e., pulse-PAM rate decreases), mainly after the first fourth of the second-note duration ( Fig. 18E, G ). Spectral traits of the second note are similar to those of call A ( Fig. 18F, H ; see some quantitative differences in Table 2 ). There is no general FM in component B ( Fig. 18F, H ).

Figures

FIGURE 13. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of eight Physalaemus species. Each graph shows a single call A of: P. nanus (A), P. spiniger (B), P. crombiei (C), P. signifer (D), P. bokermanni (E), P. angrensis (F), P. atlanticus (G), P. moreirae (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 P. nanus; A).

FIGURE 18. Calls A and B of Physalaemus bokermanni. Oscillograms (A, C, E, and G) and audiospectrograms (B, D, F, and H). A single typical call A (A and B). Last three pulses of call A (C–D). Single call B (E–F). Six pulses in detail from the middle of a call B (G–H). Horizontal scale bars have 0.1 s; vertical scale bars have 1 kHz. Filter bandwidth (Hz): 212 (H); 181 (D); 400 (B); 500 (F).