Physalaemus moreirae (Miranda-Ribeiro, 1937)

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 : 52-54

Physalaemus moreirae (Miranda-Ribeiro, 1937)

We found two different calls, referred to as call A and B. Calls A and B are composed of a single harmonic note each. Call A is composed of pulses whereas Call B is not. Moreover, call B has irregular FM segments (vs. absent in call A).

Call A ( Fig. 21 A–J and 13H). We examined three recordings, a total of one minute, with 68 calls from five males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.499 to 0.567 s. In most calls, the limits between call rise, sustain, and fall are not clear (for example in calls with elliptic envelope; Fig. 21E ). When perceptible, the call rise and fall are similar in duration and shape, both with a linear shape, and there is a long sustain. This segment can be regular and flat ( Fig. 21A ) or quite irregular with AM segments within it ( Fig. 21C ). The amplitude peak is usually at around the middle of the call duration. The envelope varies from elliptic ( Fig. 21E ) to triangular (pointed left; Fig. 21C ). More than 50 % of the energy is concentrated in 35 % of the call duration around the amplitude peak. The call has a strong PAM (with silence intervals present between pulses; Fig 21A, C, E ). The rate of the PAM is ca. 42 Hz, forming ca. 23 pulses throughout the call. Most pulses have an elliptic envelope with the amplitude peak around the middle of the pulse. The very first pulses have rise longer than fall, amplitude peak at the end of pulse and the very last pulses have the opposite shape (amplitude peak at the beginning of the pulse; Fig. 21D, F ). The last pulse is the longest ( Fig. 21 A–J). Short silence intervals are present between the pulses, but can be absent between the first and last pulses (pulses are juxtaposed to neighboring pulses; Fig. 21A, C, D, E, F ). The call has a harmonic series ( Fig. 13H ). The fundamental frequency is ca. 230 Hz and this band can be present with low energy or absent in the audiospectrograms. Usually, the wave periods are regular and harmonics are clear throughout the call. However, the short duration of the pulses (except the last) make the bands broad with narrow intervals. Where two pulses are juxtaposed, the wave periods are less regular, and the harmonics are less clear with deterministic chaos ( Fig. 21B, G, H, I, J ). The dominant frequency varies from ca. 770 to 1250 Hz ( Fig. 21B ). The dominant harmonic varies from the third to the eighth, but it is usually the third or fourth. There is no clear shift in the relative energy among the bands throughout the call. Most of the energy is concentrated between 700 and 1300 Hz (three harmonics). A few calls have a slight upward general FM ( Fig. 21H, I ). Usually, there is no clear general FM ( Fig. 21B ). Calls have a short downward FM at the end ( Fig. 21H, J ) and PFM throughout the call without clear relationship with the synchronic pulse-PAM ( Fig. 21E, F, I, J ).

Call B ( Fig. 21 K–L and 16E). We examined one recording, a total of one minute, with one call from one male. This call was also measured (see Table 2 ). A single call was recorded. Call duration is 0.254 s. The call rise and fall are similar in duration and shape (exponential-shaped). There is a long sustain, which is regular until the amplitude peak at the end of the call, around nine tenths of the call duration. The envelope is triangular (pointed left; Fig. 21K ). More than 50 % of the energy is concentrated in 54 % of the call duration around the amplitude peak. This call has no PAM. The call has a harmonic series ( Fig. 16E ). The fundamental frequency is at ca. 280 Hz and this band is generally absent in the audiospectrogram. The wave periods are regular and harmonics are clear throughout the call. However, the wave periods are less regular at the middle of the call, with biphonation regime ( Fig. 21L ). The dominant frequency is ca. 860 Hz ( Fig. 21L ). The dominant harmonic varies from the second to the fifth, but it is usually the third or fourth. There is no clear shift in the relative energy among the bands throughout the call. Most of the energy is concentrated between 800 and 1400 Hz (often, three harmonics). The long downward FM segment at the beginning makes the general FM of the call downward. There is a slight PFM throughout the call. Additionally, the call has parts with irregular up and downward FM ( Fig. 21L ).

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 16. Multiplicity relationship between “instantaneous” dominant frequency and w of calls B of five Physalaemus species. Each graph shows a single call B of: P. crombiei (A), P. signifer (B), P. bokermanni (C), P. angrensis (D), and P. moreirae (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.

FIGURE 21. Calls A and B of Physalaemus moreirae. Oscillograms (A, C, D, E, F, and K) and audiospectrograms (B, G, H, I, J, and L). A single typical call A with elliptic envelope (A and B). Variant calls A with different envelopes (C, G, E, and I). Last pulses of the calls A (D, H, F, and J). Note the longer duration of the last pulse (D, H, F, and J). A single call B (K–L). Note that only the call B has clear FM segments and no pulses. Horizontal scale bars have 0.2 s (C, G, E, and I) and 0.02 s (D, H, F, and J); vertical scale bars have 1 kHz (G, I, and J) and 0.8 kHz (H). Filter bandwidth (Hz): 84.6 (B, H, I, J, and L); 61.9 (G).