Physalaemus orophilus Cassini, Cruz & Caramaschi, 2010

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 : 72

Physalaemus orophilus Cassini, Cruz & Caramaschi, 2010

We found a single call type for the species, referred to as call A. The call has long duration and is composed of a single harmonic note with a sequence of pulses with interpulse silence intervals. The bands have a general upward FM but with a subtle downward FM at the end, yielding slightly arc-shaped bands in the audiospectrogram of some calls when considering the entire call duration.

Call A ( Fig. 41 A–H and 42A). We examined 10 recordings, a total of 26 minutes, with ca. 270 calls from 16 males. Only some of these calls were measured (see Table 2 ). Call duration varies from 3.724 to 5.432 s. Call rise and fall are very short and similar to each other in duration. There is a long sustain. This segment is usually regular and almost flat ( Fig. 41A, D ), but convex in some calls ( Fig. 41E ). The amplitude peak of these calls is at the end of the first two thirds of the call duration. The envelope of the call varies from elliptic ( Fig. 41E ) to rectangular ( Fig. 41A, D ). More than 50 % of the call energy is concentrated in 43 % of the call duration around the amplitude peak. The call has a strong PAM (silence intervals are present between peaks; Fig. 41 A–H). The rate of the PAM is ca. 11 Hz, forming ca. 57 pulses throughout the call. The pulse rise is longer than fall, with amplitude peak of the pulse at ca. two thirds of the pulse duration. The amplitude peak of the last pulse is at the beginning or middle of the pulse ( Fig. 41C ). Duration of silence intervals is similar to pulse duration. The last pulse is usually the longest (ca. 1.5 times longer than the other pulses). In some calls, the last pulse is the shortest. The call has a harmonic series ( Fig. 42A ). The fundamental frequency is ca. 290 Hz. The first five harmonics are usually absent in audiospectrograms ( Fig. 41B ). There are ca. four adjacent emphasized harmonics. The wave periods are regular and harmonics are clear throughout the call. The dominant frequency varies from ca. 2630 to 2910 Hz ( Fig. 41B ). The dominant harmonic varies from the seven to the 29 th, but it is usually the ninth ( Fig. 42A ). There is no shift in the relative energy between the bands throughout the call. Most of the call energy is between 2500 and 3350 Hz (three harmonics; Fig. 41F ). The call has a slight general upward FM and a short downward FM at the end, leading to arc-shaped bands in audiospectrograms when considering the entire call ( Fig. 41B, G, H ). Additionally, there can be a slight PFM throughout the call, which is directly proportional to the synchronic pulse-PAM, i.e. up-downward FM in each pulse.

Figures

FIGURE 41. Call A of Physalaemus orophilus. Oscillograms (A, C–E) and audiospectrograms (B, F–H). A typical call (A–B). Segment with four pulses (C and F). Variant calls with different envelopes (D–H). Horizontal scale bars have 0.05 s (C and F) and 0.5 s (D–H); vertical scale bars have 1 kHz. Filter bandwidth (Hz): 67.4 (B, F, and H); 46 (G).

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).