Physalaemus maculiventris (A. Lutz, 1925)

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 : 15-32

Physalaemus maculiventris (A. Lutz, 1925)

We found two different calls, referred to as call A and B. Calls B were common in recordings in which several males were more active and calling close to each other. Calls B are commonly observed after overlapping periods of A calls. Call B resembles a long call A with higher fundamental frequency, pulse-PAM rate, and stronger PFM.

Call A ( Fig. 5 A–D and 4B). We examined two recordings, a total of six minutes, with ca. 400 calls from four males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.172 to 0.260 s. The rise of the call is longer than the fall; the amplitude peak is approximately at the end of the first three fourths of the call duration. Since both rise and fall are relatively similar in slope and not too different in duration, the envelope of the call is fairly elliptic ( Fig. 5A, C ). More than 50 % of the call energy is concentrated in 24 % of the call duration around the amplitude peak. The call has a subtle PAM (there is no silence interval between peaks; Fig. 5C ). The rate of the PAM is ca. 39 Hz, forming ca. six amplitude peaks throughout the call. The call is composed of usually clear harmonics ( Fig. 4B ), however, eventual decreases of the wave periodicity make the harmonics less clear. The fundamental frequency is approximately 220 Hz and it can be present with low energy or absent in the audiospectrograms. The dominant frequency varies from ca. 820 to 1510 Hz ( Fig. 5B, D ). The dominant harmonic varies from the third to the sixth, but it is usually the fifth. There is no clear shift in the relative energy among the bands throughout the call. Most of the call energy is between 700 and 1500 Hz (often comprising five harmonics). The frequency bands have a general upward FM throughout the call with a rapid up-downward FM at the beginning forming arc-shaped bands in this part of the call and a short downward-FM segment at the end ( Fig. 5B ). There are irregular PFM segments throughout the entire call; these segments are usually synchronic and directly proportional to the PAM ( Fig. 5D ).

Call B ( Fig. 5 E–F and 6A). We examined one recording, a total of one minute, with six calls from two males. Only some of these calls were measured (see Table 2 ). Call duration varies from 0.375 to 0.675 s. The call rise is longer than the fall with a long regular sustain or shallow valley separating them; the shallow valley yields two amplitude peaks at the beginning and end of the call. The amplitude peak is at around the end of the first two thirds of the call duration (i.e., second amplitude peak). Depending on the slope of the sustain and the difference between the peaks, the envelope of the call can vary from rectangular to triangular (pointed left; Fig. 5E ). More than 50 % of the call energy is concentrated in 34 % of the call duration around the amplitude peak. The call has a slight PAM (there is no silence interval between the peaks; Fig. 5E ). The rate of the PAM is ca. 32 Hz, forming ca. 13 amplitude peaks throughout the call. The call is composed of harmonics ( Fig. 6A ). Usually the harmonics are clear, however, eventual decreases of the wave periodicity make the harmonics less clear. Audiospectrograms with relatively broad filter bandwidths (e.g., above 100 Hz) can show wave peaks, of some parts of the call with low fundamental frequencies (minimum 123 Hz; see Table 2 ), as broadband pulses (instantaneously high sound-pressure effect; see Littlejohn 2001). The fundamental frequency is usually ca. 240 Hz and it can be present with low energy or absent in the audiospectrograms. The dominant frequency varies from ca. 1030 to 1310 Hz ( Fig. 5F ). The dominant harmonic varies from the third to the eighth, but it is usually the fourth or the fifth harmonic. There is no clear shift in the relative energy among the bands throughout the call. Most of the call energy is between 800 and 1600 Hz (ca. three harmonics). The frequency bands have a general upward FM throughout the call with a up-downward FM segment at the beginning forming arc-shaped bands in this part of the call and a short downward FM segment at the end ( Fig. 5F ). There are irregular PFM segments throughout the entire call; these segments are usually synchronic and directly proportional to the PAM ( Fig. 5E, F ).

Figures

FIGURE 4. Multiplicity relationship between “instantaneous” dominant frequency and w of calls A of seven Physalaemus species. Each graph shows a single call A of: P. nattereri (A), P. maculiventris (B), P. erythros (C), P. rupestris (D), P. camacan (E; F), P. obtectus (G), P. irroratus (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 w of the measured 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. irroratus; H).

FIGURE 5. Call types A and B of Physalaemus maculiventris. Oscillograms (A, C, and E) and audiospectrograms (B, D, and F). A single typical call A (A and B). A single call A with a variant envelope and modulations (C and D). A single call B (E and F). Horizontal scale bars have 0.05 s; vertical scale bars have 1 KHz. Filter bandwidth (Hz): 84.6 (D); 61.4 (B); 78.9 (F).

FIGURE 6. Multiplicity relationship between “instantaneous” dominant frequency and w of calls B and C of six Physalaemus species. Each graph shows a single call. Call B of P. maculiventris (A), call B of P. erythros (B), call B of P. ruspestris (C), call B of P. nanus (D), call C of P. nanus (E), and call B of P. spiniger (F). 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.

Tables

TABLE 2. Descriptive statistics of 11 measurements of the calls typeA of 45 Physalaemus species. Species ordered according to the topology in Lourenço et al. (2015; see text and Table 1). Values are given as mean ± standard deviation (minimum – maximum) mode [number of measurements taken / number of calls]. Single asterisks indicate cells with the same values of other call. Double asterisks indicate features present only in part of the analyzed calls (see descriptions in text for details).

Species	Call Type	Call Duration (s)	Cycle or Pulse Duration (s)	Cycle or Pulse Interval (s)	Cycle or Pulse Rate (per s)	Proportion Final Cycle (per s)	Proportion Duration Dominancy Lower Bands	Proportion Initial FM	Frequency Delta Initial FM (Hz)	PFM Rate (per s)	Dominant Frequency (Hz)	Dominant Harmonic
Physalaemus nattereri	Call A	0.065 ± 0.003 (0.057–0.074) 0.067 [41/41]	–	–	–	–	–	0.673 ± 0.076 (0.511–0.831) 0.655 [41/41]	?	–	1023.2 ± 51.2 (703.1–1031.2) 1031.2 [41/41]	2.4 ± 0.6 (1–3) 2 [82/38]
Physalaemus maculiventris	Call A	0.209 ± 0.025 (0.172–0.260) 0.189 [50/50] 0.534 ± 0.101	0.030 ± 0.016 (0.011–0.107) 0.021 [145/25] 0.034 ± 0.011	–	39.0 ± 13.8 (9.3–92.4) 46.8 [145/25] 32.4 ± 8.4	1.305±0.763 (0.403–2.773) [23/23] 1.478 ± 0.392	–	0.527 ± 0.0171 (0.114–0.792) 0.588 [50/50]	-26.9 ± 65.8 (–172.3–86.1) -43.1 [24/24] 187.5 ± 132.6	34.5 ± 11.2 (11.8–66.5) 44.3 [118/50] 36.1 ± 9.2	1043.9 ± 214.6 (818.3–1507.3) 861.3 [50/50] 1171.9 ± 129.3	4.2 ± 0.5 (3–6) 4 [51/3] 4.8 ± 0.9
	Call B	(0.375–0.675)	(0.014–0.069)	–	(21.6–54.7)	(1.121–1.906)	–	?	(93.7–375.0)	(24.5–61.6)	(1031.2–1312.5)	(3–8) 5
		[6/6]	0.032 [64/4]		23.1 [17/3]	[4/4]			[4/4]	36.2 [19/4]	1031.2 [6/6]	[103/2]
		0.056 ± 0.008									1091.7 ± 41.6	5.2 ± 2.5
	Call A	(0.041–0.077)	–	–	–	–	–	–	–	–	(1022.8–1162.8)	(2–10) 3.0
Physalaemus erythros	Call B	0.055 [38/38] 0.587 ± 0.192 (0.200–0.875) [17/17]	0.045 ± 0.018 (0.015–0.087) 0.045 [86/4]	–	26.6 ± 12.8 (11.5–66.5) 22.2 [86/4]	0.750 ± 0.442 (0.179–1.495) [4/4]	–	–	–	26.6 ± 12.8 (11.5–66.5) 22.2 [86/4]	1141.3 [38/38] 1083.6 ± 220.4 (843.8–1781.2) 1031.2 [17/17]	[23/4] 4.1 ± 1.3 (3–9) 3 [99/2]
		0.106 ± 0.026	0.056 ± 0.014	0.009 ± 0.006	15.2 ± 2.8	1.565 ± 0.362					2321.2 ± 162.9	12.7 ± 6.7
	Call A	(0.057–0.149)	(0.036–0.085)	(0.000–0.022)	(10.3–19.0)	(1.033–2.202)	–	–	–	–	(1890.6–2546.9)	(5–38) 8
Physalaemus rupestris	Call B	0.112 [18/18] 1.556 ± 0.152 (1.269–1.727) [10/10]	0.046 [22/11] 0.040 ± 0.028 (0.005–0.173) 0.037 [122/6]	0.000 [11/11] 0.027 ± 0.012 (0.011–0.071) 0.019 [177/6]	17.7 [18/18] 18.9 ± 1.6 (16.3–21.1) [6/6]	[11/11] 3.545 ± 0.780 (2.420–4.459) [6/6]	–	–	–	–	2343.8 [18/18] 2368.8 ± 144.9 (2062.5–2562.5) 2365.0 [10/10]	[147/18] 22.9 ± 10.3 (7–57) 15 [240/6]

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