The advertisement call of Phyllodytes megatympanum is composed of a series of 10 to 19 unpulsed notes (n = 19 calls analyzed) with harmonic structure. Each note has seven visible harmonics and crescent modulation frequency. The first notes are shorter than the following ones, which are more intense. Notes show amplitude modulation from the beginning to the middle, when it decreases. The mean duration of each call is 5.913 ± 4.556 s (3.206–23.633 s; n = 19 calls) emitted in intervals of 30.904 ± 10.313 s (6.960–47.580 s; n = 15 intervals). The notes present mean duration of 0.092 ± 0.080 s (0.009–0.245 s; n = 254 notes) and are emitted at intervals of 0.305 ± 0.100 s (0.105–0.619; n = 235 intervals). The mean dominant frequency is 3.985 ± 0.136 kHz (3.562–4.125 kHz; n = 113 notes analyzed) and corresponds to the second harmonic. Due to its ascendant modulation, the frequency at the beginning of the second harmonic is lower than the frequency towards the end of it, raising a mean bandwidth of 0.8 kHz.[1]
References
- . A new species of Phyllodytes Wagler, 1830 (Anura, Hylidae) from the Atlantic Forest of southern Bahia, Brazil. Zootaxa. 2017;4238(1):135. Available at: http://biotaxa.org/Zootaxa/issue/view/zootaxa.4238.1.
Phyllodytes megatympanum, as the majority of the species within the genus Phyllodytes, has calls with more than one note. Out of the nine species whose advertisement call is available, only P. acuminatus and P. melanomystax have calls with one note. Based on its unpulsed structure, the call of P. megatympanum is readily distinguished from the pulsed calls of P. luteolus, P. edelmoi, P. tuberculosus, P. gyrinaethes and P. wuchereri (Weygoldt 1981; Lima et al. 2008; Juncá et al. 2012; Roberto & Ávila 2013; Cruz et al. 2014). Among the other species of Phyllodytes with unpulsed structure, P. megatympanum can be distinguished from P. kautskyi by the higher mean dominant frequency: 3.985 ± 0.136 kHz (3.562–4.125) in P. megatympanum vs. 1.37 kHz (0.87–1.81) in P. kautskyi, according to the first description of the latter. After the original description of the advertisement call from P. kautskyi by Simon & Gasparini (2003), Simon & Peres (2012) presented additional bioacoustic details from populations of P. kautskyi from southern Bahia. However, there is evidence that leads us to conclude that the studied populations could be actually assigned to P. maculosus (Marciano-Jr et al. in prep). Thus, the differences assigned to polymorphisms in the Bahian populations of P. kautskyi would represent diagnostic features of P. maculosus.
The lower number of notes per call in Phyllodytes megatympanum (10–19) distinguishes it from P. kautskyi (21–22; Simon & Gasparini 2003; Simon & Peres 2012), P. tuberculosus (14–23; Juncá et al. 2012) and P. edelmoi (22–29; Lima et al. 2008). The higher number of notes can distinguish P. megatympanum from P. gyrinaethes (4–6; Roberto & Ávila 2013) and P. luteolus (8–15; Weygoldt 1981). The longer call duration in P. megatympanum 5.91 ± 4.56 s (3.20–23.63 s) distinguishes it from P. acuminatus (0.03–0.17 s; Campos et al. 2014), P. melanomystax (0.07 ± 0.04 s; Nunes et al. 2007), P. kautskyi (3.55 ± 0.19 s; Simon & Gasparini 2003; 3.48–3.90 s in Simon & Peres 2012), P. gyrinaethes (1.7 ± 0.3 s; Roberto & Ávila 2013) and P. edelmoi (5.2 ± 0.44 s; Lima et al. 2008). The mean interval between notes of P. megatympanum 0.350 ± 0.10 s is longer than between notes of P. tuberculosus (0.214 ± 0.048 s; Juncá et al. 2012), P. kautskyi (0.060–0.120 s; Simon & Gasparini 2003) and P. wuchereri (0.120 ± 0.019 s; Magalhães et al. 2015), but not longer than in P. gyrinaethes (0.400 ± 0.030 s; Roberto & Ávila 2013). Calls from P. maculosus, P. brevirostris and P. punctatus remain undescribed.[1]
References
- . A new species of Phyllodytes Wagler, 1830 (Anura, Hylidae) from the Atlantic Forest of southern Bahia, Brazil. Zootaxa. 2017;4238(1):135. Available at: http://biotaxa.org/Zootaxa/issue/view/zootaxa.4238.1.