Vocal Repertoire of Two Bokermannohyla (Anura: Hylidae) Species, with an Overview of Advertisement Call Diversity in the Genus
Bokermannohyla treefrogs produce a rich array of acoustic signals in their vocal repertoires. Here we report and describe for the first time the vocalizations of B. caramaschii, a species lacking vocal slits. We also extend the known vocal repertoire of B. gouveai by describing a previously unreported note type and revisiting intraspecific variation based on an increased sample of recorded males. The advertisement call of both species is composed of two types of multipulsed notes with emphasized sound energy at low frequencies (<1 kHz). We discuss the possible implications of lack of vocal slits for production of vocal sounds by B. caramaschii. Furthermore, we address inconsistencies in the previous call description of B. gouveai and reassess the species' acoustic variation based on an increased sample size of topotypes. Lastly, we provide the first overview of the advertisement call diversity within Bokermannohyla, recognizing major temporal patterns of their calls.ABSTRACT
Vocal repertoire of Bokermannohyla caramaschii. (A) Oscillogram section with a series of five advertisement calls (letters above indicate note type). (B) Spectrogram and oscillogram detailing the advertisement call highlighted in A, formed by one Note A followed by one Note B. Information on sound archives is provided in Table 1.
Vocal repertoire of Bokermannohyla gouveai. (A) Oscillogram section with a series of advertisement calls (note the difference in relative sound intensity between Note A and Note B). (B) Spectrogram and oscillogram of a section highlighted in A, detailing one Note A followed by one Note B. (C) Oscillogram of a less frequent pattern of Note A (without pulse groups). (D) Spectrogram and oscillogram detailing syntopic calls of Scinax duartei (left) and B. gouveai (right) at Brejo da Lapa. Background calls of S. duartei are indicated by red dashed boxes in B and D. Information on sound archives is provided in Table 1.
Major temporal patterns of advertisement call in Bokermannohyla for the (A) presence (B. sazimai) or absence of pulses (B. oxente), (B) emission patterns: continuous (B. sazimai on top, B. oxente below) or in well-defined series (B. carvalhoi on top, B. sapiranga below), and (C) two note types (Note A and Note B) in obligatory (B. nanuzae) or facultative combination (B. gouveai). Small oscillograms in B show one call in detail. Calls formed by one Note A followed by one Note B are depicted in D as the main oscillograms.
Gular region of two Bokermannohyla species showing comparison in the expansion of the m. interhyoideus (IH, highlighted in pink) in (A) B. caramaschii (CFBH 46036; SVL = 59.0 mm) and (B) B. luctuosa (CFBH 17559; SVL = 57.1 mm). Bokermannohyla luctuosa, a species with a vocal sac and vocal slits, shows the expanded condition of the IH. Bokermannohyla caramaschii, a species lacking a vocal sac and vocal slits, does not have an expanded IH. Abbreviations: SM = m. submentalis; IM = m. intermandibularis. Both individuals are adult males and voucher specimens of call recordings.
Five major temporal patterns (P) of advertisement call recognized within Bokermannohyla. (A) P1: B. oxente, a single type of nonpulsed note emitted continuously; (B) P2: B. sapiranga, a single type of nonpulsed note emitted in well-defined series; (C) P3: B. sazimai, a single type of pulsed note emitted continuously; (D) P4: B. carvalhoi, a single type of pulsed note emitted in well-defined series; (E) P5: B. gouveai, two types of pulsed notes (Note A and Note B) emitted in well-defined series. The relative amplitude (y-axis) is not to scale.
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