Plectrohyla catracha (Porras & Wilson, 1987)

Chaves-Acuña, Wagner, Zúniga, Javier & Boza-Oviedo, Eduardo, 2025, Vocalizations of three species of Plectrohyla (Hylidae: Hylinae), with comments on natural history, Zootaxa 5665 (3), pp. 423-434 : 427-429

Advertisement call of Plectrohyla catracha ( Fig. 2A–D ).

We examined a total of 120 calls from four individuals of Plectrohyla catracha in a time lapse of 15 minutes recorded at 15ºC and 100% of relative humidity (one calling male collected, CZB-H 023). The vocalization of P. catracha is a short, pulsed call composed of 4 ± 1 pulses (2–8 pulses). The call exhibits an ascending amplitude modulation with the peak occurring towards the end of its duration, depicting a triangular wave form (pointed left; see Fig. 2D ). Call duration is about 41 ± 9 ms (20–80 ms) and the intercall interval is 13 ± 3 s (10–19 s). The pulse rate is 101 ± 13 pulses/s (67–150 pulses/s). Calls commonly exhibit a slightly ascending frequency modulation (see Fig. 2B ). The minimum frequency is 1,792 ± 104 Hz (1,535 –2,117 Hz), the maximum frequency is 3,525 ± 141 Hz (3,225 –3,838 Hz), and the dominant frequency is 2,768 ± 145 Hz (2,411 –3,100 Hz).

Territorial call of Plectrohyla catracha ( Fig. 2E–H ). Territorial calls were recorded when males called concurrently, sometimes overlapping in the timing of calls or alternating with calls from other individuals, including advertisement calls, which served as indicators of aggressive interactions. We examined a total of 46 calls from two individuals of Plectrohyla catracha (including CZB-H 023) in a time lapse of 5 minutes recorded at 15ºC and 100% of relative humidity. The territorial call consists of a repertoire of short trills emitted in brief series of 3 to 6 calls. These calls vary in structure, duration, pulse rate, and amplitude modulation compared to the advertisement call (see Discussion below). Territorial calls may exhibit amplitude modulation, with the first and/or second call generally displaying an ascending pattern, where the peak amplitude occurs toward the end of the call duration, forming a left-pointed triangular shape similar to that of the advertisement call. In contrast, subsequent calls typically show a descending pattern, with the peak amplitude occurring at the beginning of the call duration, depicting a rightpointed triangular shape (see Fig. 2H ). In some cases, calls lack amplitude modulation (see Fig. 2G ). The first call of the series is about 20 ms in duration and consists of 2 to 3 pulses, with a pulse rate of 118 ± 25 pulses/s (100–150 pulses/s). It is usually separated from the second portion of the territorial call by an intercall interval of 238 ± 6 ms (150–340 ms). From the second call onward, call duration is 15 ± 6 ms (4–20 ms), with each call composed of 2 ± 1 pulses (1–3 pulses), a pulse rate varying from 158 ± 55 pulses/s (100–250 pulses/s), and an intercall interval within the series as of the second call of 100 ± 26 ms (7–170 ms). The series of territorial calls last 650 ± 110 ms (480–840 ms). Calls typically exhibit slightly ascending or descending frequency modulation, but in some cases, calls lack frequency modulation (see Fig. 2E ). The minimum frequency is 1,663 ± 114 Hz (1,360 –1,820 Hz) and the maximum frequency is 3,693 ± 235 Hz (3,324 –4,082 Hz). The dominant frequency is 2,725 ± 410 Hz (2,067 –3,100 Hz).

Natural History of Plectrohyla catracha ( Fig. 3A–C ). The species is common at the study site and was usually detected in densities of tens to hundreds of individuals per night during our study. We found most of them perched on vegetation (leaves or stems) at 40–285 cm above the ground and 0–1.8 m from the nearest water body, but some individuals were found on the ground or floating on the water surface. An adult female was observed during the day in an epiphytic bromeliad, at 1.80 m above the ground and approximately 400 m from the nearest water body. We registered amplectant pairs floating on the water of a pool of a spring used by people to obtain water. On one occasion, we followed one pair for more than five hours but oviposition did not occur ( Fig. 3B ). For most part of our observation, the pair was partially submerged and floating on water; however, after three hours, it moved to land and stayed there for several minutes before returning back to the water. We noted the highest breeding activity of the species during the rainiest periods (from May to June and September to October). In the Las Trancas area, air temperatures ranged from 11–16ºC during nocturnal surveys.

Figures

FIGURE 2. Spectrograms (above) and oscillograms (below) of vocalizations of Plectrohyla catracha obtained from a male (CZB-H 023) at Las Trancas, Opatoro, La Paz Department, southwestern Honduras. (A–B, E–F): Spectrograms. (C–D, G–H): Oscillograms. (A–D): Advertisement call (FZ 14977). (E–H): Territorial call (FZ 14979). (F, H): Detail of the first vocalization emitted in the territorial call. Scale bar = 100 ms (horizontal), 1 kHz (vertical).

FIGURE 3. Life photographs of Plectrohyla catracha from Las Trancas, Opatoro, La Paz Department, southwestern Honduras, and P. insolita from the Texíguat Wildlife Refuge at Fortuna, western end of the Cordillera Nombre de Dios, northern Honduras. (A): Adult male (not collected). (B): Amplexus on land (not collected). (C): Metamorph (not collected). (D): Adult male (UCR 23564). (E): Adult male guarding two egg clutches (CZB-H 022).