Bioacoustics of Ptenopus adamanteus

Natural history. While its breeding phenology is not well known, our sampling suggests that calling / breeding peak activity occurs from September to November, like several other species. This species often wanders on the surface throughout the night, far from its burrow, and may be active despite cold, foggy weather, similar to P. carpi and P. sceletus sp. nov. The burrows are relatively complex with multiple side-tunnels, and a few egg clutches, usually two eggs but occasionally one, have been found inside burrows occupied by a female. This species occasionally closes the burrow entrance from the inside before daybreak, but may also be active diurnally, especially after or during foggy weather. Hatchlings have been observed digging their own burrows a day after hatching, and it is therefore expected that they do not remain in the parent burrows for any length of time. Males and females have not been observed sharing a burrow. This species has been observed feeding on spiders and termites, and it likely eats various arthropods.

Advertisement call. The advertisement call (Figs 3 , 20 C ) consists of 5 notes (range 4–6), uttered slowly at a rate of 2.81s - 1 (range 2.64–3.15). Note duration is short (29 ms [range 24–34]) and highly consistent; note 1 duration deviance 9.2 % (range - 4–16). Inter-note intervals 313 ms (range 274–341), with a notably longer final interval; inter-note interval range high, 52.2 % (range 36–66). Median call density is low, 0.09 (range 0.08–0.11); call duration 1.4s (range 1.1–1.8). The basal frequency is ~ 415 Hz (range 370–516, but very soft and may be inestimable, with harmonic bands louder towards the (upper) dominant frequency at 4.4 kHz (range 4.1–5); usually no notable lower peak frequency peak is evident. Frequency appears to remain more or less constant throughout the note, and (human) perceived pitch is notably lower in northern than southern populations, and also coastal compared to inland populations. Bandwidth (90 %) is difficult to estimate consistently: approximately 0.5–7.3 kHz. In coastal populations this species does not call often (longer call periods and fewer evenings of calling), but inland populations are more vocal. This is probably due to higher incidence of cold, foggy, windy weather closer to the coast, in which calling activity is reduced. Call period (5–20 s, mean 14 s) is short compared to most other species during peak chorus activity. It mainly calls from about 30 minutes before sunset until nightfall, with occasional calling later at night. This species may call sporadically throughout the day, particularly under foggy or cloudy conditions.