Bioacoustics of Adenomera ajurauna

Description of holotype . Robust body, snout outline rounded in dorsal view, acuminate in lateral view, snout with developed fleshy white ridge; tympanum distinct, its diameter almost half of eye diameter; vocal sac present, single, internal, with vocal slits; vomerine teeth in short transverse series, separated from each other by about length of one tooth row, located posterior to choanae; gland at posterior end of lower-jaw well developed and near to the arms. Arms robust, finger lengths IV II <III; finger tips elongated, not disked; fingers free, subarticular tubercles rounded, prominent; rounded distal subarticular tubercles on fingers I and II; supratympanic fold weakly developed; dorsal body texture ranging from smooth to granular, usually with granules or tubercles more developed posterodorsally; ventral surfaces of body and libms smooth, except ventral surface area of thighs that is areolate; toe lengths I<II<V<III<IV; toe tips slightly expanded, ungrooved disks; toes free, inner metatarsal tubercle oval, distinct, outer metatarsal tubercle distinct, rounded, 1/2 to equal in size to inner one; heel smooth; inner tarsal fold running about 3/4 length of tarsus with single row of white-tipped tubercles on crest; outer tarsal texture with a profusion of white-tipped tubercles; sole of foot with a poorly developed profusion of white-tipped tubercles. Coloration. In life the dorsal pattern uniformly dark brown, iris bronze, snout fleshy ridge white, throat overall dark (densely speckled with numerous brown spots), body, arms, and snout regions dotted with white spots. The well-developed gland found on each side of the jaw articulations similar to body coloration. In preservative, the dorsum is slightly lighter brown than in life. The white spots on body, arms and snout regions are not visible. The throat is lighter brown than in life but distinct from other species of the group. Morphological variation. Lighter specimens show a dark brown interorbital triangular spot, often an indistinct pair of broad and dark dorsolateral stripes extending from the back of eye to the groin, and a supratympanic fold usually dark outlined; flanks mottled in some individuals. Vocalization. Four vouchers were recorded on different dates. A total of ten calls were recorded and analyzed for each male ( Table 2 ). The call of the holotype of Leptodactylus ajurauna sp. nov. ( Figure 4 ) was recorded at 5 pm, at an air temperature of 19.0°C and it consists of single notes, emitted at a low call rate of 23 calls per minute, mean duration of 156ms (range 149–164ms). The notes have ascendant modulation with dominant frequency among 4052–5425Hz and frequency modulation of 746–1131Hz without harmonics, pulses or sideband structure. The analysis of all calls (including the holotype , n=4) showed single notes calls, emitted at a low call rate of 23–36 calls/min, with duration of 130–190 ms, and call rise time of 42–119ms. The notes have ascendant modulation with dominant frequency among 3723–5425 Hz and frequency modulation among 746–1285 Hz. 13/12/2005 MZUSP136720 10/08/2005 no voucher 25/09/2006 MZUSP136712 03/11/2006 MZUSP135892 Air temp. (½C) 19.2 18.3 19.0 18.4 Number of calls (indiv.) 10 10 10 10 Call duration (sec) 0.187 (0.003) 0.182–0.190 0.177 (0.007) 0.169–0.177 0.156 (0.004) 0.149–0.164 0.143 (0.008) 0.130–0.156 Call rate (Calls/min). 34 32 23 36 Call rise time (sec) 0.060–0.135 0.042–0.068 0.073–0.119 0.061–0.087 Pulses p/call 1 1 1 1 Fundamental frequency (Hz) 4096–5106 3723–5080 4052–5425 4478–4651 Dominant frequency (Hz) 4096–5106 3723–5080 4052–5425 4478–4651 Other frequencies (Hz) – – – – Frequency modulation 757–957 1025–1285 746–1131 1106–1226 Natural history and geographical distribution. The species is common in the remaining patches of Atlantic Forest at Parque das Neblinas, males are usually heard calling during the wet season. Leptodactylus ajurauna sp. nov. is rare in the Eucalypt plantations in the park, whereas Leptodactylus marmoratus is abundant in both environments. Males of Leptodactylus ajurauna sp. nov. call from the forest floor in the concealed sites among the leaf litter in afternoon and evening hours during the rainy season (September to March). On some occasions, when the forest was very wet, males were observed calling at night. The new species is known from four municipalities at São Paulo State: Bertioga (Parque das Neblinas); Mogi das Cruzes (Biritiba Ussu district), Cubatão, SP, and São Paulo (Bororé district).