The Comparative Characteristics Of Mating Calls Of Amolops Wuyiettsis、odorrana Tormotus And Odorrana Schmackeri

In recent years, several frogs living in the rapid streams become a newresearch hotspot for their unique ultrasonic communication, especially, concave-earfrog (Odorrana tormotus). We choosed three kinds of frogs inhabit the same creekin Huangshan mountain. We recorded and analyzed their advertisement callsproduced by individual males during breeding season with the ultrasonic recordingequipments. Based on the previous research, we carried on more in-depth researchof male O. tormotus vocalization, revealed that the positive correlation betweenhigh-frequency calls and background noise levels. By comparing vocalcharacteristics, sound spectrum, breeding behavior, habitat exploitation, etc.,discussed the different communication strategies facing the same ambientenvironment and the species specificity of vocalization.1. The study on the high frequence vocals of Odorrana tormotusThe vocal signals of frogs have been shown to exhibit geographical dialectsthat are optimal for detection of signals in the local environments, amidst soundsfrom competing biotic sources. Presently, the extent to which background noiseplays in shaping of the dialects is unclear. We investigated the vocal signals of maleultrasonic frogs (O. tormotus) in a remote village(Fu Creek)in Huangshan andcompared them with those of males from a different population(TaohuaCreek)within this mountain range. We found that, whereas the temporalcharacteristics of vocal signals of the two populations are indifferent, theirfundamental frequencies (F0s) differ markedly. There is a trend for frogs inhabitingnoisier background to emit calls having higher F0. These results suggest thatbackground noise has a role shaping the local dialects and also provide evidence forthe hypothesis that the frog’s high-frequency hearing is to avoid masking by theintense, predominantly low frequency background noise.2. The comparative characteristics of mating calls and adaptive strategiesof Amolops wuyiensis and Odorrana tormotusWe recorded and analyzed their advertisement calls produced by individualmales during breeding season with the ultrasonic recording equipments. The results showed that A. wuyiensis produced the single type of calls that were composed ofvariable syllables (from3to6syllables) with2~10pulses in different period oftime. The average values of call duration, dominant frequency and signal noiseratio were2198.20ms,2231.90Hz and33.00dB respectively. We found that therewere no ultrasonic elements in A. wuyiensis calls and they did not have the basis ofultrasonic communication. There were no masking effects of the noise on the callsfrom the male A. wuyiensis and male O. tormotus owing to their higher dominantfrequency and amplitude than that of noise. Because the lower vocal frequencymeans farther transmission length for the A. wuyiensis, The male individual mayfulfill the intra-species communication via adjusting its call time (e.g. call withmultiple notes, increase the call duration and vocal frequency) and may reveal itsquality to attract female via its call duration. However, the male O. tormotus mayenhance the vocal frequency which will reduce the energy expending to fulfill theintra-species communication in the same noise environment.3. The comparative characteristics of mating calls of Odorrana schmackeriand Odorrana tormotusWe recorded and analyzed advertisement calls produced by individual males(O.schmackeri) during breeding season with the ultrasonic recording equipments,compared with the mating calls of O. tormotus living in the same habitat. Theresults showed that O. schmackeri owns several basic call types, less than O.tormotus. Dominant frequency was lower than O. tormotus, mean F0was about3.3kHz, range from2-4kHz. Some vocal structures were very similar to thestructures of O. tormotus, for example, single-note call, double-note call,‘baby’call. The F0we measured was consistent with the auditory sensitive peak of O.schmackeri, gained by previous electrophysiological experiment, illustrating that O.schmackeri communicates over this frequency band. We infer that, the similarity ofvocal features show the close evolutionary relationship of two frogs. ByObservation we found O. schmackeri had a breeding peak in the mid-July, noobvious diurnal activity rules, perfered the rocks far from the water.