Male-male vocal competition in anuran species may be influenced by cues related to the temporal sequence of male calls as well by internal temporal, spectral and spatial ones. Nevertheless, the conditions under which each type of cue is important remain unclear. Since the salience of different cues could be reflected by dynamic properties of male-male competition under certain experimental manipulation, we investigated the effects of repeating playbacks of conspecific calls on male call production in the Emei music frog(Babina daunchina). In Babina, most males produce calls from nest burrows which modify the spectral features of the cues. Females prefer calls produced from inside burrows which are defined as highly sexually attractive(HSA) while those produced outside burrows as low sexual attractiveness(LSA). In this study HSA and LSA calls were broadcasted either antiphonally or stereophonically through spatially separated speakers in which the temporal sequence and/or spatial position of the playbacks was either predictable or random. Results showed that most males consistently avoided producing advertisement calls overlapping the playback stimuli and generally produced calls competitively in advance of the playbacks. Furthermore males preferentially competed with the HSA calls when the sequence was predictable but competed equally with HSA and LSA calls if the sequence was random regardless of the availability of spatial cues, implying that males relied more on available sequence cues than spatial ones to remain competitive.
Male-male vocal competition in anuran species may be influenced by cues related to the temporal sequence of male calls as well by internal temporal, spectral and spatial ones. Nevertheless, the conditions under which each type of cue is important remain unclear. Since the salience of different cues could be reflected by dynamic properties of male-male competition under certain experimental manipulation, we investigated the effects of repeating playbacks of conspecific calls on male call production in the Emei music frog(Babina daunchina). In Babina, most males produce calls from nest burrows which modify the spectral features of the cues. Females prefer calls produced from inside burrows which are defined as highly sexually attractive(HSA) while those produced outside burrows as low sexual attractiveness(LSA). In this study HSA and LSA calls were broadcasted either antiphonally or stereophonically through spatially separated speakers in which the temporal sequence and/or spatial position of the playbacks was either predictable or random. Results showed that most males consistently avoided producing advertisement calls overlapping the playback stimuli and generally produced calls competitively in advance of the playbacks. Furthermore males preferentially competed with the HSA calls when the sequence was predictable but competed equally with HSA and LSA calls if the sequence was random regardless of the availability of spatial cues, implying that males relied more on available sequence cues than spatial ones to remain competitive.