Mate choice in frogs depends heavily on acoustic communication, and females in many species possess an inherent preference for longer and/or more complex calls. Recently, it has become clear that conspecific chemical cues can also be useful in attracting potential mates in anuran species. However, how conspecific chemical cues influence mate choice decisions when paired with acoustic signals remains less clear. In the present study, we conducted three experiments to investigate whether and how male odor cues affect female choice decisions in the absence or presence of acoustic signals in serrate-legged small treefrogs (Kurixalus odontotarsus). We found that disturbance odors alone can trigger avoidance behavior of females, suggesting that the odors of disturbed K. odontotarsus can act as an alarm cue for conspecifics. Females also avoided disturbance odors in the presence of advertisement calls, except for calls with five notes. In addition, females preferred calls with two notes to calls with four notes when the latter was paired with disturbance odors. In contrast, female choice decisions were not affected by the odors of undisturbed males, either in the absence or the presence of advertisement calls. Our results indicate that disturbance odors can influence, or even reverse, mate choice by females for acoustic signals.
In addition to acoustic signals, chemical cues can also be used in close-range communication in some anuran species. In the present study, we investigated how female Kurixalus odontotarsus use male chemical cues and/or acoustic signals during the mate choice process. We demonstrate that male disturbance odors can act as an alarm cue to trigger the avoidance behavior of females. Furthermore, this alarm cue can even reverse mate choice by females for acoustic signals. Our study highlights the importance of integrating multisensory signals and cues in mate choice decisions and has important implications for understanding chemical communication in anurans.